Archive for September, 2019

Taking a Brief Break

September 30, 2019

And there is plenty to read. Go to healthymemory.wordpress.com

You can review the categories to find articles of interest or use the search block to search for posts on interesting topics.

Also go to https://centerhealthyminds.org

It is very interesting.

HM shall return.

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Anthropic Principle vs. Creationism vs. Intelligent Design

September 29, 2019

The anthropic principle is a philosophical consideration that observations of the universe must be compatible with the conscious and sapient life that observes the universe. The physical conditions that enabled the creation of the universe are very precise. Absent these conditions there would be no universe for humans to observe much less live in.

The strong anthropic principle (SAP) states that this is the case because the universe is in some sense compelled to eventually have conscious and sapient life emerge within it.

The weak anthropic principle (WAP) states that the universe’s fine tuning is the result of selection bias (survivor bias) in that only in a universe capable of eventually supporting life will there be living beings capable of observing and reflecting on the matter. Most often these arguments draw upon some notion of the multiverse for there to be a statistical population of universes to select from and from which selection (our observation of only this universe, compatible with our life) could occur.

Understand that what is being presented in this post is an enormous simplification of this issue. If interested, go to the Wikipedia and proceed from there.

However, it is hoped that enough has been written to compare the strong anthropic principle (SAP) with creationism and intelligent design.

It seems that creationists could adopt the SAP arguing that God is necessary for these conditions to occur, hence God is the creator of the universe. Although it is unlikely that most physicists would agree with this argument, creationists might argue that the law of parsimony (the simplest explanation is the best) argues for the SAP.

However, proponents of intelligent design could not employ this argument. Previous healthy memory blog posts have pointed to the flaw in intelligent design. Although one can find specific examples of intelligent design within nature, there are many more examples of failed species who died out and did not survive. So to argue for intelligent design one needs to accept a flawed entity or one who needs to learn by doing.

It would be good to teach the two anthropic principles along with creationism and intelligent design. The goal would not be to force students regarding what to believe, but rather to provide information on how science proceeds.

Unfortunately, there are many times when religions make war upon science. This is unfortunate. A religious leader who has an enlightened view of science is the Dalai Lama. He uses science to inform his religion. He sends his priests to seminars and schools to become well versed in science.

The problem with wars between science and religion is that science ultimately wins. The reason for this is that science changes as data and logic indicate. Unfortunately, dogmatic religions ultimately lose and humanity and civilization suffer.

© Douglas Griffith and healthymemory.wordpress.com, 2019. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

Truth-Default Theory (TDT)

September 28, 2019

This post is based on content in Talking to Strangers: What We Should Know About the People We Don’t Know by Malcom Gladwell. It has been noted in previous posts that we all have an initial default to believe what we read or are told. If we questioned everything our process through life, particularly at the beginning, would be enormously slow. Truth-Default Theory, by psychologist Tim Levine, capitalizes on this tendency to explain why we are vulnerable to lies. According to Levine we are normally in the truth-default mode. To snap out of this mode requires a trigger. “A trigger is not the same as a suspicion, or the first sliver of doubt. We fall out of the truth-default mode only when the case against our initial assumption becomes definitive. We do not behave, in other words, like sober-minded scientists, slowly gathering evidence of the truth or falsity of something before reaching a conclusion. We do the opposite. We start by believing. And we stop believing only when our doubts and misgivings rise to the point where we can no longer explain them away.”

A Harvard Economist, Sendhil Mullainathan, three elite computer scientists and a bail expert conducted an interesting experiment in the courts of New York City. They gathered up the records of 554, 689 defendants brought before arraignment hearings in New York from 2008 to 2013. This involved 554,689 defendants. The same information the prosecutors had given judges in these arraignment case was fed into a computer and analyzed with a program developed by these three elite computer scientists. It is presumed that these judges know how to evaluate this information. The judges decided to release just over 400,000 of the 554,689 defendants. The computer program made its own decisions regarding whom to release. So who made the best decisions? Whose list committed the fewest crimes while out on bail and was most likely to show up for their trial date? The people on the computer’s list were 25% less likely to commit crimes than the 400,000 people released by the judges of New York City. So in this contest of man versus machine, man clearly lost.

The main shortcoming of these judges was that they were human beings. Humans do not do that good a job of integrating numerical information without the aid of machines. And humans are strongly influenced by the behavior and status of the subjects they are evaluating. Gladwell reviews the case of Amanda Cox.

Amanda Cox was an American living in Italy who was falsely accused of murdering Meredith Kercher. In hindsight, it is completely inexplicable how she was convicted. There was never any physical evidence linking either Cox or her boyfriend to the crime. Nor was there ever a plausible explanation for why Cox—an immature, sheltered, middle-class girl from Seattle—would be interested in engaging in a murderous sex game with a troubled drifter she barely knew. Gladwell’s explanation is that Amanda’s behavior and the things she said convinced some people of her guilt, in spite of the hard evidence that she was innocent. So appearances, can get you in trouble, but they also provide the basis for successful lying.

The opposite case is Bernie Madoff. Bernie Madoff was the hedge-fund manager who ran a pyramid scheme that ended up defrauding many wealthy and prestigious clients. In addition to his status as the leader of a large fund, he was a genius at convincing people that all was above board. Gladwell analyzes many other interesting cases.

So what is to be learned from this book? A default mode of belief is practical, but be aware that appearances can be deceiving. So be careful about new interactions. Also be careful regarding established relationships if something questionable develops.

There are good tips on how to deceive. Simply act like you are telling the truth and stick with it.

Although Gladwell does not mention this in his book, we have an example of an extraordinary liar. He is the President of the United States, Donald Trump. And his many, many lies have been documented. He lies just as often as he tells the truth. And when caught in a lie, he doubles down. He never admits that he was wrong. This provides quite a challenge to government officials who he tries to force to back up his lies. Of course, he has no credibility with foreign leaders. How American citizens can still support him is mind boggling. And he is planning to run for re-election!

Suicide and Coupling

September 27, 2019

Part Five of “Talking to Strangers: What We Should Know About the People We Don’t Know” by Malcom Gladwell is titled Coupling. Coupling theory argues that there are certain places or conditions that increase the likelihood of committing suicide. Many think that people who commit suicide are so depressed that they will eventually commit suicide, even if it takes multiple attempts. John Bateson has written a book titled, The Final Leap, which makes the argument, and provides data, to indicate that the effect of the Golden Gate Bridge on some people is to tempt them to commit suicide.

Psychologist Richard Seiden followed up on 515 people who had tried to jump from the bridge between 1937 and 1971, but had been unexpectedly restrained. Just 25 of those 515 persisted in killing themselves some other way. Overwhelmingly, the people who want to jump off the Golden Gate Bridge at a given moment, want to jump off the Golden Gate Bridge at that given moment.

But when did the municipal authority that runs the bridge finally decide to install a suicide barrier? In 2018, more than eighty years after the bridge opened. John Bateson points out that in the intervening period the bridge authority spent millions of dollars building a traffic barrier to protect cyclists crossing the bridge, even though no cyclist has ever been killed by a motorist on the Golden Gate Bridge. It spent millions building a media to separate north- and south-bound traffic, on the grounds of “public safety.” On the southern end of the bridge, the authority put up an eight-foot cyclone fence to prevent garbage from being thrown onto Fort Baker. A protective net was even reinstalled during the initial construction of the bridge—at enormous cost—to prevent workers from falling their deaths. This net saved nineteen lives, then it was taken down. But it took eighty years to provide the means of preventing suicides from the bridge.

Having a gun in the household is another example of suicide and coupling. If someone is depressed and considering suicide, a gun provides the best means. It’s fast and efficient. Other means of suicide, such as taking pills or slashing one’s wrists often fail. But only rarely do guns fail. It is ironic. Presumably, people keep a gun in their homes for protection, to protect themselves. But it is more likely to result in a mistaken killing or in a suicide. There are many more suicides that murders.

One of HM’s best friends was affected by this coupling. One New Year’s Eve, when HM’s friend was away from home, his son and a friend of his son were playing with a gun in the house. His friend’s son accidentally shot and killed his son. HM’s friend, who was a politician, said justice would be done. What justice could be done? His son was dead and his son’s friend had to live with this killing for the rest of his life. Justice, no. Stupidity, yes.

The Effects of Alcohol

September 26, 2019

This post is based on content in Talking to Strangers: What We Should Know About the People We Don’t Know by Malcom Gladwell. Psychologists Claude Steele and Robert Josephs developed the myopia theory to explain the psychological effects of alcohol. What they mean by myopia is that alcohol’s principal effect is to narrow our emotional and mental fields of vision. In other words, “it creates a state of shortsightedness in which superficially understood, immediate aspects of experience have a disproportionate influence on behavior and emotion. Alcohol makes the thing in the foreground even more salient and the thing in the background less significant. It makes short-term considerations loom large, and more cognitively demanding, longer-term considerations fade away.”

When we get drunk what happens to us is a function of the particular path the alcohol takes as it seeps through our brain tissue. The effects being in the frontal lobes that govern attention, motivation, planning, and learning. The first drink “dampens” activity in that region. We become a little dumber, and are less capable of handling competing complicated considerations. It hits the reward centers in the brain, the areas that produce euphoria, and gives them a little jolt. It affects the amygdala. One of the amygdala’s jobs is to tell us how to react to the world around us. Are we being threatened? Should we be afraid? Alcohol turns the amygdala down a notch. These effects are what produce myopia. We don’t have the brainpower to deal with more complex, long-term considerations. The pleasure of alcohol distracts us. Our neurological burglar alarm turns off. Alcohol finds its way to our cerebellum, at the very back of the brain, which is involved in balance and coordination.

Under certain very particular circumstances—if we drink a lot of alcohol very quickly—something else happens. Alcohol hits our hippocampi that are responsible for forming memories. At a blood-alcohol level of 0.08—the level threshold for intoxication—the hippocampi begin to struggle. When you wake up the morning after and remember meeting someone but cannot remember their name or the story they told you, that’s because the two shots of whiskey you drank in quick succession reached your hippocampi. The gaps get larger when you drink a little more and the gaps get larger to the point where you remember pieces of the evening but other details can be summoned only with great difficulty.

Aaron White of the National Institutes of Health is one of the world’s leading experts on blackouts. He says that there is no particular logic to what gets remembered and what doesn’t. He says, “Emotional salience doesn’t seem to have an impact on the likelihood that your hippocampus records something. What that means is you might, as a female, go to a party and might remember having a drink downstairs, but you don’t remember getting raped. But then you do remember getting the taxi.” At the next level—roughly around a blood-alcohol level of 0.15, the hippocampus simply shuts down entirely. White said, “In the true, pre blackout, there’s just nothing. Nothing to recall.”

Unfortunately, heavy drinkers today are drinking much more than heavy drinkers fifty years ago. Alcohol researcher Kim Fromme says “When you talk to today’s students they think that four or five drinks is just getting started. She says that the heavy binge-drinking category now routinely includes people who have had twenty drinks in a setting. Blackouts have become common. Aaron White surveyed a group of more than 700 students at Duke University. Over half the drinkers in this group had suffered a blackout at some point in their lives. 40% had a blackout in the previous year, and almost one in ten had had a blackout in the previous two weeks.

Unfortunately, white women, particularly, are also drinking heavily. For physiological reasons, this trend puts women at a greatly increased risk for blackouts. If an average male of average weight has eight drinks over four hours, he would end up with a blood alcohol level of 0.107. Although that’s too drunk to drive, it is still below the 0.15 level typically associated with blackouts. If a woman of average weight has eight drinks over four hours, she’s as a blood-alcohol level of 0.173. So she’s blacked out.

Date Rape

September 25, 2019

 

This post is based on content in Talking to Strangers: What We Should Know About the People We Don’t Know by Malcom Gladwell. Of course, whether it is rape or consensual sex depends upon what the participating parties think. The following 2015 poll of one thousand college students taken by the Washington Post/ Kaiser Family Foundations reveals the problem. Students were asked whether they thought that any of the following behaviors “establishes consent for more sexual activity”

Takes off their own clothes
Men Women
Yes 50 44
No 45 52
Depends 3 3
No Opinion 2 1

Gets a Condom
Men Women
Yes 43 38
No 51 58
Depends 4 4
No Opinion 4 1

Nods in Agreement
Men Women
Yes 58 51
No 36 44
Depends 3 3
No Opinion 3 3

Engages in foreplay such as kissing or touching
Men Women
Yes 30 15
No 66 82
Depends 3 3
No Opinion * *

Does not say “No”
Men Women
Yes 20 16
No 75 80
Depends 4 2
No Opinion 1 1

A final question was ,Please tell me if you think the situation IS sex assault, IS NOT sexual assault, or is unclear. The situation is when when both people have not given clear agreement.

Men Women
Is 42 52
Is not 7 6
Unclear 50 42
No Opinion 1 0

Apparently, what is required is a consent form signed by both parties.
Alcohol makes the problem even murkier.
The following post will discuss alcohol.

My sincere apology for the pathetic formatting. They say a poor craftsman blames his tools. Obviously, HM is the poorest of craftsmen.

Alzheimer’s Disease (AD)

September 24, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

As AD progresses from earlier to later stages, atrophy starts in the medial temporal lobe, extends to the parietal lobe, and finally includes the frontal lobe. The long-term memory impairment in early AD patients can be attributed to the disrupted processing in the hippocampus and parietal cortex, to regions that have been associated with this cognitive process. As the disease progresses, other cognitive processes are disrupted such as attention and language, which both depend on the dorsolateral prefrontal cortex.

In early AD patients, as atrophy begins in the parietal cortex and the frontal cortex, there have also been reports of increases in fMRI activity within cortical regions. It is unknown whether these increases in cortical fMRI activity reflect a compensatory mechanism, which is often assumed to be the case, or reflect non-compensatory hyperactivity due to neural disruption.

In addition to brain atrophy, AD patients have abnormal high levels of proteins in different brain regions. In the medial temporal lobe, the accumulation of tau protein leads to neurofibrillary tangles. In cortical regions, such as the parietal cortex in early AD, the accumulation of amyloid-B protein leads to amyloid plaques. The neurofibrillary tangles in the medial temporal lobe and amyloid plaques in cortical regions can be assumed to disrupt neural processing in these regions.

Dr. Slotnick writes, “There is an influential hypothesis that there is a causal relationship between default network activity that leads to deposition of amyloid that results in atrophy and disrupted metabolic activity, which impairs long-term memory in AD patients. The regions in the default network are active when participants are not engaged in a task and include the dorsolateral prefrontal cortex, the medial prefrontal cortex, the inferior prefrontal cortex and the medial parietal cortex. In AD patients, amyloid deposition occurs in the same regions, which suggest the default network activity may lead to amyloid deposition. Dr. Slotnick suggests that perhaps higher level of amyloid deposition, which occurs in late AD patients, is necessary to produce atrophy in the frontal cortex.

Healthy memory readers should recognize the similarity between the default network and Kahneman’s System 1 processing. System 1 processing is the default network that needs to be disrupted to engage in System 2 processing, better known as thinking.

Dr. Slotnick continues, “If high amyloid deposition is a causal factor in developing AD, older adults with low levels of amyloid should be at decreased risk for developing this disease. There is some evidence that cognitive engagement and exercise throughout life may reduce the amyloid level in the brains of healthy older adults as a function of cognitive engagement (System 2 processing), and this was compared to the cortical amyloid levels . Participants rated the frequency which they engaged in cognitively demanding tasks such as reading, writing, going to the library, or playing games at five different ages (6, 12, 18, 40, and their current age). Healthy older adults with greater cognitive engagement throughout their lifetime, as measured by the average cognitive activity at the five ages, had lower levels of amyloid in default network regions. Moreover, the healthy older adults in the lowest one-third of lifetime engagement had amyloid levels that were equivalent to AD patients, and the healthy older adults in the highest one-third of lifetime cognitive engagement had amyloid levels that were equivalent to young adults.

It should also be noted that many have died who upon autopsy had levels of amyloid plaque and neurofibrillary tangles definitive of AD, but who never exhibited any of the behavioral or cognitive symptoms characteristics of the disease. The explanation typically offered for these individuals is that they had built a cognitive reserve as a result of the mental activities they had engaged in during their lifetimes.

There is a wide variety of products sold to prevent AD, such as computer games and pills that increase short-term memory. But it should be clear from the posts on cognitive science that the entire brain is involved. That is why the healthy memory blog strongly recommends growth mindsets with continual learning throughout the lifespan. These make heavy use of System 2 processing. Of course, a healthy lifestyle that includes physical exercise must also be part of the mix.

Transient Global Amnesia (TGA)

September 23, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

The criteria used to diagnose follow:
There is clear anterograde amnesia.
The attack must last no longer than 24 hours.
The individual must not have clouding of consciousness (drowsiness) and they must know their personal identity.
The attack must be witnessed by another person.
There should be no other neurological symptoms during or after the attack (problems speaking or partial paralysis).
There should be no recent history of head injury or epilepsy.

TGA patients often have retrograde amnesia for hours before the attack and have anterograde amnesia for 1 to 10 hours. They usually repeat the same questions, such as “where am I?” and “why am I here?” because they forget that they had already asked a question and received an answer. The most common events that precipitate an attack are emotional stress, physical effort, contact with hot or cold water, or sexual intercourse. TGA patients are usually middle-aged or elderly adults. Accompanying symptoms can include headache, nausea, and dizziness. After diagnosis, the course of treatment is to wait for the amnesia to resolve on its own.

Research provides compelling evidence that TGA is caused by a temporary lesion in the CA1 region of the hippocampus. This is consistent with the important role of the hippocampus in long term memory. The mechanism underlying hippocampal lesions in TGA patients remains unknown. One hypothesis is that TGA patients have blood flow problems due to vascular blockage, but TGA patients do not have greater vascular risk
factors, such as high blood pressure, high cholesterol, than healthy control participants.

Dr. Slotnick writes, “The only identified risk factor is a history of migraine headaches. As emotional or physical stress almost always triggers TGA attacks and stress can produce changes in blood flow, it may be that hippocampal CA2 lesions are due to stress-induced decreases in blood flow to this sub-region. The hippocampal CA1 sub-region may be particularly susceptible to reductions in blood flow because it is supplied by one large artery, while the other hippocampal sub-regions are supplied by one large artery and many small arteries. The temporary focal lesions in the hipocampas CA1 sub-region of TGA patients provide a unique opportunity for future collaborations between cognitive neuroscientists and neurologists to investigate the specific role of this region in long-term memory.

Mild Traumatic Brain Imagery (mTBI)

September 22, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Patients with mTBI do not have any brain abnormalities, as measured using structural neuroimaging methods such as anatomic MRI. The diagnosis of mTBI includes loss of consciousness for less than 30 minutes and post-traumatic amnesia for less than 24 hours. Patients with mTBI can have attention and memory deficits, but these typically resolve within a few weeks.

The performance between mTBI patients and control participants did not differ on the memory task they were performing, but the mTBI patients had a greater extent and magnitude of fMRI activity in the dorsolateral prefrontal cortex and the parietal cortex than control participants.

Fifteen mTBI patients with concussions due to sports-related injuries were tested 2 days, 2 weeks, and 2 months after the injury. Only one of the 15 patients still had symptoms 2 months after the injury. Consistent with the previous research, there were no differences in the performance of the memory task between the patients and the control participants, but there was greater fMRI activity in the mTBI patients than the control participants within the dorsolateral prefrontal cortex at all three time points and within the parietal cortex at the first two time points. This greater fMRI activity 2 months after injury is concerning because they indicate there are differences in brain processing even after behavioral symptoms have been resolved. So there can be persistent brain disruptions even though there are no behavioral symptoms or brain abnormalities observable with anatomic neuroimaging methods.

Dr. Slotnick writes, “As mTBI patients may be more sensitive to repeated head trauma, it is arguable that they should not be allowed to continue participating in impact sports until their fMRI activity returns to normal.

There is also evidence that the magnitude of fMRI activity decreases in mTBI imagery with more severe or repeated head injuries. One working memory fMRI study had mTBI patients with more severe sports-related head injuries. These not-so-mild mTBI patients were tested 1 to 14 months after the most recent head injury. The large majority of participants had multiple previous concussions, and 15 of the 16 participants had persistent symptoms. As before, behavioral measures did not differ on the memory tasks between the mTBI patients and the control subjects. There was greater activity in the dorsolateral prefrontal cortex for the control participants than in mTBI patients, in direct opposition to the previous findings for less severe mTBI patients. Additionally, participants with greater post-concussive symptoms had a smaller magnitude and extent of firm activity within the dorsolateral prefrontal cortex during visual working memory blocks. The same pattern of fMRI results was obtained in a subsequent study that employed the identical visual working memory task and a similar group of not-so-mild mTBI participants. It is important to realized that repeated mTBI and sub-concussive head injuries ( due to boxing or football, for example) can lead to chronic traumatic encephalopathy (CTE).

There are eleven previous posts addressing chronic traumatic encephalopathy.

Amnestic Mild Cognitive Impairment

September 21, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Amnestic mild cognitive impairment (aMCI) occurs in a small but significant percentage of adults who are older than 60 years of age, with incidence increasing as a function of age. Approximately 50% of these cases will become Alzheimer’s sufferers. Individuals with aMCI have a selective impairment in long-term memory as compared to healthy age-matched control participants, and are unimpaired in other cognitive domains. There is an increasing body of evidence indicating that the long-term memory impairment in aMCI patients is due to atrophy of medial temporal lobe sub regions that is increased by a paradoxical increase in fMRI activity within the medial temporal lobe.

Structural MRI was used to compare the size of the hippocampus and the entorhinal cortex in aMCI patients and control participants. aMCI patients had a smaller hippocampal value and a smaller entorhinal cortex volume in both hemispheres as compared to age-matched control participants, indicating atrophy of these regions. In addition, the white matter pathway between the entorhinal cortex and the hippocampus had a smaller volume in aMCI patients than control participants, and this was the only white matter region in the entire brain that differed in volume. These results indicate that the long-term memory impairments in aMCI patients are due to isolated atrophy in the entorhinal cortex and the hippocampus.

A relatively higher magnitude of fMRI activity within the CA3/DG sub-region during a pattern separation task reflects a non-compensatory change in processing related to neural disruption in aMCI patients.

Memory and Other Cognitive Processes

September 20, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Memory is involved in all cognitive processes. Neuroscience is a new emerging, field and the research into other cognitive processes is just beginning. Much further research is needed before it is ready for public consumption.

The few definitive facts on this topic appear in the Chapter Summary, which follow:

“*Visual attention increases activity in visual sensory regions and is also associated with activity in dorsolateral prefrontal cortex and parietal cortex control regions.

Visual working memory is associated with the same sensory regions and control regions associated with attention, which likely reflects attention to the contents of working memory.

*Visual long-term memory is associated with the same regions associated with visual attention in addition to the medial temporal lobe, which indicates this cognitive priocess is distinct from attention.

*Imagery and working memory share the same cognitive operations and are associated with the same brain regions (i.e., the sensory cortex, the dorsolateral prefrontal cortex (i.e., Broca’s area) and the left posterior superior temporal cortex (i.e., Wernicke’s area).

*Memory for emotional information is thought to be enhanced through the interaction of the amygdala and the hippocampus.”

False Memories

September 19, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

False memories often stem from memory for the general theme of previous events, called gist. The Deese-Roediger-McDermott (DRM) paradigm is commonly used to study false memory. In the DRM paradigm, lists of associated words are presented during the study phase (e.g.,”web’, ‘insect’, ‘fly’,) and then during the test phase old words, new related words (e.g., ‘spider’), and new unrelated words are presented and participants make “old” — “new” recognition judgments. Not surprisingly, participants have very high levels of false memories for new related words in these paradigms (they usually respond “old” to “spider” in the example above). It is thought that when the associated words are presented during the study phase in such paradigms, participants learn the gist of the list, and this leads to a false memory for the related item. Schacter and others have argued that remembering gist is an important feature of our memory system. Memory for gist is useful as it allows us to remember general information without getting bogged down by useless details. For example, when a person sees a friend (or an enemy) it makes more sense for them to remember the gist of that person rather than retrieve all of their previous interactions. The brain regions associated with true memory and gist-based false memories are very similar.

There are differences in brain activity between true memory and false memory. There was greater activity for true memory than false memory in more posterior early visual processing regions, including V1. These findings indicate that activity in early sensory regions can distinguish between true memory and false memory. The same pattern of visual area activity was reported in a subsequent study that used words as stimuli. So the question is if early visual regions can distinguish between true memory and false memory, why don’t participants use this information to respond “new” to related items? Slotnick and Schacter reasoned that if participants had conscious access to this information they would have used it to correctly reject new related items and, therefore, activity in early visual processing regions may reflect non consciousness. So our conscious mind remains ignorant of what our brain could tell us.

This research is important for neuroscience. However, the research on false memories in the cognitive literature is highly relevant to the law and legal issues. False memories have lead to the wrongful conviction and imprisonment of too many individuals. And there is ample research showing how false memories can be implanted into our brains. The leading researcher in this area is Elizabeth Loftus. Entering “Loftus” into the search box of the healthy memory blog will locate ten posts describing her research.
This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

False memories often stem from memory for the general theme of previous events, called gist. The Deese-Roediger-McDermott (DRM) paradigm is commonly used to study false memory. In the DRM paradigm, lists of associated words are presented during the study phase (e.g.,”web’, ‘insect’, ‘fly’,) and then during the test phase old words, new related words (e.g., ‘spider’), and new unrelated words are presented and participants make “old” — “new” recognition judgments. Not surprisingly, participants have very high levels of false memories for new related words in these paradigms (they usually respond “old” to “spider” in the example above). It is thought that when the associated words are presented during the study phase in such paradigms, participants learn the gist of the list, and this leads to a false memory for the related item. Schacter and others have argued that remembering gist is an important feature of our memory system. Memory for gist is useful as it allows us to remember general information without getting bogged down by useless details. For example, when a person sees a friend (or an enemy) it makes more sense for them to remember the gist of that person rather than retrieve all of their previous interactions. The brain regions associated with true memory and gist-based false memories are very similar.

There are differences in brain activity between true memory and false memory. There was greater activity for true memory than false memory in more posterior early visual processing regions, including V1. These findings indicate that activity in early sensory regions can distinguish between true memory and false memory. The same pattern of visual area activity was reported in a subsequent study that used words as stimuli. So the question is if early visual regions can distinguish between true memory and false memory, why don’t participants use this information to respond “new” to related items? Slotnick and Schacter reasoned that if participants had conscious access to this information they would have used it to correctly reject new related items and, therefore, activity in early visual processing regions may reflect non consciousness. So our conscious mind remains ignorant of what our brain could tell us.

This research is important for neuroscience. However, the research on false memories in the cognitive literature is highly relevant to the law and legal issues. False memories have lead to the wrongful conviction and imprisonment of too many individuals. And there is ample research showing how false memories can be implanted into our brains. The leading researcher in this area is Elizabeth Loftus. Entering “Loftus” into the search box of the healthy memory blog will locate ten posts describing her research.

Motivated Forgetting

September 18, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Like retrieval-induced forgetting, motivated forgetting refers to an active process where retrieval of an item from memory is suppressed. Unlike retrieval-induced forgetting process, motivated forgetting is an intentional process.

So the research paradigm is obvious, present lists of words where words are designated to be remembered or forgotten. But the behavioral results of such an experiment would be obvious, and many would wonder why the study was done. Participants simply ignored the words designated to be forgotten and would study the words to be remembered.

Although a simple behavioral experiment would be silly, the same experiment measuring brain regions would be informative. The first study that investigated the brain regions associated with motivated forgetting employed fMRI. During the study phase, pairs of words were presented. During the think/no think phase, the initial words of some pairs were shown in red, which meant the associated word should not be thought about. The initial words of some pairs were shown in green, which meant that the associated word should be rehearsed. The initial words of some pairs were not shown, which served as a baseline measure of memory performance. During the final recall phase, all of the initial words pairs were shown.

The percentage of associated words recalled in the no-think condition was lower than the percentage of associated words recalled in the baseline condition, which reflected motivated forgetting. The percentage of associate words recalled in the think condition was higher than baseline performance, which was expected due to additional rehearsal.

Brain activity associated with motivated forgetting was identified by contrasting non-think trials (which were assisted with subsequent forgetting) and think trials (which were not associated with subsequent forgetting). Motivated forgetting was associated with an increase in activity within the dorsolateral prefrontal cortex and a decrease of activity in the hippocampus.

A literature review has shown that motivated forgetting consistently produces an increase in activity within the dorsolateral prefrontal cortex and a decrease of activity within the hippocampus. In addition, motivated forgetting of visual information produces a decrease in activity within the visual sensory regions. This overall pattern of brain activity during motivated forgetting is identical to that of retrieval-induced forgetting. These findings provide convergent evidence that active forgetting, whether retrieval-based or motivated, is cause by a top-down signal within the dorsolateral prefrontal cortex that inhibits the hippocampus and sensory cortical regions.

Retrieval-Induced Forgetting

September 17, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Retrieval-induced is an active process where retrieval of an item from memory inhibits the retrieval of related words. For example, if the word “banana” is recalled, the memory representation of the related word “orange,” which is also a fruit, will be inhibited to some degree. Presumably such inhibition occurs to reduce the likelihood that a similar but incorrect item will be retrieved (to avoid mistakenly saying “orange” when one intends to say “banana.”)

The paradigm used to study retrieval-induced forgetting includes an initial study phase, an intermediate retrieval practice, and a final recall phase. In one fMRI experiment, participants were presented with word pairs consisting of a category and an example of the category in the study phase. During the intermediate retrieval practice phase, participants were presented with a subset of the categories along with a two-letter word cue and were asked to mentally complete each word (during this phase, non-presented words from the same categories were inhibited). In the final recall phase, participants were presented with all of the categories and word cues corresponding to the word pairs from the study phase. Categories/words that were presented in the study phase but were not presented in the retrieval practice served as a baseline level of performance (since these words were not inhibited.) Retrieval-induced forgetting was revealed as a lower percentage of recall for words that were from the same category than the percentage of recall for words that were from a different category that were not presented during retrieval practice.

To identify brain regions associated with retrieval-induced forgetting during the final recall phase, non-presented words from the same category as those presented during retrieval practice (which were inhibited) were compared with practice words (which were not inhibited). This contrast produced activity in the dorsolateral prefrontal cortex. The larger the magnitude of activity in the dorsolateral prefrontal cortex, the higher the percentage of retrieval-induced forgetting. This suggests that the dorsolateral prefrontal cortex actively inhibits non-presented words from the same category as words presented during retrieval practice.

Another retrieval-induced forgetting study used transcranial direct current stimulation (tDCS) to disrupt activity in the right dorsolateral prefrontal cortex during the practice phase. This completely eliminated the retrieval-induced forgetting effect, indicating that the dorsolateral prefrontal cortex is necessary to produce this type of forgetting.

Typical Forgetting

September 16, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Usually forgetting in everyday life can be attributed to a failure to attend to information. One might not be interested in the material, distracted by a cell phone, been sleepy, or thinking about something else. Attention is key to remembering and not forgetting. If participants are asked to deeply process words, such as deciding whether each word in a study list is “pleasant” or “unpleasant,” their memory performance will be similar whether or not they knew there is a subsequent memory test. Successfully encoding information requires attention rather than the knowledge that the information will be tested at a later time.

The pattern of brain activity associated with subsequent forgetting is the same as the pattern of brain activity that is referred to as the default network. The default network consists of the regions of the brain that become active when participants are not engaged in any particular task, such as when they lay quietly with their eyes closed, passively looking at a fixation point on the screen, or waiting between experimental trials. This network of brain activity has been associated with many cognitive states, such as daydreaming, mind wandering, lapses of attention, and retrieval of personal information.

So in the real world one knows to minimize distractions and attend to information that is important. To avoid forgetting, one needs to focus attention and stay engaged. So minimize multitasking. Staying constantly plugged in guarantees superficial understanding.

Phase and Frequency of Activity Associated with Long Term Memory

September 15, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Frequency refers to the rate of change in magnitude over time. Frequencies can be low, changing slowly over time, or high, changing rapidly over time. Brain activity time courses can be considered from a frequency perspective, with lower frequencies corresponding to slower changes in signal over time, and higher frequencies corresponding to the faster changes in signal over time. Certain frequencies of brain activity have been associated with memory and have been linked to particular brain regions. Specifically, memory has been associated with brain activity that oscillates in the theta frequency band (4 to 8 Hertz), the alpha frequency band (8 to 12 Hertz) and the gamma frequency band (greater than 30 Hertz). In the fields of visual perception and visual attention, gamma activity is known to reflect binding of features that are processed in different cortical regions (such as shape and color). Gamma activity is a mechanism that underlies the perception of unified objects. Theta activity (4 to 8 Hertz) reflects the interaction the hippocampus and cortical regions have during long-term memory, and alpha activity reflects cortical inhibition.

In addition to modulation of activity within theta, alpha, and gamma frequency bands during memory, there is evidence that brain regions with different frequencies of modulation can be in phase with each other. This is called cross-frequency coupling and indicates two brain regions interact. In a long-term memory electroencephalography (EEG) study, participants viewed picture of objects during the study phase and then during the test phase were presented with old and new pictures of objects and made “remember’ “new” judgments. Subsequently remembered items as compared to subsequently forgotten items were associated with an increase in beta activity in right frontal regions, a decrease in alpha activity in anterior and posterior regions, and an increase in gamma activity in parietal and occipital regions (from 300 to 1300 milliseconds after stimulus onset). Moreover, there was greater cross-frequency coupling for subsequently remembered than subsequently forgotten items between frontal theta activity and parietal-occipital gamma activity. The identical pattern of results for theta activity and gamma activity was observed with the same experimental protocol during memory retrieval. Based on the known role of gamma activity in visual perception and attention, it can be assumed that the increase in parietal-occipital gamma activity in these studies reflected an increase in visual object processing associated with remembered items, and frontal theta activity may have modulated the gamma activity. Of special importance, the cross-frequency coupling evidence suggests that frontal regions and parietal-occipital regions interacted during long-term memory encoding and retrieval.

To summarize succinctly, theta activity reflects the interaction between the hippocampus and cortical regions during long-term memory, alpha activity reflects cortical inhibition, and gamma activity reflects process of features in different cortical regions that are combined to create a unified memory.

Superior Long Term Memory

September 14, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Perhaps the most famous research on superior memory, one that has been reported in previous healthy memory blog posts regards London taxi drivers. At one time they needed to memorize the layout of 25,000 city streets and the locations of thousands of city attractions. One study investigated whether there were differences in the size of brain regions between taxi drivers and control participants. They found that these taxi drivers had changes in the size of only their hippocampus, with a relative increase in the amount of gray matter within the posterior hippocampus and a relative decrease in the amount of gray matter within the anterior hippocampus. Moreover, the types changes in both types of hippocampal gray matter size correlated with the length of time they had been taxi drivers, which ranged from 1.5 to 52 years (with the largest changes for those who had been taxi drivers the longest).

A follow-up study compared the brain region sizes between London taxi drivers and London bus drivers, who were a better matched control in terms of driving experience, stress, and other factors. The same results were obtained, where the taxi drivers had a relatively larger posterior hippocampus and a relatively smaller anterior hippocampus than bus drivers, and this correlated with the length of time they had been driving a taxi.

Another group of people who have superior memory are those who participate in the World Memory Championships and those who are known for extraordinary memory abilities. A study compared such individuals with control participants to asses whether there were differences in cognitive abilities, differences in the size of brain regions, and differences in the magnitude of fMRI activation during memory tasks. People defined as having superior memory did not differ from control participants in the cognitive abilities tested (IQ ranges were 95 to 119 and 98 to 119, respectively) or in the size of an brain regions. The fMRI task required superior memory for a sequence of digits (a task where those whose superior memory excelled), memory for a sequence of faces, or memory for a sequence of snowflakes. Across tasks, those with superior memory had greater activation in the posterior hippocampus, the retrosplenial cortex, and the medial parietal cortex, which are regions that have been associated with long term memory. Almost all of the participants with superior memory reported using a memory strategy called the method of loci. (entering method of loci into the search block of the healthy memory blog yields 11 hits).

Another case study investigated another individual with a superior memory, who is known as PI, was able to recall the digits of pi to more than 65,000 decimal places. His performance was similar to control participants on the large majority of cognitive tasks. Not surprisingly his working memory was in the 99.9th percentile. But it is conceivable that that might be the result of the extraordinary amount of time he spent memorizing pi. His general memory was average. He was impaired on test of visual memory (3rd percentile or below).

He also reports on individuals who are considered as having highly superior autobiographical memory or HSAMers. There have been eight previous posts on HSAMers. These are people who have detailed episodic memory for every day of their later childhood and adult life. If they are given any date, they can recall the day of the week, and public events that occurred on that day of the week. In one study of HSAMers their performance was normal on most standard cognitive tasks. A comparison of different brain regions between HSAMers and control participants revealed a number of differences including greater white matter coherence in the parahippocampal gyrus, which could reflect greater contextual processing associated with episodic retrieval, and a relatively smaller anterior temporal cortex. The decrease in size of the anterior temporal cortex, which has been associated with semantic memory, may reflect the disuse of this region because those with HSAM rely more on episodic retrieval. Much more research needs to be done with this interesting group.

Sex Differences in Long Term Memory

September 13, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Males usually perform better on navigating previously learned environment. Females usually perform better on long-term memory tasks that can depend on verbal memory such as word list recognition and recall, associative memory, and autobiographical memory. Since almost all long-term memory tasks can be performed using verbal memory strategies, females generally have better behavioral performance than males. Females have larger numbers of estrogen receptors in the hippocampus and dorsolateral prefrontal cortex. These are two of the three regions associated with long-term memory, which can increase the activity of these regions. The hippocampus and the dorsolateral prefrontal cortex are larger in females than males, relative to overall brain size. Additionally, females have relatively larger volumes of language processing cortex, which likely contributes to their superior verbal memory.

In addition, females and males often employ different cognitive strategies and have distinct patterns of brain activity while they perform the same task. An fMRI study investigated whether there were sex differences in the hippocampus during memory for object-location associations. There were 10 female and 10 male participants. During study blocks, participants viewed a video as if they were walking through a virtual environment with five colored geometric objects. During recognition blocks, an aerial view of each object was shown in a old location or a new location. Participants responded whether each was in an “old” or “new” location. Each participant also used a four-point rating scale to describe the strategy they used to learn the object locations: (1) completely verbal, (2) more verbal than pictorial, (3) more pictorial than verbal, and (4) completely pictorial.

Although there was no difference in behavioral performance between female participants and male participants, the average strategy for female participants was 2.5 and the average strategy rating for male participants was 4.0 indicating that female participants employed more verbal memory strategies and male participants employed purely spatial/non-verbal strategies. The fMRI data indicated that activity was localized to the left hippocampus in the large majority of female participants and that activity was localize to the right hippocampus in the large majority of male participants. These results are consistent with patient studies indicating the lesions in the left medial temporal lobe impair verbal memory and lesions in the right medial temporal lobe impair visual memory.

Long Term Memory Consolidation and Sleep

September 12, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

It appears that a primary role of sleep is to integrate new memories into our vast memory store with the minimal disruption of old memories. Sleep involves rapid eye movements (REM) periods and non-REM periods that alternate every ninety minutes, with four stages of progressively deeper non-REM sleep. The first half of a night’s sleep is dominated by non-REM sleep, while the amount of REM sleep increases during the second half of the night. Non-REM stages 3 and 4, referred to as slow wave sleep, are of special relevance because these periods are important for consolidation of long-term memories. REM sleep seems to be particularly important for consolidation of implicit memories.

Slow wave sleep is associated with slow (less than 1 Hertz) waves of brain activity that are measured across the entire scalp using EEG. The slow waves orchestrate a number of brain processes that mediate the process of long-term memory consolidation. Slow waves alternate between down-states corresponding to global decreases in brain activity and upstates corresponding to global increases in brain activity. Slow waves synchronize other brain waves including thalamic-cortical sleep spindles (that oscillate at frequencies of 11-16 Hertz) and hippocampal sharp-wave ripples (that oscillate at a frequency of approximately 200 Hertz). Hippocampal sharp-wave ripples are of particular importance as they are known to coordinate the hippocampal-cortical interactions that reflect the reproduction of memories from the previous waking period. In brief, important long term memories from the previous waking period are replayed during slow wave sleep, which in turn strengthens these memories and results in consolidation. Although this mechanism for memory consolidation is based on strengthening of memory representations through repeated activations, it has been proposed that sleep may also weaken memory representation of unimportant events to provide a clean slate for next day’s events. It is interesting to note that Dr. Slotnick dedicates this book to his incredible daughter Sonya, for dominating my hippocampal sharp-wave spindles these past twelve years. This section should convince all readers that all-nighters are not only fruitless, but also counterproductive. One wants to have memories well-consolidated prior to taking an exam.

Brain Regions Associated with Long-Term Memory

September 11, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Remember to consult the website http://www.brainfacts.org/
to see the anatomical information referred to in this post.

Dr. Slotnick writes, The term episodic memory can refer to many other related forms of memory including context memory, source memory, “remembering,” recollection, and autobiographical memory, which refers to a specific type of episodic memory for detailed personal events. As the names imply context memory and source memory refer to the context in which something occurred and source memory refers to where the event occurred.

Episodic memories are related to activity in both control regions and sensory regions of the brain. Sensory cortical activity reflects the contents of memory. The control regions that mediate episodic memory include the medial temporal lobe, the dorsolateral prefrontal cortex, and the parietal cortex. There are many regions associated with episodic memory but the primary regions are the medial temporal lobe, the dorsolateral prefrontal cortex, and the parietal cortex. The parahippocampal cortex processes the context of previously presented information such as the location or the color.

The hippocampus binds item information and context information to create a detailed episodic memory. Dr. Slotnick provides the following example. “If an individual went on a vacation to Newport Beach in California and later recalled meeting a friend on the beach, that individual’s perirhinal cortex would process item information (the friend), the parahippocampal cortex would process context information (the area of the beach on which they were standing), and the hippocampus would bind this information and context information into unified memory.”

Semantic memory refers to knowledge of facts that are learned through repeated exposure over a long period of time. These facts are processed and organized in semantic memory, which provides the basis for much thought. Subjectively, semantic memory is associated with “knowing.” Semantic memory includes definitions and conceptual knowledge, and this cognitive process is linked to the field of language.

Semantic memory has been associated with the left dorsolateral prefrontal cortex (in a different region associated with episodic memory), the anterior temporal lobes, and sensory cortical regions. The left dorsolateral prefrontal cortex may reflect the processing of selecting a semantic memory that is stored in other cortical memories. For example, naming animals activates more lateral inferior occipital-temporal cortex that has been associated with the perception of living things, while naming tools activates more medial inferior occipital-cortex that has been associated with perception of nonliving things.

In a study of Alzheimer’s patients, the impairment in an object naming task, which depends on intact semantic memory, was more highly correlated with cortical thinning in the left anterior temporal lobe. This finding suggests that the left anterior temporal lobe is necessary for semantic memory.

During long-term memory the hippocampus binds information between different cortical regions. But long-term memory may only depend on the hippocampus for a limited time. In the standard model of memory consolidation, a long-term memory representation changes from being based on hippocampal-cortical interactions to being based on cortical-cortical interaction, which takes a period of somewhere between 1 to 10 years. A person with hippocampal damage due to a temporary lack of oxygen might have impaired long-term memory for approximately 1 year before the time of damage from retrograde amnesia and have intact long-term memories for earlier events. This suggests that the hippocampus is involved in long-term memory retrieval for approximately 1year as more remote long-term memories no longer demand on the hippocampus so they are not disrupted.

The activity in the hippocampus did not drop to zero for older semantic memories but was well above baseline for events that were 30 years old. This indicates that the hippocampus was involved in memory retrieval for this entire period. If the hippocampus was no longer involved, the magnitude of activity in this regions would have dropped to zero for remote memories.

There is a growing body of evidence that the hippocampus is involved in long-term memories throughout the lifetime. As such, the process of consolidation does not appear to result in the complete transfer from hippocampus-cortical memory representation to cortical-cortical memory representations.

Tools of Cognitive Neuroscience

September 10, 2019

The title of this post is identical to a chapter title in an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” The tools of cognitive neuroscience are highly technical. If the reader is interested in these techniques she should read Dr.Slotnick’s book, or look up the tools of interest in the Wikipedia.

One of the earliest techniques was positron emission tomography (PET). It required that a low level of radioactive material be injected into the participants bloodstream. This technique measured increased blood flow to the portions of the brain being activated. Fortunately a new technique that measured blood flow was found that did not require the injection of radioactive dye or any other type of material.

That technique was functional magnetic resonance imaging (fMRI), which also measured where in the brain the blood flow was increasing.

Event-related potentials (ERPs) can track brain activity in real time. ERPs directly measure neural activity and have a temporal resolution in milliseconds. Its spatial resolution is in centimeters, which is much lower than fMRI.

Electroencephalography (EEG) uses the identical data acquisition as ERPs, but refers to any measure of brain activity that corresponds to electric fields. This includes ERPs, but more commonly refers to brain activity that oscillates within a specific range of frequencies. EEG frequency analysis is a powerful alternative to the more commonly employed ERP analysis. Related to EEG, magnetoencephalography (MEG) refers to any measure of brain activity that corresponds to magnetic fields, and also typically refers to brain activity that oscillates within a specific frequency range. Like ERPs that are generated by averaging all the events of a given type from EEG data during a cognitive task, event-related fields (ERFs) are generated by averaging all the events of a given type from MEG data. The more general terms EEG and MEG also refer to ERPs and ERFs.

Dr. Slotnick writes, “fMRI is by far the most popular method in the field of cognitive neuroscience. However, brain activity is not a static set of blobs that represent a cognitive process. Rather, brain activity changes across different regions in milliseconds. Only techniques with excellent temporal resolution, such as ERPs, can track the functioning brain. This book highlights the temporal dimension of brain processing in addition to the spatial dimension of brain processing. One major advantage of temporal information is that one can use it to assess whether different brain regions are synchronously active, which indicates that these regions interact. This reflects how the brain is actually operating.”

Transcranial magnetic stimulation (TMS) can be used to temporarily disrupt processing in one region of the brain.

Transcranial direct current stimulation (tDCS) is similar to TMS in that it temp[orarily modulates processing in a target cortical region by stimulating with a weak direct current rather than a magnetic field.

A relatively new method called transcranial alternating current stimulation (tACS) uses the identical setup as tDCS, but the current alternatives at a specific frequency; this, tACS can stimulate the brain at a desired frequency.

Do not let yourself be discouraged or turned off by this technical stuff, but brief explanations are needed as these are the tools used in this research. The remainder of the posts will be on memory performance and on the portions of the brain contributing to this performance.

Sensory Reactivation Hypothesis

September 9, 2019

This post is based on information in an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” The sensory reactivation hypothesis states that memory for an event can activate the same brain regions associated with the perception of that event. These sensory memory effects reflect the contents of memory for a visual experience containing visual information.

There is a large body of research supporting the memory sensory reactivation hypothesis. Memory for visual information, language information (sounds or words), movement information (actions, and olfactory information reactivate the corresponding regions of the brain.) Within the visual process regions, there is also evidence that memory for faces and houses activate the fusiform face area (FFA) and the parahippocampal place area (PPA), respectively.

Evidence has also accumulated that memory for specific features activate the corresponding feature processing brain region. Memory for shape activates the lateral occipital complex (LOC), memory for colors activates V8, memory for items in the left visual field or right visual field activate the extra striate cortex in the opposite/contralateral hemisphere, and memory for motion activates region MT.

The concept of mental practice is relevant here. Athletes or performers mentally rehearse the activities they will need to perform. This mental rehearsal activates the relevant brain areas and the communications that need to be made to perform these activities. And this mental practice has beneficial effects on performance.

This is good to keep in mind if the weather or other complications preclude regular practice. Idle moments can be filled with mental rehearsal to make best use of one’s time.

Similarly one can use this sensory reactivation to re-experience pleasant experiences, be it an view, vacation highlights, sporting events, enjoyable meals. One can get maximum value for one’s entertainment dollar in this manner.

Brain Anatomy

September 8, 2019

The title of this post is identical to the title of a section in an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” Brain Anatomy is a difficult topic to cover in a blog. The names can be learned and one can impress one’s friends and neighbors by reciting these names with their associated function. But the brain is a three dimensional structure and it is difficult illustrating these structures in two dimensions, especially since the position from which the brain is viewed is important. What is needed is a three dimensional model that can be rotated. Such a model can be found at http://www.brainfacts.org. Look for 3D Brain and click interact with the brain. It will likely take some practice interacting with the brain, but HM thinks this is the best source for this feature.

The brain is composed of four lobes: occipital, temporal, parietal, and frontal. Each lobe has gray matter on the surface, which primarily consists of cell bodies, and white matter below the surface, which primarily consists of cell axons that connect different cortical regions. The occipital lobe is associated with visual processing. The temporal lobe is associated with visual processing and language processing. The parietal lobe is associated with visual processing and attention, and the frontal lobe is associated with many cognitive processes. You can see that over half of the human brain is associated with visual processing. Obviously we are primarily visual animals.

The regions of the brain that are of relevance to memory include the occipital cortex, the temporal cortex, the parietal cortex, the dorsolateral prefrontal cortex, and the medial temporal lobe. The cortex is folded with gyri protruding out and sulk folding in.

The hippocampus (you can look for this using the link provided above) is a structure central to long-term memory. Its importance was realized when surgery was done on a patient, H.M., done to treat the severe epileptic seizures he was having. The medial temporal lobe, which contains the hippocampus, was removed in both hemispheres. This surgery did not affect his intelligence or personality, but it did cause a severe deficit in long-term memory referred to as amnesia. His semantic memory remained intact. He had almost no memory of events that occurred a few years before the surgery, and had no memory for events that occurred after the surgery. Ten months before the surgery he and his family moved to a new house a few blocks away from their old house. After the surgery he had no memory for his new address, he could not find his way to the new home, and he did not know where objects were kept in the new home. He had no memory of articles he had read before, so he would read the same articles repeatedly. He would eat lunch and a half-hour later could not remember he had eaten. Despite this severe deficit in long-term memory, his working memory appeared intact. He could remember a pair of words or a three-digit number for several minutes as long as he was not distracted. So a reasonable conclusion is that the hippocampus and the surrounding cortical regions are critical for long-term memory.

Dr. Slotnick writes, “Long-term memory typically refers to retrieval of previously presented information, However, the key stages of long-term memory include encoding, storage, and retrieval. The hippocampus has been associated with both long-term memory encoding and long-term memory retrieval. Long-term memory storage depends on a process called memory consolidation, which refers to changes in brain regions, including the hippocampus, underlying long-term memory. Thus, all three stages of long-term memory depend on the hippocampus.”

Sometimes people think of the hippocampus as being the location where long-term memories are stored. Memories are stored throughout the brain, it is the processing of these memories for which the hippocampus is critical.

The Role of Introspection

September 7, 2019

This post is based on an important book by Scott D. Slotnick titled “Cognitive Neuroscience of Memory.” The initial research approach taken in the early days of psychology was introspection. As all humans can access their own minds, it seemed like an obvious approach, to simply record how humans are using their own minds. Reams of research were collected using this approach. But no theories or hypothesis emerged, nor were there techniques for testing hypotheses, which is central to all science. The result was a radical rejection of this subjective approach and the beginning of behaviorism, in which only observed behaviors were an appropriate source of data for psychologists.

Only recently has introspection been accepted back into rigorous psychological research. Introspection has been found useful in identifying which kind(s) of memory operated during a particular task.

The renowned psychologist Endel Tulving hypothesized that there was a distinction between “remembering” and “knowing.” Tulving recognized this distinction from his own introspections. But he did not stop there. There was research on a patient with a brain lesion who had no detailed memory of the past (he could not remember) but still could define words. Tulving designed and ran experiments to test the hypothesis that “remember” responses and “know” responses were distinct. During one experiment, words were presented during the study phase, and then during the test phase old words and new words were presented and participants made “old” and “new” recognition judgments. For old items correctly classified as “old,” participants also made a “remember” – “know” judgment and a confidence-rating judgment (ranging from 1 to 3 corresponding to low confidence, intermediate confidence, and high confidence). The probability of “remember” responses increased with increasing confidence, while the probability of “know” responses was maximal at the intermediate confidence rating.

These distinct response profiles provide behavioral evidence in support of Tulving’s hypotheses that “remembering” and “knowing” are distinct types of memory. This research is strictly cognitive psychology. However, a large body of research in cognitive neuroscience has subsequently accumulated showing that “remembering” and “knowing” are also associated with distinct regions of the brain.

Cognitive Neuroscience of Memory

September 6, 2019

The title of this post is the same as the title of an important book by Scott D. Slotnick. He writes in the preface, “The human brain and memory are two of the most complex and fascinating systems in existence. Within the last two decades, the cognitive neuroscience of memory has begun to thrive with the advent of techniques that can non-invasively measure human brain activity with spatial resolution and high temporal resolution.

Cognitive neuroscience had not been created when HM was a graduate student. The field is quite new. In cognitive psychology we studied cognitive processes, of which memory was central, but little was known about the neuroscience underlying memory.

Before getting into neuroscience it is important to understand what memory encompasses. Most people think of memory as something they need to use to pass exams, are frustrated by exam failures, and by an inability to remember names. Readers should be aware of the function of memory. Memory is a tool for time travel. We use it to help us predict and deal with the future. The more we learn, the more we have information for dealing with the future. Moreover, there are many types of memory.

The first pair of memory types is explicit memory and implicit memory. These refer to conscious memory and nonconscious memory. They differ in that all forms of explicit memory are associated with conscious experience/awareness of previously experienced memory, whereas all forms of implicit memory are associated with a lack of conscious experience/awareness of the previously experienced information.

Skills are one type of implicit of memory. After a skill is learned, performance of that skill reflects nonconscious memory. Once a person has learned to ride a bike, she doesn’t think about rotating the pedals, steering, breaking, or balancing. Rather, their conscious experience is dominated by where she wants to ride or whatever else she happens to be thinking about. Repetition priming is another type of implicit memory that refers to more efficient or fluent processing of an item when it is repeated. When a television commercial is repeated, that information is processed more efficiently (and when the item from the commercial is seen again while shopping, implicit memory presumably increases the chance that it will be purchased.) Skill learning can be assumed to be based on repetition priming.

The remaining memory types are types of explicit memory. A second pair of memory types is long-term memory and working memory. Working-memory is often referred to as short-term memory. A recognition memory experiment will be described to help make the distinction between long-term memory and working memory. During the study phase of both long-term memory and working memory, items such as words or objects are presented. After the study phase, there is a delay period that will last as a function of specific amount(s) of time. During the test phase, old items from the study phase and new items are presented, and participants make “old” or “new” judgments for each item. This is termed old-new recognition. A greater proportion of “old” responses to old items than “old” responses to new items indicates the degree of accuracy of the memories.

Long-term memory and working memory differ with regard to whether or not information is kept in mind during the delay period. Typically there are many items in the study phase and the delay period is relatively long (typically minutes to hours). Obviously participants do not actively maintain information from the study phase during the delay period. In working memory experiments, there are typically a few items in the study phase, the delay period is in seconds and participants are instructed to actively maintain information from the study phase in their mind.

Another pair of memory types is episodic memory and semantic memory. Episodic memory consists of the memories we have of our experiences. Semantic memory refers to retrieval of, hopefully, factual memory that is learned over periods of time such as the definition of a word. Unfortunately, semantic memory also consists of misinformation and erroneous beliefs. And, unfortunately, this misinformation and erroneous beliefs can be further amplified via technology and social media.

Another pair of memory types is “remembering” and “knowing.” “Remembering” refers to the subjective mental experience of retrieving details from the previous experience, such as someone retrieving where they parked their car in a parking lot. If any details are recalled from a previous experience, this constitutes “remembering.” “Knowing” is defined by the lack of memory for details from a pervious experience, such as when someone is confident they have seen someone before but not where or when they saw them. Remembering is usually assumed to be related to context memory, as it is thought to occur whenever contextual information is retrieved. “Knowing” is typically assumed to be related to item memory and semantic memory. The last pair of memory types is recollection and familiarity. The terms recollection and familiarity can refer to mathematical models of these two kinds of memory, but more commonly refer to all the forms of detailed memory (episodic memory, context memory and “remembering”) and non-detailed memory (semantic memory, item memory, and knowing). Dr. Slotnick writes, “It may be useful to think of context memory and item memory as measures of task performance, “remembering” and “knowing” as measures of subjective experience, and recollection and familiarity as general terms that describe strong memory and weak memory, respectively.”

Positivity Wrap Up

September 4, 2019

It is hoped that by know you not only are aware of the extreme importance of increasing positivity and decreasing positivity in your life, but that you also have an extensive amount of guidance as to how to accomplish these goals. The title is Positivity Wrap Up rather than Positivity Conclusion because positivity is a lifelong pursuit and it is only these series of posts that are concluding. Even so, you should anticipate future posts on this topic because it is so important. The fear is that the amount of advice might be overwhelming. Use what you find relevant and what you have the resources to address.

You have the survey for assessing your own positivity. Remember that the goal, the tipping point into positivity is a ratio of 3. However, you should not stop at this level and continue your endeavor into a more flourishing life.

Remember that these blog posts cannot do justice to the complete book. So consider reading “Positivity: Discover the Upward Spiral That Will Change Your Life,” by Barbara L. Fredrickson, Ph.D.

A Positivity Toolkit

September 3, 2019

This post is based on a book by psychologist Barbara L. Fredrickson, “Positivity: Discover the Upward Spiral That Will Change Your Life.”

Tool 1. Be Open. The goal here is to experiment with mindful awareness while carrying out your day. Make your motto “be open.” Temporarily rid your mind of expectations and judgments. These can cloud your ability to be open. Instead, give yourself permission and time to experience the richness of the present moment. No matter what you encounter, no matter what happens, experiment with both awareness and acceptance.

Tool 2. Create High-Quality Connections. Any social interaction—whether with family, co-workers, or someone ahead of you in line—is a chance to create a high-quality connection. According to Jane Dutton, cofounder of the Center for Positive Organizational Scholarship at the University of Michigan’s Ross School of Business, your moments of connection with others form a dynamic, living tissue that can be either life-giving or life-depleting. High quality connections are life-giving. You recognize them instantly by several telltale signs: they foster mutual appreciation and encourage truly being or doing things together; they recharge your energy and your vitality; they bring real physiological changes. You can literally feel high-quality connections resonate within your body.

Tool 3. Cultivate Kindness. This tool draws from research done by Sonja Lyubomirsky, author of The How of Happiness. Give yourself the goal of performing five new acts of kindness on a single day. Aim for actions that really make a difference and come at some cost, such as donating blood, helping your neighbor with her yard work. Assess what those around you might need most. Although some of the kind acts you choose may take some advance planning, make a point to carry them all out on a single day. At the end of the day, take stock. Notice the good feelings that come with increasing your kindness: the positive connection to the person you helped, the fitting sense of pride you get from making a contribution. For lasting impact, make your kindness day a recurring ritual. Be creative each week. Find new ways to make a positive difference in the lives of others. Try it for a few months and see the difference it makes.

Tool 4. Develop Distractions. The suggestion is to make two lists. Label one healthy distractions and the other unhealthy distractions. Ask, “What can I do to get my mind off my troubles?” Then brainstorm, identifying things you already do,as well as new activities you’d like to try. Try to come up with things you can do in good and bad weather, at work, at home, or on the road.

Write down the unhealthy distractions that tempt to you. For each unhealthy distraction that tempts you, come with a healthy alternative: a drink or snack that doesn’t take a toll; a movie, computer game, or song list that’s more uplifting.

Tool 5. Dispute Negative Thinking. This exercise comes from the Penn Resiliency Program. This requires a set of index cards. On each one, write one of your typical negative thoughts. Write down negative thoughts that are realistic and truly yours. Capture your inner critic, that voice in your head that’s skeptical of you, of others, and of everything around you—the voice of ill will.

Then shuffle the cards and pick one at random. Read, then as fast and as thoroughly as you can—dispute it. When you’re satisfied that you’ve shot down your menacing negativity with rapid-fire facts, move on to the next card. Repeat. As you work your way through your negativity deck, let you conviction grow as you become a seasoned disputer. Whenever you find gratuitous negativity lurking in your mind, externalize it by adding it to your deck of cards. Challenge yourself to meet it out in the open—out loud—with your rapid fire facts. Be sure that these are facts and that you are not lying to yourself.

Tool 6. Find Nearby Nature. Locate places you can get to in a matter of minutes that will connect you to green or blue, to trees, water, or sky. Ample research has shown that these boost positivity.

Tool 7. Learn and Apply Your Strengths. One way to learn your strengths is to take a free, online survey that Martin Seligman (the founder of Positive Psychology) and Chris Peterson developed with support from the Values in Action Institute. Allow yourself plenty of time to take this survey: it contains 240 items to measure 24 character strengths. You can find it by visiting Seligman’s website at the University of Pennsylvania’a Positive Psychology Center, or point your browser to http://www.AuthenticHappiness.com. After completing the survey, you’ll receive a report that ranks the 24 strengths by the degree to which they characterize you. The report will also feature your top five strengths, and encourage you to reflect on which ones truly resonate for you, which strengths, when you act on them, make you come alive. This self-reflection is critical. It’s how you locate your “signature” strengths among your top five.

Tool 8. Meditate Mindfully. There are many healthy memory blog posts on this topic. Go to healthymemory.wordpress.com and enter “relaxation response” in the search box.

Tool 9. Meditate on Loving-Kindness. There are also posts on this tool. Go to
healthymemory.wordpress.com and enter loving-kindness in the search box.

Tool 10. Ritualize Gratitude. Being grateful simply requires that you notice the gifts that surround you. If you’re drawn to record your thoughts in writing, consider buying a blank book to be your gratitude journal.

Tool 11. Savor Positivity. You need two things to experiment with savoring. First is a genuine love, joy, pride, or any other flavor of positivity in your life; second a willingness to think differently about it. The key is to think about the event in away that stokes your positivity flames right now. Truly cherish the event, and its benefits to you will grow.

A Word of Caution from HM. This is an enormous toolkit. It easily overwhelms. It’s even more overwhelming when you consider your obligations. Some of the tools here should be helpful in dealing with your obligations. But you need to be selective, picking and choosing what you think is most helpful and what you think you’ll be able to devote your time to.

Increase Positivity

September 2, 2019

The title of this post is identical to the title of a chapter in a book by a book by psychologist Barbara L. Fredrickson, “Positivity: Discover the Upward Spiral That Will Change Your Life.” The chapter begins with the following Cherokee parable:

One evening an Old Cherokee told his grandson about a battle
that goes on inside people. He said, “My son, the battle is between two wolves inside us all. One is Evil. It is anger, envy jealousy,
sorrow, regret, greed, arrogance, self-pity, guilt, resentment,
inferiority, lies, false pride, superiority, and ego.

“ The other is Good. It is joy, peace, love, hope, serenity,
humility, kindness, benevolence, empathy, generosity, truth,
compassion, and faith.”

The grandson thought about it for a minute and then asked his
grandfather, “Which wolf wins?”

The old Cherokee simply replied, “The one you feed.”

Sincerity matters. Take a moment to appreciate the word “Heartfelt.” To truly feel positivity in your heart requires that you slow down. The pace of modern life is often so relentless that it keeps you focused outward, away from your inner core. To increase your positivity, you’ll need to “un-numb” your heart. Let it feel. Let it be open. Slow yourself down enough so that you can see and hear and sense with your heart, not just with your eyes, ears, and mind. Let yourself breathe in and fully absorb the goodness that surrounds you. Connect to that goodness. Revel in it. Together with a sincere attitude, this slower pace unlocks your heartfelt positivity.

Find Positive Meaning. Finding positive meaning is always possible. Most of the circumstances we face are not 100% bad. So the chance to find the good, and honestly accentuate the positive meaning in your current circumstance, is always present, even if it’s simply to realize that “this too shall pass.” When you reframe unpleasant and even dire circumstances in a positive way, you boost the odds that positive emotions—like hope—will flow forth.

Savor Goodness. Another strategy for increasing positivity, perhaps obvious is to find the good within the good, by turning something positive into something even more positive. The author suggests calling this gold-plated positivity. She writes that savoring is a mental habit we can develop.

Count Your Blessings. By moving the riverbed of your habitual thought you can reframe something bad as something good and make good things even better. You can even do the same with seemingly ordinary things. You can take something flat, dull, and commonplace and make it sparkle. Oprah popularized the idea of keeping a gratitude journal. She encouraged people to write down five things they love each day.

Kindness Counts. There are at least two sides to kindness. When you count your blessings, you often appreciate how others have been kind to you and have elicited your gratitude. Recognizing your side of kindness is another simple and cost-free way to boost your positivity. Kindness and positivity feed own each other. Simply recognizing your own acts of kindness initiates an upward spiral.

Follow Your Passions. Give yourself permission to play. Find the activities that allow you to enter flow. Flow states are those peak moments in which you become fully absorbed in an activity, when the challenges of the activity are high and well-matched by your ever increasing skills. Some people enter into flow with their hobbies.

Dream About Your Future. Another way to boost your positivity is to dream more frequently about your future. Conjure up the best possible outcomes for yourself. Visualize your future successes in great detail. People who are assigned at random to carry out such an exercise show reliable increases in their positivity relative to those who carry out more mundane self-reflective actions.

Apply Your Strengths. People who have the opportunity to do what they do best—to act on their strengths—are far more likely to flourish. Research has shown that learning about your strengths can give you a high.

Connect with Others. Flourishing is not a solo endeavor. It’s scientifically correct to say that nobody reaches his or her full potential in isolation. Every person who flourishes has warm and trusting relationships with other people.

Connect with Nature. Natural environments may be as important to flourishing as social environments. So a very simple way to increase your positivity is to go outside.

Open Your Mind. Positivity and openness feed on each other, each triggering and reinforcing the other. This bidirectional link means that another level you can gasp to increase positivity is to be open. Be open and positivity will follow.

Open Your Heart. Whereas the practice of mindfulness meditation opens your mind, other age-old meditation practices seem to more directly unlock your heart. Practicing these other forms of meditation helps you experience your connections with others, bringing forth the deep and heartfelt positivity of community. The author suggest loving-kindness meditation. Enter “loving-kindness” into the search block at
healthymemory.wordpress.com to find relevant posts on this topic.

Dealing with Negative People

September 1, 2019

The title of this post is identical to the title of a section in of a book by psychologist Barbara L. Fredrickson, Ph.D. titled “Positivity: Discover the Upward Spiral That Will Change Your Life.” The title presents a challenge to which we all will encounter. Here are three techniques for dealing with this situation.

Technique 1. Modify the situation. You need to be honest and ask yourself if there is any way that you inadvertently feed this person’s negativity. Could I somehow be baiting him with my own reaction or words? Am I to any degree closed down when we interact? What assumptions do I make about this person? Reviewing these questions might lead to better ways of interacting with this individual.

Another way to change the situation is to be proactive in setting the collective agenda. Choose joint activities that inspire you. Consider whether you might reserve the tasks that irritate you—for example, paying the bills or cleaning up—for when you’re each alone and less likely to fan the collective negativity flames.

If negativity surfaces, a final way to modify the situation is to inject compassion, hope, or even humor. Curb you tendency to respond “in kind” to gratuitous negativity with yet another helping of it. Don’t escalate the problem. Instead offer positive reframes of the negative messages delivered. Convert they “half empty” to half full.” Point out something that you both might see as funny. Scientific studies have shown that relationships in which one partner somehow manages to break the cycle of negative reciprocity—by respond to negativity in a neutral or positive way—fare far better than those in which partners mirror each other’s ill will.

Technique 2. Attend differently. Another strategy is to consider how you might attend to different aspects of this person. What are his positive qualities? What do you appreciate about him? What does he bring to the table? Perhaps your boss’s frequent bursts of anger are matched by his stand-out passion for making a positive difference in the world. Consider the times when your spouse has stood by you, loyal and faithful. Consider how you might give voice to what you appreciate. Research has documented that, in relationships, the areas where you choose to cast your attention and devote your words grow in strength and significance over time.

Technique 3. Change meanings. Instead of seeing this person as bringing you down, consider the quote by Zen teacher Charlotte Joko Beck,
Life always gives us exactly the teacher we need at every moment. This includes every mosquito, every misfortune, every red light, every traffic jam, every obnoxious supervisor (or employee), every illness, every loss, every moment of joy or depression, every addiction, every piece of garbage, every breath.
Could this person or situation be a teacher in disguise? They could be, if you reframe your time with her as a challenge—a challenge to be more mindful, less judgmental, or more compassionate. Remember that you do get to choose whether to react to the negativity this person spews. His negativity need not be yours. Working on you own reactions in a mindful way may even remove some of the fuel that keeps this person’s negativity flaming. But even if it doesn’t, you still come out ahead. You’ll have further developed your skill in mindfulness.