Posts Tagged ‘fMRI’

Suggestible You 3

March 19, 2017

“Suggestible You” is the title of a book by Erik Vance.  The subtitle is “The Curious Science of Your Brain’s Ability to Deceive, Transform, and Heal.  This book is about the placebo response and related phenomena.   This is the third post on this book.

Irving Kirsch took up psychology out of a philosophical curiosity about the brain.  He mentored Ted Kaptchuk, a researcher who earned a Chinese doctorate in Eastern medicine and was an expert in acupuncture and other alternative therapies.  These two set up a lab at Harvard and for a long time their names have been synonymous with placebo research.  Kaptchuk’s work spans many complicated aspects of placebo research—genetic, biochemical—but Vance’s favorite study is a relatively simple one.  He handed patients pills and told them it was a placebo.  He explained that placebos had been shown to be very effective agains all manner of conditions, and so forth.  When these patients took the pill, it still worked.  Not as well as a secret placebo—but it worked, even though the people taking it knew it wasn’t real.

Tor Wager conducted research using functional magnetic resonance imaging f(MRI).  fMRI measures blood flow in the brain.  This blood flow is used to infer brain activity.  It is captured in voxels. A single voxel has about 63,000 neurons in it (and four times as much connective).  Nevertheless, fMRI has been invaluable in gaining insights regarding the brain.  Wager used fMRI to capture the placebo effect in action.  The first experiment used electric shock.  The research participants saw either a red or a blue spiral on a screen warning them hey would get either a strong or a mild shock, which would hit between 3 and 12 seconds later to keep them off guard (and build expectation).  Wager  looked two skin creams explaining that a one was designed to reduce the  pain and the other was a placebo.  Actually both skin creams were placebos, but the research participants said they felt less pain with the “active” cream.

The second experiment used a hot metal pad that seared the skin for 20 seconds.  This time the screen just read, “Get Ready,” and then the pad heated up.  As in the first experiment, the research participants received placebo and “pain killing” creams, both of which were actually placebos.  Wager surreptitiously lowered the temperature of the heat pad on the fake “active” cream, fooling the research participants into thinking that the cream was reducing the level of pain they felt.  Then, in the last phase (as Collca had with Vance’s shocks), he kept the temperature high.  Researchers carefully recorded how much pain the subjects reported feeling, and Wager also had their fMRI brain scans.  What the research participants reported about their pain tracked perfectly with the activation of several parts of the brain associated with pain, such as the anterior cingulate cortex (which plays a role in emotions, reward systems, and empathy), the thalamus (which handles sensory perception and alertness), and the insula (which is related to consciousness and perception).  Those reporting less pain from the placebo effect showed less activity in the key pain-related brain regions.  And those who felt less of the placebo effect showed more activity.  So these research participants were not imaging less pain; they were feeling it.

More importantly, Wager observed the route that the placebo response takes from anticipation to the release of drugs inside the brain.  Pain signals normally begin in the more primitive base of the brain (relaying information from wherever in the body the pain starts) and radiate outwards.  What Ager observed was backward, with the pain signals starting in the prefrontal cortex—the most advanced logic part of the brain with executive functions—and working back to the more primitive regions.  Vance noted that this seemed to suggest a sort of collision of information:  half originating in the body as pain, and half originating in the advanced part of the brain as expectation.  Whatever comes out of that collision is what we feel.

The following summary comes directly from Vance’s book,”Pain, like any sensation, starts in the body, goes up the spine, and then travels to the deeper brain structures that distribute that information to places like the prefrontal cortex, where we can contemplate it.  Placebos, on the other hand, seem to start in the prefrontal cortex (just behind the right temple) and go backward.  They work their way to parts of the brain that handle opioids and release chemicals that dull the pain.  That also seem to tamp down activity in the parts of the brain that recognize pain in the first place.  And you feel better.  All in a fraction of a second.”

How powerful these placebo effects are varies.  In some people they barely register.  However, in others the opioid dumps can be so powerful that people become physically addicted to their own internal opioids, similar, in theory, to how people become addicted to laudanum. One theory even suggests that chronic pain might be the result of a brain addicted to its inner pharmacy, in essence, looking for a fix.

More than opioids are involved.  Over the past few decades, other brain chemical have been shown to trigger the placebo effect.    Our inner pharmacy also stocks endocannabinoids—the same chemicals found in marijuana that play an important role in pain suppression—and serotonin,  which is important intestinal movements and is the primary neurotransmitter involved in feelings of happiness and well-being.

The Happiness U-Curve

March 16, 2017

This post is based on a section with the same subtitle in “The Cognitive Upside of Aging” an article by Alexandra Michel in the February 2017 “Observer”, a publication of the Association of Psychological Science (APS).

Despite all the negative components of aging, researchers consistently find a happiness paradox:  As the body declines, happiness tends to increase.  Across the lifespan this “Positivity effect” follows a U-shaped pattern:  happiness starts out high in late adolescence, bottoms out in middle age, and reaches a second zenith in old age.

A 2011 Gallup analysis of 500,000 phone interviews found that “a septuagenarian is far more likely than someone in their 30s to have high emotional health.  This happiness advantage held true even after controlling for demographic factors, including gender, race, education, marital status, employment, and regional location.

This happiness U-shape appears across the world.  Economists Andrew Oswald and David G. Blanchfower documented this pattern in more than 500,000 people living in more than 70 different countries.  Their analysis concluded that from Azerbaijan to Zimbabwe, people around the world tend to be happiest in their old age regardless of their nationality.

Oswald says, “Only in their 50s do most people emerge from the low period.  But encouragingly, by the time you are 70, if you are still physically fit then on average you are as happy and mentally healthy as a 20 year old.  Perhaps realizing that such feelings are completely normal in midlife might even help individuals survive this phase better.”

This universality of happiness U-curve implies the aging may play a positive role in the brain.  A team of Australian researchers led by Leanne Williams, who is now at the Stanford University School of Medicine, argues that a combination of neurological changes and life experiences account for this phenomenon.  Using functional magnetic resonance imaging (fMRI) to monitor emotional processing as people of various ages viewed photographs of different facial expressions, the researchers found that older people were more emotionally stable and less reactive to negative emotional stimuli than younger people.

Contrary to the ubiquitous negative stereotypes of declining memory and cognitive integrity, Williams and colleagues found emotional well-being may increase with normal aging.  Their study included 242 individuals (122 males and 120 females) divided up into four major age categories:  12-19 years, 20-29 years, 30-49 years, and 50-79 years.  Participants were assessed in the scanner for the neural activation evoked by emotions of threat and happiness depicted in facial expressions.  After being shown a photograph of a face, participants had to select the best option for identifying the emotion being displayed in the photograph.  They also rated on a 1-to-5 scale, the intensity of the emotion being displayed.
Rather than showing an inevitable decline across all functions, the images displayed a linear increase in emotional stability with age, meaning that people in their 70s ultimately experience better emotional well-being than most people in their 20s.

The fMRI results suggest that as we age, the way our brains process emotional stimuli  changes in ways that favor emotional stability.  The brain scans indicated that the medial prefrontal cortex (mPFC), which is a brain area involved in the governance of emotional functions, processed stimuli differently across the lifespan, contributing to better emotional stability for older adults.  As we age, the mPFC areas become increasingly active while processing negative emotions compared with positive ones, suggesting that older people were comparatively better at controlling negative emotions.

This article ends as follows: “Ultimately Williams and colleagues argue that as we age this combination of neural processing, as well as an accumulation of life experience, provides older adults with the neural tools to take life in stride—a capability their younger counterparts will just have to wait for.”

In Search of the Daimon Inside

March 4, 2017

The title of this post is the title of a section in Victor Strecher’s Book, “Life on Purpose.”  The Japanese have a word for “Life on Purpose” and that is ikigai, which is used in these posts because it has an earlier appearance in this blog and is shorter.

The daimon is the term the Greeks used to represent the inner self.  Dr. Strecher and his research team was interested in learning how the affirmation of core values works in the brain.  This research was led by Emily Falk of the University of Pennsylvania.  The researchers started with already-identified  part of the brain related to the “self.”  It’s in an area called the ventromedial prefrontal cortex (vmPFC).  This part of the brain becomes active when we are processing information about our selves.

The researchers invited a group of sedentary people who would benefit from physical activity and gave each of them an accelerometer to measure activity changes.  After a week of learning about each participant’s activity patterns, the researchers used fMRI.  They asked half of them about the values they cared about most while scanning their brains.  For example, they’d ask a person who valued religion to “think of a time when religious values might give you a purpose in life.  Participants in the control group were asked to think about the values they cared least about.

Four four weeks following the scanning session, while their physical activity was still being monitored,  all participants were sent messages about increasing it.  Participants in the values affirmation group also received messages about their most important values, whereas those in the control group received messages about their least important values.

Compared to the control group, those in the group who considered their most important core values had greater activation of their vmPFC and went to increase their physical activity over the next month.  Moreover, the more the vmPFC became activated, the more physical activity occurred over the next month.  So the affirmation of core  purposeful values seemed to “open their minds” to change.

In another study psychologist Jennifer Crocker and her colleagues asked study participants either to write about their most important core value and why it was meaningful to them (the values affirmation group) or to write about their least important value and why it might be important and meaningful to other people (the control group).  Then, the participants were asked to rate how the essay they wrote made them feel.  Finally, they tested the participants’ defensiveness.  Participants affirming their most important values felt love, connectedness, and empathy, and these transcending feelings reduced their defensiveness.

Research Into Eudaemonia vs. Hedonia

March 2, 2017

This is another in a series of blogs based on Victor Strecher’s Book, “Life on Purpose.”  The Japanese have a word for “Life on Purpose” and that is “ikigai”, which is used in these posts because it has an earlier appearance in this blog and is shorter.

Aristotle stated that eudaemonia is found more among those who have “kept acquisition of external goods within moderate limits” and that “any excessive amount of such things must either cause its possessor some injury, or, at any rate, bring him no benefit.  Niemiec and colleagues were interested in whether eudaemonic versus hedonic aspiration  of individuals just beginning their careers had an influence on well-being.  So they did a study of graduating college students, and found first, and not surprisingly, that they were more likely to attain what they had aspired to.  Those who placed importance on hedonic pursuits, money, fame, and image were more likely to find them, whereas those who aspired to eudaemonic pursuits, greater personal growth, relationships, and community, were more likely to achieve them.

The key finding follows:  Those who attained hedonic aspirations reported greater anxiety and  physical symptoms of poor health, whereas those attaining eudaemonic aspirations reported greater life satisfaction, self-esteem, and positive feelings.

The next question is whether we vary in our neural responses to eudaemonic versus hedonic rewards.  To address this question researchers examined activation in the ventral striatum of adolescents when engaged in eudaemonic versus hedonic decision making.  The ventral striatum is located in a part deep in the brain that’s associated with rewards. The adolescents’ brains were scanned using functional magnetic resonance imaging (fMRI) while making eudaemonic decisions to donate money to others or hedonic decisions to keep the money.  Adolescents who had more blood flow to the ventral striatum during eudaemonic versus hedonic choices could be identified.  The symptoms of depression were measured in the beginning of the study and one year later.  After a year, adolescents with greater activation of their brain’s reward system while giving money had, on average, a decline in depressive symptoms, whereas those with greater activation in this system when keeping the money had an increase in depressive symptoms.

Dr. Strecher concludes, “This further confirms that eudaemonic and hedonic forms of happiness are indeed different and that they produce very different effects.”

Reading a Novel Affects the Connectivity in the Brain

December 11, 2016

This post is based on an article in BRAIN CONNECTIVITY, Volume 3, Number 6,
DOI:  10.1089/brain.2013.0166 titled “Short and Long-Term Effects of a Novel on Connectivity in the Brain.”

This study used fMRI recording resting states both before and after reading a novel.   The novel was “Pompeii: A Novel” by Robert Fawcett.  Nineteen participants read this novel over a nine day period.  Resting-state  networks (RSNs) were assessed before and after reading on each of the nine days.  Baseline RSNs were taken five days before the experiment proper and for 5 days after the conclusion of the novel.

On the days after the reading, significant increases in connectivity  were centered on hubs in the left angular/supramarginal gyri and right posterior temporal gyri.  These hubs correspond to regions previously associated with perspective taking and story comprehension, and the changes exhibited a time course that decayed rapidly after the completion of the novel.  Long-term changes in connectivity, which persisted for several days after the reading, were observed in the bilateral somatosensory cortex, suggesting a potential mechanism for “embodied semantics.”  What the authors are referring to in embodied semantics is that the body is responding emotionally to the reading.

What HM finds most interesting about this study is that it provides data showing the
changes that take place in the brain as the result of reading.  This can be regarded as “cognitive exercise” that activates brain circuits and System 2 processing building a cognitive reserve decreasing the likelihood of Alzheimer’s and dementia.

© Douglas Griffith and, 2016. 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 with appropriate and specific direction to the original content.

Transforming the Emotional Mind

June 13, 2016

The title of this post is identical to the title of Chapter nine of Sharon Begley’s “Train Your Mind, Change Your Brain.”  In the 1970s, Davidson and his colleagues discovered striking differences in the patterns of brain activity that characterize people at opposite ends of the “eudaemonic scale,” which provides the spectrum of baseline happiness.  There are specific brain states that correlate with happiness.

Secondly, brain-activation patterns can change as a result of therapy and mindfulness meditation, in which people learn to think differently about their thoughts.  This has been shown in patients with obsessive-compulsive disorder and with patients suffering from depression.  Mental training practice and effort can bring about changes in the function of the brain.

Given these two facts Davidson built the hypothesis that meditation or other forms of mental training can, by exploiting the brain’s neuroplasticity, produce changes, most likely in patterns of neuronal activation, but perhaps even in the structure of neural circuitry that underlie enduring happiness and other positive emotions.  Then therapists and even individuals by exploiting the brain’s potential to change its wiring can restore the brain and the mind to emotional health.

In 1992 Davidson and his colleagues found that activity in the brain’s prefrontal cortex, as detected by EEG, is a reflection of a person’s emotional state.  Asymmetric activation in this region corresponds to different “affective styles.”  When activity in the left prefrontal cortex is markedly and chronically higher than in the right, people report feeling alert, energized, enthusiastic, and joyous, enjoying life more and having a greater sense of  well-being.  In other words, they tend to be happier.  When there is greater activity in the right prefrontal cortex, people report feeling negative emotions including worry, anxiety, and sadness.  They express discontent with life and rarely feel elation or joy.  If the asymmetry is so extreme that activity in the right prefrontal cortex swamps that in the left, the person has a high risk of falling into clinical depression.

The Dalai Lama has noted that the most powerful influences on the mind come from within our own mind.  The findings that, in highly experienced  meditators, there is greater activity in the left frontal cortex “imply that happiness is something we can cultivate deliberately through mental training that affects the brain.”

Research has shown that every area of the brain that had been implicated in some aspect of emotion had also been linked to some aspect of thought:  circuitry that crackles with electrical activity  when when the mind feels an emotion and circuitry  that comes alive when the mind undergoes cognitive processing, whether it is remembering, or thinking, or planning, or calculating, are intertwined as yarn on a loom.  Neurons principally associated with thinking connect to those mostly associated with emotion, and vice versa.  This neuroanatomy is consistent with two thousand years of Buddhist thought, which holds that emotion and cognition cannot be separated.

Using fMRI Davidson measured activity in the brain’s amygdala, an area that is active during such afflictive emotions as distress, fear, anger,and anxiety.  Davidson said, “Simply by mental rehearsal of the aspiration that a person in a photo be free of suffering, people can change the strength of the signal in the amygdala.  This signal in he fear-generating amygdala can be modulated with mental training.

Eight Buddhist adepts and eight controls  with 256 electrodes glued to their scalps engaged in the form of meditation called pure compassion, in which the meditator focuses on unlimited compassion and loving-kindness toward all living beings.  This produces a state in which love and compassion permeates the whole mind, with no other considerations, reasoning, or discursive thoughts.  The brain waves that predominated were gamma waves.  Scientists  believe that brain waves of this frequency reflect the activation and recruitment of neural resources and general mental effort.  They are also a signature of neuronal activity that knits together far-found brain circuits.  In 2004 the results of this study were published in the “Proceedings of the National Academy of Sciences.  Not surprisingly the results of the monks were quite pronounced.  But it was encouraging to discover that some of the controls who received a crash crash course and only a week’s worth of compassion meditation, showed a slight but significant increase in the gamma signal.

fMRI images were also taken.  The differences between the adepts and the controls were quite interesting.  There was significantly greater activation in the right ins and caudate, a network that other research has linked to empathy and maternal love.  These differences were most pronounced in monks with more years of meditation.  Connections from the frontal regions to the brain’s emotion regions seemed to become stronger with more years practicing meditation.  It was clear that mental training that engages concentration and thought can alter connections between the thinking brain and the emotional brain.

A surprising finding was that when the monks engaged in compassion meditation, their brains showed increased activity in regions responsible for planned movement.   It appeared that the monks’ brains were itching to go to the aid of those in distress.  Another spot of activation in the brains of the meditating monks jumped out in  an area in the left prefrontal cortex, the site of activity association with happiness.  Activity in the left prefrontal swamped activity in the right prefrontal  to a degree never before seen from purely mental activity.

Davidson concluded, “ I believe that Buddhism has something to teach us as scientists about the possibilities of human transformation and in providing a set of methods and a road map of how to achieve that.  We can have no idea how much plasticity there really is in the human brain until we see what intense mental training, not some weekly meditation session, can accomplish.  We’ve gotten the idea in Western culture, that we can change our mental status by a once-a-week, forty-five intervention, which is completely cockamamy.  Athletes and musicians train many hours every day.  As a neuroscientist, I have to believe that engaging in compassion meditation every day for an hour each day would change your brain in important ways.  To deny that without testing it, to accept the null hypothesis, is simply bad science.”

Davidson continues, “I believe that neuroplasticity will reshape psychology in the coming years.  Much of psychology had accepted the idea of a fixed program unfolding in the brain, one that strongly shapes behavior, personality, and emotional states.  That view is shattered by the discoveries of neuroplasticity.  Neuroplasticity will be the counter to the deterministic view (that genes have behavior on a short leash).  The message I take for my own work is that I have a choice in how I react, that who I am depends on the choices I make, and that who I am is therefore my responsibility.”

The Silent

May 14, 2016

The fifth cryptomind discussed in “The Mind Club” is The Silent.  This chapter is about those we cannot communicate with who, because of trauma to the brain, cannot communicate with us.  The EEG can be used to take measurements.  Disordered conscious states can be diagnosed by the EEG patterns.  An ordering of conscious states follows:

Locked in syndrome
Minimally conscious
Vegetative State
Brain Death

It is unfortunate that unless EEG measurements are done along with further diagnosis the Locked in syndrome can be mistaken for a lower level of consciousness.

The term locked-in syndrome was coined by Fred Plume and Jerome Posner.  For many years it was not realized that someone was actually locked-in.  Healthy memory remembers watching a movie when someone asked suppose some is locked inside the unconscious state.  The reply was that that was something too horrible to imagine.  But there are real people who can accomplish some impressive feats.  Jean-Dominique Bauby was an editor who suffered a stroke and found himself locked-in.  But he was able to communicate by blinking his one eye that was functioning.  It took him 200,000 blinks to write the Diving Bell and the Butterfly.  He lived to see the book published, but he died before he saw the enormous success of the book and the beautiful movie  with the same title that was based on the book.

People react and adapt to this locked-in state differently.  Bauby could have continued a productive career had he not died.  But an Englishman, Tony Nicklinson, did not and wanted to commit suicide.  However, being locked-in he could not commit suicide.  He petitioned the court to allow doctors to provide an assisted suicide.  After much deliberation, the courts decline.  However, he did manage to commit suicide by refusing to swallow.

In addition to EEGs, fMRIs can provide very useful information.  The primary problem with fMRI’s is that they are expensive.

To read more about current research on this topic, see some of the healthy memory blog posts by Dehaene (see the Healthymemory blog post titled, “The Ultimate Test”).

The authors of  “The Mind Club” also examine the other end of life.  That is, when does life begin.  This is a large religious issue that can impact people of different religious beliefs.  A symposium organized in 1968 by the Christian Medical Society affirmed that “the preservation of fetal life…may have to be abandoned to maintain full and secure family life, as well as in cases of rape, incest, fetal deformity, and threat to the mother’s well-being, whether physical or emotional.  However, evangelical opinion swung after church leaders such as the eminent Jerry Falwell reacted to the 1973 Roe v. Wade decision and advocate a “life at conception” interpretation of the Bible.   As the Catholic Church claims that life begins at conception certain Protestant sects did not want to appear remiss.

However, if memory serves healthy memory correctly, at one time there were arguments among Catholic philosophers as to when the soul entered the body.  Furthermore, healthy memory believes that there were different times depending upon whether a male of female was involved.  If any readers can help me out on this particular point, it would be much appreciated.

Nevertheless, it is healthymemory’s belief that the soul is the issue.  The soul is a religious entity and the argument should be argued in theological terms.  Biological terms are irrelevant.

© Douglas Griffith and, 2015. 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 with appropriate and specific direction to the original content.

The Ultimate Test

April 7, 2016

The Ultimate Test is the sixth chapter of “Consciousness and the Brain:  Deciphering How the Brain Codes our Thoughts” is an outstanding book by the French neuroscientist Stanislas Dehaene who is the Chair of Experimental Psychology at the College of France.  This is the seventh consecutive post on this outstanding book. According to Dr. Dehaene the ultimate test of any theory of consciousness is the clinic.  Every year thousands of patients fall into a coma.  Unfortunately, many of these patients will remain permanently unresponsive in a dreaded condition called the “vegetative state.”  Worse yet, is that in Intensive Care Units (ICUs) over all the world, half of the deaths result from a clinical decision to remove life support.  How many of these decisions are wrongly made?

Coma is defined  clinically as a prolonged  loss of the capacity to be aroused.  However, coma patients are not brain-dead.  Brain death is a distinct state,characterized by a total absence of brain stem reflexes.  In brain-dead patients, positron emission tomography (PET) and other measures such as Doppler ultrasonography show that cortical metabolism and the perfusion of blood to the brain are annihilated.  Most countries, the Vatican included, identity brain death with death, period.

What is of primary interest is the “locked-in syndrome.”  This state typically results from a well-delimited lesion, usually on the protuberance of the brain stem.  Such a lesion disconnects the cortex the cortex from its output pathways  in the spinal cord.  If the cortex and the thalamus are spared, it often leaves consciousness intact.  As you can well imagine, this is a terrible state in which to find oneself.

The book “The Diving Bell and the Butterfly” (there is also an outstanding movie by the same name) was written by Jean-Dominique Baby, who was the editor of the French fashion magazine, “Elle.”  He wrote this book one character at a time by blinking his left eyelid while an assistant recited the letters of the alphabet.  He eloquently told his story with two hundred thousand blinks telling the story of a beautiful mind shattered by a cerebral stroke.  Fortunately he lived to se the book published, but, unfortunately, he died three days later.

Comparatively speaking, Jean-Domonique Baby was well-off. Many locked-in patients have no motor responses, no means of communicating with the world.  Fortunately fMRIs can identify these individuals, given enough time.  Unfortunately, fMRIs are extremely expensive and are beyond the budgets of too many medical facilities.  But, fortunately, Dr. Dehaene has developed an inexpensive test using EEG recordings using 256 electrodes.  Information exchanged over long cortical distances is an excellent index of consciousness in patients with brain lesions.  Computations are done for each pair of electrodes for a mathematical index of the amount of information shared by the underlying brain areas.  Vegetative-state patients showed a much smaller  amount of shared information than conscious patients and control patients.  This finding fits with  with a central tenet of global workspace theory, that information exchange is an essential function of consciousness.  A follow-up study showed that the few vegetative patients who showed high information sharing had a better chance of regaining consciousness within the next days or  months.

So technology and the global workspace theory provide good diagnostic techniques.  It is hoped that interventions will be developed in the future to unlock those in a locked-in state.  Dr. Dehaene has described some promising work being done in this area.

The Signatures of Conscious Thought

April 5, 2016

“The Signatures of Conscious Thought” is the fourth chapter of “Consciousness and the Brain:  Deciphering How the Brain Codes our Thoughts” is an outstanding book by the French neuroscientist Stanislas Dehaene who is the Chair of Experimental Psychology at the College of France.  This is the fifth consecutive post on this outstanding book.  In this chapter Dr. Dehaene discusses four reliable signatures of consciousness—physiological  markers that index whether the participant experienced a conscious percept.

The first signature is a sudden ignition of parietal and prefrontal circuits that is caused by a conscious stimulus (remember that the participant indicates whether the stimulus is conscious).

The second signature is found in the EEG in which conscious access is accompanied by a slow wave called the P3 wave, which emerges as late as one-third of a second after the stimulus.

The third signature is the result of conscious ignition that also triggers a late and sudden burst of high frequency oscillations.

The fourth signature  consists of many regions exchanging bidirectional messages over long distances in the cortes, which form a global brain web.

The conscious brain can perceive only a single chunk at a time.  Working memory rehearses these chunks to keep the active so they can be further processed.  The processing of a second chunk can be delayed if it occurs prior to the processing of the first chunk.  This is known as the psychological refractory period.

We can process a stimulus before we become consciously aware of the stimulus.  For example, if we place a hand on a hot stove, we’ll take it off the stove before we consciously perceive the pain caused by the hot stove.

Consciousness lives in  loops of reverberating neuronal activity, circulating in the web of our cortical connections, causing our conscious experience.

fMRI and scalp recording of brain potentials catch just a glimpse of the underlying brain activity.  Explorations of the third and fourth signatures require electrodes being placed directly inside the brain.  Such implantations of electrodes are indicated for certain epileptic patients, so science can capitalize on victims of this unfortunate malady.  I hope it provides some satisfaction to these patients that the data that is derived from these electrodes is greatly advancing science.

Subliminal stimuli can propagate  deeply into the cortex, but this brain activity is strongly amplified when the threshold for awareness is crossed, thus yielding reliable and valid signatures of consciousness.

Can You Remember Things that Never Happened?

March 24, 2016

This post is based largely on portions of the fourth chapter in Elixir J. Sternberg’s Book “Neurologic and the Brain’s idea Rationale Behind Our Irrational Behavior.” The title of this post is the same as the title of Chapter 4.  Regular readers of the health memory blog should know the answer to the question posed in the title.  The answer is “yes.”  Elizabeth Loftus and others have done extensive research in this area.  They have a variety of methodologies for implanting false memories so that they are definitely believed.  I saw an example of one of these experiments on the PBS program NOVA.  In this case the research participants were convinced of a crime that they never had committed.  To find previous posts on this topic enter “Loftus” into the search block of the healthy memory blog.

Sternberg begins the chapter with a quote from Gabriel Garcia Marquez that largely captures the workings of our memories.  “He was still too young to know that the heart’s memory eliminates the bad and magnifies the good, and that thanks to artifice we manage to endure the burden of the past.”

A research group in Israel filmed a young woman, with no history of memory problems for two days straight.  Except for the cameras they were ordinary days.  At various intervals over the next few years she filled out questionnaires that tested her memories of those days.  The researchers used fMRI while she was filling out these questionnaires.  Over time the more distorted her memory became for the details.  What was especially interesting was how her brain activity changed over time while filling out the recall questionnaires.  As time passed and the memory errors accumulated, her memory appeared to be less endless reliant on the activity of the hippocampus.  The fMRI revealed reduced activation there as her recollection became more distant.  Other regions of the brain, including the medial prefrontal cortex and associated regions, became more and more active.  The medial prefrontal cortex is associated with self-centered thinking.  Her memory was accessing not simply a record from a neurological file, but a representation stored across multiple systems.  Her memory drifted away from accurately recording the details of that time period and instead became focused on her.

“To a large extent, our memories define us.  Our personal history forges our self-image and assembles our store of knowledge.  When the unconscious system in the brain encodes our memories, it is shaping who we are.  It doesn’t record our experiences impartially as a video camera would, because it focuses on our role in the story, on the aspects that we care about.   At any given moment, there is a context of how we are feeling, our emotions at that instant, what we are expecting or dreading, and what that moment means to us.  It is on that basis that the brain begins to compose its first draft.”

Three years after 9/11, two groups of New York City residents were enrolled in an experiment to learn how their emotions at the time of the attacks might have affected their memory.  The first group of people who were in downtown Manhattan that day close to the World Trade Center, and who personally witnessed the events of that day,  The second group consisted of people who were in midtown several miles away.  As would be expected, the downtown group rated their memories as being more vivid, more complete, and more emotional instances that the midtown group did.  And they had more confidence in the accuracy of their memories, but the neurological results revealed a different story.

The hippocampus is the area key to episodic memory, of which recalling 9/11 is a conspicuous example, but depending on the type of memory being accessed, other areas of the brain may be recruited to varying degrees.  For example, the amygdala may be activated when the memory is of an emotional nature, and the posterior parahippocampal cortex will become more involved when the brain attempts to access the more meticulous spatial details surrounding the event.  The members of the midtown group showed activation of the posterior  parahippocampal cortex as they recalled the details of 9/11, but only trivial amygdala activity.  It was just the opposite for the downtown group.  They exhibited striking activity in the amygdala but not in the posterior parahippocampal cortex.  This neuroimaging suggests that the downtown group recalled the events of the day for their emotional impact at the expense of remembering peripheral details.  Studies have revealed that the more emotionally  affected people are in recalling 9/11, the better they are at consistently describing the central events of what happened to them that day, but the worse they are at providing reliable description of the emotionally  neutral details.

There is a technical difference between telling a lie and confabulation.  A person telling a lie knows that he is telling a lie.  However, a person confabulating is trying to make a coherent story where substantial memory loss has occurred.  The chapter begins and ends with a man with both severe mental and addiction problems and a faulty memory.  He continually tries to put together a coherent story from the scraps of memory he can access, because he does not want to admit that he does not know.  Although his is a clinical case, we all work to make coherent stories from what memories we can find.  The unconscious system takes a self-centered egocentric approach to construct good narratives.

The War On Drugs

November 16, 2015

The War On Drugs

I’ve written that an understanding of the brain is critical to effective citizenship and effective law making.  A good example of this is the war on drugs.  In one study about 36% of convicted criminals were under the influence of drugs at the time of their criminal offense.  Here are the results of criminalizing drug use.  A few decades ago, 38,000 Americans were in prison for drug-related offenses.  Now, it is half a million.  As a results there are more Americans per capita in prison, than in any other country.  It is ironic to call the United States the land of the free.  Moreover, this  mass incarceration has not slowed the drug trade.  Not only is the War on Drugs not being won, it is also extremely counterproductive.

Ir is clear that criminalization is not working, and that a medical approach is more appropriate.  Dr. Eagleman is working on a potentially effective approach for treating drug addicts.  It provides real-time feedback  during brain imaging allowing cocaine users to view their own brain activity  and learn how to regulate it.  He puts an addict into a fMRI brain scanner.  Pictures of crack cocaine are shown  and the addict is asked to crave.  This activates the particular regions of the brain that are known as the craving network.  Then the addict is asked to think about the costs of using crack cocaine in terms of finances, relationships, and employment.  This activates a different set of brain areas that are known as the suppression network.  These two networks are always battling it out for supremacy, and whichever wins at any moment determined what the addict dos when offered crack cocaine.

The scanner can measure whether the short-term thinking of the craving network, or the long-term  thinking of the impulse control network is winning.  The addict is given real-time visual feedback in the form of a speedometer so she can see how the battle is going.  When craving is winning, the needle is in the red zone.  When the impulse is successfully suppressing, the needle moves to the blue zone.  The addict can use different approaches to discover what works to tip the balance of the networks.

By practicing over and over, the addict gets better understanding what she needs to do to move the needle.  Although the addict might not be consciously aware of how she is doing it, but through repeated practice she can strengthen the neural circuitry that enables her to suppress.  The hope is that when she’s next offered crack she’ll have the cognitive skills to overcome her immediate cravings.  . The training simply provides the cognitive skills to have more control over her choice, rather than be a slave to her impulses.

Time will allow the estimation of the effectiveness of this technique.  But it does provide some insight into how research into the brain can address the problem of addiction.

The Importance of Testing

September 17, 2015

Complaints are being received from teachers that testing is interfering with the education of students because they have to teach to the test.  There are two points to be made here.  First of all, testing is necessary to measure whether anything is being learned.  The second point is that testing rather than interfere with learning, can enhance learning.  These points were effectively made in a Scientific American Article that can be found at

An example of one of these effective teaching techniques was provided in the article.  The teacher posted a multiple choice question on a smartboard screen.  The students clicked in their answers which were posted on the bottom of the smart board screen.  So the students needed to retrieve information to make their selections.  The teacher received feedback on the knowledge of the class, and was able to provide feedback for the wrong answers.  When every student provides the correct answer, the class members raise their hands and wiggle their fingers in unison, which is an exuberant gesture that they call “spirit fingers.”

There is ample evidence from research in cognitive psychology that retrieval practice increases learning.  Whenever we retrieve a memory, the memory representation changes, and its mental representation becomes stronger, more stable, and more accessible.  If material is simply reread, this retrieval practice does not occur.  Retrieval strengthens and has additional benefits noted by cognitive psychologist Jeffrey Karpicke.  He notes that as our memory is necessarily selective, the usefulness of a fact or idea—as demonstrated by how often we have reason to recall it—makes a sound basis for selection.   He said that “our minds are sensitive to the likelihood that we’ll need knowledge at a future time, and if we retrieve a piece of information now, there’s a good chance that we’ll need it again.  The process of retrieving a memory alters that memory in anticipation of demands we may encounter in the future.”

Karpicke argues that retrieving is the principal way learning happens, “Recalling information we’re already stored in memory is a more powerful learning event that storing that information in the first place.  Retrieval is ultimately the process that makes new memories stick.”  Not only does retrieval practice help students remember the specific information they retrieved, it also improves retention for related material that was not directly tested.  When we are sifting through our mind for the particular piece of information we are trying to recollect, we call up associated memories and in doing so strengthen them as well.

I remember from my college day the yellow marked sections whenever I had a previously owned text.  I made it a point to never rely upon those yellow marked sections.  It was my guess that when studying for a test, the previous user simply reread the highlighted section.  I never did that.   I always tried to recall the gist of the material, and then I checked my recall.  If just rereading highlighted sections was done, my guess is that the best result would be a C.  My goal was an A, and I often received them.

There are hundreds of studies hat have demonstrated retrieval practice is better than virtually any other method of teaching, including doing concept maps.

Research using fMRI has shown that calling up information from memory versus simply restudying it, produces higher levels of activity in particular areas of the brain. These regions are associated with the consolidation, or stabilization, of memories and with the generation of cues that makes memory readily accessible for later recall.  Research has demonstrated that the more active these regions are during an initial learning session, the more successful is recall weeks or months later.

So this testing versus learning complaint is a pseudo issue.  It is not an issue of teaching to the test.  Rather it is a matter of developing teaching plans that require students to actively recall information rather than to simply reread material that will likely be on the  test.  This is a pseudo complaint.  If done properly it is a win win issue.

However, according to the Scientific American article there is a feature of standardized tests that prevents them from being used more effectively as  occasions for learning, and that is that the questions they ask tend to be of a superficial natures, which tends to lead to superficial learning.  There is a tool called Webb’s Depth of Knowledge, created by Norman Webb, a senior scientist at the Wisconsin Center for Education Research.  This tool identifies four levels of mental rigor:
DOK1 (simple recall)
DOK2 (application of skills and concepts)
DOK3 (reasoning and inference)
DOK4 (extended planning and investigation)
Most questions on state tests were DOK1 or DOK2.

So rather than complain about testing, the complaints should be on the DOK required on the tests.  The deeper the depth of knowledge, the better the test, which leads to more effective learning.

© Douglas Griffith and, 2015. 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 with appropriate and specific direction to the original content.

Controlling Pain in Our Minds

May 16, 2015

This blog post is based on an article in the New Scientist (17 Jan 2015, p.10) by Jessica Hamzelou titled “Pain Really Can Be All in Your Mind.”  She reported research  by Tor Wager at the University of Colorado Boulder that was published in the Public Library of Science (PLoS Biology,    They used fMRI to examine the brain activity  of 33 healthy adults.  They first watched the changing activity  as they applied increasing  heat to the participants arms.  A range of brain structures lit up as the heat became painful.  This was a familiar pattern of activity  called the neurologic pain signature.

The researchers wanted to know if the participants  could control the pain by thought alone.  They asked the participants to rethink their pain either as blistering heat, or as a warm blanket on a cool day.  Although the participants couldn’t change the level of activity in the neurologic pain signature, they could alter the amount of pain they felt.  When they did this, a distinct  set of brain structures linking the nucleus accumbens and the ventromedial prefrontal cortex became active.

Vanaia Apkarian of Northwestern University noted,”It’s a major finding.  For the first time, we’ve established  the possibility of modulating pain through two different pathways.”  Brain scans can compare the strengths of activation of these two brain networks to work out how much pain has a physical cause, and how much is due to their thoughts and emotions.

These finding built on prior work by Apkarian’s team, who discovered that chronic back pain seems to be associated with a pattern of brain activity not usually seen with physical pain.  The brain regions active in Apkarian’s patients are the same as those active  in the participants controlling pain in Wager’s study.

It is possible that in chronic pain conditions, psychological pain might overtake physical pain as the main contributor to the overall sensation.  This might be the reason that traditional pain relief such as opiods don’t offer much relief from pain.

Hamezelou notes, “Wager’s study suggests that cognitive therapies and techniques such as nuerofeedback—where people learn to control their brain activity by watching how it changes in real time—might offer a better approach.”

Ben Seymour, a neuroscientist at the University of Cambridge notes, “in the next five to 10 years, we’ll see a huge change in the way clinicians deal with pain.  Rather than being passed on what the patient says, we’ll be building  a richer picture of the connections in the person’s brain to identify what type of pain they have.

More on Erroneous Eyewitness Testimony

March 11, 2015

This post is based primarily on an article by Steven J. Frenda, Rebecca M. Nichols, and Elizabeth F. Loftus titled “Current Issues and Advances in Information Research,” in Current Directions in Psychological Science (2015) 20, 20-23.  They note a recent discussion of the distorting effects witnesses have on the memory of other witnesses by Wright, Memon, Skakerberg, and and Gabbert (2009) in Current Directions in Psychological Science, 18, 174-178.  They propose that there three accounts of why eyewitnesses come to report incorrect information.
A witness’s report may be altered due to normative social influence.  A witness might decide that the cost of disagreeing with law enforcement—or with other witnesses—is too high, and so adjusts her report accordingly.
Through informational social influence processes, a witness comes to endorse a version of events that is different from what he remembers because he believes it to be truer or more accurate than hi own memory.
A witness’s memory can become distorted, sometimes as a result of being exposed to incorrect or misleading information.
It is this third possibility that this blog post addresses.

Perhaps the first question is “who is vulnerable?”  The short answer is that nobody is immune to the distorting effects of misinformation, but some people are more vulnerable than others.  Very young children and the elderly are more susceptible to misinformation than adolescents and adults.  People who report lapses in memory and attention are also specially vulnerable.  These facts suggest that a poverty of cognitive resources results in an increased reliance on external cues to reconstruct memories.  Misinformation effects are easier to obtain when individuals’ attentional resources are limited.  Similarly, people who perceive themselves to be forgetful and who experience memory lapses may be less able or willing to depend on their own resources as the sole source of information as they mental reconstruct an event.

Two major studies containing more than 400 participants explored cognitive ability and personality factors as predictors of susceptibility to misinformation.  In these studies participants viewed slides of two crimes and later read narratives of the crimes that contained misinformation.  Participants who had higher intelligence scores, greater perceptual abilities, greater working memory capacities, and greater performance on face recognition tasks tended to resist misinformation and produce fewer false memories.   Some personality characteristics were also shown to be associated with false memory formation, particularly in individuals with lesser cognitive ability.  Individuals low in fear of negative evaluation and harm avoidance, and those high in cooperativeness, reward dependence and self-directedness were associated with increased vulnerability to misinformation effects.

Functional magnetic resonance imaging fMRI is being used to investigate brain activity association with misinformation effects.  In one study participants were shown a series of photographs and later listed to an auditory narrative describing, which included misinformation.  Shortly thereafter, they were placed in an MRI scanner and given a test of their memory for the photographs.  fMRI data revealed similar patterns of brain activity, but the true memories (formed by visual information) showed somewhat more activation in the visual cortex, whereas the false memories (derived from the auditory narrative) showed somewhat more activity in the auditory cortex.

Obviously a critical question is how to protect against misinformation effects.  To this end a cognitive interview (CI) methodology, which consists of a set of rules and guidelines for  interviewing eyewitnesses.  For example, the recommended methodology uses free recall, contextual cues, temporal ordering of events, and recalling an event from a variety of perspectives (for example, from a perpetrator’s point of view).
The technique also recommends that investigators avoid suggestive questioning, that they develop rapport with the witness, and discourages witnesses from guessing.  Research has supported the idea that the CI reduces or eliminates the misinformation effect.

Here the misinformation effect is considered only in the context of eyewitness testimony.  Unfortunately misinformation is a large problem that has only been exacerbated with the advent of the internet.  The central problem is that it is difficult to correct misinformation.  I would contend that there is an epidemic of misinformation with large numbers of people holding notions contrary to science.  It is extremely difficult to correct their misconceptions.  To read more about misinformation simply enter “misinformation”  into the healthy memory search box.

Why People Play Slot Machines

May 13, 2014

Regular readers of the healthymemory blog should know that its author believes that it is foolish to play casino games.  Casino games are structured such that the odds always favor the casino, so although there might be winnings in the short run, there is no way there will be winnings in the long run.  In the case of slot machines, they’re usually set up to for a 10% share of the play.  So if you spend $100 on a slot machine, you are likely to lose $10.
So I was quite pleased to come upon an article in The Economist1  that addressed this topic.  Slot machines are tweaked within the realm of randomness  such that “near wins” of two out of three symbols appear quite often.  The notion is that players are so pepped by “almost” winning that they are stimulated to carry on playing.
Brain imaging techniques were used by Dymond of Swansea University in Britain and his colleagues to try to determine why this is the case.  functional Magnetic Resonance Imaging (fMRI) , which show which part of the brain are especially active at any given moment was one technique.  A second technique was magnetoencephalography (MEG) measure the electrical nature of that activity.   These two techniques enabled the building of a map for each research participant’s brain as she played on a simulated slot machine.
The focus was on the theta response, the electrical activity in the 4-7 Hz range.  Previous research has identified this response to be related to the processing of experiences of winning and losing.  There were two groups in the experiment.  One group consisted of participants addicted to playing slot machines.  A second group consisted of non-gamblers.  All research participants showed high theta responses to wins and low ones to loses.  The responses to near wins showed similar responses with the exception of the right orbitofrontal cortex.  The theta activity in the right orbitofrontal cortex of the gamblers showed spikes of about 32% and 27% in their theta waves for wins and near wins respectively.  Non-gamblers showed similar responses for wins, but only a 13% increase in theta wave activity for near wins.
This provides a good example of where your mind needs to control your brain.  Compulsive gamblers should realize that they are compulsive due to their brain responses and adjust their behaviors accordingly.  They need to realize that they are competing against a machine that has been cleverly designed go make them believe they are going to win, when in reality, they will lose in the end.  In other words, their minds need to overrule their brains.

© Douglas Griffith and, 2014. 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 with appropriate and specific direction to the original content.

What Is fMRI?

January 11, 2014

This blog post is based on the book Brainwashed: The Seductive Appeal of Mindless Neuroscience by Sally Satel and Scott O. Lillenfeld. Please bear with me as this is the first post that I’ve written based on a source viewed on my Kindle.

fMRI is the basis for most of the brain images we see. It stands for Functional Magnetic Magnetic Resonance Imaging. Here is a brief description of how it works. Functional MRI reveals oxygen consumption and regional blood flow in the brain. Blood that is carrying more oxygen has different magnetic properties than blood that has already given up its oxygen to supply neurons. The brain will first be scanned which the participant is resting in the device to establish a baseline level. Then the participant is asked to perform a particular task of interest. The difference between this baseline and the activity when this specific task is being performed is measured and called the BOLD (blood-oxygen level response). The higher the level of oxygenated to deoxygenated blood in a particular area of the brain, the higher the energy consumption in that region. The basic unit of analysis in fMRI is called the voxel, which is a combination of volume and pixel. It is a three dimensional unit.

Subtraction is performed on a voxel by voxel level. Each voxel is then assigned a color depending on the strength of the difference in activation of that individual voxel between the control and experimental conditions. The computer then generates an image highlighting the regions that become more active in one condition relative to the other. By convention, researchers use color gradations to reflect the likelihood that the subtraction was not due to chance. A bright color like yellow might mean that the there is only one chance in a thousand that the differences are due to chance, whereas a darker color like purple might mean that the chances are higher, and that the brain differences were more likely to be attributable to random fluctuations in the data. Finally, the computer filters out background noise and prepares the data to be mapped onto a three-dimensional template of the human brain.

The final brain scan that we see rarely portrays the brain activity of a single person. Instead it almost always represents the averaged results of all participants in the study. Any resemblance between brain scans and photographs is illusory. Photos capture images in real time and space. Functional imaging scans are constructed from information derived from the magnetic properties of blood flowing in the brain. Scans are simply a representation of local activation based on statistical differences in BOLD signals.

How Can The Brain Be Imaged?

November 20, 2009

Technologies that allow us to view what is going on inside the brain are a fairly new and exciting development. This blog provides a very brief explanation of these techniques. There will be frequent references to this blog in future presentations of brain imaging studies.

One of the first techniques was Positron Emission Tomography (PET). PET imaging requires that a radioactive substance called a radiotracer been injected into the bloodstream. This radiotracer makes its way into the brain. The level of radioactivity is extremely low so that the individual undergoing the imaging is not put at risk. The individual lies down within the PET imaging machine and is asked to perform different tasks. A computer processes the data to produce 2- or 3 – dimensional images. The images show blood flow and oxygen and glucose metabolism in the tissues of the brain. These images reflect the amount of brain activity in the different regions of the brain.

Functional Magnetic Resonance Imaging (fMRI) is a more recent development that does not require the injection of radioisotopes into the blood stream. It is an enhancement of Magnetic Resonance Imaging where the individual lies on a table with her head inside a giant magnet. Protons inside the atoms in the brain align themselves with the magnetic field and are wacked temporarily out of alignment by a pulse of radio waves aimed at the brain. As the protons relax back into alignment again, they emit radio waves that a computer uses to create a brain snapshot. fMRI takes advantage of two more facts about the body: (1) blood contains iron and (2) blood rushes to a specific part of the brain when it is activated. As freshly oxygenated blood zooms into a region, the iron distorts the magnetic field enough for the scanner to pick it up.

Prior to the development of these imaging techniques, researchers were restricted to recording electrical activity in the brain from the scalps of humans. Still much valuable data was obtained and these techniques are still used today. Event-related potentials (ERPs) are electrical waveforms that are elicited by specific sights, sounds, or other stimuli. The P300 is a bump in the electrical waveform that occurs within one-third of a second after a person is exposed to a word or some other external stimulus. This heightened activity reflects the additional processing that the brain devotes to novel, distinctive events. Larger P300s tend to be associated with greater subsequent recall.[1]

[1] Reported in Schacter (1996).  Searching for memory:  the brain, the mind, and the past.    New York:  Basic Books.   p. 55.