Posts Tagged ‘Amygdala’

Super-you: Use Your Better Instincts to Crush Your Inner Bigot

December 14, 2016

In the 10 Dec 2016 issue of the New Scientist there was a series of articles whose titles began super-you.  HM is reviewing a select sample of these pieces.  This instincts piece is written by Caroline Williams.  HM does not like this use of the word “instincts.”  “Predisposing biases” would have been a more fortunate choice.  However, this article accounts for much of the ugliness prevalent throughout the world.  The quick explanation is that these people are in their default mode of feeling and thinking.  But this is a very low level of thinking.  It is System 1 processing using Kahmeman’s terms.

The unpalatable truth is that we are biased, prejudiced and racist.   We put people into mental boxes marked “us” and them”.  Implicitly we like, respect and trust people who are similar to us and feel uncomfortable around everyone else.  This tendency towards in-group favoritism is so ingrained that we often don’t realize we are doing it.  “It is an evolutionary hangover affecting how the human brain responds to people it perceives as different.

A study from 2000 found that just showing participants brief flashes of faces of people of a different race was enough to activate the amygdala (Neuroreport 11(11):2351-5, September 2000 can be found at researchgate.net).  HM readers should know that the amygdala is a key component of the brain’s fear circuitry.  But the amygdala doesn’t just control fear; it responds to many things and calls on other brain areas to pay attention.   Although we’re not automatically scared of people who are not like us, we are hardwired to flag them.  As Williams notes, “evolutionarily, that makes sense:  It paid to notice when someone from another tribe dropped by.”

When Susan Fiske of Princeton University scanned volunteers’ brains as they looked at pictures of homeless people, she found that the prefrontal cortex, which is activated when we think about other people, stayed quiet.  Apparently these volunteers seemed to process these homeless people as subhuman (Social cognitive ad affective neuroscience, 2007 Mar. 2(1) 45-51.)

Fiske says “The good news is that his hard-wired response can be overcome depending on context.”  In both the homeless study and a rerun of the amygdala study Fiske found that fear or indifference quickly disappeared when participants were asked questions about what kind of food the other person might enjoy,   Fiske continues, “As soon as you have a basis for dealing with a person as an individual, the effect is not there.”

What we put in “them” and “us” boxes is flexible.  Jay Van Bavel of New York University created in-groups including people from various races, participants still preferred people in their own group, regardless of race.  It seems that all you have to do to head off prejudice is to convince people that they are on the same team (Pers Soc Psychol Bull, December 2012, 38, 12, 2012  1566-1578. pop.sagepub.com).

It appears that we are instinctively cooperative when we don’t have time to think about it.  Psychologist David Rand of Yale University asked volunteers to play gambling games in which they could choose to be selfish, or corporate with other players or a slightly lower, but shared, payoff.  When pressed to make a decision people were much more likely to cooperate than when given time to mull it over.

Williams concludes her article thusly:  “So perhaps you’re not an asshole after all—If you know when to stop to think about it and when to go with your gut.  Maybe, just maybe, there is hope for the world.”

© Douglas Griffith and healthymemory.wordpress.com, 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 healthymemory.wordpress.com with appropriate and specific direction to the original content.

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.

Creative Time

December 27, 2014

Creative Time is another section in the chapter Organizing Our Time in Daniel J. Levitin’s book The Organized Mind: Thinking Straight in the Age of Information Overload. The section begins with a discussion of creativity and insight. We’ll skip this as many posts were written about insight fairly recently. Then he moves on to the topic of flow. Although flow has been discussed previously in this blog, it is an important enough topic and Levitin does provide some new information. Flow refers to the experience of getting wonderfully, blissfully lost in an activity losing all track of time, of ourselves, our problems. Flow is the sixth principle of contemplative computing as formulated by Dr.Alex Soojung-Kim Pang in his book The Distraction Addiction (you can use the search box to find these posts). The phenomena of flow were identified and discussed by Mihaly Csikszentmihalyi (pronounced MEE-high, CHEECH-sent-mee-high). It feels like a completely different state of being, a state of heightened awareness coupled with feelings of well-being and contentment. Flow states appear to activate the same regions of the brain, including the left prefrontal cortex and the basal ganglia. Two key regions deactivate during flow: the portion of the prefrontal cortex responsible for self-criticism, and the brain’s fear center, the amygdala.

Flow can occur during either the planning or he execution phase of an activity, but it is most often associated with the execution of a complex task, such as playing a solo on a musical instrument, writing an essay or shooting baskets. A lack of distractability characterizes flow. A second characteristic of flow is that we monitor our performance without the kinds of self-defeating negative judgments that often accompany creative work. When we’re not in flow, a nagging voice inside our head often says, “It’s not good enough.” In flow, a reassuring voice says, “we can fix that.”

Flow is a Goldilocks experience. The task cannot be too easy or too difficult, it has to be at just the right level. It takes less energy to be in flow than to be distracted. This is why flow states are characterized by great productivity and efficiency.

As mentioned earlier, flow is also in a chemically different state, although the particular neurochemical soup has yet to be identified. There needs to be a balance of dopamine and noradrenaline, particularly as they are modulated in a brain region known as the striatum, the locus of the attentional switch, serotonin, for freedom to access stream-of-consciousness associations, and adrenaline, to stay focused and energized. GABA neurons that normally function to inhibit actions and help us exercise self-control need to reduce their activity so that we are not overly critical of ourselves, and so that we can be less inhibited in the generation of ideas.

Flow is not always good. If it becomes an addiction, it can be disruptive. And it can be socially disruptive if flow-ers withdraw from others.

Levitin goes on to describe how creative individuals and groups structure their environments and lives to enhance flow.

© Douglas Griffith and healthymemory.wordpress.com, 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 healthymemory.wordpress.com with appropriate and specific direction to the original content.

The Amygdala and the Problem of Reverse Inference

January 18, 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 just the third post that I’ve written based on a source viewed on my Kindle.

The amygdala is a small region on each side of the brain. So we all should have two amygdalae. They are located in the temporal lobes, one in each hemisphere. In popular reports the amygdala has become almost synonymous with the emotional state of fearfulness. This is true. When you experience fear, the amygdala lights up. I have personal experience with research on the amygdala that I conducted when I was a graduate student. This was back in the days before brain imaging. I surgically implanted electrodes in rats placed under anesthesia so that they would electrically stimulate only their amygdalae. They were deprived of water and when placed in the operant chamber, they immediately started drinking. They received a shock after drinking. When they were placed back into the operant chamber they would not drink even if they were thirsty. However, if an electric current had been sent to the amygdalae when they were shocked the memory of the shock would never have been formed, so they would drink without fear when placed back in the operant chamber.

Although the amygdala is involved in fearfulness, it also responds to things that are unexpected, novel, unfamiliar or exciting. “This probably explains its increased activation when men look at pictures of a Ferrari 360 Modena. The amygdala reacts to photos of faces with menacing expressions, but also to photos of friendly, unfamiliar faces. If fearful faces are expected and happy faces unexpected, the amygdala will respond more strongly to the happy faces. The amygdala also helps register the personal relevance of a stimulus at a given moment. For example, one study revealed that hungry subjects manifested more robust amygdala responses to pictures of food than did their nonhungry counterparts.1

This amygdala example illustrates the problem of reverse inference, which is a problem that plagues the popular media. Reverse inference is the common practice of reasoning backward from the neural activation viewed in an image to subjective experience. The problem is that brain structures rarely perform single tasks, so one-to-one mapping between a given region and a particular mental states is highly prone to error. So “When Jeffrey Goldberg views a picture of Mahmoud Ahmadinejad and his ventral striatum lights up like a menorah, some investigators might think, ‘Well we know that the mental striatum is involved with processing reward, so this subject, with his activated mental striatum is experiencing positive feelings for the dictator’”2 This would be true only if the ventral striatum exclusively processed the experience of pleasure. But novelty can also stimulate the ventral striatum.

1ibid

2ibid

© Douglas Griffith and healthymemory.wordpress.com, 2013. 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.

Resilience

April 15, 2012

Resilience is one of the dimensions of Davidson’s Six Dimensions of Emotional Style.1 It refers to how quickly you bounce back from adversity. Do you bounce back quickly or do you let something bad keep you down for a prolonged length of time? Resilience is another “Goldilocks” variable in that you can have either too much or too little of it. Moreover, what is “just right” regarding resilience depends on the situation. If you just failed an examination, it might be worthwhile ruminating about it for a reasonable amount of time, not too excessive, trying to understand why you failed and how you might avoid similar failures in the future. However, you often see athletes compound an initial error by stewing over it, rather than quickly getting over it and attending to the immediate needs of the game or performance.

Davidson and his colleagues have performed some interesting research regarding the brain structures underlying resilience2. They did a study in which EEGs were recorded from the research participants scalps. Recordings of brain activity were done while 51 pictures were presented on a video monitor. However, before the pictures were presented the baseline level of brain activity was assessed for eight minutes. One-third of the pictures depicted upsetting images, another third pleasant images, and the other third neutral images. Sometime during or after a picture a short burst of white noise sounding like a click was presented. This was a startle probe that tends to make people blink involuntarily. Sensors were placed under one eye to determine when the eye blinked. When people are in a negative emotional state these startle-induced blinks are stronger than in a neutral state. When in a positive emotional state these startle-induced blinks become weaker still. This allowed the researchers to gauge how quickly a research participant recovered from a negative emotional state.

People who had greater activation in the left side of the prefrontal cortex recovered more quickly than the others. The amygdala is a subcortical structure (you have one in each hemisphere of your brain) that responds to negative or unpleasant stimuli. There is communication between the prefrontal cortex and the amygdala. Activity in the left prefrontal cortex shortens the period of amygdala activation allowing the brain to bounce back from an upsetting situation.

MRI brain imaging research has shown that the more white matter (axons that connect one neuron to another) lying between the prefrontal cortex and the amygdala, the more resilient you are. The less white matter lying between the prefrontal cortex and the amygdala, the less resilient you are.

Do not conclude from this that you are stuck with a fixed level of reslience due to the amoung of white matter you have between your prefrontal cortex and your amygdala. Research has indicated that this can be changed. In a later post, I will present techniques offered by Dr. Davidson as to how to change your level of resilience.

1Davidson, R.J. & Begley, S. (2112). The Emotional Life of Your Brain. New York: Hudson Street Press.

2Ibid.