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Thursday, May 21, 2020

Brain Assignment of Values Varies with Context


This morning as you opened the refrigerator door, you looked at the food options for breakfast and asked yourself, “What shall I have for breakfast? Cereal topped with bananas? Sausage and eggs? Pancakes? Fruit bowl? Bagel? Each option has a value, which changes from morning to morning. Each morning, the brain you assess the relative values and decides which food choice counts the most for that particular moment. How does the brain determine that value?

Whether it is in the home, workplace, the school, or in inter-personal relationships, we typically face experiences to which we assign value. Often, we must weigh the relative values of several competing experiences in order to choose a single option to act upon.

In humans, it seems clear that value assignment depends heavily upon function in the prefrontal cortex (PFC). But how does this circuitry assign value? Two possibilities come to mind: 1) the neural response to the stimuli associated with an experience may be consistent across different contexts, or 2) the encoding may be relative, depending on the experience’s context. Relative coding seems likely for the breakfast choice example mentioned above. Any morning’s choice will not be the same every morning. The choice depends, among other things, on how you feel, your level of appetite, and your recent breakfast choices.

Also, value assignment can be thought of as a learning experience. If we have never tasted bananas, for example, our first exposure entails a value assessment on how good it tastes, which we then learn to apply to our future decisions about whether we want to have banana for breakfast or any other time. Clearly, feedback is important. How did it taste and how did that taste compare with other kinds of food that we have eaten, especially eaten recently? If you have had bananas every morning for a week, you may be tired of eating bananas. Then, there is the issue of the context in which perception occurs. Bananas might have more appeal for breakfast that they do for supper.

Research a decade or so ago revealed that our perception is stable across multiple contexts. For example, we can see a banana in the light or dark. We see a green banana or a ripe yellow banana, and still know it is a banana. We can even shut our eyes and feel the shape and still conclude it is a banana.

Assigning value to what we perceive could be another matter. Does value depend on the choice context, rather than being invariant across contexts? That is, do neural circuits re-scale value assignment depending on the context? Earlier fMRI brain-scan studies showed that context is important to value assessment in several areas (mPFC, orbitofrontal cortex (OFC), and cingulate cortex). A recent study has examined whether context-depending coding occurs in all PFC regions and how it is affected by feedback information. Twenty-eight human participants (both sexes) performed an instrumental learning task in which they were trained to maximize their monetary payoff. Choice options produce either reward (adding money to their account) or punishment (subtracting money). Subjects performed four learning trials while in the fMRI scanner in which they were repeatedly were presented with a pair of abstract symbols. For each run, they were presented eight different symbols pairs to produce four choice contexts (i.e., reward/partial feedback, reward/complete, punishment/partial, and punishment/complete). In each trial, they chose between two symbols associated with a certain outcome of money reward. Thus, the contexts were defined based on the possible outcome (either reward or punishment of receiving or losing a specified amount of money). Half of the trials presented complete feedback in which the outcome of the unchosen option was displayed as well, while in the other half of trials subjects were informed of only the value payoff of chosen options.

As repeated learning trials progressed, subjects were learning to optimize their payoffs. MRI signal change reflecting differences between good and bad outcomes was higher for chosen than for unchosen outcomes, with no difference between the chosen outcomes in terms of whether the feedback was partial or complete.

Increased activity in all of the PFC regions and cingulate cortex confirmed their role in encoding and processing value assessment. Anterior PFC activity increased for chosen outcomes, but decreased by unchosen outcome processing. Activity patterns also varied depending on whether partial or complete feedback was given. How does the brain assign different values according to situational context? The explanation is that the neurons must rescale their impulse discharge response to the perceived value of object properties relative to the specific context.

The amount of feedback, partial or complete, greatly affected context-dependent value learning, as revealed by brain activation in multiple regions of PFC and the cingulate cortex. Complete feedback produced the best learning and also caused a switch to assigning value depending on the context. Overall, the subjects learned equally well in reward and punishment context.

The authors used a complicated way to show what we already know from personal experience. We learn what we value from the feedback we receive from our choices, and the value we assign depends on situational context. We readily learn to like bananas on breakfast cereal, but bananas have much less value on pizza at dinner.

The demonstration of the role of prefrontal cortex is important. These results tell us that concussion, stroke, or other damage that affects this part of the brain will impair our ability to make reasoned judgments about the choices we make.
The take-home message is that value assessment occurs in multiple PFC areas in multiple ways, and neural activity does depend on situational context. The coding process is learned by experience and the comprehensiveness of feedback. This learning is consistent with what has been learned over decades of learning and memory research, as I summarize in my books on memory.

Sources:

Doris Pischedda, Stefano Palminteri and Giorgio Coricelli (2020).The effect of counterfactual Information on outcome value coding in medial prefrontal and cingulate cortex: from an absolute to a relative neural code. Journal of Neuroscience 15 April 2020, 40 (16) 3268-3277; DOI: https://doi.org/10.1523/JNEUROSCI.1712-19.2020

Klemm, W. R. (2012).  Memory Power 101. New York: Skyhorse.



Monday, April 27, 2020

Learning to Be More Truthful: Awareness

To continue excerpting from the draft of my book called, Realville, How to Get Real in an Unreal World, I now wish to examine the crucial role of being aware of one’s own habits and the behavior of others. 

Habit


Any attitude or behavior, if sufficiently rehearsed, becomes a habit. Once formed, habits automate attitude and behavior, producing mental “knee-jerk” responses to the events of life. To paraphrase the Jerry Lee Lewis song title, in our society, there is a “Whole lot of knee-jerking going on.” The key to honorable behavior is to be aware of one’s own attitudes and behaviors. Obviously, it is hard to be aware of one’s behaviors that have become an unconscious habit. If habits contribute to personal integrity, habit is a good thing. However, if you continue to repeat untruthful attitudes and behaviors, you are creating a habit to behave untruthfully. You are making yourself a dishonorable person.
A clear example of teaching oneself to be dishonorable comes from a British university study showing that people become desensitized to lying. The experiment involved creating scenarios whereby people could lie repeatedly, and they would get paid more based on the magnitude of the lies. In the experiment with 80 people, pairs of people in separate rooms viewed a photograph of a jar filled with pennies. The photo was clear only for one person in the pair, whose task was to advise the other person how many pennies were in the jar. The person making the estimate was told that the reward would vary on each trial, without knowing critical details about the built-in incentive structure. They received no feedback. The game was rigged so that the more the advice was deliberately exaggerated, the more financial reward was given. Experimenters set the conditions so that lying could benefit both partners, benefit the advising partner at the expense of the other partner, or benefit the advising partner only without affecting the other person.
The greatest lying occurred when it benefited only the lying person. Dishonesty persisted at lower levels if the partner also benefited. There was zero lying under conditions were lying was punished by lower reward while the partner benefitted. People's lies grew bolder the more they lied. They were getting into the habit of lying. Brain scans revealed that activity in a key emotional center of the brain, the amygdala, became less active and desensitized as the dishonesty grew. The amygdala processes fear, which suggests that the people became less fearful of the consequence of lying. In essence, the brain was being trained to lie.
We should conclude that a little bit of dishonesty is a slippery slope that can lead one to grow more dishonest. This provides a rationale for early realization and corrective action of untruthful behavior in children, with the aim of nipping such behavior in the bud before it becomes a habit.
If left unchecked, a person who benefits from repeated untruthfulness will likely do more of it to the point of it becoming automated. This is a classic example of the basic principle of operant conditioning: people are more likely to repeat behaviors that are repeatedly rewarded. The authors of the British study asserted that lying increased in terms of self-interest, because the greatest lying occurred when only the adviser and not the partner benefited. However, because the experiment did not allow subjects to know when their advice was being rewarded, the likely remaining explanation for the lying is that they just adapted to lying, and it didn't bother them so much to exaggerate their estimates. The absence of feedback was a crucial part of the design. The authors point out that in the real world, feedback greatly affects the extent of dishonesty in terms of whether the deceiving person thinks there will be benefit or punishment.
Emotions are at the core of the problem of drifting into a habit of untruthfulness. Normally, we tend to feel guilty when doing something we know is wrong, that is, when we have gone beyond our untruthfulness set-point. However, as we get in a habit of being untruthful, the associated shame or guilt dissipates. We get used to it, and our conscience doesn't bother us so much—a lower set-point emerges. So, we are less constrained in our future behavior. Each little untruthful act can escalate and negatively change the person we are.
One bad habit that is easy to fall into is denial. What is the typical first reaction to getting caught at bad thoughts or bad behavior? Remember when you were a kid in school when the teacher wanted to find out who did a certain bad deed. How did the class respond when she said, for example, “Who wrote this graffiti on the board?” A knee-jerk, “Not me,” goes out the cry, including from the kid who was the perpetrator. In other words, a common first response to being confronted is to deny the facts. Many children never outgrow this denial tendency.
Such denial and rationalization can become a habit. For example, a student may deny that laziness or personal problems are responsible for poor grades, rationalizing instead with a belief that the teachers are ineffective or the courses are irrelevant and boring. Eventually, people with problem attitudes and behaviors may have no choice but to admit the facts when denial becomes too awkward and implausible. Once denial is no longer tenable, an automatic response is to develop a habit of deception, deceiving others and even oneself. The alcoholic may try to hide bottles of liquor or to sneak drinks when family or friends are not watching.
The most common response to having one’s misdeeds or poor behavior discovered is to make excuses. I used to do a lot of that, now hopefully much less. I could write a whole book on that, and I did (Blame Game. How to Win It).

Behavior of Others

People certainly learn values about truthfulness from others. If the people you work and associate with place a high value on truthfulness, then you are more prone to be truthful to fit in and to avoid ostracism.
Various forms of untruthfulness can spread like an infectious disease. For example, some experiments by behavioral economist, Dan Ariely, were conducted so that unpunished cheating could occur. In one such study, experimenters planted an actor student in the room who publicly claimed he solved an implausible number of the test problems. The level of cheating by other students in the room increased, suggesting that cheating can be infectious. In test teamwork experiments, students increased cheating if they thought it would benefit their teammates as well as themselves.
Under real-world conditions, the most common way to spread untruthfulness is to repeat it, again and again. A lie, for example, repeated often enough becomes believable. This is why advertisers keep repeating the same commercial. Whatever the exaggerated claims of benefit of the product, the repetition seeps into an audience’s subconscious to become engraved as believed. This is why news media push an agenda by harping on a story theme until they shape public opinion about an issue or politician. This is why politicians use repetition to discredit and demonize their opponents.
As misinformation is repeated again and again, more and more people come to believe it.  This leads to “argument by authority” to rationalize dishonesty. Then too, the more prevalent lying, denial, pretense, etc. become in a social group, the more we either become accepting or tolerant of it. People tend to tolerate what is common, because that is “just the way things are.”  Even if you want to mount a challenge, it would just be too much trouble and not likely to be successful. Complying with the group norm is akin to the thinking error of arguing from authority, only in this case, the deception has undeserved status.

Sources:
Ariely, Dan (2012). The (Honest) Truth about Dishonesty. New York: Harper Collins.

Garrett, N. et al. (2016). The brain adapts to dishonesty. Nature Neuroscience. 24 October. doi: 10.1038/nn.4426



Monday, April 06, 2020

Learning to be Truthful


I am currently working on a book called, Realville, How to Get Real in an Unreal World.  There is so much misinformation, disinformation, and weaponizing of information in our society that I feel compelled to try to motivate us all to be more honorable and forthright.
One section of the book deals with the question of how people learn values about truthfulness and learn to recognize and moderate their natural tendencies to lie, cheat, deceive, delude, pretend, and withhold. I identify four main sources for such learning:
·         Child rearing
·         Education
·         Habit
·         Behavior of others.

Child Rearing


Michael Lewis, a prominent psychologist at Rutgers, has conducted many studies on how children learn from well-meaning parents how to lie and deceive. Certain ways of expressing emotion are taught to be acceptable, while others are not. For example, in one experiment, investigators taught children to express sadness when their mother left them with a baby sitter. However, the reality was that they were not sad and recovered quickly when the mother left. Other examples are how children learn to express responses to minor injuries. Some kids are taught that it is alright to over-react, while others are taught not to act like sissies.
It is hard to know how a child really feels, because parents are continually teaching them how they are supposed to feel and how to express feelings and reactions to life events. When children become adults, a lifetime of conditioning about expressing emotions creates problems for mental health workers to treat patients, because true feelings may be so buried and masked.
Three primary factors affect how children learn to think and behave in untruthful ways in which they do it to:
1. Avoid negative consequences or punishment.
2. Protect their ego from assaults on their sense of self-worth or confidence.
3. Benefit themselves or take advantage of others.
No wonder untruthful behavior is so common. In some respects, Lewis thinks this is a good thing, reflecting mental development to become more emotionally and socially competent as an adult. However, character development is corrupted.
Lewis and his colleagues conducted some classical experiments in young children that revealed how their tendency for untruthful behavior changed with age. The researchers secretly videotaped children in an honesty test in which they were told not to peek at a toy that was placed behind them. The child was told that the adult had to leave the room for a few minutes, but when she comes back they could play with the toy.
While the investigator was out of the room, 100% of children as young as two peeked at the toy. When asked if they peeked, 38% of two-year-olds lied about it. However, among six-year-olds, one-hundred percent of peekers lied about it. Boys generally had less self-control in resisting peeking, but no sex differences occurred in the extent of lying. The fact that all six-year-olds lied indicates a serious need to instruct children at this age on the virtue of telling the truth.
Clear correlations occurred with other aspects of cognitive function. For example, how quickly a child yielded to the temptation of peeking varied with IQ. Those who peeked sooner had lower IQ scores. They also had less emotional intelligence, that is, were less able to name the emotions revealed by pictures of human faces and less able to predict the kind of emotion they would generate to certain experiences. I have to wonder: If parents and 1st-grade teachers made more of an effort to teach honest, would 6-year olds increase their IQ and emotional intelligence?
Children also learn self-deception at rates that vary with age. A child learns to avoid or minimize honest judgments that unnecessarily diminish their self-esteem. Blame shifting or excuses come naturally to children. At the same time, a child can learn when honest self-appraisal serves the useful purpose of avoiding future mistakes or taking some necessary action.
Even so, Lewis and others perversely contend that lying and deception are normal and good, because they relieve the physiological and psychological consequences of stress. Lying seems to be associated with pro-social behavior and with creativity.
Pretend play provides a paradigm for studying self-deception. Very young children imitate the actions of others around them. As they get a little older, they pretend that one toy is doing something with another toy, as for example, toy soldiers engaging in battle.
Pretend play begins at around age one.  Lewis gives the example of a one-year-old who imitates seeing his mother talking on the phone. By age two or three the child might pretend that her doll is talking on the phone. By three years of age, a child is able to consider success or failure of the play and to assign blame or credit for it. At this point, self-conscious emotions have emerged that lead to shame for failure and pride in success.
More condemnable is to be untruthful to benefit oneself and taking advantage of others in the process, as when a child lies about a misdeed and blames it on an innocent, such as a sibling. Unfortunately, there seems to be little research on childhood development of this level of dishonesty. How does it change with age? What factors promote it? Or mitigate it? The social consequences are profound. For example, child siblings who lie about each other may become alienated from each other the rest of their lives.
Biology wires children to behave falsely. Where do they learn moral values and respect for truth? Traditionally, this was in houses of worship. However, as many parents are leaving formal religion, this teaching is increasingly absent. We know that teaching of children has lasting effects, good or bad. Both Jesuits and Communist Lenin have claimed, "Give me a child until age seven, and I have that child for life."

Education


Education can be a factor in promoting untruths because it trains the brain in thinking skills.  Educated people may be more tolerant of deceptive behavior, more effective at it, more adept at rationalizing why they do it, and they will likely be clever enough to get away with it. Getting away with it provides positive reinforcement that engenders more dishonesty.
Knowledge and life experience do change what a person thinks of as true. This can be illustrated with Winston Churchill's famous quote, "If a young man is not a socialist by the time he is 20, he has no heart. ...If he is not a conservative by the time he is 40, he has no brain."
Of course, highly intelligent youngsters can figure a lot of this out on their own. However, they need to question, and many humans are prone to take things at face value. They are easily manipulated by false teaching.
A questioning mindset formed the basis of the life of Socrates, whose mission was to show people the importance of introspection, asking questions, and reasoning to answer those questions. In my decades of teaching at the college level, I have learned that most students are intellectually compliant and do not question. Maybe this reflects prior teaching in k-12.  Even at the college level, an emphasis on career training limits use of the Socratic method of teaching. The desire to “educate the masses” provides students with the corrosive experience of 12 or more years of taking multiple-choice quizzes where each question is framed in only one way and supposedly only has one correct answer.

Habit


Any attitude or behavior, if sufficiently rehearsed, becomes a habit. Once formed, habits automate attitude and behavior, producing mental “knee-jerk” responses to the events of life. To paraphrase the Jerry Lee Lewis song title, in our society, there is a “Whole lot of knee-jerking going on.” The key to honorable behavior is to think carefully about the attitudes and behaviors one is repeating. If they contribute to personal integrity, habit is a good thing. However, if you repeat and repeat untruthful attitudes and behaviors, you are creating a habit to behave untruthfully. You are making yourself a dishonorable person.
A clear example of teaching oneself to be dishonorable comes from a British university study showing that people become desensitized to lying. The experiment involved creating scenarios whereby people could lie repeatedly, and they would get paid more based on the magnitude of the lies. In the experiment with 80 people, pairs of people in separate rooms viewed a photograph of a jar filled with pennies. The photo was clear only for one person in the pair, whose task was to advise the other person how many pennies were in the jar. The person making the estimate was told that the reward would vary on each trial, without knowing critical details about the built-in incentive structure. They received no feedback. The game was rigged so that the more the advice was deliberately exaggerated, the more financial reward was given.
Experimenters set the conditions so that lying could benefit both partners, benefit the advising partner at the expense of the other partner, or benefit the advising partner only without affecting the other person.
The greatest lying occurred when it benefitted only the lying person. Dishonesty persisted at lower levels if the partner also benefitted. There was zero lying under conditions were lying was punished by lower reward while the partner benefitted. People's lies grew bolder the more they lied. They were getting into the habit of lying. Brain scans revealed that activity in a key emotional center of the brain, the amygdala, became less active and desensitized as the dishonesty grew. The amygdala processes fear, which suggests that the people became less fearful of the consequence of lying. In essence, the brain was being trained to lie.
We should conclude that a little bit of dishonesty is a slippery slope that can lead one to grow more dishonest. This provides a rationale for early corrective action of untruthful behavior in children, with the aim of nipping such behavior in the bud before it becomes a habit.
If left unchecked, a person who benefits from repeated untruthfulness will likely do more of it to the point of it becoming automated. This is a classic example of the basic principle of operant conditioning: people are more likely to repeat behaviors that are repeatedly rewarded. The authors of the British study asserted that lying increased in terms of self-interest, because the greatest lying occurred when only the adviser and not the partner benefitted. However, because the experiment did not allow subjects to know when their advice was being rewarded, the likely remaining explanation for the lying is that they just adapted to lying, and it didn't bother them so much to exaggerate their estimates. The absence of feedback was a crucial part of the design. The authors point out that in the real world, feedback greatly affects the extent of dishonesty in terms of whether the deceiving person thinks there will be benefit or punishment.
Emotions are at the core of the problem of drifting into a habit of untruthfulness. Normally, we tend to feel guilty when doing something we know is wrong, that is, when we have gone beyond our untruthfulness set-point. However, as we get in a habit of being untruthful, the associated shame or guilt dissipates. We get used to it, and our conscience doesn't bother us so much—a lower set-point emerges. So, we are less constrained in our future behavior. Each little untruthful act can escalate and negatively change the person we are.
One bad habit that is easy to fall into is denial. What is the typical first reaction to getting caught at bad thoughts or bad behavior? Remember when you were a kid in school when the teacher wanted to find out who did a certain bad deed. How did the class respond when she said, for example, “Who wrote this graffiti on the board?” A knee-jerk, “Not me,” goes out the cry, including from the kid who was the perpetrator. In other words, a common first response to being confronted is to deny the facts. Many children never outgrow this denial tendency.
Such denial and rationalization can become a habit. For example, a student may deny that laziness or personal problems are responsible for poor grades, rationalizing instead with a belief that the teachers are ineffective or the courses are irrelevant and boring. Eventually, people with problem attitudes and behaviors may have no choice but to admit the facts when denial becomes too awkward and implausible. Once denial is no longer tenable, an automatic response is to develop a habit of deception, deceiving others and even oneself. The alcoholic may try to hide bottles of liquor or to sneak drinks when family or friends are not watching. To illustrate just how powerful this habit of deception can be, I remember that when I quit smoking I had occasional dreams over several years where I had hidden a pack of cigarettes and cheated on my pledge to quit smoking.
The most common response to having one’s misdeeds or poor behavior discovered is to make excuses. I used to do a lot of that, now hopefully much less. I could write a whole book on that, and I did (Blame Game. How to Win It).
Because deception is usually discovered, the only real hope is to do something constructive to resolve the problem that tempts one to deny and deceive.

Behavior of Others

People certainly learn values about truthfulness from others. If the people you work and associate with place a high value on truthfulness, then you are more prone to be truthful to fit in and to avoid ostracism.
Various forms of untruthfulness can spread like an infectious disease. For example, some experiments by behavioral economist, Dan Ariely, were conducted so that unpunished cheating could occur. In one such study, experimenters planted an actor student in the room who publicly claimed he solved an implausible number of the test problems. The level of cheating by other students in the room increased, suggesting that cheating can be infectious. In test teamwork experiments, students increased cheating if they thought it would benefit their teammates as well as themselves.
Under real-world conditions, the most common way to spread untruthfulness is to repeat it, again and again. A lie, for example, repeated often enough becomes believable. This is why advertisers keep repeating the same commercial. Whatever the exaggerated claims of benefit of the product, the repetition seeps into an audience’s subconscious to become engraved as believed. This is why news media push an agenda by harping on a story theme until they shape public opinion about an issue or politician. This is why politicians use repetition to discredit and demonize their opponents. “Opposition research” is now standard practice in political parties, and the politicians often repeat exaggerated or otherwise distorted negative information.

Sources:

Ariely, Dan (2012). The (Honest) Truth about Dishonesty. New York: Harper Collins.

Lewis, Michael. (2015). The origins of lying and deception in everyday life. American Scientist. 103: 128-135.


Saturday, April 04, 2020

The Truth

I am writing a book, “Realville. How to Get Real in an Unreal World.” Are you interested in being a beta reader? Perhaps you might even find it in your interest to arrange some kind of publication sponsorship. The synopsis is shown below:


Realville. How to Get Real in an Unreal World

Synopsis


People use social media to misrepresent themselves,
Politicians attack their opponents with lies and blatant misrepresentations.
Corruption can be found at all levels of government,
News media spin or withhold news to support their socio-political agendas,
Government officials lie to the public, even to Congress.
Companies exaggerate the merits of products and services.
Students cheat, and teachers inflate grades,
Résumés are padded,
Competing co-workers misrepresent their skills and attributes to advance their own careers.
Hackers use your identity for nefarious purposes,

… and then there are hustles by used-car and timeshare salesmen.

The list goes on. Can you believe everything you read? ... everything you hear? ... even everything you see? In this age of Photoshop, botox, and breast implants, the truth eludes us, made harder to find in the world-wide disinformation morass of the Internet, hundreds of TV channels, and social media.

THIS BOOK shows you how to recognize, understand, and pursue truth in all its forms of betrayal: lying, cheating, denial, delusion, deception, pretension, and withholding. The focus of this book is on truthfulness in our everyday lives in the family, school, workplace, and social activities. Three foundational chapters show readers how to:

1.    Recognize untruthfulness in any of its forms, 
2.    Analyze what causes people to be untruthful, even unintentionally,
3.    Employ strategies to become more truthful themselves and thus more trustworthy. 

This book is not just about the fake news of politics or monopolistic newspapers, or agenda-driven TV news anchors. It is about the value of evidence as the basis for establishing what we regard as true. Without evidence, people drift into irrationality and magical thinking. In human culture, disregard for evidence and truth foments distrust, alienation, and animosity.  I hope to sensitize us to the importance of evidence, as opposed to opinion, which often masquerades as fact.

This book should appeal to several kinds of people:

     Those who want to spot the charlatans, manipulators, and others they should not trust.
     Those bent on becoming a more honorable person more able to live up to the ethical standards of their personal values, profession, culture, and religious faith. 
     Those in all situations where character development is taught: the family, schools, churches, the military, and the legal profession. A closing feature of the book is a process and worksheet template that people can use for a variety of real-world situations. 



Saturday, March 21, 2020

The Electrical Nature of Conscious Memory Formation and Retrieval


When you memorize something, the brain creates a nerve-impulse code to create a representation of the information represented in brain, and this code can get stored in memory. Upon retrieval, the code is replayed, and thus what the code represents becomes consciously available again as a simulation. At least that’s the theory. Until now, the evidence for this explanation has been derived mostly from rodents. But now rather direct evidence is available from humans.
In one new study, human subjects created memory associations between word pairs, while experimenters simultaneously recorded single-neuron impulses and their associated field potentials from an implanted microelectrode array in the medial temporal cortex, which is known to participate in memory formation. The EEG was also recorded from subdural electrodes implanted over the temporal cortex immediately above the microelectrode array. This allowed simultaneous observation of the local nerve impulse discharges, their associated local field potentials, and the EEG during memory formation and retrieval after a brief distraction period.
Recordings revealed the well-known relationship that EEG signals often have superimposed low-voltage high-frequency waves, which are called ripples. As expected, the ripples appeared at the same time of the impulse discharges from the microelectrodes, indicating that the impulses actually cause the small field potential changes of ripples.

In the top signal, we have the sum of a fast and slow oscillations, where the power of fast oscillation's envelope changes with the phase of the slower oscillation. The bottom signal shows only the filtered fast oscillation and the variation in its power. As it is obvious from comparison of two signals, the fast rhythm's power is always maximum at a certain coupled phase of slower oscillation (From Samiee et al.).
In the experiment, impulse burst clusters occurred throughout the presentation of word pairs while subjects were encoding the pairs. Trial-specific spike sequences observed during encoding were replayed during correct recall. As expected, ripples during recall appeared at the same time as the impulse sequences.
Not mentioned by the authors is that their findings have implications for neural correlates of consciousness. After all, forming the word-pair associations was a conscious operation. In the field of consciousness research, neural correlates are clearly evident in the EEG in that the frequency of voltage shifts predictably as the brain progresses from large slow waves during anesthesia or sleep to increasingly faster and smaller waves during alert arousal.  Relatively high frequencies (40-200 waves per second) appear more prominently when the brain is working on difficult tasks. Moreover, hard tasks are associated with more phase-locking of the EEG oscillations at different locations of the cortex.
Conscious perceptions seem to involve short- and long-range oscillations in the vertically oriented network columns in the cortex. Each column contains a local network that processes input locally in oscillatory activity that is gated at certain frequencies by inhibitory neurons in the circuit.  
At the same time, local oscillations from large pyramidal cell firings spread to distant columns both within and between the cortical hemispheres. The frequencies of this long-range activity may be slower because of the longer impulse conduction and synaptic delays. Collectively, local and distant networks interact and may likely be the basis for consciousness. The electrographic correlate is that of fast frequencies from local processing being nested within more globally generated slow frequencies. The timing phase relationships would clearly influence how much integration of local and distant processing occurs and the likelihood that the processing could be consciously perceived.
Many experiments have shown that selective attention is needed for conscious perception. Such attention activates local processing (and ripples in the local field potential). Bear in mind, however, that the ripples are not the source of processing but rather an associated manifestation of the processing that is actually occurring via the impulse timing in the local circuitry.
Two basic kinds of coupling can be seen in brainwave activity: 1) the phase of the slower frequency modulates the faster frequency, and (2) the phase coupling between two overlapping frequencies occurs when one frequency is a harmonic multiple of the other.
Conscious processing seems to be crucially dependent on the cross-frequency coherence of neural activity that can be seen at the local circuit level in multiple local sites of neocortex, hippocampus, and basal ganglia. There are different varieties of cross-frequency coupling (phase-phase, amplitude-amplitude, and phase-amplitude coupling), each of which may reflect distinctive processing. Such coherence differs across brain areas in a task-relevant manner, and changes quickly in response to sensory, motor, and cognitive events, and correlates with performance in learning tasks. Moreover, cross-frequency coherence increases with level of task demand. For example, continuous EEG recordings obtained during an arithmetic task, rest and breath focus revealed that cross-frequency alpha and theta peak-frequency coherence significantly higher when cognitive demands increased (Rodriguez-Larios and Alaerts, (2019). What is likely to remain enigmatic is how such cross-frequency coupling yields a conscious perception.
The most significant neural correlation of consciousness may prove to be time locking of nested oscillation of different frequencies whose underlying impulse patterns carry different aspects of information. The time locking of nested high- and low-frequency activity likely increases information throughput in the local circuits participating in selective attention, occludes noisy disruption from other inputs, and improves the signal-to-noise ratio of neural activity that is processing the target of attention. Parsimonious as this view might be, it still does not fully explain how a conscious percept emerges.

Sources:

Rodriguez_Larios, Julio and Alaerts, Kaat (2019). Tracking transient changes in the neural frequency architecture: harmonic relations between theta and alpha peaks facilitate cognitive performance. J. Neurosci. 7 August, 39 (32) 6291-6298; DOI: https://doi.org/10.1523/JNEUROSCI.2919-18.2019

Samiee, Sohelila et al. (2019) Phase-amplitude coupling. Nov. https://neuroimage.usc.edu/brainstorm/Tutorials/TutPac

Vaz, Alex P. et al. (2020). Replay of cortical spiking sequences during human memory retrieval. Science. 367,1131-1134.

Sunday, March 01, 2020

On Becoming More Human: The Two Human Distinctions


To become more human, it seems we must first recognize what is distinctive about being human. Basic biology is about the same in all higher animals and humans. So for distinctiveness we must look to mental and behavioral functions. It seems that only two mental characteristics are distinctively human. These are commonly referred to as constructed imagined scenarios and deliberate practice.

The clarification of human scenario building became evident from the research of Thomas Suddendorf at the University of Queensland. He challenged the usual claim that humans are distinct because of their capacity for “speech, fire, agriculture, writing, tools, and large-scale cooperation.” Actually, certain animal species can perform one or more of these activities in their own way. As examples, Suddendorf reminds us that "If you set the bar low, you can conclude that parrots can speak, ants have agriculture, crows make tools, and bees cooperate on a large scale." What sets people apart from others in the animal kingdom is that humans have imagination that enables them to develop scenarios and link other scenario-building minds. Such use of creative imagination, he says, allows humans to turn animal communication ”into open-ended human language, memory into mental time travel, social cognition into theory of mind, problem solving into abstract reasoning, social traditions into cumulative culture, and empathy into morality."

Suddendorf concedes that some animals, like great apes, seem to have some scenario-building capability. But human capability explodes after about age 2, while this does not happen in great apes. Age 2 is about when humans show signs of conscious self-awareness, which may be the key determinate for scenario-building capability.

We should not overlook the creativity element of scenario-building. Creativity has certainly been central to cultural advancement. Animal cultures, if they evolve at all, mostly seem to arise from trial-and-error learning.

A second uniquely human feature is captured in the term "deliberate practice." This term was apparently first coined in 1993 by Florida State University professor, K. Anders Ericsson and colleagues, as a result of observing the development of expertise by budding musicians. Their report has been cited an astounding 10,000 times according to Google Scholar. Key principles include the importance of purposeful learning involving individualized instruction and a focus on identifying goals and methods for achieving musical mastery. The phenomenon has since been named "structured practice" to capture the essential feature of systematic growth of expertise. I take the liberty of adding to the original ideas about deliberate practice by identifying several central elements for success of deliberate practice:

·       Motivation to develop expertise,
·       A specific learning regimen,
·       Learner control,
·       Knowledge on how to improve,
·       Time on task,
·       Repetition that features explicit awareness of how well mastery develops,
·       Immediate performance feedback,
·       Analysis of corrective feedback needed,
·       Successive approximations of feedback correction and attendant positive reinforcement of improvement,
·       Repetition that incorporates corrections.

Though Erickson originally claimed that a challenging expert teacher or coach is needed, the learner need not have direct supervision of a teacher, as long as there is an external source of information on the nature of the expertise, advice on how to develop it, and an objective metric for the extent of growth in expertise. Obviously, deliberate practice is more efficient when performed under the guidance of an expert coach or teacher.

Obviously, deliberate practice is most needed for development of specific skills, as in sports, music, and competitive games like chess. My own experience with use of mnemonics suggests a role for deliberate practice in the ability to memorize. Also relevant to the effectiveness of deliberate practice are the memory principles of focused attention, conditions supporting memory consolidation, and spacing of practice session. Other aspects of learning experience can be a kind of deliberate practice that promotes learning sets and a learning-how-to-learn expertise.

So, if we want to become more human, it seems necessary to develop our capacity for creativity and scenario building and for deliberate practice. Numerous writings, including my own, suggest ways to become more creative. Deliberate practice is achieved by doing it, especially in a way that promotes remembering what the practice is teaching you. As described on my web site (WRKlemm.com), my four books on memory seem to cover the breadth of memory theory and application.

Sources:

Ericsson, K. A., Krampe, R. T., and Tesch-Römer, C. (1993). The role of deliberate practice in the acquisition of expert performance. Psychol. Rev. 100, 363–406. doi: 10.1037/0033-295X.87.3.215

Ericsson, K. Anders, and Harwell, Kyle W. (2019), Deliberate practice and proposed limits on the effects of practice on the acquisition of expert performance: Why the original definition matters and recommendations for future research. Front. Psychol., 25 October 2019, https://doi.org/10.3389/fpsyg.2019.02396

Klemm, W. R. (2018). Developing a strategic and systematic idea creation and management system. International Journal of Creativity and Problem Solving. 28(1), 7-26.

Klemm, W. R. (2017). Leadership and creativity, p. 263-296. In Leadership Today, edited by Joan Marques and Satinder Dhiman. New York: Springer.

Klemm, W. R. (2017). Reason and creativity require free will. Chapter 2, in Free Will: Interpretations, Implementations and Assessments  In Hauppauge, NY: Nova Science.

Klemm, W. R. (1990). Leadership: creativity and innovation, p. 426-439. Concepts for Air Force Leadership, 2nd Ed. Air University, Maxwell AFB, Ala. Available on-line at the Air War College website, http://www.au.af.mil/AU/AWC/AWCGATE/au-24/au24-401.htm. (Used as a text in several military academies for multiple years).

Suddendorf, Thomas (2013). The Gap: The Science of What Separates Us from Other Animals. New York, NY, United States: Basic Books).

Monday, February 17, 2020

New Research on How Learning Changes the Brain


Learning programs the brain. It is nature’s way to create simultaneously both “hardware” and “software” for the brain. Neuroscientists have long known that learning experiences change the functional circuitry that is used to process and remember a given learning event. The circuit change is anatomical: electron microscope photographs reveal that the synaptic changes take the form of little blebs located on dendrites. These blebs are called “dendritic spines,” and their size and number change in response to learning and memory formation. You might think of the induced change as a physical location for information storage. What is stored at any given spine is an increase in the probability that the spine will participate in activations that generate recall of the stored memory from all the spines that were enhanced in creating the memory.
Functionally, the change operates as a template that resides more or less permanently that is available not only to recall the original learning event but to respond to similar events in the future. Of course, no one synapse accounts for these recall and programming effects. However, the learning and memory results from the collective enhancement of all the enhanced dendritic spines in the participating circuitry. The templates thus created provide a way for the brain to program itself for future capabilities. Learning how to solve one kind of task makes it easier to learn new tasks that are similar. This is the basis for the so-called “learning-set,” a concept introduced many decades ago by Harry Harlow.
We tend to think about such matters in the education of children. However, the principle applies at all ages, including seniors. The aging brain responds to learning the same way a child’s brain does: it grows new task-specific synapses that can be recruited for other uses.
The learning effect is manifest in the growth of existing synapses and the formation of new synapses. In the absence of mental stimulation, the spines degenerate. Indeed, a typical effect of aging is that the brain actually shrinks as a consequence of the cumulative shrinkage of spines. Many neurological diseases are characterized by reduced synaptic density: schizophrenia, autism, and dementia. An opposite problem occurs with drug addiction, where certain synaptic connections are strengthened by the drug, essentially creating a way to store a memory for the addiction.
Until now, we have not learned as much about the chemical changes that occur with learning. A recent study from Thomas Jefferson University reveals that new patterns of molecular organization develop as connections between neurons strengthen during learning. The researchers basically asked the question, “What does learning look like at the molecular level? Using super-resolution live-cell microscopy, the researchers confirmed the enlargement of synapses previously reported by others. But they also saw that that during a learning experience the molecules involved in sending and receiving the signals between neurons appeared to be organized in clumps or "nanomodules" that both dance and multiply when stimulated by learning-like signals.
The researchers developed a novel technique wherein they could visualize the chemical involved in transmitting signal from one neuron to another. Chemicals on the pre-synaptic side appeared green and those on the receiving postsynaptic sign appeared as red. Then while observing the colors, they observed live neurons in real time as they sent signals to each other via their neurotransmitter chemical systems. The color changes indicated that during signaling activity, the presynaptic chemicals clumped together and bound to clumped molecules on the postsynaptic side. The clumps appeared to have a uniform size. When the presynaptic neurons were stimulated in a way that promoted spine enlargement, they saw that the number of chemical clumps increased. Such stimulation caused non-moving clump to jiggle and move around the synaptic spine, with pre- and post-synaptic chemicals moving in lock-step. Maybe this jiggling helps to trigger the biochemical cascade that neurotransmission causes to change activity in the post-synaptic neuron.
Perhaps we don’t think enough about the movement of molecules in living tissue. All chemicals in solution bounce around randomly. Clumping together and jiggling in lock-step creates new ways for chemicals to produce their effects. Apparently, the clumping is the triggering event for the enlargement of dendritic spines that creates a structural basis for memory.
This kind of chemical interaction is not only relevant to learning. It also applies in unknown ways to the altered function in addictions and other neurological diseases in which strong interneuronal connections become too strong. Research on neurotransmitter clumping in disease states has not yet begun, but here we may find clues on how to treat some of these conditions. Clearly, disrupting the clumping would disrupt the ability to strengthen synapses. While we want our synapses strengthened to promote normal learning, we don’t want this to happen for example, for opiate pain relievers, which create addiction. At the molecular level, addiction is a learned condition.

Sources
Hruska, M. et al., "Synaptic nanomodules underlie the organization and plasticity of spine synapses," Nature Neuroscience, DOI: 10.1038/s41593-018-0138-9, 2018.
Klemm, W. R. Core Ideas in Neuroscience. https://www.smashwords.com/books/view/390780

Monday, February 03, 2020

Lifestyles that Promote Living Longer and Better



People in many parts of the world are living longer, due largely to improvements in medicine and healthier lifestyle afforded by less poverty. The downside is that the longer one lives the more likely a debilitating disease will emerge, such as cardiovascular disease, cancer, diabetes, or Alzheimer's Disease. For many people, the important thing is not how long they live, but how long they can live without serious physical suffering.

Many studies have established that the incidence of the common debilitating diseases can be reduced or delayed by modifiable lifestyle factors. While genes can obviously affect one’s vulnerability to disease, genes may not be the primary factor in how long or how well one lives. This is suggested, for example, by one study of over 110,000 healthcare professionals (about 1/3 male, 2/3 female) that clearly showed the value of healthy lifestyles.

The investigators queried these subjects and categorized them according to five lifestyle criteria:

    Diet, as assessed using the Alternate Healthy Eating Index, with a score in the upper 40% indicating a healthy diet;
    Smoking (never vs ever);
    Moderate to vigorous physical activity (≥ 30 minutes/day);
    No alcohol consumption above 15 g/day for women, 30 g/day for men;
    Body mass index (18.5-24.9 kg/m2).

Women who met four of the five low-risk lifestyle factors lived 10 more years free of cancer, cardiovascular disease, and type 2 diabetes at 50 years than women who followed none of the low-risk factors. In men, the gain in disease-free life expectancy was near 8 years. In terms of total life expectancy, women in the low-risk group at age 50 showed an increase from 31.7 years to 41.1 and men increased their life span from 31.3 years to 39.4 years.

This large-scale study confirms what has been indicated by a host of earlier studies that healthy lifestyles involve proper diet, absence of smoking, low consumption of alcohol, substantial exercise, and a BMI in the range of 18.5-24.9 kg/m.2  Moreover, both women and men who have a healthy lifestyle have significantly more years in which they avoid crippling heart disease, cancer, and type 2 diabetes.

The largest impact was on reduced incidence of cardiovascular disease and diabetes in both women and men. The lifestyles that were most likely to increase the three major diseases were smoking and obesity, in both women and men. Perhaps beneficial effects would be magnified by more stringent healthy lifestyle criteria (for example, upper 10% of healthy diet or level of exercise).

Other posts on lifestyle and aging research have clearly identified other healthy factors, such as  the value of emotional well-being and reduced psychological stress. Anecdotes suggest that living a life of worthy purpose may also promote aging well and living longer, though apparently there is not much formal research on this possibility.

Though we have no direct control over our genes, most of us can largely control how we live our lives. The beneficial effects of healthy lifestyle on aging well and longevity surely include direct enhancement of organ function and indirect effects on gene expression. Healthy lifestyles will help you, as we say in Texas, "Go out with your boots on."

Source

Li, Yanping, et al. (2020). Healthy lifestyle and life expectancy free of cancer, cardiovascular disease, and type 2 diabetes: prospective cohort study, January 8, BMJ 2020; 368 doi: https://doi.org/10.1136/bmj.l6669