Monday, November 19, 2012

Prospect Theory and Psychiatry

Kahneman's most ingenious aspects of psychological theory have to do with quantifying psychological gains and losses.  These findings were the result of years of careful, clever, imaginative studies. 

The mind does not function according to the standard laws of economics.  In the mind, losses are weighted more heavily than equivalent gains.  This is due to the mind's tendency to form a personal attachment to an object or phenomenon associated with the present state.    In a sense, current possession is given extra value in the mind, even if there is no other rationale for it.  The value of any change is dependent on the initial baseline (so finding a quarter will seem much luckier if you are just short on bus fare home, compared to a different situation where your wallet is full of bus tickets).   We are willing to "pay" disproportionate amounts, psychologically or economically, for certainty, or for possibility.    People would "pay" an amount much more than 10% higher to have 100% instead of 90% certainty of safety or gain.  This is the basis on which the insurance industry thrives.  And people are willing to pay much more than 1% of a potential gain to raise the probability of gain from 0 to 1% (we see this phenomenon every day when people buy lottery tickets).

Psychologically, this means that we may distribute mental time, energy, or attachment irrationally.  We may chase irrationally after long shots, or invest an excess of energy into a task--perfectionistically--in a way which is unnecessary and depriving to other goals.  And the core mental property of loss aversion may cause us to hold onto aspects of the status quo too tenaciously, and cause us to be unreasonably unwilling to take small risks, if these risks involve letting go of something we currently have.

On the other hand, some of these phenomena could be viewed as intrinsic elements of what "makes us human."  While buying lottery tickets or doing other types of gambling activities are on the one hand irrational, they on the other hand could be viewed as game playing.  And we are willing to pay to play games.  (in the case of gambling, we pay with financial loss and lost time).  I think if such activities could be framed as play activities, it might help people to assign fair values to the activities.  The act of risk-taking might actually feel enjoyable, particularly if there are other positive cues associated (for the gambler, it might be the glitzy casino), even though the net result of the activity is loss.  The problem is, many people who gamble actually frame the activity as a profit-building venture, which is highly irrational and would be expected to lead to financial ruin if pursued to the fullest extent.  Also, the mind tends not to frame probabilities accurately, and is prone to see causal patterns in random sets; therefore many a gambler comes to believe that he or she is having some kind of exceptional luckiness that is different from average. 

Similarly, insurance purchasing is on the on hand an often inefficient use of money, but on the other hand it could be viewed as the cost of feeling more secure.  Or of paying someone else to take on some of your life risks.

The phenomenon of loss aversion is part of what helps us maintain stability in our relationships with people, belongings, and activities.

But sometimes this phenomenon can cause us to irrationally hold onto relationships, behaviours, commitments, or objects which would be healthier to let go of.   

Kahneman's research shows us that these phenomena cause extremely strong biases in decision making.  While some of these biases may be an intrinsic part of our humanity, I think that at the very least, his work invites us to think much more closely about the rationality of our decisions, when it comes to economic or psychological changes, acquisitions, or losses.  








Psychiatry & Decision Utility

In Kahnemann's chapter called "Two Selves" from Thinking, Fast and Slow, he discusses a very interesting bias having to do with how we feel about, value, or rate experiences having positive or negative attributes.

In a simple economic model, it would make sense to assume that a positive experience lasting 2 hours would be "worth" twice as much as a positive experience lasting only 1 hour.

Conversely, a negative or painful experience lasting 2 hours (or 2 months, or 2 years!) would be twice as bad as a negative or painful experience lasting only 1 hour (or 1 month, or 1 year).

One way to state this, is that if we were to graph painfulness vs. time, then it would make sense to say that the total negative impact of the pain should be the area under the curve.  

But this is not so!

The mind is not wired to make such evenly weighted evaluations.

Redelmeier's and Kahneman's 1996 study of colonoscopy pain showed that the negativity of patients' experiences depends on how severe the pain of the procedure was at its peak, and on how painful the procedure was when it was ending.  It DID NOT depend on how long the procedure lasted.  Other research has shown similar results. 

Therefore, if two painful events occur for an equal length of time, after which the pain of one of the events suddenly stops, while the pain of the other event gradually diminishes, people will rate the second event more favourably, because they experience gradual relief at the end of the event.   This is even though the second event technically involves a larger total amount of pain (since the painfulness continues for a longer time). 

Even if one painful event is much longer than another, it will be experienced in retrospect to have been more comfortable if the discomfort diminishes near the end.    Similarly, a brief but intensely painful experience will  have a more negative experiential impact compared to a much longer period of moderate painfulness.

As Kahneman shows so well, the mind exhibits "duration neglect"-- it tends not to calculate the goodness or badness of things according to adding up all the good or bad experiences over time.  Instead, the mind attends to the very worst moment, and to the period of time which is most recent.

 This bias could lead to a variety of problems in making healthy choices.  A problem which causes gradual health deterioration over many years could be preferred to another problem which would cause much less long-term harm, but which would be acutely more uncomfortable.  Addictions are an obvious example--the long term deterioration due to addictive behaviour may be barely noticeable, and quite tolerable in the moment.  Even the cumulative effect of the harm (the "area under the curve") might not be attended to experientially.  But acute withdrawal would be very uncomfortable, despite being much more favourable to long-term health.

In relationships, people might be tempted to stay in a chronically bad situation, if each time a severe problem occurs, there is a gentle apology or other positive relief afterwards.  The mind preferentially attends to the end of episodes, so if the ending is "positive" it may cause us to view an overall negative experience as much more positive than it warrants.

Similarly, we may undervalue long-term positives, if the ending happens to deteriorate.  A relationship which was thoroughly enjoyed in the moment every day for years might be remembered, and assimilated into retrospective experience, much, much more unfavourably if it ended in a negative way.  

This touches on the human tendency to view and experience life as we would a novel or other narrative:  we highly value the intense moments of the story, and we highly value the ending.  If the story is long and enjoyable, but has a disappointing, weak, or negative ending, then we are likely to devalue the entire story.

What implications does this have for psychiatric therapy?

First, I think it is important to acknowledge this fact about how the mind is "wired."  In a therapeutic environment, it may be especially important to work towards having positive endings to appointments if at all possible, particularly if there has been difficult or painful subject matter dealt with.

A converse point, one which I think Kahneman does not attend to very much in his work, is to consider whether the brain can be trained systematically to over-ride its biases.  Kahneman at times seems resigned to assume that nothing can over-ride these phenomena, as for example he observed that his well-informed psychology student subjects were just as vulnerable to biases as anyone else.  But Kahneman has not, in his current work, looked at ways to intensively train the mind to overcome specific biases.  I suspect that, as with any skill, it would take hundreds of hours of deliberate, focused practice to have any chance to change an ingrained mental habit.

I am therefore curious to explore the possibility of re-evaluating the "weighting" of experience as a sort of cognitive-behavioural exercise.  The mind tends to focus on peaks and endings, but perhaps through disciplined, prolonged mental effort (in a sort of CBT style), we could practice ways of emphasizing in our memory those points of experience between the peaks of pain, and before any endings.  This idea resonates with a sort of "positive psychology" or gratitude-journal approach, but in this case specifically recognizing that our brains may over-attend to strong negatives, therefore we should work at bolstering our attention to other points of experience.








Tuesday, July 17, 2012

Tests for Asperger's & Autism-Spectrum symptoms

Asperger Syndrome is an example of a mild autism-spectrum disorder.  Individuals with this condition have difficulty with social and communicative skills, particularly those skills requiring an understanding and awareness of others' emotional states, and those requiring emotional expressivity in speech and non-verbal gestures.  Usually individuals with an autistic-spectrum condition have a diminished interest in relationships with other people, and therefore prefer solitary activities. 

The possibility of Asperger Syndrome should be considered, in my opinion, when the history is of social difficulties & social withdrawal.  Often times these problems could be the result of social anxiety, depression, etc. but I think we realize these days that mild autistic symptoms are more common in the population.  This may indeed be due to an increase in the rate of autistic symptoms over time, but it could conceivably be due as well to being more aware of this syndrome, and therefore more able to recognize it.

I have found a site with some good tests for autism-spectrum syndromes, from the Cambridge Autism Research Centre.  Here is a link to the tests: http://www.autismresearchcentre.com/arc_tests

The particuar tests I find most useful are the Autism Spectrum Quotient, which is a symptom checklist.  Average scores on this checklist from a healthy population are about 15 for females and 18 for males, slightly higher for individuals in an analytical scientific profession such as mathematics (typically in the low 20's), but above 30 (typically 35 or higher) for individuals with an autistic spectrum disorder.

I have a few criticisms about some of the autism quotient questions, which I think cause the questionnaire to spuriously inflate the scores of people who are not autistic at all, but rather either socially anxious (e.g. the question "I find social situations easy") , socially more introverted but still very attuned to emotions and other people (e.g. the question "I would rather go to a library than a party"), or having particular intellectual interests (e.g. "I am fascinated by dates" or "I am fascinated by numbers").  Thus, shy people, historians, and mathematicians may have scores on the autism spectrum quotient which suggest that they are more "autistic" than they really are.  Here, I would define an autism-spectrum symptom to be much more specifically addressed by other questions having to do with reduced awareness of other people's emotional states, clear reduced interest in social engagement or communication, and impairment in understanding social norms in verbal and non-verbal interaction.  Yet, I think the questionnaire is sensitive, with a large difference in scores between Asperger patients and control patients without Asperger Syndrome.   

Also on this site there is an interesting set of tests having to do with accurately identifying emotions in pictures, sound clips, or film.  One particularly useful example is the "eyes test," in which you have to identify the emotion represented by a picture of someone's eyes.  Here again the mean in a non-Asperger population is about 26-28 correct, but an average of 22 in Asperger's patients.    If you try this test yourself, I suggest that you review the instructions first, and also make sure you are familiar with all the vocabulary words used in the test (these are all available in the downloads).   The test could be biased against individuals who are just a bit less familiar with the vocabulary words used.

It is on my list of things to write about to discuss the issue of autism-spectrum disorders further, since it is a theme that comes up not infrequently, especially in a university population.  Part of the discussion could include discussion about things that might help (such as social skills training, etc.) but also of understanding the issue, in its mild forms at least, as a character variant with a variety of positive aspects for the individual and for society, rather than as an overt "pathology."  In any case, I think understanding and discussion will help.

Thursday, May 10, 2012

"The Lazy Controller" -- reflections about Kahneman's book

This is the first of a series of posts I've been planning based on Daniel Kahneman's book Thinking, Fast and Slow. 

I found this book to be excellent, an account of how the brain is very biased in its mode of forming decisions and judgments, loaded with very abundant solid research over 40-50 years in the social and cognitive psychology literature.

My purpose of reflecting on this book in detail is hopefully to add ideas about understanding the brain's biases in the context of psychiatric symptoms, and then to propose therapeutic exercises which could counter or resolve the biases, and strengthen cognitive faculties which may intrinsically be weak.

----

The first few chapters of this book are introductions to the idea that the brain can be understood as having two main modes of processing and responding to information; the author calls these "system 1" and "system 2."

System 1 is rapid, automatic, reflexive, and often unconscious.  It is the dominant system in most cases.  It is the foundation of "intuition."  It is built upon deeply engrained memory for similar situations.  It is a foundation of all talent and mastery of skills, in that it permits one to perform a difficult task with ease, without even having to "think" about it (e.g. for a master musician, athlete, surgeon, or really any other occupation).  But system 1 is extremely prone to biases.  Its mode of processing data is based on what it has experienced repeatedly in the past -- so it is a kind of autopilot -- and it can be very easily fooled  (yet, on the other hand, its rich set of past associations may be a fertile ground for imagination, creativity, and inspired insight). 

System 2 is a highly conscious, intellectually analytical mode.  It permits us to systematically solve a multi-step difficult problem of any sort.  It permits us to cope with situations which differ from an overlearned template.  It would be like the true pilot landing a plane in difficult or rapidly changing conditions, instead of letting the autopilot trying to land it.

One of Kahneman's main theses is that system 2 can be easily fooled too!  While system 2 is the only cognitive mechanism which could prevent biased interpretation of information, Kahneman shows that system 2 is intrinsically "lazy."  Because engaging system 2 is effortful -- it demands energy -- we are strongly drawn to intellectual processes which minimize the energy expenditure.  If system 1 has an automatic, "intuitive" answer for us, then we would tend not to engage system 2 at all.  And if a rapid engagement of system 2 appears to be sufficient to get an answer, we will usually not spend extra time or energy.  Thus system 2 can easily lead us to a premature and inaccurate conclusion.

Another of Kahneman's main theses has to do with the nature of phenomena, cause-and-effect, and data in general.  Accurate conclusions about cause and effect often require a type of statistical analysis (even a simple one, employing quite straightforward rules of probability), but Kahneman shows that the brain (both system 1 and system 2) are not intrinsically designed to think in a statistical fashion.  Therefore we tend to greatly distort the likelihood of various types of events.

An area I would want to extend beyond Kahneman's main theses is that I suspect both system 1 and system 2 could be very specifically trained to reduce biases.  Kahneman seems somewhat resigned to conclude that the brain simply can't resist the types of biases he describes (citing, for example, profoundly biased thinking in his psychology student subjects--or even in himself-- whose biases were evidently not reduced by understanding and education).  But I do not see that very much work has been done to very specifically and intensively train the mind to reduce biases -- I think that simply learning about bias is not enough, it is something that must be practiced for hundreds of hours, just like any other skill. (this reminds me of something said in psychotherapy:  "insight alone is not enough to effect change -- it must be accompanied by action.")

I believe this is relevant to psychiatry, in that all mental illnesses (such as depression, anxiety disorders, personality disorders, psychosis, and attention/learning disorders) contain symptoms which affect cognition.  In  cognitive therapy theory, it is assumed that depressive cognitions cause and perpetuate the mood disorder.    Many such "cognitive distortions" could be looked at through the lens of "system 1" and "system 2" problems.    For example, in many chronic symptom situations, system 2 may have developed a very deeply ingrained reflexively negative expectation about a great many situations, with many of these reflexes being unconscious.  These reflexes could possibly have been developed based on childhood experience of parents (consistent with a sort of psychoanalytic model), but I think the most prominent source of such reflexes would simply be due to having had a particular symptom frequently for years or decades at a time, regardless of that symptom's original cause.    Under such conditions the brain would change its expectation about the outcome of many events, based on the repeated negative experiences of the past (which could have been due to poor external environmental conditions, but also simply to the past chronicity of symptoms).

A proposed treatment for this phenomenon could very much be along the lines of cognitive therapy.  But I might suggest extending a specific focus on depressive "cognitive distortions" etc. to work on understanding and countering bias in systems 1 and 2 in general.  I propose that intellectual exercises to minimize biased interpretation of perceptions -- even if these exercises have little directly to do with psychiatric symptoms or depressive cognitions, etc. -- could be useful as a therapy for psychiatric disorders.

As outrageous as it seems, educating oneself about statistics, and practicing statistics problems repeatedly -- may be therapeutic for psychiatric illness!  

I'll try to continue this discussion with more specific examples in later posts.

Wednesday, May 9, 2012

Blueberries are good for your brain


Another study published in 2012 about dietary berry intake associated with slower rates of cognitive decline:
http://www.ncbi.nlm.nih.gov/pubmed/22535616

Here's a reference to a 2010 article by Krikorian et al. published in The Journal of Agriculture and Food Chemistry:
http://www.ncbi.nlm.nih.gov/pubmed/20047325

The article describes a randomized, placebo-controlled study in which 9 elderly adults were given about 500 ml/day of blueberry juice, with another 7 given a placebo fruit juice without blueberries. The study lasted 12 weeks, at which time cognitive and mood tests were administered.

The blueberry group clearly showed better memory performance than the placebo group, and the results had a robust level of statistical significance. The blueberry group also showed some improvement in depression symptoms.

Here's a reference to another review article on this:
http://www.ncbi.nlm.nih.gov/pubmed/18211020

The authors allude to other studies showing improved cognitive performance in animals given blueberry supplementation.

In the meantime, it seems quite sound advice to include more blueberries in your diet. An excellent snack food, a much healthier alternative than junk foods such as chips or candies, etc.