Archive for August, 2011

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Basic Emotions

Facial emotions.

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This post is an attempt to get to the basic emotions. Regular readers of this blog will readily appreciate when I claim that there are eight basic emotions and that they follow a developmental/evolutionary time-course and follow a  particular order.

 

First let us review the attempts made till now to classify and identify the basic emotions- foremost amongst them is the tradition of Tomkins and Ekman that looked at basic and universal emotional facial expressions to come up with their list of basic emotions.

 

Tomkins listed the following as basic emotions: Anger, interest, contempt, disgust, distress, fear, joy, shame, surprise;

I agree more or less with the list except for dropping shame or subsuming it under contempt (along with say guilt too making a triad of social emotions)

Ekman on the other hand thought that only Anger, Disgust, Fear, Happiness, Sadness and Surprise were basic based on clearly identifiable facial expressions. He left out contempt and Interest , but I am not too sympathetic to that position, though I understand that being evolutionarily novel these would be least permanently identifiable using fixed facial expressions.

Another towering figure in the emotion research is Plutchick and his wheel is a wonderful figure that not only lists the basic emotions but also highlights the relations between them- which are opposed (180 degree to each other).

The 8 basic emotions Plutchik lists are Trust(Acceptance), anger, anticipation (interest) , disgust, joy, fear, sadness, surprise .

Astute readers will note that the list is more or less same as that of Tomkins except for substitution of Trust )(acceptance) for contempt (reverse scored but same?)

Izards list viz Anger, contempt, disgust, distress, fear, guilt, interest, joy, shame, surprise is also the same as above list if we group contempt/shame/guilt together as one social emotion category.

That finally brings me to my list and ordering and how the emotions are opposed to each other on some aspect or the other, here I would like to utilize some terminology from astrology where not only opposed (180 degrees) are bad or disharmonious but even squares (90 degrees ) are somewhat disharmonious.

with that lets take a look at Plutchiks wheel and order emotions as follows:
1. Fear
2. Joy/happiness
3. Anger
4. Sadness
5. Disgust
6. Surprise
7. Contempt
8. Interest (anticipation)

One would note that on Plutchik’s wheel Fear is opposed to Anger; Happiness to Sadness; Disgust to Trust (contempt in our scheme) and Surprise to Interest.

what I will argue is that while on one intuitive level Sadness is opposed to happiness and fear to anger on a deeper level the square relation between fear and happiness is more important and similarly between anger and sadness is more important; rather I would go ahead and claim that if I had to fit them on a wheel I would have fitted them as opposites instead of squares.

why the above claim; read this post for some background, but basically my claim is that these opposed pairs follow the opposed polarities of four tasks of existence, adaptation, replication and abstraction as outlined by Theodore Millon and also the eight basic adaptive problems faced by all animals. .

To elaborate, on their opposed natures, consider the first problem of arrival of a stimuli /something/some person; now this (con-specific/ other species animal) could be either predator or prey and thus arouse either feelings of Fear or Happiness depending on whether the arrival is viewed disfavorably or favroably- as foe or as food.

Consider second, the loss (departure) of a stimuli/ something/ some person. This can either arouse feelings of anger to restore the earlier status-qua or lead to feelings of sadness if nothing can be done and this is inevitable/ unavoidable.

Now consider a novel stimuli/person/thing introduced in the environment. This can either lead to disgust reaction if intuitively it is appraised that the stimuli in question is not good for self; or the stimuli/person/thing may arouse feelings of surprise if a positive outcome is anticipated nonetheless the stimuli being novel/ unexpected. when a new person mates another that person can be seen as a constant source of surprises.

Lastly consider a familiar or expected stimuli being present in the environment; this can either lead to contempt reaction as we all know that familiarity breeds contempt; or we could still remain engaged with that and still pay attention and be interested in that familiar stimuli/person/ thing.

This also squarely fits with my earlier basic emotions post based on work by Jaak Panksepp. There the basic emotions (in the particular order that I imposed) were fear, seeking (or happiness) , anger, panic(distress) , lust (mapped to disgust they even rhyme:-) , care (mapped to Surprise) and play (mapped to contempt in new model) and lastly SELF mapped to Interest/anticipation.

Of course one can also readily see that happiness and sadness are opposed; but that misses the finer opposition and continuum on a single dimension of fear-happiness (anxiety-calmness scale) ; anger-sadness (mania-depression scale); disgust-surprise and contempt-interest (psychosis-autism scale).

To me the basic emotions and there ordering seems just perfect- and these are same set of emotions that I have also mapped to personality as enduring traits.something seems to be falling in place and I am most reasonably elated.

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Dopamine: prediction-error vs. incentive salience

ResearchBlogging.org

Delay and Trace conditioning. CS = conditioned...

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The exact role that dopamine plays in learning remains controversial; some think it acts as a prediction error signal, while Berrdige et al believe that dopamine codes for incentive salience.

 

A recent paper throws some light on the issue. It uses a  simple Pavlovian conditioning paradigm. To recap, US and CS are paired and after some time CS starts predicting the reward ; however the twist to usual Pavlovian conditioning is that when CS is presented before US; some rats become ‘sign trackers’ i.e. as soon as the CS comes start engaging with it; while other are ‘goal trackers’ i.e. as soon as CS comes start engaging with where the US would ultimately appear.

To elaborate,  both types of rats are able to learn that CS predicts US , but only sign tracker s attach importance to CS in itself. Also if they are given an option to indulge in instrumental behavior to bring forth the CS (in absence of US) , it seems only the sign trackers are more willing to do work to get the CS and are thus motivated enough by Cs in itself. In other words, while both goal trackers and sign trackers endow CS with predictive capabilities; only sign trackers also endow it with incentive salience.

 

If all this seems confusing , consider the fact that we are all conditioned to like food/sex; but a secondary reinforcer like money which may predict that food will follow, might become a reward in itself and motivate some of us. while for some money may be as good as it is an indicator of food/sex to come; for other money may acquire an importance/ motivational value in itself.

 

After that crude analogy, lets return to our sign trackers; these rats are found in wild populations also, but a selectively bred rat breed that has been bred for Novelty preference (bHR)  also displays these behaviors  prominently. On the other hand those selectively bred not to show novelty preference are goal trackers by large. (bLR)

What the authors of this study showed was a dissociation between the necessity of dopamine for learning and performance in Pavlovian conditioning. they showed that while dopamine is not required for learning the prediction part (i.e. even in absence of dopamine both goal trackers and sign trackers could learn that CS predicts US) , it is indeed required for performance (i.e. in absence of dopamine neither goal trackers or sign trackers would perform the task whereby their learning of CS/US association resulted in overt behavior. ) . Further , it was found that for sign tracker dopamine was required for the sign tracking behavior.

To me, and to the authors too,  the results seem to indicate that some individuals are more prone to associate incentive salience to CS and their primary mode of learning is via incentive salience mechanism of dopamine; these are also the one more susceptible to maladaptive behavior. However the learning that results in association of CS with US does not need dopamine; the association can happen without dopamine; but no behavior results if either CS/ US is not able to trigger dopamine release or able to tell the brain that this incentive/stimuli is salient.

To me this bodes victory for the Berridge et al camp of incentive salience theory of dopamine function, to whom I have always been more sympathetic ! do you agree?

Flagel, S., Clark, J., Robinson, T., Mayo, L., Czuj, A., Willuhn, I., Akers, C., Clinton, S., Phillips, P., & Akil, H. (2010). A selective role for dopamine in stimulus–reward learning Nature, 469 (7328), 53-57 DOI: 10.1038/nature09588

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Schizophrenia: 4 a’s and ABCD

The term Schizophrenia , as many of the readers will recall, was coined by Eugen Bleuler, a Swiss psychiatrist , who  intended the ‘split personality’ to reflect the fact that there was an underlying dissociation between various functions like memory, cognition, emotion that are normally integrated in normal people.

He also gave the famous 4 a’s that he presumed lied at the core of the schizophrenia and were fundamental aspects of the disorder.

To recall:

‘affect’: Inappropriate or flattened affect-emotions in-congruent to circumstances/situation.

autism’: social withdrawal- preferring to live in a fantasy world rather than interact with social world appropriately.

‘ambivalence’ : holding of conflicting attitudes and emotions towards others and self; lack of motivation and depersonalization.

‘associations’ : loosening of thought associations leading to word salad/ flight of ideas/ thought disorder.

Bleuler maintained that these distinctive and fundamental  features identified and formed the core of Schizophrenia while the manifest symptoms like hallucinations and delusions (first rank symptoms as per Schneider) were peripheral and not that important).

The readers of this blog will also be familiar with the ABCD model of psychology where Affect, Behavior (social aspects), Cognition and Desire (motivation/ dynamics)  are the four fundamental domains; it is easy to see how the four a’s of Bleuler map to the 4 domains of psychology and it seems that schizophrenics have major troubles in each domain:

affect: this directly maps to Affect dimension and inappropriate affect is a major core part of the syndrome.

autism: though named somewhat incorrectly the intent of autism was to catch the behavioral and social impediments of the schizophrenics.

ambivalence: here there are conflicts and ambiguities regarding what one desires; for self and for others; lack of motivation/conflicted motivation  is significant at this dimension.

associations: here the cognitive underpinnings are all too evident- the thought disorganization and flight of ideas is all too cognitive in nature.

It is amazing how the insights of Bleuler from a century before lend themselves so easily to fit the ABCD framework. What do you think, a bit stretched? or have I started making loose associations myself :-) ?

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