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Thursday, June 21, 2007

Antonio Damasio reinvents the wheel

As the adage goes, there is nothing new under the sun, but if you change your labels a bit, and add mysterious (yet irrelevant) ingredients, you can sell tap water in a bottle. Which come to think of it, has already been done.

So it is no great revelation you can a fool lot of the people all of the time, and that I assert includes academic psychologists who should know better, given of course a standard knowledge of their discipline, which generally escapes them.

Consider this example:

In 1935, the psychologist and learning theorist Neal Miller conducted the following experiment.

To human subjects he presented in unpredictable order the symbols T (followed by electric shock) and 4 (not followed by shock). The shock was followed by a large galvanic response (GSR) that was soon conditioned not only by seeing the symbol T, but by anticipating it. From this and subsequent experiments Miller concluded that organisms should "behave 'foresightfully' because fear (i.e. anxiety), would be mediated by cues from a distinctive anticipatory goal response." Miller further concluded that the 'learned drive' of fear or anxiety, as marked by the GSR, obeys the same laws as do overt responses.

In other words, if you suspect that in the future you will engage in something painful, like having a tooth pulled or finding your final grade in a course, you will get a bit anxious about it, which will cause you to attempt to avoid the inevitable, and if successful will reward or reinforce the anxiety. Common sense I'd say.

Now compare this experiment with Antonio Damasio’s IGT (Iowa Gaming Task) experiment performed in the early 90's, where an individual again is confronted with a succession of symbols (in this case, markings on a card), and with unpredictable aversive consequences, in this case large negative card values occurring from time to time. If you ever played poker, that was the essence of the experiment. The experiment measured the SCR, a dependent variable equivalent to the GSR. If it is assumed that unexpected 'bad information' is painful as well, then both experiments assume equivalence. In other words, get a bad card, and you feel a bit anxious about it. Damasio concluded that anxiety or arousal helped you make better choices than merely avoiding a bad one, and to demonstrate it charted out a neural mechanics for the whole thing that would have done Rube Goldberg proud.

How the Neural Self Operates a Napkin: As interpreted by Rube Goldberg

In spite of his confidence, psychologists who have replicated the IGT experiment have found no evidence that anxiety makes you think better, but they have forgotten Neal Miller's experiment, and the work that followed that would have forewarned them of Damasio's hooey of a hypothesis.

So Damasio is wrong, and he ain't original either. But by affixing a simple experiment with a list of irrelevant neural ingredients, he succeeded metaphorically in bottling tap water, which given Damasio's resulting rise in stature, has proven to be a very profitable thing indeed.

A few side notes on the Miller and Damasio experiments:

The difference between both experiments is not in their structure, which are more or less equivalent, but rather in the interpretation of the role of the galvanic skin response as a dependent measure. Specifically, the GSR for the Miller experiment correlated with a subjective response that was interpreted as anxiety or fear. For Damasio, the subjective response to arousal as marked by the SCR was subtler, or a mildly or non aversive ‘gut feeling’. In other words, if one assumes that the level of arousal was higher for Miller’s subjects than Damasio’s, the level of arousal could lead to distinctly different interpretations as to the role of arousal. Thus, it is easy to see how Miller assumed that tension based arousal (or anxiety) mediated avoidance, and why Damasio assumed that arousal mediated choice. In other words, if turning a bad card in the IGT experiment signified not a loss of play money but a loss of real money or a painful shock, then avoidance and not choice would have been a more likely interpretation.

So we are left with the original question: what is the role of autonomic arousal? If arousal is dependent upon learning, as both Miller and Damasio hold, what is its function: avoidance, choice, or some mixture of the two that is dependent upon the level of arousal?

One way to ascertain the role of avoidance is to simply examine whether elevated autonomic arousal occurs under response contingencies that either eliminate the ability to avoid or obviate the need to avoid. If results under a response contingency are all bad and unavoidable, then we have Seligman’s learned helplessness, and if all results are good and thus create no need to avoid, then we have Csikszentmihalyi’s ‘flow’ response. Both are marked by low autonomic arousal as marked by a reduction in SCR and a corresponding lack of reported tension, anxiety, or fear. Thus it may be construed that avoidance is an essential function of autonomic arousal. This of course does not directly challenge Damasio’s position, but raises the avoidance hypothesis front and center as an alternative explanation for his findings.

For more on the somatic marker, see my new ebook:


Miller, N. E. (1971) Selected Papers, Atherton, Chicago

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