Annotated Readings for Systems Neuroscience Seminar

This page points you toward secondary sources that I've found useful


Bouret and Sara (PMID: 16165227) propose a fairly simple metaphor for the action of Norepinephrine: 'Network Reset'. They present a fair bit of interesting data. They claim their metaphor explains most of the data presented. I think the metaphor is vague enough to be able to explain many imaginable data sets. The recent paper by the same authors (PMID: 15255989) presents quite a bit more interesting data, some of which seems harder to explain.

Aston-Jones and Cohen (PMID: 16022602) propose a more cognitive metaphor in terms of eliminating distractors, which is presumably a good thing. I'm impressed by their detailed neuroanatomy, with primate data differing from rodent, but I feel that they don't present enough data to really test the value of the fairly flexible model that they propose.

Spring Term 2009

In my opinion neuroscience has very interesting data but interpretation is confused by the dead hand of behaviorist and information processing metaphysics. Emotion has long been relegated to subsidiary status in neuroscience, presumed less interesting than 'cognitive' functions, and less accessible to investigation. Recently emotion has become fashionable again, and many of the metaphysical presumptions, which have informed (or mis-informed) interpretation of neuroscientific data, are again in flux. In particular the wall between cognition and emotion is again recognized as uncertain; this tension is represented in the literature on 'decision', which partakes of both emotion and knowledge. The readings this term are constructed around documenting the role of specific brain regions in 'decision' processes.

Murray (PMID: 17988930) tries to rescue the amygdala from the confusions engendered by: (i) the behaviorist metaphysics of 'reward' and 'punishment', and (ii) the natural (reductionist) hope of experimenters that the amygdala functions as a single unit. Assumptions (i) and (ii) have led to the widespread idea that the amygdala is the way station for negative reinforcement or 'punishment'.

Murray is most successful at undermining the persistent view of the amygdala. She cites evidence from monkey and rat studies, and human imaging studies, that the amygdala is active during anticipation of welcome experiences as well as of unpleasant. However she doesn't distinguish carefully (nor is the experimental data sufficient to distinguish) between pleasure and motivation toward 'positive' experiences.

Murray then tries to use amygdala data to take on the behaviorist interpretation of emotion as mediating reinforcement. I think this is not particularly meaningful to people who aren't invested in that kind of research. Murray gives a richer description of her own approach to emotion, based on behavioral syndromes. I find her description of PIT (p494 2nd column) unconvincing; it seems to use abstract language about aspects of emotion, for which we don't have enough detail to pretend to abstract the important themes. The final section seems rather poorly integrated; it mixes detailed descriptions of very specific brain regions with abstract speculations. The most prominent theme is the use of amygdala in anticipation and linking amygdala activity to subsequent OFC activity; this OFC activity is presumed to be more directly related to decision-making. Figure 3 is the best summary of this section.