10 June 2010

[Citing Unsworth et al. 2004] individuals who recalled more items on the working memory task, in this case operation span, were less likely to have their attention captured by the anti-saccade task. This finding makes no sense from a view that working memory capacity is limited by either the number of items or by processing speed, but it makes perfect sense if that limitation reflects differences in the ability to control the contents of working memory.

One problem with this view is that executive attention is the most difficult aspect of attention to model in any substantial way because it seems homuncular in nature. However, cognitive control can be conceptualized in computational terms (O'Reilly et al. 1999) and it is becoming clear that this ability is mediated by brain circuits associated with the prefrontal cortex and the anterior cingulate, that dopamine is the principle neurotransmitter associated with cognitive control and that these abilities have strong genetic underpinnings, particularly the catechol-O-methyltransferase (COMT) gene, which is critical to the regulation of dopamine in the brain. We seem well on the way to mechanizing the homunculus.

Randall W. Engle, "What is the role of attention in working memory?" Science of Memory: Concepts. Oxford, 2007.

antipsychotic medications dampen dopamine activity in the brain (sometimes leading to effects in other parts of the body. Dopamine is for example part of coordinating large muscle movement). The one thing left would be to figure out which receptor types (D1-D5) are involved.

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