08 September 2008

Synchronized

Robert Desimone - Neural Synchrony and Selective Attention (54 min, iTunes U)

In this lecture Desimone describes his work on the relation between neural synchrony and attention (awareness). Like animals, neurons have to produce limited but useful (axonal-) output from an enormous quantity of (dendritic-) input. Neurons respond most strongly when this input is synchronized, thanks to cumulative excitation I guess.

Desimone has been recording from all over monkey cortex during attention tasks and finds synchronized activity in neurons that process visual information that animals have been trained (juice reward..) to attend to. Importantly, he notes that this synchrony begins DOWNSTREAM, in frontal cortex, and propagates BACKWARDS to early visual cortex, where cells have smaller receptive fields (and do not receive dopamine from that juice reward..). Very interesting. Desimone focuses primarily on synchrony in the gamma oscillations of the outer cortical layers, I'm not sure what kind of activity those oscillations refer to, probably local field potentials but what's the spatial resolution?

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