Thursday, December 08, 2011

Good Or Bad: Surprises Drive Learning In Same Neural Circuits

Primates learn from feedback that surprises them, and in a recent investigation of how that happens, neurosurgeons have learned something new...Some scientists have posited that separate anatomical structures, or at least distinct circuits, process positive or negative feedback to direct future behavior, but there has been little proof, at least at the level of individual neurons. Asaad said he expected to find some of those hypothesized processing differences between the lateral prefrontal cortex and the subcortical caudate nucleus, which govern high-level planning, by probing hundreds of individual neurons in each structure in two macaque monkeys while they worked on trial-and-error learning tasks. Monkeys received juice for guessing right or none for being wrong. Instead, he and Eskandar found the neurons in both structures acted very similarly for both positive and for negative feedback. "We were looking for differences and we just didn't detect any in the signals we were looking for," said Asaad, who is affiliated with the Brown Institute for Brain Science. more

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