Catecholamine-Mediated Increases in Gain Enhance the Precision of Cortical Representations.

Norepinephrine and dopamine are among the most widely distributed and ubiquitous neuromodulators in the mammalian brain and have a profound and pervasive impact on cognition. Baseline catecholamine levels tend to increase with increasing task engagement in tasks involving perceptual decisions, yet there is currently no direct evidence of the specific impact of these increases in catecholamine levels on perceptual encoding. Our results fill this void by showing that catecholamines enhance the precision of encoding cortical object representations, and by suggesting that this effect is mediated by increases in neural gain, thus offering a mechanistic account of our key finding.