Abstract
Attention is known to affect the response properties of sensory neurons in visual cortex. These effects have been traditionally classified into two categories: 1) changes in the gain (overall amplitude) of the response; and 2) changes in the tuning (selectivity) of the response. We performed an extensive series of behavioral measurements using psychophysical reverse correlation to understand whether/how these neuronal changes are reflected at the level of our perceptual experience. This question has been addressed before, but by different laboratories using different attentional manipulations and stimuli/tasks that are not directly comparable, making it difficult to extract a comprehensive and coherent picture from existing literature. Our results demonstrate that the effect of attention on response gain (not necessarily associated with tuning change) is relatively aspecific: it occurred across all the conditions we tested, including attention directed to a feature orthogonal to the primary feature for the assigned task. Sensory tuning, however, was affected primarily by feature-based attention and only to a limited extent by spatially directed attention, in line with existing evidence from the electrophysiological and behavioral literature.