Linking attentional changes in neuronal responses to perception


April 16, 2019 - 12:00pm
BioLabs Building, Room 1080
About the Speaker
Marlene Cohen
Speaker Title: 
University of Pittsburgh
Speaker Affiliation: 
Associate Professor

Visual attention dramatically improves subjects' ability to see and also modulates the responses of visual and oculomotor neurons. Despite hundreds of studies demonstrating the co-occurrence of behavioral and neuronal effects of attention, the relationship between neuronal modulations and improved performance remains unknown. Three dominant hypotheses have guided previous work: that attention 1) improves visual information coding, 2) improves communication between visual and oculomotor brain areas, or 3) reduces uncontrolled fluctuations in the animals' cognitive state, thereby improving performance and rendering observed effects of attention on response variability as epiphenomena. By recording from groups of neurons at multiple stages of visuomotor processing, we showed that none of these hypotheses account for observed perceptual improvements. Instead, our data suggest a novel hypothesis: that the well known effects of attention on firing rates and shared response variability in visual cortex reshape the representation of attended stimuli such that they more effectively drive downstream neurons and guide decisions without explicitly changing the weights relating sensory responses to downstream neurons or behavior. In general, constraining our analyses by the animals' behavior and the simultaneous recordings from multiple brain areas allowed us to reject each prior hypothesis and greatly clarified the relationship between attention, neuronal responses and behavior.