Our research is aimed at understanding how neuronal signals in visual cerebral cortex generate perceptions and guide behavior. Our approach is to record from individual neurons in trained, behaving monkeys and mice while they perform visual tasks.
Much of our work is directed at understanding how paying attention to specific visual targets affects the way that they are represented in the brain, and how changes in the sensory representation caused by attention relate to changes in perception and behavior. We have shown that attention increases the strength of neuronal responses without changing their selectivity, effectively representing the attended stimulus as if it were more intense than it really is. Paired measurements of neuronal responses and behavioral performance have shown that much of the behavioral advantage conferred by attention may be explained by this change it causes in the sensory representation, rather than decision processes.
Another line of research has been exploring the more general question of how the activity of given neurons contributes to specific visual behaviors. Measurements of the trial-to-trial correlation between the strength of a neuron's responses to a weak stimulus and the animal's performance detecting that stimulus have shown that different neurons contribute to a greater or lesser degree to particular behaviors depending on which stimuli they are most sensitive to.
We also use electrical and optical microstimulation to explore how different regions in visual cortex contribute to visual perceptions. By measuring the stimulus strength needed to produce a just-detectable stimulus in different cortical areas, we have found that all regions of cerebral cortex are comparable in their ability to produce detectable percepts.
BS - Zoology
California Institute of Technology
PhD - Biology
Massachusetts Institute of Technology
Postdoc - Psychology
Rodent attention: Probing the mouse mind with reverse correlation.
Rodent attention: Probing the mouse mind with reverse correlation. Curr Biol. 2023 09 11; 33(17):R916-R918.
Temporal weighting of cortical and subcortical spikes reveals stimulus dependent differences in their contributions to behavior.
Temporal weighting of cortical and subcortical spikes reveals stimulus dependent differences in their contributions to behavior. bioRxiv. 2023 Aug 24.
Increments in visual motion coherence are more readily detected than decrements.
Increments in visual motion coherence are more readily detected than decrements. J Vis. 2023 05 02; 23(5):18.
Normalization in mouse primary visual cortex.
Normalization in mouse primary visual cortex. bioRxiv. 2023 Apr 18.
Neuronal correlates of selective attention and effort in visual area V4 are invariant of motivational context.
Neuronal correlates of selective attention and effort in visual area V4 are invariant of motivational context. Sci Adv. 2022 06 10; 8(23):eabc8812.
Perceptual Weighting of V1 Spikes Revealed by Optogenetic White Noise Stimulation.
Perceptual Weighting of V1 Spikes Revealed by Optogenetic White Noise Stimulation. J Neurosci. 2022 04 13; 42(15):3122-3132.
Single trial neuronal activity dynamics of attentional intensity in monkey visual area V4.
Single trial neuronal activity dynamics of attentional intensity in monkey visual area V4. Nat Commun. 2021 03 31; 12(1):2003.
An Open Resource for Non-human Primate Optogenetics.
An Open Resource for Non-human Primate Optogenetics. Neuron. 2020 12 23; 108(6):1075-1090.e6.
The Mind of a Mouse.
The Mind of a Mouse. Cell. 2020 09 17; 182(6):1372-1376.
Mice Preferentially Use Increases in Cerebral Cortex Spiking to Detect Changes in Visual Stimuli.
Mice Preferentially Use Increases in Cerebral Cortex Spiking to Detect Changes in Visual Stimuli. J Neurosci. 2020 10 07; 40(41):7902-7920.
Dana Alliance for Brain Initiatives
American Academdy of Arts and Science
Astor Visiting Lecturer
American Academy for the Advancement of Science
1991 - 1993
Young Investigator Award
Office of Naval Research
1986 - 1989
Outstanding PhD Thesis Award
Intra-Science Research Foundation