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Spatial Attention and Temporal Expectation Under Timed Uncertainty Predictably Modulate Neuronal Responses in Monkey
Jitendra Sharma1, Hiroki Sugihara2, Yarden Katz3
1Picower Institute for Learning and Memory, MIT, Cambridge, MA 01239, USA Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA.
Cerebral Cortex (New York, N.Y. : 1991)
|May 20, 2014
Summary
Primary visual cortex (V1) neurons show time-dependent changes in response to attention and expectation. These neural signals correlate with improved behavioral performance and faster reaction times in monkeys during tasks with unpredictable timing.
Area of Science:
- Neuroscience
- Cognitive Neuroscience
- Visual Neuroscience
Background:
- Attention and expectation are crucial for optimizing behavioral responses to unpredictable events.
- While higher brain areas are known to mediate attention and expectation, their impact on primary visual cortex (V1) is unclear.
Purpose of the Study:
- To investigate whether single-neuron responses in the primary visual cortex (V1) of monkeys are modulated by attentional demands and temporal expectations in tasks with unpredictable event timing.
Main Methods:
- Monkeys performed a covert attention task where a visual target disappeared at unpredictable times.
- Single-neuron activity in V1 was recorded during the task.
- Behavioral responses (reaction time, accuracy) were measured.
- Neural activity was analyzed in relation to task engagement and temporal expectation.
Main Results:
- Monkeys exhibited faster reaction times and improved performance as trial duration increased.
- V1 neural responses showed a bimodal pattern: early facilitation followed by a sustained late increase correlating with expectation.
- This late attentional modulation was negatively correlated with reaction time.
- These time-dependent neural changes were absent in a control task lacking explicit attentional engagement.
Conclusions:
- Primary visual cortex (V1) neurons encode signals related to attention and temporal expectation.
- These neural signals dynamically track task engagement and predict behavioral performance.
- V1 plays a more active role in processing temporal expectations than previously thought.
