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Activity of primate V1 cortical neurons during blinks
1Department of Physiological Optics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA. tgawne@icare.OPT.UAB.EDU
Journal of Neurophysiology
|November 9, 2000
Summary
Even during a blink, our visual perception remains continuous because neuronal activity in the visual cortex (V1) is actively suppressed. This suppression, unlike external darkening, prevents noticeable image interruptions.
Area of Science:
- Neuroscience
- Visual Perception
- Sensory Processing
Background:
- Human perception of continuous visual input contrasts with the physical reality of brief retinal darkness during blinks.
- The neural basis for ignoring blinks, despite their visual interruption, remains incompletely understood.
Purpose of the Study:
- To investigate the activity of V1 neurons during natural blinks compared to other visual interruptions.
- To determine if neuronal activity suppression explains the lack of perceived disruption during blinks.
Main Methods:
- Recorded activity from 63 supragranular V1 neurons in two awake monkeys.
- Compared neuronal responses under four conditions: constant stimulus, reflex blink, stimulus gap, and external darkening.
Main Results:
- V1 neuronal activity was significantly suppressed during reflex blinks (8.2 spikes/s) compared to constant stimuli (27.2 spikes/s).
- Neuronal responses during blinks were lower than during external darkening (12.7 spikes/s), which often elicited transient bursts.
- The absence of a transient burst during blinks, unlike external darkening, correlated with ignored visual interruptions.
Conclusions:
- Neuronal activity in V1 is actively shut off during blinks, contributing to seamless visual perception.
- The suppression of transient neuronal responses during blinks, rather than the mere absence of input, is key to ignoring them.