Rhythmic fluctuations of saccadic reaction time arising from visual competition
Samson Chota1,2, Canhuang Luo3,4, Sébastien M Crouzet3,4
1Université de Toulouse, UPS, Centre de Recherche Cerveau et Cognition, 31052, Toulouse, France. samson.chota@googlemail.com.
Scientific Reports
|October 28, 2018
Summary
Attentional stimulus selection is a rhythmic process. Human saccadic response times fluctuate rhythmically in the theta range, mirroring competitive neural interactions observed in monkeys.
Area of Science:
- Neuroscience
- Cognitive Science
- Visual Attention
Background:
- Attentional stimulus selection is increasingly understood as a rhythmic neural process.
- Previous studies in monkeys demonstrated rhythmic neural activity in V4 and IT neurons within the theta range.
- These rhythmic responses show anti-phase patterns for competing stimuli, suggesting neural competition.
Purpose of the Study:
- To investigate whether rhythmic attentional processes observed in monkeys are also present in humans.
- To examine the relationship between neural oscillations and behavioral responses in a human visual attention task.
Main Methods:
- A human behavioral task replicating a monkey study involving competing visual stimuli.
- Participants (7 individuals) performed 4000 trials each.
- Analysis focused on saccadic response times and their temporal fluctuations.
Main Results:
- Human saccadic response times exhibited significant fluctuations in the theta frequency range (approximately 6 Hz).
- These theta-range fluctuations occurred in an anti-phase pattern for targets presented on distinct competing stimuli.
- The findings align with previous observations in monkey V4 neurons.
Conclusions:
- Human visual attention and stimulus selection involve rhythmic processes operating in the theta frequency band.
- These rhythmic fluctuations in behavior reflect underlying competitive neural interactions.
- The study provides cross-species evidence for theta-range oscillations modulating attentional selection and response timing.
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