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Alteration of the microsaccadic velocity-amplitude main sequence relationship after visual transients: implications for models of saccade control
- Source :
- Journal of Neurophysiology. 117:1894-1910
- Publication Year :
- 2017
- Publisher :
- American Physiological Society, 2017.
-
Abstract
- Microsaccades occur during gaze fixation to correct for miniscule foveal motor errors. The mechanisms governing such fine oculomotor control are still not fully understood. In this study, we explored microsaccade control by analyzing the impacts of transient visual stimuli on these movements’ kinematics. We found that such kinematics can be altered in systematic ways depending on the timing and spatial geometry of visual transients relative to the movement goals. In two male rhesus macaques, we presented peripheral or foveal visual transients during an otherwise stable period of fixation. Such transients resulted in well-known reductions in microsaccade frequency, and our goal was to investigate whether microsaccade kinematics would additionally be altered. We found that both microsaccade timing and amplitude were modulated by the visual transients, and in predictable manners by these transients’ timing and geometry. Interestingly, modulations in the peak velocity of the same movements were not proportional to the observed amplitude modulations, suggesting a violation of the well-known “main sequence” relationship between microsaccade amplitude and peak velocity. We hypothesize that visual stimulation during movement preparation affects not only the saccadic “Go” system driving eye movements but also a “Pause” system inhibiting them. If the Pause system happens to be already turned off despite the new visual input, movement kinematics can be altered by the readout of additional visually evoked spikes in the Go system coding for the flash location. Our results demonstrate precise control over individual microscopic saccades and provide testable hypotheses for mechanisms of saccade control in general. NEW & NOTEWORTHY Microsaccadic eye movements play an important role in several aspects of visual perception and cognition. However, the mechanisms for microsaccade control are still not fully understood. We found that microsaccade kinematics can be altered in a systematic manner by visual transients, revealing a previously unappreciated and exquisite level of control by the oculomotor system of even the smallest saccades. Our results suggest precise temporal interaction between visual, motor, and inhibitory signals in microsaccade control.
- Subjects :
- Male
0301 basic medicine
Visual perception
genetic structures
Physiology
Models, Neurological
Fixation, Ocular
03 medical and health sciences
Optics
0302 clinical medicine
Saccades
Animals
Control (linguistics)
Sequence (medicine)
Physics
Communication
business.industry
General Neuroscience
Superior colliculus
Eye movement
Cognition
Macaca mulatta
Sensory Systems
eye diseases
Biomechanical Phenomena
Ophthalmology
030104 developmental biology
Velocity amplitude
Saccade
Visual Perception
Evoked Potentials, Visual
Microsaccade
business
Psychology
Algorithm
Neuroscience
030217 neurology & neurosurgery
Research Article
Subjects
Details
- ISSN :
- 15221598 and 00223077
- Volume :
- 117
- Database :
- OpenAIRE
- Journal :
- Journal of Neurophysiology
- Accession number :
- edsair.doi.dedup.....8effaa63db03324a0d13aec602600144