The Effect Of Behavior Tasks With Different Difficulty Levels On Microsaccades Frequency And Amplitude In Macaques

There is about80%to90%of the information from outside worldobtained by the human visual system. In our daily life, our eyemovements play a vital role in the processing of visual information. It canhelp us to integrate visual perception of the surrounding environment intoa coherent visual picture. While our eyes fixating, they involves in threetypes of eye movement: microsaccade, drift, and tremor. Microsaccadesare the largest and fastest eye movements. It can promise continuousvisual stimulation to the retinal photoreceptors and all visual system bychanging the position of an object projected into the retina. Somicrosaccades can help primates, including humans, eliminate the effectof visual fading which caused by the adaptability of visual nervoussystem, and ensure that the image will not disappear when we fixate on astatic object.Recent studies have shown that microsaccades are closely relatedwith visual perception functions, such as visual attention. So the nervous system generating microsaccades may be potentially associated withmany eye and visual system diseases. We studied the relationshipbetween microsaccades and visual perception behavior, such as fixationtasks and attention tasks, to explain some of the findings in the field ofvisual perception. The understanding of the neural correlates ofmicrosaccades generation is beneficial for further exploration of the brainmechanisms of visual information processing. Specifically, we studiedtwo monkeys’ microsaccades parameters including amplitude, velocityand frequency in different visual tasks and different difficulty levels infixation tasks.We developed the behavior experimental platform to do the visualfixation tasks and attention tasks. The platform consists of Cortex system,Eye Coil system, Bar system, Reward system and Plexon multi-channelrecording system. We analyzed eye movement signals from two monkeysto get the relationship of amplitude, velocity and frequency ofmicrosaccades under different visual tasks and different difficulty levelsin fixation tasks.