Evaluation of cognition with eyelink: Visual search and saccadic eye movements in healthy controls

The aim of the study is to evaluate the relation eye movements and cognitive functions of healthy subjects and to provide normative data. The study is included 76 healthy subjects between the age of 18-27, 28-37, 38-47, 58-67 and 68-77+. The neuropsychological test batery and eye movements applied to evaluate cognition of each participant. Pupil diameter, eye blinks, microsaccade, macrosaccade, squarewave, latency, antisaccade error rate, express antisaccade rate and anticipatory antisaccade rate were measured by applying fixation, prosaccade and antisaccade paradigms differences in age groups. Number of saccade, saccade sequence, fixation duration, number of fixation, reaction time are measured by applying visual search paradigms to analyze differences based on age groups. The findings of this study, there were significant differences between the age groups and eye movements. It was showed that antisaccade correct response (p = 0.00), antisaccade amplitude (p = 0.04), prosaccade amplitude (p = 0.09), pupil diameter (p = 0.01) are significantly decreases with increasing age. It was observed that antisaccade corrected saccade (p = 0.00), anticipatory saccade (p = 0.02), saccade latency (p = 0.00), total saccade (p = 0.01), uncorrect response (p = 0.008), prosaccade latency (p = 0.00), microsaccade fixation frequency (p = 0.01) significantly increases with increasing age. Significant differences were detected between the executive functions, attention, language, memory, visuospatial memory and eye movements in age groups. On the other hand, first fixation duration, fixation duration, fixation count and saccade count were not statistically significant in the analysis of visual search based on age groups As a result of the study, it has been observed that cognitive functions are related with the eye movements. The impact of age factor in the eye movement has been found. Some of the measurements in visual search and eye movements were not significant showed the neccesisty of conducting studies with larger samples. Keywords: age, cognitive functions, eye movements, saccade, visual search Page number of the thesis: 109 Advisor: Prof. Dr. Gülden AKDAL HALMÁGYI