Visual asymmetries and the effect of gaze direction on memory

Abstract

The goal of the present work was to investigate both horizontal and vertical asymmetries. In the first chapter we used different types of visual search tasks in which geometrical shapes and face stimuli were displayed on peripheral vision. Our findings show that both laterality and elevation affect reaction times when searching for a singleton. For geometrical shapes, presenting singletons in the right and lower hemifields, which favor high-resolution processing, results in better performance. However, for face stimuli, participants responded more quickly when targets were presented in the upper left quadrant, which suggests that the left hemifield advantage for holistic processing and the upper hemifield advantage for object recognition interact. In the second chapter, we used gaze direction as a tool to investigate hemispheric asymmetries on visuospatial short-term memory. Better memory performance was found in the upper left quadrant compared to the three other quadrants.