Memory-guided Visual Localization

Visual localization is an indispensable part of our daily life. A number of studies have been carried out on this topic and related theories are developed. One of the most famous theories is Visual Perception-Action double-system theory. Will this theory be still compatible when we make a visual sensory memory-guided localization? We recorded eye movements and hand movements to examine the accuracy of visual localization under different delayed-response time (200ms, 600ms, 1000ms) and stimuli-render position (2°, 5°, 9°) towards to chromic/none-chromic stimuli. Sixteen colleague students participated in the experiment. In each trial, there is a cross in the center of screen for participant to fixate. After 1000ms, a white/red/green dot flashed 150ms around the center cross. Participants fixated on the cross for a period after the dot disappeared till a mouse arrow replaced the cross. Participants were asked to use the mouse to locate the place where the dot appeared earlier within 3000ms. The depend variables are displacement error, first saccade latency, manual RT, and eye-hand RT. Results indicated that: (1) dot's position (not color) effect the localization displacement error, so the Perception-Action double-system theory is still compatible under memory-guided localization; (2) delayed-response time and stimuli-render position effect not only displacement error but also first saccade latency and manual RT differently; (3) the eye and hand coordinate in localization, eye starts to move before the hand does systematically.