Blue-light Effects on Saccadic Eye Movements and Attentional Disengagement

• Main Authors: Hsing-Hao Lee, 李興皓
• Other Authors: Su-Ling Yeh
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/5j7p3e

碩士 === 國立臺灣大學 === 心理學研究所 === 107 === People nowadays usually read or browse on 3C products (such as computer screen or cell phone) via saccades, hence exposing to high intensity of blue light very often. Recently, several products that claimed to filter blue light spring up, and yet whether filtering blue light is beneficial or detrimental to saccadic efficiency is unknown. It has been shown that exposure to blue light affects our circadian rhythm, alertness, executive functions, and dynamic visual acuity. Recent studies also showed that brain regions related to eye movements and attentional orientation such as frontal eye fields were activated by blue-light-sensitive intrinsically photosensitive retinal ganglion cells (ipRGCs). The current study adopted the gap effect paradigm to investigate whether saccadic eye movement and attentional disengagement would be affected by blue light. The gap effect refers to the phenomenon of facilitated saccadic or manual response to a peripherally presented target by extinguishing the fixation shortly before the target onset (compared to when the fixation remains on the screen and overlaps with the target presentation). Participants were exposed to blue (vs. orange) light in two consecutive days, and they were instructed to respond to peripherally presented targets as quickly and accurately as possible. Experiment 1 showed that blue light facilitated saccade latency in the overlap condition. Results from Experiment 2 indicated that only when attention and eye movements activated simultaneously would we obtain a stable blue-light facilitation effect. Experiment 3 further showed that blue light also facilitated the processing of a salient target. We conclude that when attention and oculomotor system operate together, blue light facilitates saccade latency, supporting the premotor theory of attention. Our findings provide evidence and suggest a way for facilitating the efficiency of saccade. When reading or browsing on 3C products, the exposure of blue light is beneficial to saccadic eye movement.