呈示刺激数とその規則性が視覚探索課題遂行中の事象関連電位に及ぼす影響 <論説>

Effects of display set size and its variability on the event-related potentials during a visual search task <Articles>

Miyatani Makoto

Sakata Sumiko

広島経済大学研究論集

This study investigated the effects of display set size and its variability on the event-related potentials (ERPs) during a visual search task. In Experiment 1, subjects were required to respond if a visual display, which consisted of two, four, or six alphabets, contained one of two members of memory set. In Experiment 2, subjects detected the change of the shape of a fixation stimulus, which was surrounded by the same alphabets as in Experiment 1. In the search task (Experiment 1), the increase of display set size resulted in the negative shift of the ERPs between 320-640 ms after the stimulus onset. This negative shift (visual search negativity) was almost the same in amplitude over the whole scalp. The variability of the display set size also affected the ERPs between 280-400 ms, so that the ERPs were more negative when the display set size was constant, compared to when it changed randomly within an experimental block. This effect of variability did not interact with that of display set size, which suggested the search processes reflected in the visual search negativity were not affected by a visuo-spatial attention. In the non-search task (Experiment 2), the ERP changes caused by display set size were limited to the occipital and posterior temporal regions, smaller in amplitude, and later in latency than those in Experiment 1. These results suggested that the visual search negativity might be composed of several sub-components, which reflect the activity of sub-processes involved in visual search processes.

visual search

display set size

event-related potentials (ERPs)

visual search negativity

Psychology [ 140 ]

jpn

広島経済大学経済学会

Copyright (c) 1999 Authors

[ISSN] 0387-1444

[NCID] AN00408380