Exploring The ISI Effect Of N170 Adaptation

The adaptation of perception is an important trait of the expert objects processing. Recent studies have shown that, with a short inter-stimuli interval(ISI; 200ms), the adaptation effect can be generated by both the face and the character, two expert stimuli. When ISI exceeds to 1000ms, however, it is little known about whether the adaptation effect can be generated by these two categories of stimuli. So, it remains unknown how the adaptation effects change with different ISI conditions (i.e., the time course of adaptation effect). Therefore, to exploring the time course of adaptation effect by systematically investigating the association between ISI and ERP adaptation, two experiments were conducted in present study.18 college students chosen from Zhejiang Normal University took apart in the present study. The experimental materials of this study contained faces, characters and house. In Experiment 1, the time course of adaptation effect of the face and the character under six ISI conditions (200,500,800,1100,1500,2500ms) were explored separately. In Experiment 2, only long ISIs (1500ms) were used to discuss the adaptation effect of faces and words.The present study concluded that:(1) the adaptation effect within category could be generated by both face and character when short ISI conditions (i.e.200ms,500ms) were introduced.(2) N170 adaptation effect of face would change when ISI was beyond 1100ms, while that of character would change when ISI was beyond 500ms.(3) In the long ISI conditions (i.e.800ms,1500ms), the adaptation effect within category could be generated by both face and character. However, there was a significantly competition effect between the face and the character in these long ISI conditions.