Poster B5, Sunday, March 25, 8:00-10:00 am, Exhibit Hall C
Attention and self-reported ADHD tendency modulate very early electrophysiological responses for visual words
Tetsuko Kasai1, Aiko Tanaka2, Yasuko Okumura3, Tomoki Uno2; 1Faculty of Education, Hokkaido University, 2Graduate School of Education, Hokkaido University, 3National Center of Neurology and Psychiatry
Purpose. Previous behavioral studies suggest that visual words operate as perceptual units or “objects”, whereas early electrophysiological responses (e.g., N170) does not necessarily discriminate words from nonwords. The present study examined whether the activation of perceptual word representations involves attention and/or individual differences in attention, by indexing event-related potentials. Methods. Sixteen participants were presented with hiragana (2-letter words and nonwords) or symbol strings, overlapped with horizontal lines. They detected infrequent color changes of either the strings (attend-string) or the lines (attend-line) during their rapid presentations in given blocks. After recording sessions, participants filled the symptom checklist of adult ADHD self-report scale (ASRS-v1.1). Results. Increased behavioral performance and letter-string-specific (words and nonwords vs. symbols) left-lateralized negativities (190-220 ms post-stimulus) were observed in the attend-string against attend-line condition. More importantly, P1 (130-160 ms) was enlarged for words compared to nonwords in the attend-line condition (i.e., when strings were ignored). Furthermore, an attention effect (attend-string minus attend-line) at an earlier range (70-100 ms) for words were positively correlated with ASRS scores. Conclusions. We found that visual cortex is organized to represent visual words, or learned combinations of letters, at very early stages of processing, the manifestations of which depend on the state of attention and attentional traits of individuals. These findings suggest a tight link between fluent reading and attention.
Topic Area: ATTENTION: Nonspatial