The N170 Adaptation And Competition Between Face And Word

Face and word are the most common visual stimulus in the daily life for an adult who has ability to read and write. Recent research indicated that the N170 amplitude has been found to be larger for faces and words compared to other control stimulus. Related studies have achieved some consensus in the field of function properties of N170 component for faces and words. However, whether the N170 index same cognitive processes for faces and words is still in debate. ERP adaptation paradigm and competition paradigm are robust tools to resolve the issue. Previous studies mainly focused on the same-category adaptation effect and competition effect. Recent studies have started to focus on the cross-category adaptation effect and competition effect. Thus, in the present study, faces and Chinese characters are presented to explore category-level N170 adaptation effect and competition effect between faces and Chinese characters to investigate the mechanisms of early stages of perceptual processing for faces and words.In the current study, four experiments were conducted to explore whether the N170 index same cognitive processes for faces and words. Experiment 1A adopted the same adaptation paradigm as Cao et al. (2014)’s to investigate adaptation effect between faces and Chinese characters. Experiment 1B adopted the similar competition paradigm to Fan et al. (2015)’s to investigate competition effect between faces and Chinese characters. Experiment 2 and experiment 3 examined the effects of inter-stimulus interval (ISI) and adapter duration on the adaptation effect between faces and Chinese characters. Experiment 2 examined the adaptation effect between faces and Chinese characters in the ISI of 20 ms (experiment 2A) and 0 ms (experiment 2B) when the adapter duration was 200 ms. Experiment 3 examined the adaptation effect between faces and Chinese characters in the ISI of 200 ms (experiment 3A),20 ms (experiment 3B) and 0 ms (experiment 3C) when the adapter duration was 600 ms. Experiment 4 explored the competition effect between faces and Chinese characters in the ISI of 200 ms (experiment 4A),20 ms (experiment 4B).Results:(1) Experiment 1A indicated that no significant adaptation effect of N170 component occurred between faces and Chinese characters with an ISI of 200 ms when adapter was presented for 200 ms. Experiment 1B shown a significant competition effect of N170 component occurred between faces and Chinese characters.(2) Experiment 2 found that no significant adaptation effect of N170 component occurred between faces and Chinese characters with ISIs of 20 ms and 0 ms when adapter was presented for 200 ms. Experiment 3B found that a significant adaptation effect of N170 component occurred between faces and Chinese characters occurred with an ISI of 0 ms when adapter was presented for 600 ms, yet no significant adaptation effect of N170 component occurred between faces and Chinese characters with ISIs of 200 ms and 20 ms when adapter was presented for 600 ms.(3) Experiment 4 revealed that when S1 were presented discontinuously with ISIs of 20 ms and 0 ms, a significant competition effect of N170 component occurred between faces and Chinese characters only in the left hemisphere when face was presented in the left-visual field.Conclusions:(1) The significant adaptation effect and competition effect of N170 component occurred between faces and words indicated the N170 index same cognitive processes for faces and words.(2) The adaptation effect between faces and words is modulated by ISI and adapter duration.