A startle reflex to a startle pulse is inhibited when preceded by a prestimulus. We introduced a key‐press action (self‐action) or an 85 dB noise burst as a prestimulus, followed by a 115 dB noise burst as a startle pulse. We manipulated temporal offsets between the prestimulus and the startle pulse from 30–1,500 ms to examine whether self‐action modulates the startle reflex and the temporal properties of the modulatory effect. We assessed eyeblink reflexes by electromyography. Both prestimuli decreased reflexes compared to pulse‐alone trials. Moreover, the temporal windows of inhibition were different between the types of prestimuli. A faster maximal inhibition and narrower temporal window in self‐action trials suggest that preceding self‐action inhibits the startle reflex and allows prediction of the coming pulse in different ways from auditory prestimuli.（大きな音への驚愕反射は、小さな音刺激が先行して呈示されると抑制されてしまう（プレパルス抑制）。本研究では、驚愕刺激である115 dBの音刺激の前に、85 dB の音刺激か被験者によるキー押し（自己動作）を先行刺激として呈示した。その結果、先行刺激を自己動作にした場合においても、プレパルス抑制が生じることが示された。）
総p.6, 51(1), pp.97-102
Yousuke Kawachi, Yoshihiko Matsue, Michiaki Shibata, Osamu Imaizumi, Jiro Gyoba
