School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavioral and Mental Health, Peking University, Beijing, 100080, China.
Department of Health Industry Management, Beijing International Studies University, Beijing, 100024, China.
Sci Rep. 2018 Jan 11;8(1):472. doi: 10.1038/s41598-017-18793-x.
Prepulse inhibition (PPI) is the suppression of the startle reflex when the intense startling stimulus is shortly preceded by a weaker non-startling stimulus (prepulse). In rats, the auditory precedence-effect-induced perceived spatial separation between the fear-conditioned prepulse and a noise masker facilitates selective attention to the prepulse and enhances PPI. However, whether the perceptual separation between the prepulse and a noise masker can also enhance PPI in humans remains unclear. Also, the relationship between the PPI enhancement and the change in early cortical representations of prepulse signals is unclear. This study for the first time reveals that in a sound-attenuated laboratory environment, relative to the listening condition with perceptual co-location between the prepulse stimulus and a noise-masking stimulus, the perceptual separation between the two stimuli significantly enhances the group-mean PPI. More importantly, the early cortical responses (N1/P2 complex) to the prepulse stimulus are also enhanced by the perceptual separation in most listeners, and the perceptual-separation-induced enhancement of the N1 component is positively correlated with the perceptual-separation-induced PPI enhancement. Thus, the perceptual separation enhances PPI through facilitating selective attention to the prepulse, leading to an enhancement of the early cortical representation of the prepulse signal in temporal auditory cortical fields.
预备性脉冲抑制（PPI）是指当强烈的起始刺激被一个较弱的非起始刺激（预备脉冲）短暂预先刺激时，起始反射被抑制。在大鼠中，听觉优先效应引起的对恐惧条件反射的预备脉冲和噪声掩蔽之间的感知空间分离，有利于对预备脉冲的选择性注意，并增强 PPI。然而，预备脉冲和噪声掩蔽之间的感知分离是否也能增强人类的 PPI 尚不清楚。此外，PPI 增强与预备脉冲信号早期皮层表示变化之间的关系也不清楚。这项研究首次表明，在声音衰减的实验室环境中，与预备脉冲刺激和噪声掩蔽刺激之间感知共定位的聆听条件相比，两个刺激之间的感知分离显著增强了组平均 PPI。更重要的是，在大多数听众中，预备脉冲刺激的早期皮层反应（N1/P2 复合体）也因感知分离而增强，并且 N1 成分的感知分离诱导增强与感知分离诱导的 PPI 增强呈正相关。因此，感知分离通过促进对预备脉冲的选择性注意来增强 PPI，从而增强时间听觉皮层区域中预备脉冲信号的早期皮层表示。
