Abstract:

Prepulse inhibition (PPI) is considered as a measurement of sensory gating, reflecting the function of early auditory sensory information selection. Although the main neural correlates of PPI lie in the brainstem, previous researches have revealed that PPI could be top-down modulated by attention. However, different forms of attention, such as feature-based attention and spatial attention, have not been investigated together in the specific modulation of PPI. Moreover, the neural mechanism of attentional modulation of PPI in humans has been focused on the cortical level, whereas the subcortical mechanism has remained unclear. Based on the dual-pathway model for auditory processing, the present project aims to use behavioral testing, electroencephalogram recording and functional magnetic resonnance imaging, to investigate the various levels of neural representations of attentional modulation of PPI in the auditory system. The paper will 1) establish the behavioral paradigm of feature-based attentional and spatially attentional modulation of PPI, and examine the temporal dynamic processing differences between feature-based attentional modulation and spatially attentional modulation of PPI; 2) use brainstem frequency following responses (FFRs) to examine the subcortical neural mechanism of two types of attentional modulation of PPI, focusing on the envelope and fine structure processing differences of prepulse stimuli in the two types of attentional PPI modulation; 3) investigate the key brain areas and neural networks involved in feature-based attentional modulation and spatially attentional modulation of PPI.

Key words: attention, auditory sensory gating, prepulse inhibition, dual-pathway model