AI Insight
This study demonstrates that click-train sounds with identical average timing but different millisecond-scale temporal patterns produce distinct behavioral and neural responses in both humans and rats. Using EEG in humans and invasive recordings in rats, researchers traced how these temporal patterns are processed along the auditory pathway from the inferior colliculus through the medial geniculate body to the primary auditory cortex. The findings reveal that sensitivity to temporal patterns increases at higher levels of the auditory system, with the strongest discrimination occurring in the auditory cortex, particularly in its upper layers, and that feedback from cortex to thalamus contributes to this enhanced sensitivity.
Why it matters
Understanding how the brain processes fine temporal patterns in sound has implications for improving hearing aids and cochlear implants, which often struggle to preserve temporal information. This research could also inform treatments for auditory processing disorders and advance our knowledge of how sensory systems build increasingly complex representations of stimuli.
Understand the Science
by Yuying Zhai, Peirun Song, Ana Belén Lao-Rodríguez, Xinyu Du, Haoxuan Xu, Hangting Ye, Xuehui Bao, Ishrat Mehmood, Nayaab Shahir Pandit, Cheng Chang, Zhouyou Dai, Zhiyi Tu, Pei Chen, Tingting Zhang, Lingling Zhang, Xuan Zhao, David Pérez-González, Manuel S. Malmierca, Xiongjie Yu
Natural sounds are shaped by both spectral content and temporal patterning. Here we ask whether click trains with the same mean inter-click interval, but different millisecond-scale temporal patterns evoke distinct behavioral and neural responses. Human listeners discriminated several such click-train patterns, and human EEG revealed context-dependent deviance-related responses. Awake rats showed analogous cortical response differences at the ECoG level. Along the IC–MGB–A1 pathway, unit recordings revealed weak oddball/context sensitivity in IC, intermediate sensitivity in MGB, and stronger stimulus-specific adaptation in A1. Reversible inactivation of the auditory cortex reduced MGB sensitivity, indicating a contribution of corticothalamic feedback. Further A1 layer analyses showed stronger effects in supragranular than deep cortical layers. Together, these results show that distinct click-train temporal patterns are differentially represented across the auditory system, with stronger sensitivity emerging in higher auditory structures.