Stimulus Temporal Coherence Strongly Influences Rapid Plasticity in Primary Auditory Cortex under Global Attention

Abstract

Temporal coherence of stimulus features is a key property of sounds that emanate from single source. Consequently, it is important to understand how it may influence the direction and extent of the rapid plasticity postulated to occur during the streaming of concurrent sounds. We postulated that when animals listen attentively to coherent or incoherent stimuli, responses would adapt to effectively encode the correlational structure of the stimuli. In this study, ferrets were trained to attend globally to two-tone sequences which were played either simultaneously (SYNC) or alternatively (ALT) on a trial-by-trial basis, and to detect a transition to a random cloud of tones by licking a waterspout for reward. Neuronal activities were collected in the primary auditory cortex during performing the task and passively listening to the same stimuli sequences. Compared with the passive condition, neuronal responses changed distinctively between SYNC and ALT trials under the effect of attention. These results provide neuronal evidence for the role of stimulus temporal coherence in modulating responses during attentive listening to complex sounds.