Echolocation reverses information flow in a cortical vocalization network

Abstract

The mammalian frontal and auditory cortices are fundamental structures supporting vocal behaviour, yet the patterns of information exchange between these regions during vocalization remain unknown. Here, we address this issue by means of electrophysiological recordings in the fronto-auditory network of freely-vocalizing Carollia perspicillata bats. We show that oscillations in frontal and auditory cortices predict vocalization type with complementary patterns across structures. Transfer entropy analyses of oscillatory activity revealed directed information exchange in the circuit, predominantly of top-down nature (frontal to auditory). The dynamics of information flow depended on vocalization type and on the timing relative to vocal onset. Remarkably, we observed the emergence of predominant bottom-up information transfer, only when animals produced calls with imminent post-vocal consequences (echolocation signals). These results unveil changes of information flow in a large-scale sensory and association network associated to the behavioural consequences of vocalization in a highly vocal mammalian model.