The Representation of Time Windows in Primate Auditory Cortex.

Pradeep Dheerendra,Fabien Balezeau,Timothy D Griffiths,Simon Baumann,Olivier Joly,Christopher I Petkov,Alexander Thiele

doi:10.1093/cercor/bhab434

Pradeep Dheerendra, Fabien Balezeau + Show 5 more

Open Access

https://doi.org/10.1093/cercor/bhab434

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Abstract

Whether human and nonhuman primates process the temporal dimension of sound similarly remains an open question. We examined the brain basis for the processing of acoustic time windows in rhesus macaques using stimuli simulating the spectrotemporal complexity of vocalizations. We conducted functional magnetic resonance imaging in awake macaques to identify the functional anatomy of response patterns to different time windows. We then contrasted it against the responses to identical stimuli used previously in humans. Despite a similar overall pattern, ranging from the processing of shorter time windows in core areas to longer time windows in lateral belt and parabelt areas, monkeys exhibited lower sensitivity to longer time windows than humans. This difference in neuronal sensitivity might be explained by a specialization of the human brain for processing longer time windows in speech.

Highlights

Primate vocalizations contain features that vary over time at different rates
The blood oxygen level–dependent (BOLD) activation associated with sound stimulation was analyzed in voxel space
In the main experiment on time windows, the functional magnetic resonance imaging (fMRI) BOLD response was recorded across the entire auditory cortex to sound stimuli with five different spectrotemporal correlations

Summary

Introduction

Primate vocalizations contain features that vary over time at different rates. The optimal duration of a time window depends upon the underlying acoustic features that need to be processed. The window duration is operationalized as time required for the correlation between amplitude spectra to recede to a target value (see Materials and Methods). Both human and monkey calls contain features at a range of different rates. We consider here whether human and nonhuman primates share a common functional anatomy to support the analysis of different-length time windows and whether this anatomy is adapted in the two species to reflect differences in the time windows needed to process species-specific vocalizations

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