Title
Encoding Of Natural Sounds At Multiple Spectral And Temporal Resolutions In The Human Auditory Cortex
Abstract
Functional neuroimaging research provides detailed observations of the response patterns that natural sounds (e.g. human voices and speech, animal cries, environmental sounds) evoke in the human brain. The computational and representational mechanisms underlying these observations, however, remain largely unknown. Here we combine high spatial resolution (3 and 7 Tesla) functional magnetic resonance imaging (fMRI) with computational modeling to reveal how natural sounds are represented in the human brain. We compare competing models of sound representations and select the model that most accurately predicts fMRI response patterns to natural sounds. Our results show that the cortical encoding of natural sounds entails the formation of multiple representations of sound spectrograms with different degrees of spectral and temporal resolution. The cortex derives these multi-resolution representations through frequency-specific neural processing channels and through the combined analysis of the spectral and temporal modulations in the spectrogram. Furthermore, our findings suggest that a spectral-temporal resolution trade-off may govern the modulation tuning of neuronal populations throughout the auditory cortex. Specifically, our fMRI results suggest that neuronal populations in posterior/dorsal auditory regions preferably encode coarse spectral information with high temporal precision. Vice-versa, neuronal populations in anterior/ventral auditory regions preferably encode fine-grained spectral information with low temporal precision. We propose that such a multi-resolution analysis may be crucially relevant for flexible and behaviorally-relevant sound processing and may constitute one of the computational underpinnings of functional specialization in auditory cortex.
Year
DOI
Venue
2014
10.1371/journal.pcbi.1003412
PLOS COMPUTATIONAL BIOLOGY
Keywords
Field
DocType
sound,brain mapping,speech,magnetic resonance imaging,signal to noise ratio
Auditory cortex,Functional specialization,Biology,Functional magnetic resonance imaging,Spectrogram,Natural sounds,Inferior colliculus,Speech recognition,Neuronal tuning,Audio signal processing
Journal
Volume
Issue
ISSN
10
1
1553-7358
Citations 
PageRank 
References 
16
1.06
5
Authors
7
Name
Order
Citations
PageRank
Roberta Santoro1211.52
Michelle Moerel2545.77
Federico De Martino332520.34
rainer goebel447640.13
Kamil Ugurbil52129128.69
Essa Yacoub61800107.62
Elia Formisano777858.91