An information theoretic characterisation of auditory encoding.
The entropy metric derived from information theory provides a means to quantify the amount of information transmitted in acoustic streams like speech or music. By systematically varying the entropy of pitch sequences, we sought brain areas where neural activity and energetic demands increase as a function of entropy. Such a relationship is predicted to occur in an efficient encoding mechanism that uses less computational resource when less information is present in the signal: we specifically tested the hypothesis that such a relationship is present in the planum temporale (PT). In two convergent functional MRI studies, we demonstrated this relationship in PT for encoding, while furthermore showing that a distributed fronto-parietal network for retrieval of acoustic information is independent of entropy. The results establish PT as an efficient neural engine that demands less computational resource to encode redundant signals than those with high information content.
Overath
Tobias
T
Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom. t.overath@fil.ion.ucl.ac.uk
Cusack
Rhodri
R
Kumar
Sukhbinder
S
von Kriegstein
Katharina
K
Warren
Jason D
JD
Grube
Manon
M
Carlyon
Robert P
RP
Griffiths
Timothy D
TD
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001303:Auditory Cortex / Q000033:anatomy & histology / Q000502:physiology; D001306:Auditory Pathways / Q000033:anatomy & histology / Q000502:physiology; D001931:Brain Mapping; D019277:Entropy; D005260:Female; D006801:Humans; D007257:Information Theory; D008279:Magnetic Resonance Imaging; D010898:Pitch Perception / Q000502:physiology*