title: How do auditory cortex neurons represent communication sounds?
abstract: A major goal in auditory neuroscience is to characterize how communication sounds are represented at the cortical level. The present review aims at investigating the role of auditory cortex in the processing of speech, bird songs and other vocalizations, which all are spectrally and temporally highly structured sounds. Whereas earlier studies have simply looked for neurons exhibiting higher firing rates to particular conspecific vocalizations over their modified, artificially synthesized versions, more recent studies determined the coding capacity of temporal spike patterns, which are prominent in primary and non-primary areas (and also in non-auditory cortical areas). In several cases, this information seems to be correlated with the behavioral performance of human or animal subjects, suggesting that spike-timing based coding strategies might set the foundations of our perceptive abilities. Also, it is now clear that the responses of auditory cortex neurons are highly nonlinear and that their responses to natural stimuli cannot be predicted from their responses to artificial stimuli such as moving ripples and broadband noises. Since auditory cortex neurons cannot follow rapid fluctuations of the vocalizations envelope, they only respond at specific time points during communication sounds, which can serve as temporal markers for integrating the temporal and spectral processing taking place at subcortical relays. Thus, the temporal sparse code of auditory cortex neurons can be considered as a first step for generating high level representations of communication sounds independent of the acoustic characteristic of these sounds. This article is part of a Special Issue entitled "Communication Sounds and the Brain: New Directions and Perspectives".
authors.affiliation: Centre de Neurosciences Paris-Sud (CNPS), CNRS UMR 8195, Université Paris-Sud, Bâtiment 446, 91405 Orsay cedex, France.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Gaucher
authors.forename: Chloé
authors.initials: C
authors.lastname: Huetz
authors.forename: Boris
authors.initials: B
authors.lastname: Gourévitch
authors.forename: Jonathan
authors.initials: J
authors.lastname: Laudanski
authors.forename: Florian
authors.initials: F
authors.lastname: Occelli
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Edeline
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception; D003463:Cues; D004192:Discrimination, Psychological; D005072:Evoked Potentials, Auditory; D006801:Humans; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D017711:Nonlinear Dynamics; D046709:Pattern Recognition, Physiological; D013060:Speech; D013067:Speech Perception; D013997:Time Factors; D014828:Vocalization, Animal; D014831:Voice
keywords: ACx; AI; CL; CM; EPSP; GBZ; HPC; HVC; High probability connection; LPC; ML; MLd; R; STG; STRF; auditory cortex; caudo-lateral area of the monkey auditory cortex; caudo-medial area of the monkey auditory cortex; excitatory post-synaptic potential; gabazine; high vocal center; low probability connection; mesencephalicus lateralis dorsalis; middle lateral of the monkey auditory cortex; primary auditory cortex; rMTF; rate Modulation Transfer Function; rostral area of the monkey auditory cortex; spectro-temporal receptive field; superior temporal gyrus; tMTF; temporal Modulation Transfer Function; vPFC; ventrolateral prefrontal cortex