title: Emergence of invariant representation of vocalizations in the auditory cortex.
abstract: An essential task of the auditory system is to discriminate between different communication signals, such as vocalizations. In everyday acoustic environments, the auditory system needs to be capable of performing the discrimination under different acoustic distortions of vocalizations. To achieve this, the auditory system is thought to build a representation of vocalizations that is invariant to their basic acoustic transformations. The mechanism by which neuronal populations create such an invariant representation within the auditory cortex is only beginning to be understood. We recorded the responses of populations of neurons in the primary and nonprimary auditory cortex of rats to original and acoustically distorted vocalizations. We found that populations of neurons in the nonprimary auditory cortex exhibited greater invariance in encoding vocalizations over acoustic transformations than neuronal populations in the primary auditory cortex. These findings are consistent with the hypothesis that invariant representations are created gradually through hierarchical transformation within the auditory pathway.
authors: Department of Otorhinolaryngology and Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania; Graduate Group in Physics, University of Pennsylvania, Philadelphia, Pennsylvania;
authors: Isaac M
authors: IM
authors: Carruthers
authors: Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil; and.
authors: Diego A
authors: DA
authors: Laplagne
authors: Department of Otorhinolaryngology and Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania; Graduate Group in Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania.
authors: Andrew
authors: A
authors: Jaegle
authors: Department of Otorhinolaryngology and Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania; Graduate Group in Physics, University of Pennsylvania, Philadelphia, Pennsylvania;
authors: John J
authors: JJ
authors: Briguglio
authors: Department of Otorhinolaryngology and Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania;
authors: Laetitia
authors: L
authors: Mwilambwe-Tshilobo
authors: Department of Otorhinolaryngology and Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania; Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil; and.
authors: Ryan G
authors: RG
authors: Natan
authors: Department of Otorhinolaryngology and Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania; Graduate Group in Physics, University of Pennsylvania, Philadelphia, Pennsylvania; Graduate Group in Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania mgeffen@med.upenn.edu.
authors: Maria N
authors: MN
authors: Geffen
mesh_terms: D000200:Action Potentials; D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D013018:Sound Spectrography; D014828:Vocalization, Animal / Q000502:physiology*
keywords: auditory cortex; hierarchical coding; invariance; processing; vocalizations