title: Cortical plasticity as a mechanism for storing Bayesian priors in sensory perception.
abstract: Human perception of ambiguous sensory signals is biased by prior experiences. It is not known how such prior information is encoded, retrieved and combined with sensory information by neurons. Previous authors have suggested dynamic encoding mechanisms for prior information, whereby top-down modulation of firing patterns on a trial-by-trial basis creates short-term representations of priors. Although such a mechanism may well account for perceptual bias arising in the short-term, it does not account for the often irreversible and robust changes in perception that result from long-term, developmental experience. Based on the finding that more frequently experienced stimuli gain greater representations in sensory cortices during development, we reasoned that prior information could be stored in the size of cortical sensory representations. For the case of auditory perception, we use a computational model to show that prior information about sound frequency distributions may be stored in the size of primary auditory cortex frequency representations, read-out by elevated baseline activity in all neurons and combined with sensory-evoked activity to generate a perception that conforms to Bayesian integration theory. Our results suggest an alternative neural mechanism for experience-induced long-term perceptual bias in the context of auditory perception. They make the testable prediction that the extent of such perceptual prior bias is modulated by both the degree of cortical reorganization and the magnitude of spontaneous activity in primary auditory cortex. Given that cortical over-representation of frequently experienced stimuli, as well as perceptual bias towards such stimuli is a common phenomenon across sensory modalities, our model may generalize to sensory perception, rather than being specific to auditory perception.
authors.affiliation: Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America.
authors.forename: Hania
authors.initials: H
authors.lastname: Köver
authors.forename: Shaowen
authors.initials: S
authors.lastname: Bao
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001303:Auditory Cortex / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology*; D001499:Bayes Theorem; D015982:Bias; D002452:Cell Count; D002540:Cerebral Cortex / Q000502:physiology*; D016013:Likelihood Functions; D008959:Models, Neurological; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000502:physiology
references.citation: Science. 1992 Jan 31;255(5044):606-8
references.pmid: 1736364
references.citation: J Neurosci. 2006 May 3;26(18):4970-82
references.pmid: 16672673
references.citation: Nat Neurosci. 2007 Sep;10(9):1191-7
references.pmid: 17660815
references.citation: J Neurosci. 2009 Apr 22;29(16):5163-9
references.pmid: 19386912
references.citation: Cognition. 2003 Feb;87(1):B47-57
references.pmid: 12499111
references.citation: Network. 2001 Aug;12(3):241-53
references.pmid: 11563528
references.citation: Exp Brain Res. 1998 Nov;123(1-2):110-6
references.pmid: 9835399
references.citation: J Acoust Soc Am. 1996 Aug;100(2 Pt 1):1111-21
references.pmid: 8759964
references.citation: Trends Cogn Sci. 2006 Jul;10(7):319-26
references.pmid: 16807063
references.citation: J Neurosci. 2009 Apr 29;29(17):5456-62
references.pmid: 19403813
references.citation: J Comput Neurosci. 2008 Jun;24(3):277-90
references.pmid: 17917802
references.citation: Neuron. 2007 Oct 4;56(1):171-84
references.pmid: 17920023
references.citation: Nat Neurosci. 2006 Apr;9(4):578-85
references.pmid: 16547513
references.citation: Annu Rev Neurosci. 2000;23:501-29
references.pmid: 10845073
references.citation: Psychol Rev. 2009 Oct;116(4):752-782
references.pmid: 19839683
references.citation: Nat Neurosci. 1999 Aug;2(8):727-32
references.pmid: 10412062
references.citation: Nat Neurosci. 2003 Apr;6(4):414-20
references.pmid: 12627164
references.citation: Annu Rev Psychol. 2004;55:271-304
references.pmid: 14744217
references.citation: Nature. 2004 Jan 15;427(6971):244-7
references.pmid: 14724638
references.citation: Science. 1996 Sep 27;273(5283):1868-71
references.pmid: 8791593
references.citation: Nature. 2004 Sep 30;431(7008):573-8
references.pmid: 15457262
references.citation: Neuron. 2005 May 19;46(4):681-92
references.pmid: 15944135
references.citation: Nature. 1997 Sep 4;389(6646):66-9
references.pmid: 9288967
references.citation: Proc Natl Acad Sci U S A. 1993 Nov 15;90(22):10749-53
references.pmid: 8248166
references.citation: Nat Neurosci. 2006 Nov;9(11):1432-8
references.pmid: 17057707
references.citation: Nat Neurosci. 2006 May;9(5):690-6
references.pmid: 16617339
references.citation: Percept Psychophys. 1991 Aug;50(2):93-107
references.pmid: 1945741