title: Cortical activity patterns predict robust speech discrimination ability in noise.
abstract: The neural mechanisms that support speech discrimination in noisy conditions are poorly understood. In quiet conditions, spike timing information appears to be used in the discrimination of speech sounds. In this study, we evaluated the hypothesis that spike timing is also used to distinguish between speech sounds in noisy conditions that significantly degrade neural responses to speech sounds. We tested speech sound discrimination in rats and recorded primary auditory cortex (A1) responses to speech sounds in background noise of different intensities and spectral compositions. Our behavioral results indicate that rats, like humans, are able to accurately discriminate consonant sounds even in the presence of background noise that is as loud as the speech signal. Our neural recordings confirm that speech sounds evoke degraded but detectable responses in noise. Finally, we developed a novel neural classifier that mimics behavioral discrimination. The classifier discriminates between speech sounds by comparing the A1 spatiotemporal activity patterns evoked on single trials with the average spatiotemporal patterns evoked by known sounds. Unlike classifiers in most previous studies, this classifier is not provided with the stimulus onset time. Neural activity analyzed with the use of relative spike timing was well correlated with behavioral speech discrimination in quiet and in noise. Spike timing information integrated over longer intervals was required to accurately predict rat behavioral speech discrimination in noisy conditions. The similarity of neural and behavioral discrimination of speech in noise suggests that humans and rats may employ similar brain mechanisms to solve this problem.
authors.affiliation: The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR41 Richardson, TX 75080-3021, USA.
authors.forename: Jai A
authors.initials: JA
authors.lastname: Shetake
authors.forename: Jordan T
authors.initials: JT
authors.lastname: Wolf
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Cheung
authors.forename: Crystal T
authors.initials: CT
authors.lastname: Engineer
authors.forename: Satyananda K
authors.initials: SK
authors.lastname: Ram
authors.forename: Michael P
authors.initials: MP
authors.lastname: Kilgard
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology; D005260:Female; D006801:Humans; D009474:Neurons / Q000502:physiology; D009622:Noise; D010700:Phonetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013067:Speech Perception / Q000502:physiology*
references.citation: Nat Neurosci. 2005 Jul;8(7):862-3
references.pmid: 15924138
references.citation: Neuron. 2009 Feb 26;61(4):597-608
references.pmid: 19249279
references.citation: J Exp Anal Behav. 2003 Sep;80(2):205-15
references.pmid: 14674729
references.citation: J Comp Psychol. 1997 Mar;111(1):3-13
references.pmid: 9090135
references.citation: Ann N Y Acad Sci. 1993 Jun 14;682:1-22
references.pmid: 8323106
references.citation: Ear Hear. 2011 Feb;32(1):53-60
references.pmid: 20890206
references.citation: Dev Sci. 2009 Sep;12(5):732-45
references.pmid: 19702766
references.citation: Proc Natl Acad Sci U S A. 2007 Mar 20;104(12):5175-80
references.pmid: 17360369
references.citation: J Speech Lang Hear Res. 1999 Apr;42(2):271-86
references.pmid: 10229446
references.citation: J Acoust Soc Am. 1997 Oct;102(4):2403-11
references.pmid: 9348698
references.citation: Annu Rev Neurosci. 1997;20:331-53
references.pmid: 9056717
references.citation: Cereb Cortex. 2005 Feb;15(2):170-86
references.pmid: 15238437
references.citation: Ann N Y Acad Sci. 1993 Jun 14;682:27-47
references.pmid: 7686725
references.citation: J Acoust Soc Am. 2010 Dec;128(6):3715-23
references.pmid: 21218903
references.citation: J Acoust Soc Am. 1980 Jan;67(1):318-26
references.pmid: 7354199
references.citation: J Neurosci. 2000 Jul 15;20(14):5392-400
references.pmid: 10884324
references.citation: Lang Speech. 1967 Jul-Sep;10(3):194-202
references.pmid: 5583885
references.citation: Ear Hear. 1998 Jun;19(3):218-31
references.pmid: 9657596
references.citation: J Acoust Soc Am. 2008 Feb;123(2):899-909
references.pmid: 18247893
references.citation: Proc Natl Acad Sci U S A. 2009 Jun 9;106(23):9471-6
references.pmid: 19458263
references.citation: Behav Brain Funct. 2010 Oct 16;6:60
references.pmid: 20950487
references.citation: J Neurophysiol. 1996 Aug;76(2):1356-60
references.pmid: 8871243
references.citation: Proc Natl Acad Sci U S A. 2001 Nov 6;98(23):13367-72
references.pmid: 11698688
references.citation: J Acoust Soc Am. 1981 Jan;69(1):249-61
references.pmid: 7217523
references.citation: J Neurosci. 2007 Jan 17;27(3):582-9
references.pmid: 17234590
references.citation: J Neurosci. 2005 Jan 19;25(3):711-22
references.pmid: 15659609
references.citation: Nature. 2011 Feb 3;470(7332):101-4
references.pmid: 21228773
references.citation: Clin Neurophysiol. 2001 May;112(5):758-67
references.pmid: 11336890
references.citation: J Neurophysiol. 1993 Oct;70(4):1629-38
references.pmid: 8283219
references.citation: J Acoust Soc Am. 2008 Aug;124(2):1220-33
references.pmid: 18681609
references.citation: J Speech Lang Hear Res. 2008 Aug;51(4):1026-41
references.pmid: 18658069
references.citation: Brain Res Bull. 2007 Mar 15;71(5):508-14
references.pmid: 17259020
references.citation: J Neurosci. 2004 Aug 18;24(33):7266-71
references.pmid: 15317852
references.citation: Nature. 2007 Sep 6;449(7158):92-5
references.pmid: 17805296
references.citation: Nat Rev Neurosci. 2003 Mar;4(3):203-18
references.pmid: 12612633
references.citation: Neuropsychologia. 2009 Feb;47(3):693-703
references.pmid: 19124032
references.citation: J Neurophysiol. 1988 May;59(5):1627-38
references.pmid: 3385476
references.citation: Nat Neurosci. 2008 May;11(5):603-8
references.pmid: 18425123
references.citation: J Exp Child Psychol. 1986 Jun;41(3):489-507
references.pmid: 3734692
references.citation: Hear Res. 2002 Jul;169(1-2):97-111
references.pmid: 12121743
references.citation: J Acoust Soc Am. 2007 Apr;121(4):2312-26
references.pmid: 17471744
references.citation: Neuron. 2011 Apr 14;70(1):121-31
references.pmid: 21482361
references.citation: J Acoust Soc Am. 1985 Dec;78(6):1958-65
references.pmid: 4078172
references.citation: Neurosci Lett. 2001 Feb 23;299(3):197-200
references.pmid: 11165769
references.citation: Ear Hear. 2010 Jun;31(3):302-24
references.pmid: 20084007
references.citation: Behav Processes. 2005 Jun 30;69(3):331-41
references.pmid: 15896531
references.citation: J Acoust Soc Am. 1973 Nov;54(5):1248-66
references.pmid: 4765809
references.citation: J Neurophysiol. 1999 Nov;82(5):2346-57
references.pmid: 10561410
references.citation: Science. 1987 Sep 4;237(4819):1195-7
references.pmid: 3629235
references.citation: Nat Rev Neurosci. 2009 Feb;10(2):113-25
references.pmid: 19145235
references.citation: Science. 2000 Apr 14;288(5464):349-51
references.pmid: 10764650
references.citation: Ear Hear. 2005 Apr;26(2):195-213
references.pmid: 15809545
references.citation: Science. 1996 Jan 5;271(5245):77-81
references.pmid: 8539603
references.citation: Proc Natl Acad Sci U S A. 1999 Feb 2;96(3):1106-11
references.pmid: 9927701
references.citation: Nat Neurosci. 2006 Mar;9(3):420-8
references.pmid: 16474393
references.citation: Nat Neurosci. 2007 Dec;10(12):1601-7
references.pmid: 17994016
references.citation: Hear Res. 2011 Jan;271(1-2):147-58
references.pmid: 20116422
references.citation: J Acoust Soc Am. 1971 Jun;49(6):1849-56
references.pmid: 5125732
references.citation: Front Synaptic Neurosci. 2010 Jun 14;2:17
references.pmid: 21423503
references.citation: Nat Neurosci. 2004 Mar;7(3):295-301
references.pmid: 14966525
references.citation: Science. 1996 Jan 5;271(5245):81-4
references.pmid: 8539604
references.citation: J Neurosci. 2010 Apr 7;30(14):4922-6
references.pmid: 20371812
references.citation: J Speech Hear Res. 1992 Feb;35(1):208-15
references.pmid: 1370969
references.citation: J Acoust Soc Am. 1985 Aug;78(2):488-94
references.pmid: 4031248
references.citation: J Neurophysiol. 2008 Jul;100(1):268-80
references.pmid: 18400959
references.citation: J Neurosci. 2006 May 3;26(18):4785-95
references.pmid: 16672651
references.citation: Ear Hear. 1996 Dec;17(6):478-89
references.pmid: 8979036
references.citation: Neuron. 2001 Mar;29(3):769-77
references.pmid: 11301035
references.citation: Proc Natl Acad Sci U S A. 2005 Sep 27;102(39):14110-5
references.pmid: 16162673
references.citation: Science. 1975 Oct 3;190(4209):69-72
references.pmid: 1166301
references.citation: J Cogn Neurosci. 2011 Sep;23(9):2268-79
references.pmid: 20681749
references.citation: Hear Res. 2005 Jan;199(1-2):31-9
references.pmid: 15574298
references.citation: Clin Neurophysiol. 2004 Sep;115(9):2021-30
references.pmid: 15294204
references.citation: J Acoust Soc Am. 1987 Apr;81(4):1130-8
references.pmid: 3571730
references.citation: Science. 1995 Feb 17;267(5200):1028-30
references.pmid: 7863330
references.citation: J Neurosci. 2009 May 13;29(19):6078-87
references.pmid: 19439585
references.citation: J Acoust Soc Am. 1965 Jan;37:158-66
references.pmid: 14265103
references.citation: J Neurosci. 2000 Feb 1;20(3):1216-28
references.pmid: 10648726
references.citation: Q J Exp Psychol A. 1991 Aug;43(3):349-72
references.pmid: 1775647
references.citation: Hear Res. 2002 Aug;170(1-2):96-106
references.pmid: 12208544
references.citation: J Cogn Neurosci. 2009 Sep;21(9):1790-805
references.pmid: 18823249