title: Coding of vocalizations by single neurons in ventrolateral prefrontal cortex.
abstract: Neuronal activity in single prefrontal neurons has been correlated with behavioral responses, rules, task variables and stimulus features. In the non-human primate, neurons recorded in ventrolateral prefrontal cortex (VLPFC) have been found to respond to species-specific vocalizations. Previous studies have found multisensory neurons which respond to simultaneously presented faces and vocalizations in this region. Behavioral data suggests that face and vocal information are inextricably linked in animals and humans and therefore may also be tightly linked in the coding of communication calls in prefrontal neurons. In this study we therefore examined the role of VLPFC in encoding vocalization call type information. Specifically, we examined previously recorded single unit responses from the VLPFC in awake, behaving rhesus macaques in response to 3 types of species-specific vocalizations made by 3 individual callers. Analysis of responses by vocalization call type and caller identity showed that ∼19% of cells had a main effect of call type with fewer cells encoding caller. Classification performance of VLPFC neurons was ∼42% averaged across the population. When assessed at discrete time bins, classification performance reached 70 percent for coos in the first 300 ms and remained above chance for the duration of the response period, though performance was lower for other call types. In light of the sub-optimal classification performance of the majority of VLPFC neurons when only vocal information is present, and the recent evidence that most VLPFC neurons are multisensory, the potential enhancement of classification with the addition of accompanying face information is discussed and additional studies recommended. Behavioral and neuronal evidence has shown a considerable benefit in recognition and memory performance when faces and voices are presented simultaneously. In the natural environment both facial and vocalization information is present simultaneously and neural systems no doubt evolved to integrate multisensory stimuli during recognition. This article is part of a Special Issue entitled "Communication Sounds and the Brain: New Directions and Perspectives".
authors.affiliation: Dept. Neurobiology & Anatomy, Univ. of Rochester, Box 603, Rochester, NY 14642, USA.
authors.forename: Bethany
authors.initials: B
authors.lastname: Plakke
authors.forename: Mark D
authors.initials: MD
authors.lastname: Diltz
authors.forename: Lizabeth M
authors.initials: LM
authors.lastname: Romanski
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception; D008253:Macaca mulatta / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D046709:Pattern Recognition, Physiological; D017397:Prefrontal Cortex / Q000502:physiology*; D021641:Recognition, Psychology; D012919:Social Behavior; D013997:Time Factors; D014828:Vocalization, Animal
references.citation: Nature. 2004 Jan 29;427(6973):448-51
references.pmid: 14749833
references.citation: J Neurosci. 2006 Oct 25;26(43):11138-47
references.pmid: 17065454
references.citation: Science. 2003 Jan 24;299(5606):568-72
references.pmid: 12543977
references.citation: Neuroimage. 2005 Jan 1;24(1):224-34
references.pmid: 15588614
references.citation: Cereb Cortex. 1994 Sep-Oct;4(5):470-83
references.pmid: 7530521
references.citation: J Cogn Neurosci. 2005 Sep;17(9):1471-82
references.pmid: 16197700
references.citation: Eur J Neurosci. 2002 Jul;16(2):291-310
references.pmid: 12169111
references.citation: J Comp Psychol. 2003 Dec;117(4):380-90
references.pmid: 14717639
references.citation: Nature. 2005 Aug 25;436(7054):1161-5
references.pmid: 16121182
references.citation: Brain Res. 1999 Jan 30;817(1-2):45-58
references.pmid: 9889315
references.citation: Science. 1997 Nov 7;278(5340):1135-8
references.pmid: 9353197
references.citation: Nat Neurosci. 1999 Dec;2(12):1131-6
references.pmid: 10570492
references.citation: Hear Res. 2007 Jul;229(1-2):204-12
references.pmid: 17208397
references.citation: Curr Biol. 2010 Jan 12;20(1):19-24
references.pmid: 20036538
references.citation: Biol Lett. 2006 Jun 22;2(2):261-5
references.pmid: 17148378
references.citation: J Neurophysiol. 1995 Dec;74(6):2685-706
references.pmid: 8747224
references.citation: Neuron. 2009 Mar 26;61(6):930-40
references.pmid: 19324001
references.citation: Proc Natl Acad Sci U S A. 2012 Jul 24;109(30):12237-41
references.pmid: 22778411
references.citation: Cereb Cortex. 2007 Sep;17 Suppl 1:i61-9
references.pmid: 17634387
references.citation: J Neurophysiol. 2005 Sep;94(3):2251-4
references.pmid: 15928057
references.citation: Nat Neurosci. 2002 Jan;5(1):15-6
references.pmid: 11753413
references.citation: J Neurophysiol. 2005 Feb;93(2):734-47
references.pmid: 15371495
references.citation: Memory. 2012 Jul;20(5):527-34
references.pmid: 22646520
references.citation: Proc Natl Acad Sci U S A. 2012 Jun 26;109 Suppl 1:10717-24
references.pmid: 22723356
references.citation: Curr Opin Neurobiol. 1998 Aug;8(4):516-21
references.pmid: 9751652
references.citation: Curr Biol. 2011 Aug 23;21(16):1408-15
references.pmid: 21835625
references.citation: PLoS Comput Biol. 2011 Sep;7(9):e1002165
references.pmid: 21998576
references.citation: J Neurosci. 2010 May 26;30(21):7434-46
references.pmid: 20505110
references.citation: J Acoust Soc Am. 1998 Jan;103(1):602-14
references.pmid: 9440345
references.citation: Exp Brain Res. 2003 May;150(2):142-53
references.pmid: 12669171
references.citation: J Neurophysiol. 2004 Jun;91(6):2897-909
references.pmid: 15136606
references.citation: J Neurosci. 2009 Sep 9;29(36):11192-202
references.pmid: 19741126
references.citation: Science. 2001 Jan 12;291(5502):312-6
references.pmid: 11209083
references.citation: J Comp Neurol. 1997 May 26;382(1):89-103
references.pmid: 9136813
references.citation: PLoS Biol. 2006 Oct;4(10):e326
references.pmid: 17002519
references.citation: Proc Natl Acad Sci U S A. 2005 Jun 28;102(26):9359-64
references.pmid: 15967995
references.citation: Exp Brain Res. 1988;69(2):315-26
references.pmid: 3126080
references.citation: J Neurosci. 2010 Sep 29;30(39):13021-30
references.pmid: 20881120
references.citation: J Comp Neurol. 1991 Aug 22;310(4):507-49
references.pmid: 1719039
references.citation: J Neurophysiol. 2012 Feb;107(4):1123-41
references.pmid: 22131372
references.citation: J Neurosci. 2012 Nov 14;32(46):16149-61
references.pmid: 23152599
references.citation: J Comp Neurol. 1999 Jan 11;403(2):141-57
references.pmid: 9886040
references.citation: Primates. 2004 Apr;45(2):119-28
references.pmid: 14673661
references.citation: Cereb Cortex. 2009 May;19(5):1042-54
references.pmid: 18787230
references.citation: Hear Res. 2013 Feb;296:131-40
references.pmid: 23168357
references.citation: Nature. 2000 Jan 20;403(6767):309-12
references.pmid: 10659849
references.citation: Cereb Cortex. 2012 Apr;22(4):838-53
references.pmid: 21709178
references.citation: Cereb Cortex. 1999 Jul-Aug;9(5):459-75
references.pmid: 10450891
references.citation: Neuroscience. 2012 Jul 12;214:36-48
references.pmid: 22516006
references.citation: J Comp Neurol. 1988 Oct 15;276(3):313-42
references.pmid: 3192766
references.citation: Nat Neurosci. 2008 Mar;11(3):367-74
references.pmid: 18264095
references.citation: Science. 2001 Apr 13;292(5515):290-3
references.pmid: 11303104
references.citation: Cereb Cortex. 1996 Jan-Feb;6(1):31-8
references.pmid: 8670636
references.citation: J Neurophysiol. 2007 Feb;97(2):1470-84
references.pmid: 17135477
references.citation: Science. 1995 Apr 7;268(5207):111-4
references.pmid: 7701330
references.citation: J Neurosci. 2006 Oct 25;26(43):11023-33
references.pmid: 17065444