title: Carving the clock at its component joints: neural bases for interval timing.
abstract: Models of time perception often describe an "internal clock" that involves at least two components: an accumulator and a comparator. We used functional magnetic resonance imaging to test the hypothesis that distinct distributed neural networks mediate these components of time perception. Subjects performed a temporal discrimination task that began with a visual stimulus (S1) that varied parametrically in duration of presentation. A varying interstimulus interval was followed by a second visual stimulus (S2). After the S2 offset, the subject indicated whether S2 was longer or shorter than S1. We reasoned that neural activity that correlated with S1 duration would represent accumulator networks. We also reasoned that neural activity that correlated with the difficulty of comparisons for each paired-judgment would represent comparator networks. Using anatomically defined regions of interest, we found duration of S1 significantly correlated with left inferior frontal, supplementary motor area (SMA) and superior temporal regions. Furthermore, task difficulty correlated with activity within bilateral inferior frontal gyri. Therefore accumulator and comparator functioning of the internal clock are mediated by distinct as well as partially overlapping neural regions.
authors.affiliation: Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, USA. ewencil@psych.upenn.edu
authors.forename: Elaine B
authors.initials: EB
authors.lastname: Wencil
authors.forename: H Branch
authors.initials: HB
authors.lastname: Coslett
authors.forename: Geoffrey K
authors.initials: GK
authors.lastname: Aguirre
authors.forename: Anjan
authors.initials: A
authors.lastname: Chatterjee
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D003116:Color; D003627:Data Interpretation, Statistical; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D013998:Time Perception / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen
references.citation: Curr Opin Neurobiol. 1996 Dec;6(6):851-7
references.pmid: 9000026
references.citation: Exp Brain Res. 1999 Apr;125(3):271-80
references.pmid: 10229018
references.citation: Brain Res Cogn Brain Res. 2004 Oct;21(2):133-7
references.pmid: 15464347
references.citation: Neuropsychologia. 1998 Dec;36(12):1283-93
references.pmid: 9863682
references.citation: Neuron. 2003 Apr 24;38(2):317-27
references.pmid: 12718864
references.citation: Pharmacol Biochem Behav. 1986 Dec;25(6):1185-9
references.pmid: 2880350
references.citation: J Neurosci. 1998 Feb 1;18(3):1085-95
references.pmid: 9437028
references.citation: Exp Brain Res. 1990;79(3):504-14
references.pmid: 2340870
references.citation: Neuroimage. 1995 Sep;2(3):173-81
references.pmid: 9343600
references.citation: J Cogn Neurosci. 2008 Jun;20(6):1054-62
references.pmid: 18211231
references.citation: Neuroreport. 2005 Sep 8;16(13):1467-71
references.pmid: 16110273
references.citation: Neuroreport. 1997 Mar 24;8(5):1273-6
references.pmid: 9175128
references.citation: Mem Cognit. 1994 Nov;22(6):673-86
references.pmid: 7808276
references.citation: Neuroimage. 2000 Mar;11(3):228-42
references.pmid: 10694465
references.citation: Endeavour. 1997;21(2):82-7
references.pmid: 9237431
references.citation: Neuropsychologia. 1999 Aug;37(9):1061-70
references.pmid: 10468369
references.citation: Neuropsychologia. 2007 Jan 28;45(2):321-31
references.pmid: 16934301
references.citation: Brain Cogn. 2002 Feb;48(1):195-211
references.pmid: 11812042
references.citation: Brain Res Cogn Brain Res. 2004 Oct;21(2):206-15
references.pmid: 15464352
references.citation: Nat Neurosci. 2001 Mar;4(3):317-23
references.pmid: 11224550
references.citation: Ann N Y Acad Sci. 1984;423:528-41
references.pmid: 6588813
references.citation: Trends Cogn Sci. 2003 Nov;7(11):483-8
references.pmid: 14585444
references.citation: Neurosci Lett. 1997 Oct 10;235(1-2):21-4
references.pmid: 9389586
references.citation: Neurosci Biobehav Rev. 2004 Nov;28(7):747-69
references.pmid: 15555682
references.citation: Pharmacol Biochem Behav. 2003 Apr;75(1):9-15
references.pmid: 12759108
references.citation: Science. 2004 Mar 5;303(5663):1506-8
references.pmid: 15001776
references.citation: Behav Neurosci. 1984 Feb;98(1):3-22
references.pmid: 6696797
references.citation: Neuroimage. 2001 Jan;13(1):37-45
references.pmid: 11133307
references.citation: Perception. 1990;19(6):705-43
references.pmid: 2130371
references.citation: Behav Neurosci. 1988 Feb;102(1):54-60
references.pmid: 3355658
references.citation: Rev Neurosci. 1999;10(2):91-116
references.pmid: 10658954
references.citation: Behav Processes. 2006 Feb 28;71(2-3):107-15
references.pmid: 16413701
references.citation: Curr Opin Neurobiol. 2008 Apr;18(2):137-44
references.pmid: 18692573
references.citation: Trends Cogn Sci. 2006 Sep;10(9):401-6
references.pmid: 16899395
references.citation: J Exp Psychol Hum Percept Perform. 2000 Dec;26(6):1770-87
references.pmid: 11129373
references.citation: Curr Opin Neurobiol. 2003 Apr;13(2):250-5
references.pmid: 12744981
references.citation: Brain Res Cogn Brain Res. 2004 Oct;21(2):193-205
references.pmid: 15464351
references.citation: J Neurophysiol. 2000 Feb;83(2):1079-87
references.pmid: 10669519
references.citation: Exp Brain Res. 2000 Feb;130(3):328-37
references.pmid: 10706432
references.citation: Hum Brain Mapp. 2000 Jun;10(2):49-60
references.pmid: 10864229
references.citation: J Cogn Neurosci. 2006 Mar;18(3):376-87
references.pmid: 16513003
references.citation: J Neurosci. 1997 Jul 15;17(14):5528-35
references.pmid: 9204934
references.citation: Curr Opin Neurobiol. 2008 Apr;18(2):145-52
references.pmid: 18708142
references.citation: Psychopharmacology (Berl). 1983;79(1):10-5
references.pmid: 6403957
references.citation: Neuroreport. 2001 Apr 17;12(5):939-42
references.pmid: 11303764
references.citation: Cognition. 1990 Nov;37(1-2):55-81
references.pmid: 2269008
references.citation: Behav Processes. 2006 Feb 28;71(2-3):226-34
references.pmid: 16434151
references.citation: Neuroimage. 1997 Apr;5(3):199-212
references.pmid: 9345549
references.citation: Psychopharmacology (Berl). 2005 Oct;182(2):232-44
references.pmid: 16001114
references.citation: Brain Res Cogn Brain Res. 2004 Oct;21(2):171-82
references.pmid: 15464349
references.citation: Exp Brain Res. 2002 Feb;142(4):475-85
references.pmid: 11845243
references.citation: Brain Res Cogn Brain Res. 1996 Jun;3(3-4):227-42
references.pmid: 8806025
references.citation: Neuroimage. 2003 Aug;19(4):1532-44
references.pmid: 12948709
references.citation: Ann N Y Acad Sci. 2002 Dec;978:302-17
references.pmid: 12582062