title: The neural correlates of habituation of response to startling tactile stimuli presented in a functional magnetic resonance imaging environment.
abstract: Functional magnetic resonance imaging (fMRI) provides a means of identifying neural circuitry associated with startle and its modulation in humans. Twelve subjects who demonstrated eyeblink startle in the laboratory were recruited for an fMRI study in which they were scanned while presented with two identical runs consisting of alternating blocks of no stimuli and startling tactile stimuli. Together, behavioral and imaging data are consistent with a pattern of general cortical and thalamic activation induced by startling stimuli that shows habituation both across and within runs. From Run 1 to Run 2, both the eyeblink amplitude and the fMRI signal decreased. Within Run 1, there was a graded decrease in eyeblink amplitude and whole-brain fMRI signal across blocks of startling stimuli. A similar graded decrease was observed in the thalamus signal, as well. Thus, startling tactile stimuli initially induce widespread cortical and thalamic activity, perhaps mediated by the reticular activating system. The activity then habituates in a graded fashion with repeated presentations of the stimuli.
authors.affiliation: Department of Psychology, University of Georgia, Athens, GA 30602, USA. jemcd@uga.edu
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: McDowell
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Brown
authors.forename: Nicole
authors.initials: N
authors.lastname: Lazar
authors.forename: Jazmin
authors.initials: J
authors.lastname: Camchong
authors.forename: Richard
authors.initials: R
authors.lastname: Sharp
authors.forename: Kirsten
authors.initials: K
authors.lastname: Krebs-Thomson
authors.forename: Lisa T
authors.initials: LT
authors.lastname: Eyler
authors.forename: David L
authors.initials: DL
authors.lastname: Braff
authors.forename: Mark A
authors.initials: MA
authors.lastname: Geyer
mesh_terms: D000328:Adult; D001767:Blinking / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006179:Gyrus Cinguli / Q000502:physiology; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010100:Oxygen / Q000097:blood*; D010296:Parietal Lobe / Q000502:physiology; D013216:Reflex, Startle / Q000502:physiology*; D013788:Thalamus / Q000502:physiology*; D014110:Touch / Q000502:physiology*
chemical_list: D010100:Oxygen