title: Auditory temporal processing in Parkinson's disease.
abstract: Previous research has suggested that Parkinson's disease (PD) impairs perceptual acuity in the temporal domain. In the present study, psychophysical tests assessing several aspects of auditory temporal processing were administered to a group of PD patients treated with bilateral subthalamic nucleus (STN) stimulation and to a normal control group. Each patient was tested in three clinical conditions: without treatment, with levodopa therapy, and during STN stimulation. In all three conditions, the patients showed a significant deficit in the detection of very short temporal gaps within noise bursts and in the discrimination between the durations of two well-detectable time intervals (circa 50ms) bounded by two temporally non-contiguous pairs of clicks. However, the patients showed no deficit in the detection of a temporal break produced by a local interval change in an otherwise isochronous sequence of 10 clicks spaced by 50-ms intervals. The latter result contradicts previous suggestions that PD slows down an internal clock or pacemaker involved in the perception of short durations. In this regard, we reinterpret previous evidence. Remarkably, the patients' deficits were not diminished by levodopa therapy; in contrast, STN stimulation slightly improved performance, overall. We tentatively ascribe the deficit observed in the gap-detection test to a dysfunctioning of the auditory cortex, impairing its ability to track rapid fluctuations in sound intensity. We argue that the deficit in the duration-discrimination test is the consequence of an impairment in memory and/or attention rather than in the perception of time per se.
authors.affiliation: Laboratoire Mouvement, Adaptation, Cognition, CNRS and Université Bordeaux 2, Bordeaux, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Guehl
authors.forename: Pierre
authors.initials: P
authors.lastname: Burbaud
authors.forename: Christian
authors.initials: C
authors.lastname: Lorenzi
authors.forename: Christophe
authors.initials: C
authors.lastname: Ramos
authors.forename: Bernard
authors.initials: B
authors.lastname: Bioulac
authors.forename: Catherine
authors.initials: C
authors.lastname: Semal
authors.forename: Laurent
authors.initials: L
authors.lastname: Demany
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000009:adverse effects / Q000627:therapeutic use; D001299:Audiometry / Q000379:methods; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology; D004192:Discrimination, Psychological / Q000187:drug effects / Q000502:physiology*; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000379:methods; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007980:Levodopa / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000503:physiopathology / Q000601:surgery; D013647:Task Performance and Analysis; D013702:Temporal Lobe / Q000187:drug effects / Q000503:physiopathology*; D013998:Time Perception / Q000187:drug effects / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa