hide
Free keywords:
-
Abstract:
What mechanisms guide attention along temporally structured signals? Dynamic attending theory (DAT, Large & Jones, 1999) models attention as an oscillation that adjusts its phase and period in an attempt to synchronize internal resources with the temporal structure of external events, thereby allocating attention to specific points in time. As an instance of anticipatory stimulus-driven attending (Jones et al., 2002) this adaptation has to rely on an internal representation of temporal structure, possibly generated by neural systems implicated in temporal processing. The cerebellum (CE) and the basal ganglia (BG) are assumed to perform either pre-attentive, event-based or attention-dependent, interval-based temporal processing (Buhusi & Meck, 2005). To elaborate on these positions, the current study exploited the high temporal resolution of the Electroencephalogram (EEG) to investigate whether the amplitude of the event-related potential (ERP) associated with the attentive detection of change (P300) indicates the quality of synchronization in healthy and patient populations. The EEG was recorded from controls as well as patients with focal cerebellar or basal ganglia lesions while these participants directed their attention to two-tone auditory oddball sequences (600 Hz standard, 660 Hz deviant). The inter-stimulus-interval (ISI) in each sequence was manipulated to convey either isochronous or random temporal structure. Results suggest that this manipulation indeed has an impact on P300 amplitude. In comparison to controls and CE patients, the effect was strongest for BG patients. These findings support DAT as well as the proposed roles of the CE and the BG in pre-attentive, event-based and attention-dependent temporal processing, respectively.
