Timing expectations in the human brain. (360G-Wellcome-089903_Z_09_Z)

We have come to understand that perception is a highly proactive process, biased to deliver the events that are most relevant to our current motivational state and task goals. Attention research has shown how signals coding predictions about the location, identity or simple features of relevant events can influence several stages of neural processing. Though expectations about the timing of events are also pervasive, the temporal dimension has been left out of mainstream research. The experiment s proposed redress this imbalance by investigating the neural systems and neural mechanisms by which temporal expectation modulates information processing and influences top-down modulation by other types of attention. In order to understand whether temporal expectation operates through a modality-independent set of mechanisms, direct comparisons will be made between effects within the visual and auditory modalities, as well as across modalities. Nine experiments are proposed, using systematic m anipulations of temporal and other types of expectations (Series 1) and of sensory modalities (Series 2). In order to reveal the neural systems and mechanisms with high spatial and temporal resolution, and to test for their causal role; the methodology includes complementary hemodynamic (fMRI) and magneto/electrophysiological (MEG/EEG) brain-imaging methods, complemented by non-invasive transcranial magnetic stimulation (TMS).