The long term objective of this application is to understand how behavioral goals and expectations about visual events are represented and used within the human brain. Event-related fMRI methods are developed to distinguish the neural signals representing behavioral goals and expectations from the signals reflecting their effects on perceptual analysis. These methods are then used to study the dependence of these signals on the content of the expectation (e.g. an expectation about the motion of an object or its color), on how the expectation is generated (e.g. from verbal or non- verbal commands, or from instructions presented in different sensory modalities), and on how it is used during visual perception (e.g. to detect a stimulus or to categorize it). This information will advance our theoretical understanding of visual perception and awareness. These studies will also help to elucidate the pathophysiology of clinical brain disorders, that involve attentional and visual perceptual deficits, e.g. unilateral neglect, attentional deficit disorders, or dyslexia. A finer understanding of attentional mechanisms will also facilitate the development of neurobiologically- driven rehabilitative strategies.
