The transition from unconscious to conscious visual perception in the intact and damaged human brain. (360G-Wellcome-096005_Z_11_Z)

Clarifying the processes that determine the transition from unconscious to conscious perception is a central theme in visual awareness research. Emotionally-significant or familiar stimuli have modulatory influences on this perceptual transition, but such influences can be disrupted in perceptual and affective disorders. This research project will investigate the neural mechanisms underlying such modulatory effects on awareness in healthy human subjects as well as patients with focal brain lesio ns and congenital disorders of face perception. Presentation of a different image to each eye leads to spontaneous alternations in perceptual experience without any change to the external visual stimulus. Face stimuli with parametrically manipulable emotional and familiarity traits will be presented under such conditions of bistable perception. Structural and functional magnetic resonance imaging, magnetoencephalography, transcranial magnetic stimulation, and pharmacological intervention, will b e used to explore the neural structures and mechanisms enabling emotional significance and familiarity to influence visual awareness. This project will provide new insight into the mechanisms through which emotion or familiarity-related information can modulate awareness. It is anticipated that findings from this work will directly enhance understanding of impairments in the specific patient groups studied, but will also have a wider relevance to understanding other perceptual and affective dis orders.