Prof. Alan J. Pegna演講兩場 – 10/23(三) 14:30 臺大心理系
主題：Affective blindsight: Evidence for and against a rapid subcortical route
Destruction of the brain’s primary visual areas leads to blindness of cortical origin. Following bilateral destruction of the visual cortices, some patients remain capable of correctly guessing facial expressions of emotion despite a lack of awareness of having seen the stimuli. The brain regions and pathways involved in this so-called “affective blindsight” are still controversial and little is known about the speed at which this processing occurs. In this talk we will present a series of studies carried out on a cortically blind patient, as well as a group of healthy controls using EEG and fMRI. In these investigations, we present evidence against and in favor of a rapid subcortical pathway for unconscious processing of visual stimuli.
主題：Conscious and non-conscious processing of facial characteristics
Recent research has suggested that emotional faces can be processed without awareness. One aspect that has received less attention however is whether it is the emotional expression strictly speaking that is processed this manner, or whether non-conscious processing also applies to other equally relevant aspects of a face (e.g., identity, gaze direction). This presentation will provide evidence from EEG and fMRI, as well as from brain-damaged patients, suggesting that non-conscious processing occurs prior to visual awareness, but most likely only for behaviorally relevant stimuli, while awareness of the stimulus arises later in time.
Representative publications of Alan J. Pegna:
Pegna, A. J.*, Khateb, A., Lazeyras, F., & Seghier, M. (2005). Discriminating emotional faces without the primary visual cortices involves the right amygdala. Nature Neuroscience,8(1), 24-25.
Thierry G, Martin CD, Downing P, Pegna AJ. (2007). Controlling for interstimulus perceptual variance abolishes N170 face selectivity. Nature Neuroscience. 10(7), 802-803.
Pegna, A. J.*, Landis, T., & Khateb, A. (2008). Electrophysiological evidence for early non-conscious processing of fearful facial expressions. International Journal of Psychophysiology, 70(2), 127-136.
Simon SR, Darque A, Khateb A, Lazeyras F, Mayer E, Pegna AJ. (2011) When the brain remembers, but the patient doesn’t: Converging EEG and fMRI evidence for covert recognition in a case of prosopagnosia. Cortex, 47, 823-838.