NEUR 3303 Lecture Notes - Lecture 3: Parahippocampal Gyrus, Thalamus, Lateral Geniculate Nucleus
Document Summary
Visual awareness and unconscious processes, both involuntary or unprompted by observer. Minimal contrast approach: conditions that stimuli can be seen vs conditions where stimulus cannot be seen or reported. Temporal cortex (it: when 2 related images are flashed: the image that is perceived is a fusion of the. In both images fmri shows activity in the early visual pathways (the visual thalamus, lateral geniculate nucleus (lgn), and the primary visual areas (v1, v2, v3)) Increased activation in these areas for the image that was currently conscious to the person, decreased activation for supressed image as soon as it was reported, the activation/deactivation was seen on fmri lasting as long as report lasted. When the images switch (conscious -> suppressed) the fmri also switched. Higher visual areas show activity that includes both images but different degree - e. g. the extrastriate visual areas (v4-v8) show activity that correlates with stability of consciousness especially for preferred image.