Apparent motion: event-related functional magnetic resonance imaging of perceptual switches and States.
When spatially segregated visual stimuli are presented in alternation, subjects may perceive a single stimulus moving between the two positions (apparent motion). By adjusting spatial and temporal parameters, an ambiguous condition can be created in which perception of back-and-forth motion alternates with the perception of two stationary blinking stimuli. We presented subjects with such ambiguous stimuli, asked them to signal periods of perceived motion and blinking, and measured brain activity with functional magnetic resonance imaging. Multiple regression analysis revealed that early visual areas responded with equal strength during both perceptual conditions, whereas hMT+(V5) (the human motion complex that includes the human homolog of MT and its satellites) was more active during the perception of apparent motion. These results indicate that neurons in hMT+ participate in the constructive process that creates a continuous motion percept from a discontinuous visual input.
Muckli
Lars
L
Max Planck Institute for Brain Research, Neurophysiology, 60528 Frankfurt am Main, Germany. muckli@mpih-frankfurt.mpg.de
Kriegeskorte
Nikolaus
N
Lanfermann
Heinrich
H
Zanella
Friedhelm E
FE
Singer
Wolf
W
Goebel
Rainer
R
D001931:Brain Mapping; D005133:Eye Movements / Q000502:physiology; D005403:Fixation, Ocular / Q000502:physiology; D005425:Flicker Fusion / Q000502:physiology; D005625:Frontal Lobe / Q000502:physiology; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D009039:Motion Perception / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics / Q000379:methods; D012438:Saccades / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology; D013997:Time Factors