Segregation and persistence of form in the lateral occipital complex.
While the lateral occipital complex (LOC) has been shown to be implicated in object recognition, it is unclear whether this brain area is responsive to low-level stimulus-driven features or high-level representational processes. We used scrambled shape-from-motion displays to disambiguate the presence of contours from figure-ground segregation and to measure the strength of the binding process for shapes without contours. We found persisting brain activation in the LOC for scrambled displays after the motion stopped indicating that this brain area subserves and maintains figure-ground segregation processes, a low-level function in the object processing hierarchy. In our second experiment, we found that the figure-ground segregation process has some form of spatial constancy indicating top-down influences. The persisting activation after the motion stops suggests an intermediate role in object recognition processes for this brain area and might provide further evidence for the idea that the lateral occipital complex subserves mnemonic functions mediating between iconic and short-term memory.
Department of Psychology, University of Toronto, 100 St. George Street Toronto, Ont., Canada M5S 3G3. ferber@psych.utoronto.ca
Susanne
S
Ferber
G Keith
GK
Humphrey
Tutis
T
Vilis
D000328:Adult; D000465:Algorithms; D003463:Cues; D005260:Female; D005556:Form Perception / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009778:Occipital Lobe / Q000502:physiology*; D010775:Photic Stimulation