Temporal dissociation of global and local features by hierarchy of vision.
Most objects in our environment are organized hierarchically with a global whole embedding its local parts, but the way we recognize these features remains unclear. Using a visual masking paradigm, we examined the temporal dissociation between global and local feature as proposed in Reverse Hierarchy Theory, RHT (Ahissar & Hochstein, 2000), where global and local information are assumed to be processed, respectively, by feed-forward and feedback systems. We found that in a long Stimulus Onset Asynchrony (SOA) condition, both global and local information were recognized adequately. However, in a short SOA condition, global information was recognized correctly while local recognition was critically disrupted. Consistent with RHT, it is suggested that local information is processed in a feedback system; this processing is then interrupted by the mask stimulus presented later at the primary visual area. Global information, by contrast, is transferred via a feed-forward system, and is not disrupted by the mask.
Ishizu
Tomohiro
T
Department of Psychology, Graduate School of Human Relations, Keio University, Mita, Minato-ku, Tokyo, Japan. tishizu@z3.keio.jp
Ayabe
Tomoaki
T
Kojima
Shozo
S
D005246:Feedback / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008959:Models, Neurological; D009483:Neuropsychological Tests; D009949:Orientation / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors; D013998:Time Perception / Q000502:physiology; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology*; D014795:Visual Pathways / Q000033:anatomy & histology / Q000502:physiology*; D055815:Young Adult