The time course of visual processing: backward masking and natural scene categorisation.
Human observers are very good at deciding whether briefly flashed novel images contain an animal and previous work has shown that the underlying visual processing can be performed in under 150 ms. Here we used a masking paradigm to determine how information accumulates over time during such high-level categorisation tasks. As the delay between test image and mask is increased, both behavioural accuracy and differential ERP amplitude rapidly increase to reach asymptotic levels around 40-60 ms. Such results imply that processing at each stage in the visual system is remarkably rapid, with information accumulating almost continuously following the onset of activation.
Bacon-Macé
Nadège
N
Centre de Recherche Cerveau et Cognition (UMR 5549, CNRS-UPS), Faculté de Médecine de Rangueil,133, Route de Narbonne, 31062 Toulouse, France. nadege.bacon-mace@cerco.ups-tlse.fr
Macé
Marc J-M
MJ
Fabre-Thorpe
Michèle
M
Thorpe
Simon J
SJ
D000328:Adult; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004192:Discrimination, Psychological; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010470:Perceptual Masking / Q000502:physiology*; D011601:Psychophysics; D011930:Reaction Time; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014795:Visual Pathways; D014796:Visual Perception / Q000502:physiology*