title: Rapid categorization of natural scenes in monkeys: target predictability and processing speed.
abstract: Three monkeys performed a categorization task and a recognition task with briefly flashed natural images, using in alternation either a large variety of familiar target images (animal or food) or a single (totally predictable) target. The processing time was 20 ms shorter in the recognition task in which false alarms showed that monkeys relied on low-level cues (color, form, orientation, etc.). The 20-ms additional delay necessary in monkeys to perform the categorization task is compared with the 40-ms delay previously found for humans performing similar tasks. With such short additional processing time, it is argued that neither monkeys nor humans have time to develop a fully integrated object representation in the categorization task and must rely on coarse intermediate representations.
authors.affiliation: Centre de recherche Cerveau & Cognition, CNRS-UPS - UMR 5549, Faculté de Médecine de Rangueil, 133 route de Narbonne, 31062 Toulouse Cedex, France. marc.mace@cerco.ups-tlse.fr
authors.forename: Marc J-M
authors.initials: MJ
authors.lastname: Macé
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Richard
authors.forename: Arnaud
authors.initials: A
authors.lastname: Delorme
authors.forename: Michèle
authors.initials: M
authors.lastname: Fabre-Thorpe
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D008253:Macaca mulatta; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D011237:Predictive Value of Tests; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D013997:Time Factors