Does neuroscience belong here? Parallel processing in high-level categorization of natural images Guillaume A. Rousselet, Michèle Fabre-Thorpe & Simon J. Thorpe Centre de Recherche Cerveau and Cognition (UMR 5549, CNRS-UPS), Faculté de Médecine de Rangueil, 133 route de Narbonne, 31062 Toulouse, France Correspondence should be addressed to G A Rousselet. e-mail: firstname.lastname@example.org Models of visual processing often include an initial parallel stage that is restricted to relatively low-level features, whereas activation of higher-level object descriptions is generally assumed to require attention1-4. Here we report that even high-level object representations can be accessed in parallel: in a rapid animal versus non-animal categorization task, both behavioral and electrophysiological data show that human subjects were as fast at responding to two simultaneously presented natural images as they were to a single one. The implication is that even complex natural images can be processed in parallel without the need for sequential focal attention.