title: The influence of context on recognition memory in monkeys: effects of hippocampal, parahippocampal and perirhinal lesions.
abstract: This study further investigated the specific contributions of the medial temporal lobe structures to contextual recognition memory. Monkeys (Macaca mulatta) with either neurotoxic lesions of the hippocampus, aspiration lesions of the perirhinal cortex and parahippocampal areas TH/TF, or sham operations were tested on five conditions of a visual-paired comparison (VPC) task in which 3-dimensional objects were presented over multicolored backgrounds. In two conditions (Conditions 1 and 2: Context-changes), the sample object was presented on a new background during the retention tests, whereas in the three others (Conditions 3-5: No-context-changes) the sample object was presented over its familiar background. Novelty preference scores of control animals were weaker, but still significantly different from chance, in the Context-changes conditions than on the No-context-changes conditions. Animals in the three experimental groups showed strong preference for novelty on the No-context-change conditions, but weaker novelty preference on the Context-change conditions than controls. Thus, animals in all three lesion types had greater difficulty recognizing an object when its background was different from that used during encoding. The data are consistent with the view that the hippocampal formation, areas TH/TF, and perirhinal cortex contribute interactively to contextual memory processes.
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Health Science Center, Houston, TX, USA. Electronic address: jbachev@emory.edu.
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Bachevalier
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Health Science Center, Houston, TX, USA. Electronic address: sarah.nemanic@oregonstate.edu.
authors.forename: Sarah
authors.initials: S
authors.lastname: Nemanic
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Health Science Center, Houston, TX, USA. Electronic address: malvara@emory.edu.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Alvarado
mesh_terms: D000818:Animals; D005260:Female; D006624:Hippocampus / Q000502:physiology* / Q000503:physiopathology; D007051:Ibotenic Acid; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D019635:Neurosurgical Procedures; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D021641:Recognition, Psychology / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology* / Q000503:physiopathology
chemical_list: D007051:Ibotenic Acid
keywords: Contextual binding; Contextual memory; Rhesus monkey; Visual Paired Comparison