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The prefrontal cortex is implicated in such human characteristics as volition, planning, abstract reasoning and affect. Frontal-lobe damage can cause disinhibition such that the behaviour of a subject is guided by previously acquired responses that are inappropriate to the current situation. Here we demonstrate that disinhibition, or a loss of inhibitory(More)
Using a primate analogue of the Wisconsin Card Sort Test, this study demonstrated, for the first time, that lesions of the prefrontal cortex in monkeys produce a qualitatively similar impairment in attentional set-shifting to that seen following prefrontal cortical damage in humans. Although damage to the prefrontal cortex did not disrupt the ability of(More)
RATIONALE Paired-associate learning (PAL), as part of the Cambridge Neuropsychological Test Automated Battery, is able to predict who from an at-risk population will develop Alzheimer's disease. Schizophrenic patients are also impaired on this same task. An automated rodent model of PAL would be extremely beneficial in further research into Alzheimer's(More)
Attentional set-shifting and discrimination reversal are sensitive to prefrontal damage in the marmoset in a manner qualitatively similar to that seen in man and Old World monkeys, respectively (Dias et al., 1996b). Preliminary findings have demonstrated that although lateral but not orbital prefrontal cortex is the critical locus in shifting an attentional(More)
RATIONALE Selective cognitive impairments, including those of executive function as assessed using the Wisconsin Card Sort Test or intradimensional-extradimensional (ID-ED) tests, are a key feature of schizophrenia but remain inadequately treated by existing therapies. Recently, however, modafinil has been shown to improve attentional set-shifting(More)
To gain insight into the nature and neural specificity of the relationship between simple problem solving, inhibitory control and prefrontal cortex, comparison of the effects of excitotoxic lesions of the orbitofrontal and lateral prefrontal cortex were examined on the performance of common marmosets on a detour reaching task. Monkeys were required to(More)
Activity of the immediate early gene c-fos was compared in rats with neurotoxic lesions of the anterior thalamic nuclei and in surgical controls. Fos levels were measured after rats had been placed in a novel room and allowed to run up and down preselected arms of a radial maze. An additional control group showed that in normal rats, this exposure to a(More)
Activity of the immediate early gene c-fos was compared across hemispheres in rats with unilateral anterior thalamic lesions. Fos protein was quantified after rats performed a spatial working memory test in the radial-arm maze, a task that is sensitive to bilateral lesions of the anterior thalamic nuclei. Unilateral anterior thalamic lesions produced(More)
Phencyclidine (PCP) was administered to male and female Lister hooded rats on postnatal days (PND) 7, 9 and 11. All PCP animals tested in adulthood (PND 53-93) showed deficits in cognitive flexibility, specifically in their ability to shift attentional set, compared to controls. This novel finding is reminiscent of the impairment observed in schizophrenia(More)
The present study investigated the contributions of the medial prefrontal cortex and its major subdivisions, the dorsal anterior cingulate (ACd) and prelimbic-infralimbic (PL) cortices, to spatial working memory and inhibitory control processes. In experiment 1, excitotoxic lesions centred in the ACd or PL cortex did not affect acquisition of a(More)