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The relationship between anterograde and retrograde amnesia remains unclear. Previous data from both clinical neuropsychology and monkey lesion studies suggest that damage to discrete subcortical structures leads to a relatively greater degree of anterograde than retrograde amnesia, whereas damage to discrete regions of cortex leads to the opposite pattern(More)
Disconnection of the frontal lobe from the inferotemporal cortex produces deficits in a number of cognitive tasks that require the application of memory-dependent rules to visual stimuli. The specific regions of frontal cortex that interact with the temporal lobe in performance of these tasks remain undefined. One capacity that is impaired by(More)
It has been hypothesized that some fornical fibres may instantiate a neuromodulatory reinforcement signal supporting memory acquisition in medial temporal cortical regions. This suggests that fornix transection should impair postoperative new learning more severely than the recall of preoperatively acquired information. Here, postoperative recall of 288(More)
Both frontal-inferotemporal disconnection and fornix transection (Fx) in the monkey impair object-in-place scene learning, a model of human episodic memory. If the contribution of the fornix to scene learning is via interaction with or modulation of frontal-temporal interaction--that is, if they form a unitary system--then Fx should have no further effect(More)
In the macaque monkey, disconnection syndromes can be produced experimentally either by selective section of axonal pathways or by crossed unilateral asymmetrical ablations. Behavioural investigation of the effects of these disconnections gives information that cannot be derived either from clinical studies or from the effects of bilateral symmetrical(More)
In the absence of external stimuli or task demands, correlations in spontaneous brain activity (functional connectivity) reflect patterns of anatomical connectivity. Hence, resting-state functional connectivity has been used as a proxy measure for structural connectivity and as a biomarker for brain changes in disease. To relate changes in functional(More)
Anatomical and functional studies of the prefrontal cortex (PFC) have identified multiple PFC subregions. We argue that the PFC is involved in cognitive functions exceeding the sum of specific functions attributed to its subregions. These can be revealed either by lesions of the whole PFC, or more specifically by selective disconnection of the PFC from(More)
Prefrontal cortex (PFC) is thought to have a wide-ranging role in cognition, often described as executive function or behavioral inhibition. A specific example of such a role is the inhibition of representations in more posterior regions of cortex in a "top-down" manner, a function thought to be tested by reversal learning tasks. The direct action of PFC on(More)
The hippocampus has a well established role in spatial memory, but increasing evidence points to a role in nonspatial aspects of memory. To investigate such a role, six macaque monkeys received a bilateral transection of the fornix to disconnect subcortical inputs and outputs of the hippocampus. An additional six macaque monkeys constituted an unoperated(More)
Electrophysiological evidence in macaque monkeys indicates that when the monkey views a visual scene with objects present in both visual hemifields, the cells of the temporal lobe respond to objects in the contralateral field, but are hardly affected by objects in the ipsilateral field. If visual memories are stored in the temporal lobes, as is generally(More)
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