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The psychological construct 'sustained attention' describes a fundamental component of attention characterized by the subject's readiness to detect rarely and unpredictably occurring signals over prolonged periods of time. Human imaging studies have demonstrated that activation of frontal and parietal cortical areas, mostly in the right hemisphere, are(More)
Neurophysiological studies demonstrated that increases in cholinergic transmission in sensory areas enhance the cortical processing of thalamic inputs. Cholinergic activity also suppresses the retrieval of internal associations, thereby further promoting sensory input processing. Behavioral studies documented the role of cortical cholinergic inputs in(More)
Cortical cholinergic inputs are hypothesized to mediate attentional functions. The present experiment was designed to determine the single unit activity of neurons within the medial prefrontal cortex (mPFC) of rats performing a sustained visual attention task. Demands on attentional performance were varied by the presentation of a visual distractor. The(More)
The relationship between memory and rhythmic neural activity in the dentate gyrus was investigated by analyzing spontaneous dentate field potentials in rats performing either a working or reference memory task. The baseline level of rhythmic theta activity was similar in both groups. Following an initial negative potential in the sensory-evoked response, a(More)
Experimental manipulations that compromise the medial septal area consistently and selectively impair working memory. The electrophysiological and pharmacological properties of medial septal neurons have been studied extensively, but the relation between medial septal neuronal activity and ongoing behavior has not been systematically analysed. Working(More)
The role of the septohippocampal pathway in working memory was investigated by direct microinfusion of compounds into the medial septal area (MSA). Behavior was measured by performance in a continuous spatial alteration task in a T maze, and hippocampal theta rhythm was also recorded. Intraseptal saline had no effect on choice accuracy or hippocampal theta(More)
The hypotheses that the medial septal area (MSA) is critical for working memory and that MSA neural activity is positively regulated by cholinergic inputs leads to two testable predictions: (1) working memory can be bidirectionally modulated by muscarinic manipulations of the MSA and (2) muscarinic activation of the MSA can enhance memory under conditions(More)
Long-term potentiation (LTP), a leading neural mechanism of memory, is profoundly affected by ethanol in vitro, but ethanol's effect on LTP in vivo has not been studied at doses known to impair memory. In this study, LTP was induced in the dentate hilus by theta-pattern stimulation of the perforant path. Dentate evoked responses were recorded during a 3 h(More)
The conceptual foundations of a research aimed at the determination of potential neuronal, neuropharmacological, and behavioral/cognitive mechanisms mediating drug-induced cognition enhancement are discussed. The available evidence justifies a focus on attentional processes as a target for drug-induced cognition enhancement. Neuropharmacological mechanisms(More)
The posterior parietal cortex (PPC) plays an integral role in visuospatial attention. Evidence suggests that neuronal activity in the PPC predicts the allocation of attention to stimuli. The present experiment tested the hypothesis that in rats performing a sustained attention task, the detection of signals, as opposed to missed signals, is associated with(More)