Showing papers by "Eraldo Paulesu published in 1992"
TL;DR: In vivo evidence for the role of a functional network as a basis of human memory is found in patients with “pure” amnesia, finding a significant bilateral reduction in metabolism in a number of interconnected cerebral regions.
Abstract: Summary: Human amnesia is a clinical syndrome exhibiting the failure to recall past events and to learn new information. Its “pure” form, characterized by a selective impairment of long-term memory without any disorder of general intelligence or other cognitive functions, has been associated with lesions localized within Papez's circuit and some connected areas. Thus, amnesia could be due to a functional disconnection between components of this or other neural structures involved in long-term learning and retention. To test this hypothesis, we measured regional cerebral metabolism with 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) and positron emission to mography (PET) in 11 patients with “pure” amnesia. A significant bilateral reduction in metabolism in a number of interconnected cerebral regions (hippocampal formation, thalamus, cingulate gyrus, and frontal basal cortex) was found in the amnesic patients in comparison with normal controls. The metabolic impairment did not correspond to alterations in structural anatomy as assessed by magnetic resonance imaging (MRI). These results are the first in vivo evidence for the role of a functional network as a basis of human memory.
119 citations
TL;DR: Psychopharmacological activation and positron emission tomographic measurements of regional cerebral blood flow were used to investigate the neurotransmitter basis of a specific cognitive function in man and regionally selective interactions may represent neuromodulatory effects of monoaminergic neurotransmission.
Abstract: Psychopharmacological activation, in conjunction with positron emission tomographic measurements of regional cerebral blood flow (rCBF), was used to investigate the neurotransmitter basis of a specific cognitive function in man. Monoaminergic neurotransmission was pharmacologically manipulated during performance of auditory - verbal memory tasks. Statistical parametric mapping was used to identify the brain sites of interaction between memory-induced increases in rCBF and active drugs. Memory task-induced increases in rCBF in the left prefrontal cortex were attenuated by apomorphine, a non-selective dopamine agonist, whilst buspirone, a serotonin1A partial agonist, augmented rCBF increases in this area. In addition, apomorphine and buspirone augmented memory-induced increases in rCBF centred in the posterior cingulate cortex, whilst buspirone alone attenuated rCBF increases in the retrosplenial cortex and posterior parahippocampal gyrus. These regionally selective interactions may represent neuromodulatory effects of monoaminergic neurotransmission on a specific cognitive function in man.
45 citations
TL;DR: The data suggest that CC atrophy interfers more with left than with right metabolic function, although a slight metabolic reduction was observed in both MS groups compared with normal controls.
37 citations