Search results for " amnesia"
showing 10 items of 25 documents
Loss of spatial learning in a patient with topographical disorientation in new environments
2003
The case is described of a patient who, following cerebral hypoxia, developed severe difficulty in orienting himself in new environments in the context of a mild global amnesic syndrome. Some episodes he related suggested that his main difficulty was remembering the spatial/directional value of landmarks he recognised. A neuroradiological examination documented severe bilateral atrophy of the hippocampi associated with atrophic changes in the cerebral hemispheres, most marked in the dorsal regions. Neuropsychological and experimental evaluation showed a severe deficit of spatial learning with substantially preserved ability to learn verbal and visual-object information. He was also virtuall…
Recognition memory for single items and for associations in amnesic patients
2004
Recognition memory performance reflects two distinct processes or types of memory referred to as recollection and familiarity. According to theoretical claims about the two types of memory, single item and associative recognition tasks can be used as an experimental method to distinguish recollection and familiarity processes. Associative recognition decisions can be used as an index of recollection while memory for single items is mostly based on familiarity judgement. We employed this procedure to examine a possible dissociation in the memory performance of amnesic patients between spared single item and impaired associative recognition. Twelve amnesic patients, six with damage confined t…
Selective sparing of face learning in a global amnesic patient
2001
Objective - To test the hypothesis that visual memory for faces can be dissociated from visual memory for topographical material. Method - A patient who developed a global amnesic syndrome after acute carbon monoxide poisoning is described. A neuroradiological examination documented severe bilateral atrophy of the hippocampi. Results - Despite a severe anterograde memory disorder involving verbal information, abstract figures, concrete objects, topographical scenes, and spatial information, the patient was still able to learn previously unknown human faces at a normal (and, in some cases, at a higher) rate. Conclusions - Together with previous neuropsychological evidence documenting selecti…
Influence of comorbidity and cognitive status on instrumental activities of daily living in amnestic mild cognitive impairment: results from the ReGA…
2007
Objectives To investigate whether amnestic mild cognitive impairment (aMCI) is characterised by restriction in instrumental activities of daily living (IADL). Further, to examine the role of comorbidity and cognitive performance on IADL changes in aMCI subjects. Methods The study included 132 subjects with aMCI and 249 subjects with no cognitive impairment (NCI), consecutively enrolled as outpatients in a multicentric Italian clinical-based study, the ReGAl Project. All subjects underwent a comprehensive evaluation including clinical examination, laboratory screening, neuroimaging and cognitive and behavioral assessments. Functional status was evaluated by the Lawton's Instrumental Activiti…
Recollection and familiarity in dense hippocampal amnesia: A case study
2004
In the amnesia literature, disagreement exists over whether anterograde amnesia involves recollective-based recognition processes and/or familiarity-based ones depending on whether the anatomical damage is restricted to the hippocampus or also involves adjacent areas, particularly the entorhinal and perirhinal cortices. So far, few patients with well documented anatomical lesions and detailed assessment of recollective and recognition performance have been described. We report a comprehensive neuroanatomical assessment and detailed investigation of the anterograde memory functions of a previously described severe amnesic patient (VC). The results of four previously published neuroradiologic…
Hippocampal reversible lesions in a case of transient global amnesia
2018
We report the case of 55-year-old man that after an emotional stress showed retrograde and anterograde amnesia with impairment of orientation in space and time but undisturbed consciousness. A neurological examination excluded other neurological signs or symptoms. The amnesic syndrome resolved spontaneously within 24 hours and the hypothesis of transient global amnesia was placed. Brain CT scan and conventional MRI sequences did not show any relevant pathological findings but diffusion-weighted imaging (DWI) showed two millimetric bright spot of restricted diffusion in the right hippocampus; in a brain MRI follow-up those findings were no more appreciable. The diagnosis of transient global …
Memory function after resolution of post traumatic amnesia
2005
Primary objectives: The aims of this pilot study were (1) to examine neuropsychological, particularly memory functions immediately after post-traumatic amnesia (PTA) resolution according to the Galveston Orientation and Amnesia Test (GOAT), and (2) to provide a preliminary exploration of pattern of performance on GOAT items across PTA duration. Methods and procedures: Thirty-seven head injured patients were administered the Recognition Memory Tests on the day that PTA resolved. Formal neuropsychological assessment was conducted on average 10 days after PTA resolution. Main outcomes and results: All the patients in the series showed memory impairment which varied in severity but was typicall…
Recollection and familiarity in hippocampal amnesia
2008
Currently, there is a general agreement that two distinct cognitive operations, recollection and familiarity, contribute to performance on recognition memory tests. However, there is a controversy about whether recollection and familiarity reflect different memory processes, mediated by distinct neural substrates (dual-process models), or whether they are the expression of memory traces of different strength in the context of a unitary declarative memory system (unitary-strength models). Critical in this debate is the status of recognition memory in hippocampal amnesia and, in particular, whether the various structures in the medial temporal lobe (MTL) contribute differentially to the recol…
Independence of first- and second-order memories in newborn rabbits
2011
WOS:000291649400006; International audience; The mammary pheromone promotes the acquisition of novel odorants (CS1) in newborn rabbits. Here, experiments pinpoint that CS1 becomes able to support neonatal learning of other odorants (CS2). We therefore evaluated whether these first- and second-order memories remained dependent after reactivation. Amnesia induced after CS2 recall selectively blocked this memory, when recall and amnesia of CS1 left the souvenir of CS2 safe; this finding partially differed from results obtained in adult mammals. Thus, in this model of neonatal appetitive odor learning, second-order memory seems to depend on first-order memory for its formation but not for its m…
Standardizzazione di tre nuovi test di memoria di riconoscimento verbale e non verbale: uno studio preliminare.
2010
Il lavoro presenta la costruzione e standardizzazione di una nuova batteria di test neuropsicologici per la valutazione della memoria di riconoscimento verbale e non verbale. La batteria è composta da tre subtest: parole, volti non familiari ed edifici sconosciuti. I test sono stati standardizzati su un campione italiano di 308 soggetti normali di entrambi i sessi, di età compresa tra 20 e 80 anni e scolarità da 5 a 19 anni. I punteggi ai tre test risultano normalmente distribuiti. Le tre prove risultano di difficoltà uguale e graduata e sono confrontabili tra loro. La batteria consente di differenziare sia deficit globali che selettivi.