Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Spatial memory”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36Linked to original sources
PubMed1996

Sex differences in neuropsychological functioning among schizophrenic patients.

OBJECTIVE: The view of schizophrenic men as having poorer premorbid development, earlier age at onset, and worse outcome than schizophrenic women predicts greater neuropsychological impairment in the former than the latter. The authors examined in detail neuropsychological functioning in a large group of schizophrenic patients and a healthy comparison group. METHOD: Neuropsychological functioning in 132 male and 63 female patients with schizophrenia or schizoaffective disorder was extensively studied and compared with that of 99 (40 male, 59 female) healthy individuals. RESULTS: As expected, the schizophrenic patients as a group were pervasively and significantly more impaired than the comparison group. Within schizophrenia, in contrast to the prediction, women performed significantly more poorly than men in verbal memory, spatial memory, and visual processing. Female schizophrenic patients also had significantly poorer right than left hemisphere performance, whereas male schizophrenic patients had identical scores for right and left hemisphere impairment. CONCLUSIONS: The findings are consistent with the hypothesis that schizophrenia among women may be partially understood as a right hemisphere dysfunction. Sampling, diagnostic, and epidemiologic factors may have affected the results.

Adult↗
PubMed2002

Effect of atropine and the oxime HI-6 on low-level sarin-induced alteration of performance of rats in a T-maze.

1. To study the influence of antidotes on low-level sarin-induced alteration of cognitive functions, male albino Wistar rats were exposed to three various low concentrations of sarin for 60 minutes in the inhalation chamber. One minute following sarin exposure, the rats were i.m. treated with the oxime HI-6 in combination with atropine. Control rats were treated with antidotes as experimental rats but exposed to the pure air instead of sarin. Cognitive functions of the rats were tested using a T-maze where spatial memory and spatial orientation were evaluated. The performance of sarin-exposed and treated rats in the T-maze was tested several times within six weeks (single exposure) or five weeks (repeated exposure) following inhalation exposure to evaluate cognitive impairments. 2. In the case of single exposure to sarin, no statistically significant differencies between the performances of the control and the experimental groups in the alteration of spatial memory and spatial orientation were observed. The repeated exposure of treated rats to clinically asymptomatic dose of sarin (LEVEL 2) did not change the effect of low-level sarin exposure on spatial memory of the experimental rats compared to the single exposure to the same dose of sarin. 3. The decrease in the T-maze performance of the control rats was caused by the impairments of rat's mobility due to the features of a solution of antidotes.

Animals↗
PubMed1998

The effects of MK-801 on spatial working memory and within-session spatial learning.

The present study investigated the effects of the NMDA channel blocker MK-801 (0.05, 0.10, and 0.15 mg/kg) on a task that allows for the assessment of both spatial working memory and within-session spatial learning. During the first trial of each day, subjects were shown the spatial location of a food reward on a six-arm radial-arm maze. During nine subsequent free-choice trials, subjects were reinforced for returning to that same spatial location. The location of the food reward varied across days. Thus, choosing correctly on any given trial required subjects to remember where food had been received during the previous trials of that day. The effects of MK-801 on working memory were assessed by analyzing the overall number of errors committed during the nine free-choice trials of each day. The effects of MK-801 on within-session learning were assessed by comparing the number of errors committed during the first three trials of each day to the number of errors committed during the last three trials of each day. Only the highest dose of MK-801 tested (0.15 mg/kg) impaired spatial working memory. No dose of MK-801 impaired the ability of subjects to acquire spatial information within a given session. The failure of MK-801 to impair within-session spatial learning stands in contrast to the well-known effects of MK-801 on spatial learning measured across days. Thus, when coupled with previous research, the findings of the present study further suggest that the NMDA receptor plays a role in the long-term, but not short-term, storage of spatial information.

Adaptation, Psychological↗
PubMed1996

The bailiwick of visuo-spatial working memory: evidence from unilateral spatial neglect.

An accurate representation of the visual environment is crucial for successful interaction with objects in that environment. The means by which that representation is formed in working memory is a major focus of the issues and research discussed in this paper. The discussion draws on experimental studies of healthy adults and of patients with impairments of visual perceptual processing or of visuo-spatial mental representation. These disorders are most commonly linked with the disorder referred to clinically as unilateral spatial neglect. We discuss the observed dissociation between perceptual neglect and representational neglect, and the phenomenon of implicit processing of information in the neglected hemifield. In so doing we explore the implications of the findings from this literature for the development of theories of visuo-spatial working memory.

Attention↗
PubMed1993

Memory impairments following lesions to the mammillary region of the rat.

The contribution of the mammillary region to learning and memory was investigated. It was demonstrated that lesions of this region impair performance on tasks that require memory for spatial information but that the deficit depends both on the amount of damage within the region and the difficulty of the task. A dissociation in the effect of such lesions on performance of comparable spatial and non-spatial memory tasks was shown. In contrast to the deficits observed on spatial memory tasks, the acquisition and retention of a complex non-spatial memory task was not impaired after extensive damage to the mammillary region. Such lesions also did not impair performance in a conditioned taste aversion task. These experiments suggest that the mammillary region may be selectively involved in spatial learning and memory.

Animals↗
PubMed1995

Visuo-spatial working memory limitations in low visuo-spatial high verbal intelligence children.

Visuo-spatial working memory was investigated in a group of 37 children aged between 10 and 14 years with low visuo-spatial intelligence. Their performance was poorer than that of a matched control group on a series of tests devised to ascertain visuo-spatial working memory yet was broadly similar in a language test and in school achievement tests. It is argued that low visuo-spatial intelligence children typically present limitations in the storage capacity of a passive system of the visuo-spatial working memory (with a raw measure of four-five stored elements) and especially in the operations required to process that information.

Adolescent↗
PubMed2003

The subtype-selective nicotinic acetylcholine receptor agonist SIB-1553A improves both attention and memory components of a spatial working memory task in chronic low dose 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated monkeys.

Monkeys that receive chronic low dose (CLD) 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration develop deficits in spatial delayed-response task performance. The present study examined the extent to which SIB-1553A [(+/-)-4-[[2-(1-methyl-2-pyrrolidinyl)ethyl]thio]phenol hydrochloride], a novel neuronal nicotinic acetylcholine receptor (nAChR) agonist with selectivity for beta4 subunit-containing nAChRs, could counteract this cognitive deficit produced by CLD MPTP exposure. Prior to MPTP treatment, monkeys displayed a delay-dependent decrement in performance on a variable delayed response task. CLD MPTP treatment caused a shift to a delay-independent pattern of responding on this task, such that short-delay trials were performed as poorly as long-delay trials. At lower doses (e.g., 0.025 mg/kg), SIB-1553A significantly improved performance on short-delay trials but only at 24 h after drug administration. At higher doses (e.g., 0.50 mg/kg), SIB-1553A significantly improved performance on both short- and long-delay trials at both 20 min and 24 h after drug administration. When tested 24 h after drug administration, monkeys performed long-delay trials with greater accuracy than they did under normal (pre-MPTP) conditions. These results suggest that at lower doses, SIB-1553A may be more effective in improving attentional deficits associated with CLD MPTP exposure, whereas at higher doses, SIB-1553A may effectively improve both attentional and memory performance.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1996

Executive and mnemonic functions in early Huntington's disease.

Eighteen patients with early Huntington's disease were compared with age- and IQ-matched control volunteers on tests of executive and mnemonic function taken from the Cambridge Neuropsychological Test Automated Battery. Tests of pattern and spatial recognition memory, spatial span, spatial working memory, spatial planning and visual discrimination learning/attentional set shifting were employed. These tests have previously been found to be sensitive to the later stages of Huntington's disease. Patients with early Huntington's disease were found to have a wide range of cognitive impairments encompassing both visuospatial memory and executive functions, a pattern distinct from those seen in other basal ganglia disorders. In contrast to patients with more advanced Huntington's disease, early Huntington's disease patients were not impaired at simple reversal learning, but were impaired at performing an extradimensional shift (EDS). The results will be discussed in relation to the hypothesized neuropathological staging of Huntington's disease and to the anatomical connectivity of the striatum.

Adult↗
PubMed1999

Storage and processing in visuo-spatial working memory.

Visuo-spatial working memory has been used to account for performance in a wide range of visuo-spatial tasks, including perceptuo-motor tracking and immediate recall of visually presented patterns. However a developing body of evidence points to a fractionation of the concept into visuo-spatial processing that calls on general purpose executive resources, and a visual 'cache' memory for temporary storage in on-line cognition. Two related experiments are described which address whether processing and temporary memory draw on overlapping or on distinct resources in working memory. Experiment 1 demonstrates that participants can accurately respond to a series of targets appearing in random locations whether or not they have the additional load of retaining and subsequently recalling the appearance of each target. Memory for target appearance likewise is largely unaffected by the additional load of requiring a response to each target. Experiment 2 demonstrates similar findings when verbal labeling of the patterns is inhibited through the use of articulatory suppression. Results are interpreted as consistent with a multiple component working memory system.

Adult↗
PubMed2003

Oculomotor control and the maintenance of spatially and temporally distributed events in visuo-spatial working memory.

Previous studies have demonstrated that working memory for spatial location can be significantly disrupted by concurrent eye or limb movement (Baddeley, 1986; Smyth, Pearson, & Pendleton, 1988). Shifts in attention alone can also interfere with spatial span (Smyth & Scholey, 1994), even with no corresponding movement of the eyes or limbs (Smyth, 1996). What is not clear from these studies is how comparable is the magnitude of effect caused by different forms of spatial disrupter. Recently, it has been demonstrated that limb movements produce as much interference with spatial span as do reflexive saccades (Lawrence, Myerson, Oonk, & Abrams, 2001). In turn this has led to the hypothesis that all spatially directed movement can produce similar effects in visuo-spatial working memory. This paper reports the results of five experiments that have contrasted the effect of concurrent eye movement, limb movement, and covert attention shifts on participants' working memory for sequences of locations. All conditions involving concurrent eye movement produced significantly greater reduction in span than equivalent limb movement or covert attention shifts with eyes fixated. It is argued that these results demonstrate a crucial role for oculomotor control processes during the rehearsal of location-specific representations in working memory.

Adult↗
PubMedDate not supplied

Behavioral studies of the effects of moderate oligemic hypoxia caused by bilateral clamping of carotid arteries in mice. Impairment of spatial working memory.

The experiments carried out on Albino Swiss mice indicated that bilateral clamping of carotid arteries (BCCA) for 30 min caused no neuronal damage but produced an increase in GABA content in the hippocampus, striatum and frontal cortex. The behavioral studies have shown that BCCA did not influence the motor coordination, the spontaneous locomotor activity, the reactivity to pain and the cataleptic response to haloperidol of the mice. However, a significant increase in amphetamine-induced hyperactivity was observed after BCCA. In mice, BCCA did not impair long-term memory and spatial working memory, reflected by alternation behavior in the Y-maze. The same dose of scopolamine impaired the working memory in mice which underwent BCCA much more than sham-operated controls. Naftidrofuryl improved the working memory in mice subjected to BCCA as measured 48 h after the surgery. Pretreatment with naftidrofuryl protected the animals against the impairment of alternation behavior caused by scopolamine administration.

Anesthesia↗
PubMedDate not supplied

A spatial arrangement memory testing unit.

The Spatial Arrangement Memory Testing Unit is a new apparatus which has been designed to provide a low-cost, portable instrument for assessing visuo-spatial memory performance. It is particularly useful for aiding diagnosis and planning rehabilitation programmes for patients that have suffered brain damage. The application of microprocessor technology has allowed a flexible programmable approach to the operation of the equipment. The system uses a dedicated Zilog Z80 microprocessor with associated software held in EPROM. An integral printer is used to provide a permanent record of patient performance.

Biomedical Engineering↗
PubMed1980

Memory for verbal and spatial information as a function of age.

The present study investigated whether there is a differential decline with age in verbal and spatial memory, by measuring the ability of 24 young (mean age = 18.8) and 24 elderly (mean age = 69.5) subjects to remember verbal and spatial information under identical task conditions. Subjects recalled either the identities or spatial locations of seven letters arranged randomly within a 5 x 5 grid. To determine whether subjects actually encoded the verbal and spatial characteristics of the array differently, verbal and spatial interference tasks were administered during the retention interval. Results showed that the memory decrement in the elderly was not greater for the spatial aspects of the stimulus array than for its verbal aspects. Thus, there was no evidence for a greater decline with age in spatial memory than in verbal memory. Limited support was found for the utility of the selective interference paradigm to demonstrate separate and independent verbal and spatial memory codes.

Adolescent↗
PubMed1999

Hemispheric asymmetry of spatial working memory deficit in schizophrenia.

Spatial working memory function was assessed in schizophrenia patients, hypothetically 'psychosis-prone' individuals who report unusual perceptual experiences and normal control subjects with an oculomotor delayed response task. Past studies point to the important role of dorsolateral prefrontal system in spatial working memory deficits of schizophrenia patients. In order to better understand the processes precipitating in working memory deficit, two types of working memory errors were examined: never-corrected vs. immediately-corrected errors. In schizophrenia patients, the loss of spatial representation in working memory, as captured by the presence of never-corrected errors, was much more severe when the target was presented in the right visual hemifield than when the target was presented in the left visual field. The same pattern was observed in healthy, psychometrically ascertained 'psychosis-prone' subjects. Therefore, the observed asymmetry of spatial working memory deficit seems unlikely to be a mere side-effect of medication or hospitalization. Normal control subjects did not show hemispheric asymmetry in error patterns. These results suggest that the loss of spatial representation during a delay period may be more severe in the left hemisphere in patients with schizophrenia and in 'psychosis-prone' individuals.

Adult↗
PubMed2000

Memory for drawings in locations: spatial source memory and event-related potentials.

Event-related potentials (ERPs) were recorded during recognition tasks for line drawings (items) or for both drawings and their spatial locations (sources). Recognized drawings elicited more positive ERPs than new drawings. Independent of accuracy in the spatial judgment, the old/new effect in the source recognition task was larger over the prefrontal scalp, and of longer temporal duration than in the item recognition task, suggesting that the source memory task engaged a qualitatively distinct memory process. More posterior scalp sites were sensitive to the accuracy of the source judgment, but this effect was delayed relative to the difference between studied and unstudied drawings, suggesting that source memory processes are completed after item recognition. Similarities and differences between spatial source memory and memory for conjunctions of other stimulus attributes are discussed, together with the role of prefrontal cortex in memory.

Adult↗
PubMed1996

Oxotremorine infusions into the medial septal area of middle-aged rats affect spatial reference memory and ChAT activity.

Age-related spatial memory deficits are correlated with septohippocampal cholinergic system degeneration. The present study examined the effect of intraseptal infusions of the cholinergic agonist, oxotremorine, on spatial reference memory in middle-aged rats using place discrimination in the water maze, and on cholinergic activity using choline acetyltransferase (ChAT) activity. Oxotremorine mildly improved the rate of place discrimination acquisition of middle-aged rats during initial sessions only, but did not affect asymptotic levels of performance achieved. Of the brain regions assayed, ChAT activity increased with age in the temporal cortex and dorsal CA2/3 region of the hippocampus. Oxotremorine significantly decreased ChAT activity in the dorsal hippocampus. In contrast to our previous results in aged rats indicating a more robust effect of oxotremorine on spatial working memory, the present results suggest a modest effect of intraseptal oxotremorine on the acquisition of a spatial reference memory task.

Aging↗
PubMed2003

GluR-A-Deficient mice display normal acquisition of a hippocampus-dependent spatial reference memory task but are impaired during spatial reversal.

Acquisition and reversal of a spatial discrimination were assessed in an appetitive, elevated plus-maze task in 4 groups of mice: knockout mice lacking the AMPA receptor subunit GluR-A (GluR1), wild-type controls, mice with cytotoxic hippocampal lesions, and controls that had undergone sham surgery. In agreement with previous studies using tasks such as the water maze, GluR-A(-/-) mice were unimpaired during acquisition of the spatial discrimination task, whereas performance in the hippocampalgroup remained at chance levels. In contrast to their performance during acquisition, the GluR-A(-/-) mice displayed a mild deficit during reversal of the spatial discrimination and were profoundly impaired during discrete trial, rewarded-alternation testing on the elevated T maze. The latter result suggests a short-term, flexible spatial working memory impairment in GluR-A(-/-) mice, which might also underlie their mild deficit during spatial reversal.

Animals↗
PubMed1999

Impairment of olfactory identification in obsessive-compulsive disorder.

BACKGROUND: Olfactory identification ability has been associated with processing in the orbitofrontal cortex (OFC), an area that has been implicated in the pathophysiology of obsessive-compulsive disorder (OCD). Although olfactory sensitivity is normal in patients with OCD, no study has investigated olfactory identification in this disorder. METHODS: A group of 20 subjects with OCD and 23 age- and education-matched controls performed a standardized test of olfactory identification. They also performed computerized tests of spatial memory span, spatial working memory and spatial recognition memory that have been shown previously to be sensitive to cognitive deficits in patients with OCD. RESULTS: Performance on the olfactory identification task, spatial recognition task and spatial span task was significantly worse in the OCD group than controls. CONCLUSIONS: While impairment in spatial cognition is consistent with previous studies of OCD, its significance for brain-behaviour models of OCD is unclear. However, the finding of abnormal olfactory identification in patients with OCD is consistent with the hypothesis that there is a disruption to processing at the level of the OFC in the disorder.

Adult↗