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 1,279 records · Page 71Linked to original sources
PubMed2004

An investigation of the effect of tacrine and physostigmine on spatial working memory deficits in the olfactory bulbectomised rat.

The olfactory bulbectomised (OB) rat is being increasingly used as a model of impaired learning and mnemonic functioning. In this study the model has been utilised to determine the effect of the acetylcholinesterase inhibiting compounds tacrine and physostigmine on spatial working memory deficits associated with the OB rat. One-hundred and twenty male rats were randomly allocated to OB or sham operated groups and received chronic i.p. treatment with either saline, physostigmine (0.1 mg/kg) or tacrine (0.1 and 0.3 mg/kg). Two weeks after beginning treatment animals were tested on the Morris water maze and open field test. The results indicated that the OB surgery was associated with spatial working memory disturbances that were effectively attenuated with both doses of tacrine, but not physostigmine. Increased hyperactivity and defecation was observed in OB animals in the Open-field test, however, these changes were not ameliorated by either drug treatment. The ability for tacrine but not physostigmine to attenuate OB cognitive deficits may be associated with the different half-life of these compounds. This study provides further support for the use of the OB rat as a drug discovery model for the investigation of novel therapeutic compounds that target the cholinergic system.

Alzheimer Disease↗
PubMed2006

The role of sleep in the consolidation of route learning in humans: a behavioural study.

Considerable evidence support the role of sleep in learning and memory processes. In rodents, the relationships between sleep and memory consolidation have been extensively investigated by taking into account mainly spatial learning. On the contrary, in humans the relationship between sleep and spatial memory consolidation has so far been scarcely taken into account. Here, we investigated the importance of sleep in the consolidation of the spatial memory traces of a new route learned in a real-life unfamiliar environment. Fifty-one subjects followed a defined route in a neighbourhood they had never been to before. Then, they were tested in the laboratory in a sequence-recognition test requiring them to evaluate whether or not sequences of three views, taken along the route, represented a correct sequential order as seen while walking along the route. Participants were then assigned to one of three groups: the sleep group was retested after one night's sleep, the sleep-deprived group was retested after a night of sleep deprivation, and the day-control group was retested the same day after 8h of wakefulness. At retest, performance speed increased in all groups, whereas the accuracy in the sequence-recognition task was improved only in the sleep group: neither sleep deprivation nor the simple passage of time gave way to any performance improvement. These preliminary findings shed more light on the role of sleep in spatial memory consolidation by extending to humans the considerable evidence found in animals.

Adult↗
PubMed2004

Seizures in the developing brain cause adverse long-term effects on spatial learning and anxiety.

PURPOSE: Seizures in the developing brain cause less macroscopic structural damage than do seizures in adulthood, but accumulating evidence shows that seizures early in life can be associated with persistent behavioral and cognitive impairments. We previously showed that long-term spatial memory in the eight-arm radial-arm maze was impaired in rats that experienced a single episode of kainic acid (KA)-induced status epilepticus during early development (postnatal days (P) 1-14). Here we extend those findings by using a set of behavioral paradigms that are sensitive to additional aspects of learning and behavior. METHODS: On P1, P7, P14, or P24, rats underwent status epilepticus induced by intraperitoneal injections of age-specific doses of KA. In adulthood (P90-P100), the behavioral performance of these rats was compared with that of control rats that did not receive KA. A modified version of the radial-arm maze was used to assess short-term spatial memory; the Morris water maze was used to evaluate long-term spatial memory and retrieval; and the elevated plus maze was used to determine anxiety. RESULTS: Compared with controls, rats with KA seizures at each tested age had impaired short-term spatial memory in the radial-arm maze (longer latency to criterion and more reference errors), deficient long-term spatial learning and retrieval in the water maze (longer escape latencies and memory for platform location), and a greater degree of anxiety in the elevated plus maze (greater time spent in open arms). CONCLUSIONS: These findings provide additional support for the concept that seizures early in life may be followed by life-long impairment of certain cognitive and behavioral functions. These results may have clinical implications, favoring early and aggressive control of seizures during development.

Animals↗
PubMed1986

Loss of perforated synapses in the dentate gyrus: morphological substrate of memory deficit in aged rats.

Most, but not all, aged rats exhibit a profound deficit in spatial memory when tested in a radial maze--a task known to depend on the integrity of the hippocampal formation. In this study, animals were divided into three groups based on their spatial memory capacity: young adult rats with good memory, aged rats with impaired memory, and aged rats with good memory. Memory-impaired aged animals showed a loss of perforated axospinous synapses in the dentate gyrus of the hippocampal formation in comparison with either young adults or aged rats with good memory. This finding suggests that the loss of perforated axospinous synapses in the hippocampal formation underlies the age-related deficit in spatial memory.

Aging↗
PubMed2000

The alpha-2A-adrenoceptor agonist, guanfacine, increases regional cerebral blood flow in dorsolateral prefrontal cortex of monkeys performing a spatial working memory task.

Research indicates that norepinephrine enhances the working memory functions of the prefrontal cortex (PFC) through actions at post-synaptic, alpha-2A adrenoceptors. The current study examined the effects of the alpha-2A adrenoreceptor agonist, guanfacine (0.7 mg/kg, i.m.), compared to saline on SPECT measures of regional cerebral blood flow (rCBF) in monkeys performing a spatial working memory task. Animals were infused with the SPECT blood flow tracer, Tcm-99m ECD, through an indwelling intravenous catheter while performing the working memory task. Guanfacine treatment significantly improved cognitive performance of the working memory task, and significantly increased rCBF values in the dorsolateral PFC, the brain region most tightly associated with performance of spatial working memory tasks. In contrast, guanfacine had no significant effect on rCBF in the superior temporal cortex, an auditory association area unrelated to task performance. These data are consistent with the hypothesis that alpha-2A adrenoceptor stimulation preferentially enhances functioning of the PFC.

Adrenergic alpha-2 Receptor Agonists↗
PubMed1987

Verbal and spatial immediate memory span: normative data from 1355 adults and 1112 children.

Norms are provided for verbal and visuo-spatial immediate memory span, two tasks widely used in the clinical assessment of short-term memory and its neurological disorders. Data have been collected from 1355 male and female adult subjects, with various educational backgrounds and a 20-99 years age range. Span shows a major decrement after the late sixties and is affected by educational level. Male subjects score better on the spatial task. Data collected from 1112 male and female children, 4-to-10 year-old, show that span increases with age and boys score better on the spatial test.

Adult↗
PubMed1989

Memory for spatial location in children, adults, and mentally retarded persons.

Two experiments extended earlier research showing age- and intelligence-invariance in memory for spatial location. Second and sixth graders, college students, and mildly retarded persons relocated pictures after looking through a 100-picture book. There were no differences due to age, IQ, or instruction (intentional or incidental) in location memory; there were differences in picture recall. In a second experiment persons with Down syndrome, as a group, were less accurate in location memory than were college students, but many individuals performed as accurately. A 3-month follow-up on the subjects with Down syndrome revealed greater consistency in location memory than in recall. Overall, the results show that young children and mildly mentally retarded persons process spatial location information as well as do college students. Some, but not all, of the more severely mentally retarded persons had deficits in processing memory for location. All persons with mental retardation had deficits in effortful processing as reflected by free recall.

Adolescent↗
PubMed2002

Effects of chronic administration of huperzine A on memory in guinea pigs.

Effects of subchronic administration of huperzine A, a cholinesterase inhibitor, on spatial memory were studied in guinea pig. Spatial memory was appreciated by the Morris water maze test. At a dose of 0.25 microgram/h, inhibiting 36% of blood AChE and 14-20% of central AChE, no effect on spatial learning was found. At a dose of 1 microgram/h, inhibiting 20% of blood AChE and 14-20% of central AChE, no memory impairment was found, on the other hand, a memory enhancing effect, limited to the first day was shown. It thus appears that subchronic administration of huperzine A did not induce deleterious effects on spatial memory.

Acetylcholinesterase↗
PubMed1999

Spatial learning deficit after NMDA receptor blockade and state-dependency.

The non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine (MK-801) (0.08 and 0.12 mg/kg, i.p.) was used to examine whether spatial memory is learned state-dependently. Rats pre-treated with drug or saline were trained for 9 days in an eight-arm radial maze, in which four arms were baited. On the tenth day MK-801-treated rats were injected with saline and one group of saline-treated rats were injected with MK-801 (0.12 mg/kg) while another received saline. Performance of spatial memory was analysed for state-dependency. Neither rats treated with 0.08 mg/kg nor 0.12 mg/kg of MK-801 for 9 days were impaired in recall of spatial memory under saline. However, MK-801 impaired acquisition of spatial memory, with deficits in working memory and less marked deficits in reference memory. Motor activity (speed) was enhanced at both doses. Thus, learning under NMDA receptor blockade does not necessarily produce a condition that impedes the expression of the learning task under a different condition.

Animals↗
PubMed2000

Researching a differential impairment of frontal functions and explicit memory in early Parkinson's disease.

An impairment at tasks sensitive to frontal lobe damage has been repeatedly reported in Parkinson's disease, but the exact nature of these deficits has not yet been clarified. Similarly, deficits of visuo-spatial functions have been frequently observed, but it is still debated whether verbal and visuo-spatial memory can be differentially affected. In this study we have compared the performance of 20 mild Parkinson's disease patients (I-II Hoehn and Yahr stage) and 18 matched normal controls, at tasks assessing frontal functions and explicit memory. We detected a selective deficit in set shifting and maintaining, without impairment in categorization and set formation. The lack of a selective increase in perseverative errors might indicate that perseverations either measure something different from set shifting or that they do not represent an index sensitive enough to set shifting impairment. Parkinson's disease patients were also significantly impaired at Raven's Progressive Matrices, a task assessing both frontal and visuo-spatial aspects. However, they did not show any differential impairment of visuo-spatial memory. Indeed, despite a trend of lower performance in visuo-spatial learning, memory performance of Parkinson's disease patients was significantly different from that of controls only at a free recall test which involved both verbal and visuo-spatial memory. We suggest the exploration of set shifting and maintaining to detect 'frontal' deficits in mild Parkinson's disease. We argue that Raven's Progressive Matrices is a valuable task for detecting subclinical cognitive deficits in Parkinson's disease, even if it does not show a specific profile of impairment in these patients. According to our results, a differential evaluation of verbal vs. visuo-spatial memory is not necessary in clinical practice, whilst free recall confirms its usefulness to detect subclinical impairments of memory functions.

Aged↗
PubMed2003

The memory effects of general anesthesia persist for weeks in young and aged rats.

UNLABELLED: Studies demonstrate lasting cognitive impairment in elderly persons after anesthesia and surgery. We tested the hypothesis that general anesthesia contributes to this cognitive impairment. Six- and 18-mo-old Fischer 344 rats were trained in a 12-arm radial arm maze and were then randomized to anesthesia for 2 h with 1.2% isoflurane/70% nitrous oxide/30% oxygen or a control treatment consisting of 30% oxygen. Rats recovered for 24 h and then were tested daily on the radial arm maze for 8 wk. Performance of young control rats was stable throughout the experiment. In contrast, aged control rats improved their performance as measured by time to complete the maze but not by error rate. After anesthesia, time to complete the maze did not change in young rats, but error rate decreased (P < 0.05 at 1 and 3 wk), indicating improved performance. In contrast, previously anesthetized aged rats failed to improve with repeated testing and took longer to complete the maze than aged control rats (P < 0.05 at 1 and 3 wk). These data demonstrate that general anesthesia with isoflurane and nitrous oxide improves the memory performance on an established spatial memory task in young rats, but in aged rats it attenuates the improvement in performance that otherwise occurs with repeated testing. Therefore, isoflurane and nitrous oxide anesthesia produces a sustained learning impairment in aged rats. IMPLICATIONS: This study demonstrates that general anesthesia with isoflurane and nitrous oxide improves spatial memory in young rats but impairs it in aged rats for at least 3 wk, indicating that it can influence memory for much longer than previously recognized and may adversely affect memory processes in the aged.

Aging↗
PubMed2001

Dorsal hippocampal kindling selectively impairs spatial learning/short-term memory.

Kindling with electrical stimulation of the dorsal hippocampus has been shown to disrupt spatial task performance in rats. The present study investigated the specificity of this effect in terms of the possible contribution of nonmnemonic effects, the presence of a more general mnemonic deficit, and the involvement of learning/short-term memory and/or long-term memory processes. Rats were fully kindled with stimulation of the dorsal hippocampus and subsequently tested for acquisition, 7-day retention, and 28-day retention of a hidden platform (HP) location in the Morris water maze and an object discrimination problem in a modified water maze. To control for nonmnemonic behavioral impairments, testing on both tasks was preceded by training on visible platform control tasks. Kindling impaired acquisition of the HP location but spared performance on all other aspects of testing, indicating a specific impairment of spatial learning/short-term memory. These results suggest that epileptogenesis induced by hippocampal stimulation is indeed associated with a selective disruption of the mechanisms mediating spatial learning/short-term memory.

Animals↗
PubMed1999

Local infusion of an alpha-1 adrenergic agonist into the prefrontal cortex impairs spatial working memory performance in monkeys.

BACKGROUND: Stimulation of alpha-2 adrenoceptors in the monkey or rat prefrontal cortex (PFC) has been known to improve spatial working memory (SWM) and stimulation of alpha-1 adrenoceptors in the rat PFC has been reported to impair SWM. The present study attempted to replicate in monkey the rat experiments on alpha-1 adrenoceptor stimulation. METHODS: The alpha-1 adrenergic agonist phenylephrine or the alpha-2 adrenergic agonist guanfacine was infused into the dorsolateral prefrontal cortex (dlPFC) of monkeys performing the delayed-response (DR) task, a task of SWM, to see how the drugs affect SWM performance. RESULTS: Phenylephrine infusion in dlPFC significantly impaired DR performance, whereas guanfacine improved performance. The effects of both drugs were delay-dependent. Infusions outside dlPFC were ineffective. CONCLUSIONS: Stimulation of prefrontal cortical alpha-1 adrenoceptors impairs SWM function in monkeys, consistent with the parallel study in rats, whereas stimulation of alpha-2 adrenoceptors improves SWM, indicating that alpha-1 and alpha-2 adrenoceptors may have opposing roles in the PFC.

Adrenergic alpha-1 Receptor Agonists↗
PubMed1996

Effects of tacrine (THA) on spatial reference memory and cholinergic enzymes in specific rat brain regions.

Cognitive function of rats treated with saline (control), THA (8 mg/kg, i.p.), scopolamine (5 mg/kg, i.p.), or a combination of THA (8 mg/kg) and scopolamine (5 mg/kg) was tested in the Morris water maze. The latency to find the platform in the water maze was used to evaluate performance. THA did not significantly alter the latency period as compared to control rats. Scopolamine resulted in a highly significant (p<0.01) increase in latency period (183% increase) as compared to saline treated controls. However, when THA was concurrently administered with scopolamine, it was able to completely reverse the performance decrement induced by scopolamine. Immediately following spatial reference memory testing, animals were sacrificed by decapitation one hour post injection. Brains were immediately removed and the cortex, hippocampus, hypothalamus, and pituitary were dissected and their choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity were determined spectrophotometrically. THA administration resulted in a significant increase in ChAT activity in the cortex (23% increase). However, when THA was concurrently administered with scopolamine, a significant increase in ChAT activity was observed in cortex (77% increase), hippocampus (32% increase), hypothalamus (97% increase), and pituitary (92.5% increase). THA administration resulted in a significant decrease in AChE activity (p<0.001) in cortex (62% decrease), hippocampus (78% decrease), and hypothalamus (90% decrease). When tacrine was administered with scopolamine, a significant increase was found in the cortex (197% increase) and the hippocampus (207% increase). In conclusion, the increase in ChAT activity produced by tacrine may in part explain its ability to reverse the scopolamine induced decrease in spatial reference memory and may play a role in its beneficial effect in improving cognitive ability.

Acetylcholinesterase↗
PubMed2001

Some measures of verbal and spatial working memory in eight- and nine-year-old hearing-impaired children with cochlear implants.

OBJECTIVE: The purpose of this study was to examine working memory for sequences of auditory and visual stimuli in prelingually deafened pediatric cochlear implant users with at least 4 yr of device experience. DESIGN: Two groups of 8- and 9-yr-old children, 45 normal-hearing and 45 hearing-impaired users of cochlear implants, completed a novel working memory task requiring memory for sequences of either visual-spatial cues or visual-spatial cues paired with auditory signals. In each sequence, colored response buttons were illuminated either with or without simultaneous auditory presentation of verbal labels (color-names or digit-names). The child was required to reproduce each sequence by pressing the appropriate buttons on the response box. Sequence length was varied and a measure of memory span corresponding to the longest list length correctly reproduced under each set of presentation conditions was recorded. Additional children completed a modified task that eliminated the visual-spatial light cues but that still required reproduction of auditory color-name sequences using the same response box. Data from 37 pediatric cochlear implant users were collected using this modified task. RESULTS: The cochlear implant group obtained shorter span scores on average than the normal-hearing group, regardless of presentation format. The normal-hearing children also demonstrated a larger "redundancy gain" than children in the cochlear implant group-that is, the normal-hearing group displayed better memory for auditory-plus-lights sequences than for the lights-only sequences. Although the children with cochlear implants did not use the auditory signals as effectively as normal-hearing children when visual-spatial cues were also available, their performance on the modified memory task using only auditory cues showed that some of the children were capable of encoding auditory-only sequences at a level comparable with normal-hearing children. CONCLUSIONS: The finding of smaller redundancy gains from the addition of auditory cues to visual-spatial sequences in the cochlear implant group as compared with the normal-hearing group demonstrates differences in encoding or rehearsal strategies between these two groups of children. Differences in memory span between the two groups even on a visual-spatial memory task suggests that atypical working memory development irrespective of input modality may be present in this clinical population.

Audiometry, Pure-Tone↗
PubMed2003

Female advantage for spatial location memory in both static and dynamic environments.

A female advantage has previously been found for spatial location tests of object memory. Previous studies have used static, 2-D tasks to test this advantage. This study used a computerized adaptation of the game Concentration to test object location memory in both a static and dynamic array of 24 pairs of line drawings. The dynamic version of this task was used to better reflect the dynamic real world in which we usually use object location memory. Consistent with previous research, we observed a female advantage. This advantage was found to a similar extent in both the static and dynamic versions of the task. The female advantage for object location memory is a concrete advantage in spatial cognition that females show on the Concentration Task, regardless of the nature of the presentation environment.

Adult↗
PubMed2003

Spatial working memory ability is a marker of risk-for-psychosis.

BACKGROUND: Working memory has been identified as a core cognitive deficit in schizophrenia that is associated with negative symptoms, but it is unclear whether it is impaired prior to onset of psychosis in symptomatic patients. METHOD: Thirty-eight young people at ultra high-risk (UHR) of developing psychosis (of whom nine later became psychotic) were compared with 49 healthy controls on tests of spatial working memory (SWM) and delayed matching-to-sample (DMTS). RESULTS: Both SWM and DMTS performance was significantly poorer in the UHR groups. Those who later became psychotic generally performed more poorly than those who did not, although this did not reach significance for any measure. A significant association between SWM errors and negative symptoms was seen in the later-psychotic group only (P = 0.02). CONCLUSIONS: Spatial working memory abilities are impaired in those at high-risk for psychosis. The relationship between working memory and negative symptoms may be useful as a predictive tool.

Adolescent↗
PubMed2004

Altered neurometabolite development in HIV-infected children: correlation with neuropsychological tests.

BACKGROUND: HIV-infected children have abnormal cerebral metabolites, measured by proton MR spectroscopy ((1)H-MRS), but how these abnormalities relate to brain function is unclear. METHODS: Metabolite concentrations in five brain regions of 20 HIV-infected and 13 control children were measured, and these findings were correlated with age, log(10) plasma viral load, CD4 count, and neuropsychological scores. RESULTS: Compared with control subjects, HIV patients had decreased choline concentration [Cho] in left frontal white matter (LFW) (-12%; p = 0.04); those with high viral load (>5,000 HIV RNA copies/mL) had decreased right basal ganglia (RBG) [Cho] (-15%; p = 0.005), and [Cr] (-13%; p = 0.02). Patients with high viral load also had higher [Cho] in the midfrontal gray matter (MFG) (+25%; p = 0.002) and lower myo-inositol [Ins] in the RBG (-18%; p = 0.04) than patients with low HIV viral load. N-Acetyl aspartate concentration ([NAA]) correlated with age in right frontal white matter (RFW) (r = 0.59, p = 0.04), LFW (r = 0.66, p = 0.02), and right hippocampus (RHIP) (r = 0.69, p = 0.02) only in control subjects. In contrast, [Ins] correlated with age in both RFW and LFW (r = 0.71, p = 0.0006; r = 0.65, p = 0.006) only in the HIV patients. Log(10) plasma viral load correlated positively with [Ins] in RFW (r = 0.54, p = 0.02) and [Cho] in MFG (r = 0.49, p = 0.04). Compared with control subjects, HIV patients had poorer spatial memory (p = 0.045) and delayed spatial memory correlated with [Cho] in RHIP (r = 0.68, p = 0.02). CONCLUSIONS: These data suggest that normal brain development may be affected in children infected with HIV at birth, particularly evidenced by the lack of age-related increases in the neuronal marker [NAA]. Early, aggressive treatment of infants with HIV before development of encephalopathy is warranted.

Adolescent↗