Visuospatial Learning Research Articles

Memory and obstructive sleep apnea: a meta-analysis.

To examine episodic memory performance in individuals with obstructive sleep apnea (OSA). Meta-analysis was used to synthesize results from individual studies examining the impact of OSA on episodic memory performance. The performance of individuals with OSA was compared to healthy controls or normative data. Forty-two studies were included, comprising 2,294 adults with untreated OSA and 1,364 healthy controls. Studies that recorded information about participants at baseline prior to treatment interventions were included in the analysis. PARTICIPANTS WERE ASSESSED WITH TASKS THAT INCLUDED A MEASURE OF EPISODIC MEMORY: immediate recall, delayed recall, learning, and/or recognition memory. The results of the meta-analyses provide evidence that individuals with OSA are significantly impaired when compared to healthy controls on verbal episodic memory (immediate recall, delayed recall, learning, and recognition) and visuo-spatial episodic memory (immediate and delayed recall), but not visual immediate recall or visuo-spatial learning. When patients were compared to norms, negative effects of OSA were found only in verbal immediate and delayed recall. This meta-analysis contributes to understanding of the nature of episodic memory deficits in individuals with OSA. Impairments to episodic memory are likely to affect the daily functioning of individuals with OSA.

Optimization of apparatus design and behavioral measures for the assessment of visuo-spatial learning and memory of mice on the Barnes maze

We have previously shown that apparatus design can affect visual-spatial cue use and memory performance of mice on the Barnes maze. The present experiment extends these findings by determining the optimal behavioral measures and test procedure for analyzing visuo-spatial learning and memory in three different Barnes maze designs. Male and female C57BL/6J mice were trained with a stable or random escape hole location and the sensitivities (statistical power) of four commonly used measures of learning and three measures of memory to detect differences between these training procedures were compared on each maze design. A maze design with a large diameter and no wall was optimal, because mice showed a reliable use of extra-maze visual cues, visuo-spatial search strategies, and spatial memory. A maze design with a small diameter, surrounding wall, and intra-maze visual cues was the least sensitive for determining visuo-spatial learning and memory, because mice showed little evidence of extra-maze cue use. Errors, distance traveled, and hole deviation scores were more sensitive measures of learning than latency to find the escape hole. Measures based on locating the escape hole (primary measures) were more sensitive than measures based on entering the escape hole (total measures). Measures of memory had similar levels of sensitivity on each maze. This experiment demonstrates that both apparatus design and the behavioral measures used as indicators of learning and memory can influence the ability of the Barnes maze to detect visuo-spatial learning and memory impairments in mice.

Habitual fat intake predicts memory function in younger women

High intakes of fat have been linked to greater cognitive decline in old age, but such associations may already occur in younger adults. We tested memory and learning in 38 women (25 to 45 years old), recruited for a larger observational study in women with polycystic ovary syndrome. These women varied in health status, though not significantly between cases (n = 23) and controls (n = 15). Performance on tests sensitive to medial temporal lobe function (CANTABeclipse, Cambridge Cognition Ltd, Cambridge, UK), i.e., verbal memory, visuo-spatial learning, and delayed pattern matching (DMS), were compared with intakes of macronutrients from 7-day diet diaries and physiological indices of metabolic syndrome. Partial correlations were adjusted for age, activity, and verbal IQ (National Adult Reading Test). Greater intakes of saturated and trans fats, and higher saturated to unsaturated fat ratio (Sat:UFA), were associated with more errors on the visuo-spatial task and with poorer word recall and recognition. Unexpectedly, higher UFA intake predicted poorer performance on the word recall and recognition measures. Fasting insulin was positively correlated with poorer word recognition only, whereas higher blood total cholesterol was associated only with visuo-spatial learning errors. None of these variables predicted performance on a DMS test. The significant nutrient–cognition relationships were tested for mediation by total energy intake: saturated and trans fat intakes, and Sat:UFA, remained significant predictors specifically of visuo-spatial learning errors, whereas total fat and UFA intakes now predicted only poorer word recall. Examination of associations separately for monounsaturated (MUFA) and polyunsaturated fats suggested that only MUFA intake was predictive of poorer word recall. Saturated and trans fats, and fasting insulin, may already be associated with cognitive deficits in younger women. The findings need extending but may have important implications for public health.

Prevention of vision loss protects against age-related impairment in learning and memory performance in DBA/2J mice

The DBA/2J mouse is a model of pigmentary glaucoma in humans as it shows age-related increases in intraocular pressure (IOP), retinal ganglion cell death and visual impairment. Previously, we showed that visual ability declines from 9 to 12 months of age and visual impairment is correlated with poor learning and memory performance in visuo-spatial tasks but not in tasks that do not depend on visual cues. To test the “sensory impairment” hypothesis of aging, which postulates that sensory impaired individuals are disadvantaged in their performance on psychometric tests as a direct result of difficulties in sensory perception, we treated DBA/2J mice with a conventional glaucoma medication used in humans (Timoptic-XE, 0.00, 0.25, or 0.50%) daily from 9 weeks to 12 months of age to determine whether prevention of vision loss prevented the decline in visuo-spatial learning and memory performance. At all ages tested (3, 6, 9, and 12 months of age), mice treated with Timoptic-XE (0.25 and 0.50%) maintained a high level of performance, while 12 month old control mice (0.00%) exhibited impaired performance in visually-dependent, but not non-visual tasks. These results demonstrate that when sensory function is preserved, cognitive performance is normalized. Thus, as in many aging humans, DBA/2J mice show age-related decrements in performance on visually presented cognitive tests, not because of cognitive impairment but as a direct consequence of poor visual ability. Our results demonstrate that age-related impairment in performance in visuo-spatial tasks in DBA/2J mice can be prevented by the preservation of visual ability.

976 – Shortned visuo-spatial questionnaire: an useful tool for the early identification of children with non verbal syndrome living in rural areas

Visuo-spatial deficits interfere with learning geography, geometry, natural sciences, drawing, arithmetic calculation and can also play a crucial role in the acquisition of reading and writing abilities. In order to identify early students with low non verbal abilities, Cornoldi, Venneri, Marconato, Molin & Montinari (2003) have proposed a questionnaire for teachers, the so called Shortened Visuo-Spatial Questionnaire (SVS). However, this tool has been validated in urban contexts mainly located in North-East Italy. Present research was aimed to investigate whether the SVS can identify children with low visuo-spatial abilities living in Sardinian rural areas. Experiment 1 was aimed to verify the reliability of the assessments of visuo-spatial abilities of 8-11 years aged children attending two primary schools in the province of Nuoro done by the teachers that used the SVS questionnaire. Results show that the questionnaire by Cornoldi et al. (2003) is a reliable tool for the early identification of children with scarce visuo-spatial abilities living in agropastoral cultural contexts. Finally, Experiment 2 was aimed to investigate which variables predict SVS scores. Results show that children chronological age and teachers previous educational experience predict the accuracy level of students visuo-spatial functions which were assessed by the teachers using the SVS questionnaire. In conclusion the SVS is an useful tool for the early identification of children with Non Verbal Syndrome, a disability that can cause low self-esteem and depression in children and adolescent with visuo-spatial learning problems

The influence of Catechol-O-methyltransferase on cognition is modulated by bipolar disorder diagnosis

Event Abstract Back to Event The influence of Catechol-O-methyltransferase on cognition is modulated by bipolar disorder diagnosis Tamsyn E. Van Rheenen1, 2*, Kiymet Bozaoglu3 and Susan L. Rossell1, 2 1 Swinburne University, Brain and Psychological Sciences Research Centre, Australia 2 Monash University, Monash Alfred Psychiatry Research Centre, Australia 3 Baker IDI Heart and Diabetes Institute, Genomics and Systems Biology, Australia Background: Catechol-O-Methyltransferase (COMT) variations have been implicated in the genetic predisposition to bipolar disorder (BD) and may modulate candidate endophenotypes related to neurocognition. Given the sparse empirical data examining this, the aim of the current study was to determine the relationship of three single nucleotide polymorphisms (SNPs) within the COMT gene (rs165599, rs4680 and rs4818) and performance on standardised cognitive battery in a well characterised sample of BD patients compared to controls. Methods: Fifty BD patients and 52 healthy controls were genotyped across rs165599, rs4680 and rs4818, and their association with performance on a battery of cognitive measures tested in a case-control design. Results: Significant interaction effects were evident for executive functioning across all three SNP’s, and for visuospatial learning on the rs4680. On these tasks, G allelotype carrier performance was associated with better performance in the control group, but worse performance in the patient group. Conclusions: These novel findings suggest that aberrations of executive function and visuospatial memory in BD are, at least partially, the result of a significant influence of COMT on these particular domains. Thus, COMT may be involved in the pathophysiology of the disorder by influencing the capacity for certain cognitive processes. Acknowledgements The authors would like to acknowledge the late Associate Professor Jeremy Jowett for his kindness, advice and support of this research, as well as the financial support of the Australian Rotary Health/Bipolar Expedition, Helen McPherson Smith Trust and an Australian Postgraduate Award. Keywords: COMT, Val158Met, rs165599, rs4680, rs4818, MCCB, Stroop, Dopamine Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Oral Topic: Executive Processes Citation: Van Rheenen TE, Bozaoglu K and Rossell SL (2013). The influence of Catechol-O-methyltransferase on cognition is modulated by bipolar disorder diagnosis. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00156 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Oct 2013; Published Online: 25 Nov 2013. * Correspondence: Mrs. Tamsyn E Van Rheenen, Swinburne University, Brain and Psychological Sciences Research Centre, Melbourne, Australia, tvanrheenen@swin.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Tamsyn E Van Rheenen Kiymet Bozaoglu Susan L Rossell Google Tamsyn E Van Rheenen Kiymet Bozaoglu Susan L Rossell Google Scholar Tamsyn E Van Rheenen Kiymet Bozaoglu Susan L Rossell PubMed Tamsyn E Van Rheenen Kiymet Bozaoglu Susan L Rossell Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

The cognitive profile of children treated with radiation for acute lymphoblastic leukaemia

Background. Cranial radiation is part of a treatment protocol for childhood acute lymphoblastic leukaemia (ALL) in South Africa. Radiation is known to disrupt the myelination and integrity of white matter tracts in the brain. Associated cognitive impairment has been well documented in other countries, but not to the same extent in the multicultural and multilingual South African context. Objectives. The current study focused on the assessment of memory and learning, two imperative cognitive functions. A quantitative evaluation of verbal and visuospatial memory performance in a cohort of ALL patients was done in order to establish whether there was a difference in performance between verbal and visuospatial tasks. Methods. Eight patients with a low socio-economic background and being educated in their second language were included in the cognitive evaluation. All had received 18 Gy of radiation as part of their treatment protocol and were on maintenance treatment at the time of the study. Results. In all the patients, primary cognitive impairment was demonstrated in ostensibly right hemisphere visuospatial tasks in comparison with ostensibly left hemisphere verbal tasks. Because deficits in visuospatial attention and working memory were identified, qualitative analysis of the results suggested that the white matter tracts in the right frontoparietal region and prefrontal cortex may be particularly vulnerable to radiation injury. Conclusion. The study findings support vulnerability of the right hemisphere, particularly the right frontoparietal region and prefrontal cortex, to radiation injury. The decline in visuospatial cognitive abilities has major implications for second-language learners, as visuospatial learning is particularly important for them.

Massed versus spaced visuospatial memory in cognitively healthy young and older adults

BackgroundThe present study examined the effect of massed versus spaced learning trials on 24-hour delayed recall for a visuospatial learning task. To determine the utility of measuring the incremental benefit of spaced training as a cognitive assay that may be useful in early clinical trials, we used a within-subject crossover design, with two small samples (typical sample sizes for phase I clinical trials). MethodsYoung adults and cognitively healthy older adults without significant physical, neurological, or psychiatric illness were trained on a visuospatial paired-associate learning task under a massed condition (learning trials were presented in immediate succession) and a spaced condition (learning trials were presented with 15-minute intertrial delays). ResultsStatistically significant differences between training conditions on the visuospatial task, such that young adult participants performed better on delayed recall after spaced training, were identified. Large effect sizes for young and older adults on this task suggest meaningful differences between training conditions, reflecting the expected “spacing effect.” The role of amyloid aggregation was also considered for a subset of participants; as amyloid levels increased, the benefit of spaced training decreased, suggesting that the effect of this training paradigm is modulated by disease burden. ConclusionsThe utility of this paradigm as a potential assay for phase I proof-of-concept trials, targeting molecular mechanisms that are central to the encoding and consolidation of new learning, is discussed.

The involvement of Type II Neuregulin-1 in rat visuospatial learning and memory

The cognitive deficits observed in schizophrenia are considered a core feature of the disease. Neuregulin-1 is a risk gene for schizophrenia that is involved in many neurodevelopmental and synaptic plasticity-related processes relevant to schizophrenia. Here, we have utilized a rat model (Nrg1Tn), which is hypomorphic for the neuregulin-1 (Nrg1) gene, to test whether reduced Type II NRG1 in the rat brain leads to cognitive deficits relevant to schizophrenia. Wild-type and homozygous Nrg1Tn male rats were tested in memory tasks that evaluated spatial memory (Morris water maze) and visuospatial working and reference memory (Can Test). Nrg1Tn rats were not impaired on the Morris water maze, but did show a deficit in the appetitive visuospatial discrimination test. Nrg1Tn rats committed more reference and working memory errors in this test. These results indicate that decreased Type II NRG1 in the brain may lead to deficits in visuospatial learning and memory.

Mephedrone (4-methylmethcathinone) and d-methamphetamine improve visuospatial associative memory, but not spatial working memory, in rhesus macaques.

The novel cathinone derivative 4-methylmethcathinone (4-MMC; mephedrone) is increasingly popular with recreational users. Little scientific information is available but users report both entactogen-like and classic stimulant-like subjective properties. A recent study in humans reported psychomotor speed improvement after intranasal 4-MMC suggesting classic stimulant properties. Limitations of the user group (which was impaired on some tasks) prompt controlled laboratory investigation. Adult male rhesus monkeys were trained to perform tasks from the non-human primate Cambridge Neuropsychological Test Automated Battery, which assess spatial working memory, visuospatial associative memory, learning and motivation for food reward. Test of bimanual motor coordination and manual tracking were also included. The subjects were challenged with 0.178-0.56 mg·kg(-1) 4-MMC and 0.056-0.56 mg·kg(-1) d-methamphetamine (MA), i.m., in randomized order for behavioural evaluation. A pronounced improvement in visuospatial memory and learning was observed after the 0.32 mg·kg(-1) dose of each compound, this effect was confirmed with subsequent repetition of these conditions. Spatial working memory was not improved by either drug, and the progressive ratio, bimanual motor and rotating turntable tasks were all disrupted in a dose-dependent manner. These studies show that 4-MMC produces behavioural effects, including improvements in complex spatial memory and learning that are in large part similar to those of MA in non-human primates. Thus, the data suggest that the effects of 4-MMC in monkeys can be classified with classical psychomotor stimulants.

Functional asymmetries in early learning during right, left, and bimanual performance in right‐handed subjects

To elucidate differences in activity and connectivity during early learning due to the performing hand. Twenty right-handed subjects were recruited. The neural correlates of explicit visuospatial learning executed with the right, the left hand, and bimanually were investigated using functional magnetic resonance imaging. Connectivity analyses were carried out using the psychophysiological interactions model, considering right and left anterior putamen as index regions. A common neural network was found for the three tasks during learning. Main activity increases were located in posterior cingulate cortex, supplementary motor area, parietal cortex, anterior putamen, and cerebellum (IV-V), whereas activity decrements were observed in prefrontal regions. However, the left hand task showed a greater recruitment of left hippocampal areas when compared with the other tasks. In addition, enhanced connectivity between the right anterior putamen and motor cortical and cerebellar regions was found for the left hand when compared with the right hand task. An additional recruitment of brain regions and increased striato-cortical and striato-cerebellar functional connections is needed when early learning is performed with the nondominant hand. In addition, access to brain resources during learning may be directed by the dominant hand in the bimanual task.

The effect of apamin, a small conductance calcium activated potassium (SK) channel blocker, on a mouse model of neurofibromatosis 1

Neurofibromatosis 1 (NF1) is a common genetic disorder known to cause a variety of physiological symptoms such as the formation of both benign and malignant tumors, and is also known to cause visuospatial learning deficits. Mouse models of NF1 show increased GTP activation of ras which may alter K+ channels. One candidate K+ channel that may contribute to deficits in NF1 is the SK (small conductance calcium-activated potassium) channel due to its role in regulation of long term potentiation (LTP), a mechanism of learning which has been shown to be impaired in Nf1+/− mice. We found that administration of apamin (SK antagonist) either through i.p. injection or micro-osmotic pump to Nf1+/− mice significantly improved performance on the water maze task in comparison to saline treated Nf1+/− mice on the third day of training and on the corresponding probe test. In this study we demonstrate a possible mechanism for the learning deficits seen in Nf1+/− mice and a possible drug therapy for rescuing these deficits.

Paired associate learning in children with neurofibromatosis type 1: implications for clinical trials

Studies investigating behavior in mice with a heterozygous null mutation of the NF1 gene (Nf1 (+/-)) have provided critical insights into the molecular and cellular mechanisms underlying cognitive impairments associated with neurofibromatosis type 1 (NF1). Hyperactivation of the Ras-MAPK signaling cascade, which results in increased GABA-mediated inhibition and significantly reduced long-term potentiation, has been proposed as a core mechanism underlying Nf1 (+/-) mice deficits in visuospatial learning and attention. This assertion has been reinforced by preclinical trials that reveal that these impairments can be rescued both at a cognitive and cellular level. We attempted to demonstrate a phenotypic parallel between Nf1 (+/-) mice and children with NF1 using a well-validated measure of visuospatial learning. Children with NF1 (n = 71) and healthy controls (n = 29) were assessed on a computerized paired associate learning task. Interrelationships between visuospatial learning and other cognitive abilities that may influence performance, such as intelligence, attention and visuospatial function, were explored. Children with NF1 displayed significant impairments in visuospatial learning, with reduced initial retention and poorer learning across repeated trials. Importantly, we demonstrated that visuospatial learning was inferior in NF1 even after accounting for group differences in intelligence, sustained attention and visuospatial abilities. We have thus identified impaired visuospatial learning as a core phenotypic feature in children with NF1. These findings imply that hippocampal-based learning networks are dysfunctional in children with NF1 and provide validation for a primary outcome measure for clinical trials aiming to correct aberrant Ras signaling.

Predictors of virtual radial arm maze performance in adolescent Italian children

BackgroundComparisons between animal and human neurotoxicology studies are a foundation of risk assessment, but are hindered by differences in measured behaviors. The radial arm maze (RAM), a rodent visuospatial learning and memory task, has a computerized version for use in children, which may help improve comparisons between animal and human studies. ObjectiveTo describe the characteristics and correlates of the virtual radial arm maze (VRAM) in 255 children age 10–15 years from Italy. MethodsWe administered the VRAM using a laptop computer and measured children's performance using the latency, distance, and working/reference memory errors during eight trials. Using generalized linear mixed models, we described VRAM performance in relation to demographic factors, child activities, and several standard neuropsychologic tests (Italian translations), including the Conners Parent Rating Scales-Short Version (CPRS), California Verbal Learning Test (CVLT), Wechsler Intelligence Scales for Children, finger tapping speed, reaction time, and motor skills. ResultsChildren's VRAM performance tended to improve between trials 1 and 6 and then plateaued between trials 6 and 8. Males finished the task 14s faster (95% confidence interval [CI]: −20, −9) than females. Children who played 2+h of video games per day finished 16s faster (CI: −26, −6) and with 34% (CI: 5, 54%) fewer working memory errors than children who reported not playing video games. Higher IQ and better CVLT scores were associated with better VRAM performance. Higher cognitive/inattention CPRS scores were associated with more working (11%; CI: 1, 22) and reference memory errors (7%; CI: 1, 12). ConclusionsConsistent with animal studies, VRAM performance improved over the course of test trials and males performed better than females. Better VRAM performance was related to higher IQ, fewer inattentive behaviors, and better verbal memory. The VRAM may help to improve the integration and comparison between animal and epidemiological studies of environmental neurotoxicants.

Comparison of neuropsychological functioning and emotional processing in major depression and social anxiety disorder subjects, and matched healthy controls

Few studies of neuropsychological function in major depression have examined emotional processing or the impact of gender. Patients have also been compared with highly selected control participants and rarely with other patient groups. The objective of this study was to compare neuropsychological function in a major depressive episode (MDE) with a group of patients with an anxiety disorder, social anxiety disorder (SAD), and healthy controls, to include measures of emotional processing and to analyse the effects of gender on neuropsychological function and emotional processing in these groups. One hundred and one medication-free patients with MDE, 30 patients with SAD and 76 healthy control participants were recruited. The groups were matched for age and estimated premorbid intelligence and education. Subjects performed a battery of neuropsychological tests assessing; verbal learning and memory, visuospatial learning and memory, attention, executive function and psychomotor performance. They also performed a task measuring the accuracy of recognition of facial emotional expressions. Compared with healthy participants and those with SAD, patients with MDE were significantly impaired in verbal learning and spatial working memory. The SAD group misclassified significantly more neutral expressions as angry and fewer as sad, compared with the MDE group and healthy controls, but there were no significant differences between the MDE group and healthy controls. The profile of performance was the same regardless of gender. The study confirms a significant impairment in neuropsychological function in a clinical sample of outpatients with MDE, which is likely to have important implications for day-to-day functioning and treatment.

WAIS-IV Visual Puzzles in a Mixed Clinical Sample

Little is known about which cognitive functions underlie the new Visual Puzzles subtest of the Wechsler Adult Intelligence Scale – Fourth Edition (WAIS-IV). The purpose of this study was to investigate relationships between Visual Puzzles and common neuropsychological measures in a mixed clinical sample. A total of 44 veterans (75% men) were administered the WAIS-IV as part of a neuropsychological evaluation. Average age was 47.4 years (SD = 11.8), and average education was 13.8 years (SD = 2.3). Correlations were conducted to examine relationships between Visual Puzzles, demographic variables, and neuropsychological measures. Hierarchical regression analysis was used to determine which measures contributed the most variance to Visual Puzzles. Visual Puzzles correlated significantly with measures of visuospatial reasoning, verbal learning and recall, mental flexibility, processing speed, and naming, which accounted for 50% of the variance in Visual Puzzles performance. The results indicate that Visual Puzzles is not a pure measure of visuoperceptual reasoning, at least in a mixed clinical sample, because memory, mental flexibility, processing speed, and language abilities also contribute to successful performance of the task. Thus it may be important to consider other aspects of cognitive functioning when interpreting Visual Puzzles performance.

Δ9tetrahydrocannabinol impairs visuo-spatial associative learning and spatial working memory in rhesus macaques

Cannabis remains the most commonly abused illicit drug and is rapidly expanding in quasi-licit use in some jurisdictions under medical marijuana laws. Effects of the psychoactive constituent Δ⁹tetrahydrocannabinol (Δ⁹THC) on cognitive function remain of pressing concern. Prior studies in monkeys have not shown consistent evidence of memory-specific effects of Δ⁹THC on recognition tasks, and it remains unclear to what extent Δ⁹THC causes sedative versus specific cognitive effects. In this study, adult male rhesus monkeys were trained on tasks which assess spatial working memory, visuo-spatial associative memory and learning as well as motivation for food reward. Subjects were subsequently challenged with 0.1-0.3 mg/kg Δ⁹THC, i.m., in randomized order and evaluated on the behavioral measures. The performance of both vsPAL and SOSS tasks was impaired by Δ⁹THC in a dose and task-difficulty dependent manner. It is concluded that Δ⁹THC disrupts cognition in a way that is consistent with a direct effect on memory. There was evidence for interference with spatial working memory, visuo-spatial associative memory and incremental learning in the latter task. These results and the lack of specific effect of Δ⁹THC in prior visual recognition studies imply a sensitivity of spatial memory processing and/or working memory to endocannabinoid perturbation.

Adult neuropsychological performance following prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water

This population-based retrospective cohort study examined adult performance on a battery of neuropsychological tests in relation to prenatal and early postnatal exposure to tetrachloroethylene (PCE)-contaminated drinking water on Cape Cod, Massachusetts. Subjects were identified through birth records from 1969 through 1983. Exposure was modeled using pipe network information from town water departments, a PCE leaching and transport algorithm, EPANet water flow modeling software, and a Geographic Information System (GIS). Results of crude and multivariate analyses among 35 exposed and 28 unexposed subjects showed no association between prenatal and early postnatal exposure and decrements on tests that assess abilities in the domains of omnibus intelligence, academic achievement or language. The results were suggestive of an association between prenatal and early postnatal PCE exposure and diminished performance on tests that assessed abilities in the domains of visuospatial functioning, learning and memory, motor, attention and mood. Because the sample size was small, most findings were not statistically significant. Future studies with larger sample sizes should be conducted to further define the neuropsychological consequences of early developmental PCE exposure.

Age-related changes in visual acuity, learning and memory in the APPswe/PS1dE9 mouse model of Alzheimer's disease

Mouse models of Alzheimer's disease (AD) are often tested for learning and memory deficits using visuo-spatial tasks such as the Morris water maze. Performance on these tasks is dependent on vision and the APPswe/PS1dE9 mouse model has amyloid beta plaques in their retinas which might influence their performance in these tasks. In a visual learning task, old (20–26 months) transgenic mice and their wildtype littermates of both sexes had poorer visual ability than young (5–8 months) mice and old transgenic mice had poorer visual acuity than old wildtype mice. Old transgenic mice also had deficits in visuo-spatial learning and memory on the Morris water maze. The transgenic mice had no deficits in the conditioned odour preference or conditioned taste aversion memory tests at any age. These results indicate that the old APPswe/PS1dE9 mice and their wildtype littermates both have a deficit in their visual ability and that visually dependent measures alone should not be used to assess learning and memory in this strain.

Enhancing visuospatial map learning through action on cellphones

The visuospatial learning of a map on cellphone displays was examined. The spatial knowledge of human participants was assessed after they had learned the relative positions of London Underground stations on a map via passive, marginally active, or active exploration. Following learning, the participants were required to answer questions in relation to the spatial representation and distribution of the stations on the map. Performances were compared between conditions involving (1) without auditory cues versus continuous auditory cues; (2) without auditory cues versus noncontinuous auditory cues; and (3) continuous auditory cues versus noncontinuous auditory cues. Results showed that the participants perfomed better following active and marginally-active explorations, as compared to purely passive learning. These results also suggest that under specific conditions (i.e., continuous sound with extremely fast tempo) there is no benefit to spatial abilities from active exploration over passive observation; while continuous sound with moderate to fast tempo is effective for simple actions (i.e., key press).