Studies suggest a greater reliance on visual information for maintaining balance in anxious subjects. Nevertheless, links between this supposed preferred visual processing and spatial orientation have not yet been evaluated. Two groups of subjects differing in their level of trait anxiety were formed. Equipped with a head-mounted visual display, they learned a virtual corridor using passive translation but active rotation, both with normal and with two different conflicting sensory conditions. After two visual navigation trials in the corridor, they were blindfolded and asked to reproduce the same trajectory from memory. In addition, subjects drew a map of the remembered corridor. Anxious subjects were comparable to non-anxious subjects when asked to reproduce the trajectory from memory, but exhibited a deficit when drawing a map of the corridor they were in. The results do not support the hypothesis that anxious subjects use preferentially one type of sensory cue over another for spatial orientation, but instead manifest difficulties in constructing more global representations of space.

Previously, it has been shown that strawberry (SB) or blueberry (BB) supplementations, when fed to rats from 19 to 21 months of age, reverse age-related decrements in motor and cognitive performance. We have postulated that these effects may be the result of a number of positive benefits of the berry polyphenols, including decreased stress signalling, increased neurogenesis, and increased signals involved in learning and memory. Thus, the present study was carried out to examine these mechanisms in aged animals by administering a control, 2 % SB- or 2 % BB-supplemented diet to aged Fischer 344 rats for 8 weeks to ascertain their effectiveness in reversing age-related deficits in behavioural and neuronal function. The results showed that rats consuming the berry diets exhibited enhanced motor performance and improved cognition, specifically working memory. In addition, the rats supplemented with BB and SB diets showed increased hippocampal neurogenesis and expression of insulin-like growth factor 1, although the improvements in working memory performance could not solely be explained by these increases. The diverse polyphenolics in these berry fruits may have additional mechanisms of action that could account for their relative differences in efficacy.

The goal of this meta-analysis was to provide an estimation of the average effect of aging on intentional memory for spatial location in small-scale space. Findings from 22 studies, which represent the testing of 1,598 subjects, were compared using the following statistics: (a) d (Cohen, 1988), (b) omega2 (Hays, 1963), and (c) Proportion of classified subjects. The meta-analysis suggests that the effect of aging is “large” (e.g., the average d was 0.81), and that it is proportional to the number of dimensions of the array used. However, these conclusions have to be treated with caution because of some methodological limitations of the reviewed literature. In particular, less than half of the studies mentioned (a) control for differences often found between young and elderly adults in visual acuity, and (b) having used a test phase of fixed duration. It is recommended that future research on age-related deficits in spatial memory take into account these confounds.

Memory for object locations, as part of spatial memory function, has rarely been studied in patients with Alzheimer dementia (AD), while studies in patients with Mild Cognitive Impairment (MCI) patients are lacking altogether. The present study examined categorical spatial memory function using the Location Learning Test (LLT) in MCI patients (n = 30), AD patients (n = 30), and healthy controls (n = 40). Two scoring methods were compared, aimed at disentangling positional recall (location irrespective of object identity) and object-location binding. The results showed that AD patients performed worse than the MCI patients on the LLT, both on recall of positional information and on recall of the locations of different objects. In addition, both measures could validly discriminate between AD and MCI patients. These findings are in agreement with the notion that visual cued-recall tests may have better diagnostic value than traditional (verbal) free-recall tests in the assessment of patients with suspected MCI or AD. (JINS, 2010, 16, 200–204.)

In most individuals, language production and visuospatial skills are subserved predominantly by the left and right hemispheres, respectively. Functional Transcranial Doppler (fTCD) provides a noninvasive and relatively low-cost method for measuring functional lateralization. However, while the silent word generation task provides an accurate and reliable paradigm for investigating lateralization of language production, there is no comparable gold-standard method for measuring visuospatial skills. Thirty undergraduate students (19 females) completed a task of spatial memory while undergoing fTCD recording. Participants completed this task at two different time points, separated by between 26 to 155 days. The relative activation between hemispheres averaged across all participants was found to be consistent across testing sessions. This was observed at the individual level also, with a quantitative index of lateralization showing high reproducibility. These findings indicate that the use of the spatial memory task with fTCD is a robust methodology for examining laterality of visuospatial skills. (JINS, 2009, 15, 1028–1032.)

Aged rats show decrements in performance on motor and cognitive tasks that require the use of spatial learning and memory. Previously we have shown that these deficits can be reversed by the polyphenolics in fruits and vegetables. Walnuts, which contain the n-3 fatty acids α-linolenic acid and linoleic acid, are a dietary source of polyphenols, antioxidants and lipids. Thus, the present study examined the effects of walnut supplementation on motor and cognitive ability in aged rats. Fischer 344 rats, aged 19 months, were fed a control, or a 2, 6 or 9 % walnut diet for 8 weeks before motor and cognitive testing. Results for the motor testing showed that the 2 % walnut diet improved performance on rod walking, while the 6 % walnut diet improved performance on the medium plank walk; the higher dose of the 9 % walnut diet did not improve psychomotor performance and on the large plank actually impaired performance. All of the walnut diets improved working memory in the Morris water maze, although the 9 % diet showed impaired reference memory. These findings show for the first time that moderate dietary walnut supplementation can improve cognitive and motor performance in aged rats.

There is evidence that the prevention of errors during learning might be helpful in improving an impaired memory performance, both in amnesia as well as in normal age-related memory decline. Although errorless learning is a promising technique for use in rehabilitation practice, the underlying mechanisms are unclear. That is, it has been suggested that the beneficial effects of errorless learning operate through implicit memory, whereas others implicate that it is explicit memory that is responsible for the enhanced memory performance after errorless learning. The current study examined the contribution of implicit and explicit memory function to the memory performance after errorless and errorful learning using the process-dissociation procedure. A group of young adults (N = 40) was compared to a matched group of older individuals (N = 40) on a spatial memory task (i.e., learning the locations of everyday objects in a room). The results clearly show age-related decline in explicit spatial memory, while implicit spatial memory was unaffected. Furthermore, the young group benefited from errorless learning compared to errorful learning, while the older group did not show a difference between the two learning conditions. Also, it was found that the effects of errorful learning were related to explicit memory function, and not implicit processing, corroborating and extending recent findings. (JINS, 2005, 11, 144–151.)

The present study investigated the differential involvement of the right and left hippocampus in various forms of spatial memory: spatial search, positional memory versus object–location binding, and coordinate versus categorical processing. Twenty-five epilepsy patients with selective amygdalohippocampectomy were examined using a sensitive computer paradigm to measure these spatial memory aspects. The patients' performance was compared to a group of thirty healthy controls. The results show that the left amygdalohippocampectomy group performed poorly on the ability to bind together object information to coordinate spatial locations. In turn, the right amygdalohippocampectomy group was impaired in coordinate positional memory. Both patient groups were unimpaired on the spatial search task. These findings are discussed focusing on the “binding device” hypothesis in combination with the cognitive map theory. (JINS, 2004, 10, 907–912.)

Performance on long delays of delayed response tasks is associated with medial temporal function, a region of the brain affected by severe hypoglycemia. A previous study showed that children with type 1 diabetes mellitus (T1DM) with higher risk for severe hypoglycemia performed worse than controls on long delays of a spatial delayed response (SDR) task. We tested the more specific hypothesis that frequency of severe hypoglycemia would relate to long delay SDR performance. Children with T1DM (n = 51) and controls (n = 32) performed the SDR task with short and long delays. Information was collected on children's past severe hypoglycemia. In children with T1DM, number of past severe hypoglycemic episodes accounted for a significant portion of the variance in long delay SDR after controlling for age and age of onset. This relationship was not seen with short delay SDR or with other tasks (verbal or object memory, attention, motor speed). These results support the hypothesis that severe hypoglycemia has specific, negative effects on memory skills in children. If this relationship is extrapolated to children with higher frequency of severe hypoglycemia, due to longer duration of disease or poorer glucose control, it may affect daily functioning and thus need to be considered in treatment decisions. (JINS, 2003, 9, 740–750.)

This study investigated the effects of type of encoding strategy (organized and disorganized) and of active versus passive encoding on memory for interrelated spatial material. Delayed recall performance for a complex, nonrepresentational two dimensional figure was measured in 120 normal young adults assigned to one of three groups that varied as to the approach used during the initial construction of the figure. Those applying self-generated strategies performed best. In addition, recall performances were significantly better for those applying a prescribed, organized strategy as compared with performances of those applying a prescribed, disorganized strategy. These effects were not attributable to differences on measures of IQ or spatial information processing. The findings indicated that, independent of memory ability, both the degree of organization and of active strategizing at encoding are determinants of recall ability for complex spatial information and suggest that these factors have implications for memory processes more generally. (JINS, 2001, 7, 728–733.)

Darwin argued that between-species differences in intelligence were differences of degree, not of kind. The contemporary ecological approach to animal cognition argues that animals have evolved species-specific and problem-specific processes to solve problems associated with their particular ecological niches: thus different species use different processes, and within a species, different processes are used to tackle problems involving different inputs. This approach contrasts both with Darwin's view and with the general process view, according to which the same central processes of learning and memory are used across an extensive range of problems involving very different inputs. We review evidence relevant to the claim that the learning and memory performance of non-human animals varies according to the nature of the stimuli involved. We first discuss the resource distribution hypothesis, olfactory learning-set formation, and the ‘biological constraints’ literature, but find no convincing support from these topics for the ecological account of cognition. We then discuss the claim that the performance of birds in spatial tasks of learning and memory is superior in species that depend heavily upon stored food compared to species that either show less dependence upon stored food or do not store food. If it could be shown that storing species enjoy a superiority specifically in spatial (and not non-spatial) tasks, this would argue that spatial tasks are indeed solved using different processes from those used in non-spatial tasks. Our review of this literature does not find a consistent superiority of storing over non-storing birds in spatial tasks, and, in particular, no evidence of enhanced superiority of storing species when the task demands are increased, by, for example, increasing the number of items to be recalled or the duration of the retention period. We discuss also the observation that the hippocampus of storing birds is larger than that of non-storing birds, and find evidence contrary to the view that hippocampal enlargement is associated with enhanced spatial memory; we are, however, unable to suggest a convincing alternative explanation for hippocampal enlargement. The failure to find solid support for the ecological view supports the view that there are no qualitative differences in cognition between animal species in the processes of learning and memory. We also argue that our review supports our contention that speculation about the phylogenetic development and function of behavioural processes does not provide a solid basis for gaining insight into the nature of those processes. We end by confessing to a belief in one major qualitative difference in cognition in animals: we believe that humans alone are capable of acquiring language, and that it is this capacity that divides our intelligence so sharply from non-human intelligence.

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.