Object Location Recall Research Articles

The Position of Sound in Audiovisual Maps: An Experimental Study of Performance in Spatial Memory

Digital maps are known as reliable media for communicating spatial information. People use maps to make themselves familiar with new environments and to form cognitive representations of spatial configurations and additional semantic information that are coupled with locational information. Since the mid-1990s, cartographers have explored auditory media as cartographic elements to transfer spatial information. Among the established sound variants used in multimedia cartography, speech recordings are a popular auditory tool to enrich the visual dominance of maps. The impact of auditory elements on human spatial memory has hardly been investigated so far in cartography and spatial cognition. A recent study showed that spoken object names bound to visual location markers affect performance in memory of object locations. Map users tend to make significantly smaller spatial distortion errors in the recall of object locations if these locations are coupled with auditory semantic information (place names). The present study extends this approach by examining possible effects on sound position as cues for spatial memory performance. A monaural condition, where an auditory name is presented in a spatial location corresponding to the object location, is compared with a binaural condition (of no directional cue). The results show that a monaural communication additionally improves spatial memory performance. Interestingly, the semantic information bound to an object location appears to be the driving factor in improving this effect.

Correcting distortion errors in memory of object locations: the example of grid line spacing in topographic maps

ABSTRACTThe omnipresence of orientation, wayfinding and navigation tasks in everyday life calls for high-quality cartographic media that help people to solve their tasks in the best possible way. Modern maps should not only consider modern visualization techniques and design approaches but also knowledge on the map user’s cognitive processing. Previous studies of cognitive cartography and spatial cognition identified grids as suitable cartographic elements that can enhance the accuracy of cognitive representations of geographic space. Grid lines form grid cells and these cells subdivide a map layout into different regions. These regions seem to contribute to a categorization of cartographically represented contents. The categorical organization of a map provides a superordinate spatial structure that can improve the recall of object locations. An important parameter influencing categorization is the distance between grid lines (spacing/separation). A previous study suggested 5 cm (paper distance) spacing as being suitable for an accurate performance in recalling object locations in topographic maps. Based on a recall-memory-paradigm adopted from experimental studies in cognitive psychology, the experiments reported in the present study take up this value and aim at specifying the ideal value of grid line spacing for object location memory. The results show that previous findings can be extended. The results allow the proposal of ideal grid line spacing in a 6.5-7.5 cm range. These spacing values help to reduce spatial distortion errors in the memory of object locations, especially in maps with a low amount of visual details.

Impact of Omega-3 Fatty Acid Supplementation on Memory Functions in Healthy Older Adults.

As the process of Alzheimer's disease (AD) begins years before disease onset, searching for prevention strategies is of major medical and economic importance. Nutritional supplementation with long-chain polyunsaturated omega-3 fatty acids (LC-n3-FA) may exert beneficial effects on brain structure and function. However, experimental evidence in older adults without clinical dementia is inconsistent, possibly due to low sensitivity of previously employed test batteries for detecting subtle improvements in cognition in healthy individuals. Here we used LOCATO, recently described as a robust and sensitive tool for assessing object-location memory (OLM) in older adults, to evaluate the impact of LC-n3-FA supplementation on learning and memory formation. In a double-blind placebo-controlled proof-of-concept study, 44 (20 female) cognitively healthy individuals aged 50-75 years received either LC-n3-FA (2,200 mg/day, n = 22) or placebo (n = 22) for 26 weeks. Before and after intervention, memory performance in the OLM-task (primary) was tested. As secondary outcome parameters, performance in Rey Auditory Verbal Learning Test (AVLT), dietary habits, omega-3-index, and other blood-derived parameters were assessed. Omega-3 index increased significantly in the LC-n3-FA group compared with the placebo group. Moreover, recall of object locations was significantly better after LC-n3-FA supplementation compared with placebo. Performance in the AVLT was not significantly affected by LC-n3-FA. This double-blind placebo-controlled proof-of-concept study provides further experimental evidence that LC-n3-FA exert positive effects on memory functions in healthy older adults. Our findings suggest novel strategies to maintain cognitive functions into old age.

Identifying, locating, and sequencing picture communication symbols: Contributions from developmental visuospatial and temporal memory

This study investigated visuospatial and temporal working memory through assessment of feature binding abilities of typically developing first-, third-, and fifth-grade school-age children. One hundred and twelve children were asked to identify, locate, and sequence various numbers and arrays of picture communication symbols during a picture span assessment task. Feature binding was assessed through analysis of object recall, location recall, object–location recall, object–sequence recall, and location–sequence recall. Significant increases in picture span occurred with increasing grade level. Objects were highly salient with most children having recall greater than 90%. Most children had difficulty with recall of location, object sequence, and location sequence. A significant increase in location–sequence binding ability was noted as grade level increased from first to third grade. When visuospatial and temporal working memory capacity is exceeded, limitations in the ability to bind multiple features (object, location, and sequence) may reduce children’s abilities to successfully use visual graphic displays for communication.

Integrating actions into object location memory: A benefit for active versus passive reaching movements

We tested whether learning the mapping between objects and their locations is better when actively moving the hand to these locations, to reveal the object, compared to when the hand is passively moved by a robotic manipulandum. Recall of object locations was more accurate in the active compared to passive condition. We also found that recall was less accurate when participant made active movements that were not directed to the object locations. These results indicate that the well-established active exploration advantage for spatial memory extends to location memory for objects within reach. Such active learning is likely important for manipulation tasks.

Resting-state fMRI activity predicts unsupervised learning and memory in an immersive virtual reality environment.

In the real world, learning often proceeds in an unsupervised manner without explicit instructions or feedback. In this study, we employed an experimental paradigm in which subjects explored an immersive virtual reality environment on each of two days. On day 1, subjects implicitly learned the location of 39 objects in an unsupervised fashion. On day 2, the locations of some of the objects were changed, and object location recall performance was assessed and found to vary across subjects. As prior work had shown that functional magnetic resonance imaging (fMRI) measures of resting-state brain activity can predict various measures of brain performance across individuals, we examined whether resting-state fMRI measures could be used to predict object location recall performance. We found a significant correlation between performance and the variability of the resting-state fMRI signal in the basal ganglia, hippocampus, amygdala, thalamus, insula, and regions in the frontal and temporal lobes, regions important for spatial exploration, learning, memory, and decision making. In addition, performance was significantly correlated with resting-state fMRI connectivity between the left caudate and the right fusiform gyrus, lateral occipital complex, and superior temporal gyrus. Given the basal ganglia's role in exploration, these findings suggest that tighter integration of the brain systems responsible for exploration and visuospatial processing may be critical for learning in a complex environment.

Age-related impairments in active learning and strategic visual exploration

Old age could impair memory by disrupting learning strategies used by younger individuals. We tested this possibility by manipulating the ability to use visual-exploration strategies during learning. Subjects controlled visual exploration during active learning, thus permitting the use of strategies, whereas strategies were limited during passive learning via predetermined exploration patterns. Performance on tests of object recognition and object-location recall was matched for younger and older subjects for objects studied passively, when learning strategies were restricted. Active learning improved object recognition similarly for younger and older subjects. However, active learning improved object-location recall for younger subjects, but not older subjects. Exploration patterns were used to identify a learning strategy involving repeat viewing. Older subjects used this strategy less frequently and it provided less memory benefit compared to younger subjects. In previous experiments, we linked hippocampal-prefrontal co-activation to improvements in object-location recall from active learning and to the exploration strategy. Collectively, these findings suggest that age-related memory problems result partly from impaired strategies during learning, potentially due to reduced hippocampal-prefrontal co-engagement.

Human Cortical θ during Free Exploration Encodes Space and Predicts Subsequent Memory

Spatial representations and walking speed in rodents are consistently related to the phase, frequency, and/or amplitude of θ rhythms in hippocampal local field potentials. However, neuropsychological studies in humans have emphasized the importance of parietal cortex for spatial navigation, and efforts to identify the electrophysiological signs of spatial navigation in humans have been stymied by the difficulty of recording during free exploration of complex environments. We resolved the recording problem and experimentally probed brain activity of human participants who were fully ambulant. On each of 2 d, electroencephalography was synchronized with head and body movement in 13 subjects freely navigating an extended virtual environment containing numerous unique objects. θ phase and amplitude recorded over parietal cortex were consistent when subjects walked through a particular spatial separation at widely separated times. This spatial displacement θ autocorrelation (STAcc) was quantified and found to be significant from 2 to 8 Hz within the environment. Similar autocorrelation analyses performed on an electrooculographic channel, used to measure eye movements, showed no significant spatial autocorrelations, ruling out eye movements as the source of STAcc. Strikingly, the strength of an individual's STAcc maps from day 1 significantly predicted object location recall success on day 2. θ was also significantly correlated with walking speed; however, this correlation appeared unrelated to STAcc and did not predict memory performance. This is the first demonstration of memory-related, spatial maps in humans generated during active spatial exploration.

An Evaluation of Nonclinical Dissociation Utilizing a Virtual Environment Shows Enhanced Working Memory and Attention

Dissociation is a mental process resulting in the disruption of memory, perception, and sometimes identity. At a nonclinical level, only mild dissociative experiences occur. The nature of nonclinical dissociation is disputed in the literature, with some asserting that it is a beneficial information processing style and others positing that it is a psychopathological phenomenon. The purpose of this study was to further the understanding of nonclinical dissociation with respect to memory and attention, by including a more ecologically valid virtual reality (VR) memory task along with standard neuropsychological tasks. Forty-five undergraduate students from a small liberal arts college in the northeast participated for course credit. The participants completed a battery of tasks including two standard memory tasks, a standard attention task, and an experimental VR memory task; the VR task included immersion in a virtual apartment, followed by incidental object-location recall for objects in the virtual apartment. Support for the theoretical model portraying nonclinical dissociation as a beneficial information processing style was found in this study. Dissociation scores were positively correlated with working memory scores and attentional processing scores on the standard neuropsychological tasks. In terms of the VR task, dissociation scores were positively correlated with more false positive memories that could be the result of a tendency of nonclinical highly dissociative individuals to create more elaborative schemas. This study also demonstrates that VR paradigms add to the prediction of cognitive functioning in testing protocols using standard neuropsychological tests, while simultaneously increasing ecological validity.

Item and associative memory in amnestic mild cognitive impairment: Performance on standardized memory tests.

The earliest neuroanatomical changes in amnestic mild cognitive impairment (aMCI) involve the hippocampus and entorhinal cortex, structures implicated in the integration and learning of associative information. The authors hypothesized that individuals with aMCI would have impairments in associative memory above and beyond the known impairments in item memory. A group of 29 individuals with aMCI and 30 matched control participants were administered standardized tests of object-location recall and symbol-symbol recall, from which both item and associative recall scores were derived. As expected, item recall was impaired in the aMCI group relative to controls. Associative recall in the aMCI group was even more impaired than was item recall. The best group discriminators were measures of associative recall, with which the sensitivity and specificity for detecting aMCI were 76% and 90% for symbol-symbol recall and were 86% and 97% for object-location recall. Associative recall may be particularly sensitive to early cognitive change in aMCI, because this ability relies heavily on the medial temporal lobe structures that are affected earliest in aMCI. Incorporating measures of associative recall into clinical evaluations of individuals with memory change may be useful for detecting aMCI.

Video training of imagery for mature adults

To examine the effectiveness of videotaped memory training, two groups of middle-aged and older adults were given imagery training that included videotaped presentation of interactive imagery for object location recall and linking items on a list, and the image-name match method for name recall. The training group performed significantly better than the waiting list on the initial post-test, and the two groups were comparable after both groups had received training. Evidence for both maintenance and generalization was found. Videotaped presentation of imagery training is effective for mature adults as a self-paced at-home intervention, and has cost-saving advantages over the predominant training methodology.

The misplaced objects test: A measure of everyday visual memory

The Misplaced Objects Test is a computerized test of object location recall. The test is structurally similar to tasks used in the evaluation of age and drug effects in preclinical animal research. Delayed recall of 20 common objects which the subject has placed using a touch sensitive screen in a computer-simulated 12-room house is evaluated with three measures. Scores include the number of objects found on the first attempt (Found 1), the number of objects found on the second attempt (Found 2), and the total number of objects found on both attempts (Found T). Performance was evaluated in relation to age, gender, education, and affective status, as well as in relation to several traditional neuropsychological measures. Misplaced Objects Test performance was most strongly associated with age and Wechsler Memory Scale Paired Associate Learning. Additional significant relationships were found with gender, education, and the WAIS Digit Symbol subtest. Potential future applications of the test were discussed.

Performance subtypes of everyday memory function

Normal 18‐ to 77‐year‐olds were administered a computerized battery of everyday memory tests. Cluster and discriminant function analyses yielded a variety of memory subtypes, including age‐independent and age‐dependent forgetfulness, and varying patterns of strengths and weaknesses on name‐face memory, object location recall, and facial memory. Results are discussed in relation to “benign” forgetfulness, age‐associated memory impairment, and material‐specific memory subtypes.

Memory assessment: The next step

A computerized assessment battery was developed to determine memory impairment in head-injured individuals, using an interactive video system, consisting of a videodisc player, microcomputer, and video display. Subtests measure reaction time; reaction time with distractors; recall of object locations, grocery list, and names/faces; telephone use; delayed nonmatching to sample; and first-last names. (JDD) Language: en

Measurement of imagery mediated performance

The present study attempted to circumvent previous problems in measuring imagery due to memory processing requirements in the tasks used. Objective performance measures and self-reports of clarity and ease of visual imagery production were derived from incidental learning, picture memory, and signal detection tasks. The tasks were administered in two different orders to 16 male and 16 female subjects. The three measures from each of the tasks were intercorrelated to determine the consistency of individual differences. Recall of paired nouns imagined as interacting, in the incidental learning task, and recall of object locations from imagined pictures in the picture memory task, were significantly correlated. However, the incidental learning and picture memory tasks yielded correlations of zero magnitude with reductions in detection of visual signals during imagining of nouns in the signal detection task. These findings were attributed to the use of imagery in memory processing rather than to effects of imagery production per se. Ratings of image clarity and ease of producing images were consistently correlated with each other but not with performance measures.