No evidence for chunking in spatial memory of route experience.

Spatial memory is important for supporting the successful completion of everyday activities and is a particularly vulnerable domain in late life. Grouping items together in memory, or chunking, can improve spatial memory performance. In memory for desktop scale spaces and well-learned large-scale environments, error patterns suggest that information is chunked in memory. However, the chunking mechanisms involved in learning new large-scale, navigable environments are poorly understood. In five experiments, two of which included young and older adult samples, participants watched movies depicting routes through building-sized environments while attempting to remember the locations of cued objects. We tested memory for the cued objects with virtual pointing, distance estimation, and map drawing tasks after participants viewed each route. Patterns of error failed to show consistent evidence of chunking in spatial memory across all experiments. One possibility is that chunking in spatial memory relies on visual perceptual grouping mechanisms that are not in play during encoding of large-scale spaces encountered through extended route experiences that do not afford concurrent viewing of target locations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Virtual navigation in healthy aging: Activation during learning and deactivation during retrieval predicts successful memory for spatial locations.

Spatial navigation and spatial memory are two important skills for independent living, and are known to be compromised with age. Here, we investigate the neural correlates of successful spatial memory in healthy older adults in order to learn more about the neural underpinnings of maintenance of navigation skill into old age. Healthy older adults watched a video shot by a person navigating a route and were asked to remember objects along the route and then attempted to remember object locations by virtually pointing to the location of hidden objects from several locations along the route. Brain activity during watching and pointing was recorded with functional MRI. Larger activations in temporal and frontal regions during watching, and larger deactivations in superior parietal cortex and intraparietal sulcus during pointing, were associated with smaller location errors. These findings suggest that larger evoked responses during learning of spatial information coupled with larger deactivation of canonical spatial memory regions at retrieval are important for effective spatial memory in late life.

Event memory uniquely predicts memory for large-scale space.

When a person explores a new environment, they begin to construct a spatial representation of it. Doing so is important for navigating and remaining oriented. How does one's ability to learn a new environment relate to one's ability to remember experiences in that environment? Here, 208 adults experienced a first-person videotaped route, and then completed a spatial map construction task. They also took tests of general cognitive abilities (working memory, laboratory episodic memory, processing speed, general knowledge) and of memory for familiar, everyday activities (event memory). Regression analyses revealed that event memory (memory for everyday events and their temporal structure), laboratory episodic memory (memory for words and pictures) and gender were unique predictors of spatial memory. These results implicate the processing of temporal structure and organization as an important cognitive ability in large-scale spatial-memory-from-route experience. Accounting for the temporal structure of people's experience while learning the layout of novel spaces may improve interventions for addressing navigation problems.

Age differences in spatial memory for mediated environments.

Compared with younger adults, older adults have more difficulty with navigation and spatial memory in both familiar and unfamiliar domains. However, the cognitive mechanisms underlying these effects have been little explored. We examined three potential factors: (a) use of and coordination across spatial reference frames, (b) nonspatial cognitive abilities, and (c) the ability to segment a route into effective chunks. In two experiments, healthy young and older adults watched videos of navigation in a novel environment and had to remember the placement of landmarks along the route. Participants completed three spatial memory tasks-a virtual pointing task, a distance estimation task, and sketch map drawing-for each route. The pointing task depends on updating and accessing the updated egocentric reference frame relative to other frames. Map drawing may rely more on environment-centered processing. The distance estimation task could be solved using either frame of reference. Last, participants segmented each route. In a separate session, working memory, processing speed, and verbal memory were assessed. Older adults performed less well on all spatial tasks compared with younger adults; aging had a stronger negative effect on pointing performance. This may point to impairments in older adults' ability to update and coordinate information across reference frames. Performance on all spatial tasks was predicted by nonspatial task performance. Segmentation did not predict spatial memory. These results underline the importance of situating age differences in navigation in the context of basic transformations of spatial reference frames, and also in the context of nonspatial cognitive abilities. (PsycINFO Database Record

Attentional focus affects how events are segmented and updated in narrative reading.

Readers generate situation models representing described events, but the nature of these representations may differ depending on the reading goals. We assessed whether instructions to pay attention to different situational dimensions affect how individuals structure their situation models (Exp. 1) and how they update these models when situations change (Exp. 2). In Experiment 1, participants read and segmented narrative texts into events. Some readers were oriented to pay specific attention to characters or space. Sentences containing character or spatial-location changes were perceived as event boundaries-particularly if the reader was oriented to characters or space, respectively. In Experiment 2, participants read narratives and responded to recognition probes throughout the texts. Readers who were oriented to the spatial dimension were more likely to update their situation models at spatial changes; all readers tracked the character dimension. The results from both experiments indicated that attention to individual situational dimensions influences how readers segment and update their situation models. More broadly, the results provide evidence for a global situation model updating mechanism that serves to set up new models at important narrative changes.

Posttraumatic Stress and the Comprehension of Everyday Activity.

People with Posttraumatic Stress Disorder (PTSD) often report difficulties with attention and memory on tasks that are unrelated to their trauma. One important component of everyday event comprehension is the segmentation of ongoing activity into meaningful events. The present study asked whether PTSD symptom severity was associated with impaired segmentation and memory for neutral, ongoing activity. A sample of 137 participants, ages 21-79, completed event segmentation and memory tasks, general cognitive functioning tasks, and questionnaires assessing PTSD symptom severity. People with higher levels of PTSD symptoms had poorer event segmentation and event memory performance. Hierarchical multiple regression analyses demonstrated that PTSD symptom severity explained unique variance in event segmentation performance, even after controlling for general cognitive function. These results suggest that interventions aimed at improving event comprehension may help compensate for memory disruptions in PTSD.

APOE ε4 genotype predicts memory for everyday activities.

The apolipoprotein E (ApOE) ε4 allele is associated with neuropathological buildup of amyloid in the brain, and with lower performance on some laboratory measures of memory in some populations. In two studies, we tested whether ApOE genotype affects memory for everyday activities. In Study 1, participants aged 20-79 years old (n = 188) watched movies of actors engaged in daily activities and completed memory tests for the activities in the movies. In Study 2, cognitively healthy and demented older adults (n = 97) watched and remembered similar movies, and also underwent structural MRI scanning. All participants provided saliva samples for genetic analysis. In both samples we found that, in older adults, ApOE ε4 carriers demonstrated worse everyday memory performance than did ε4 noncarriers. In Study 2, ApOE ε4 carriers had smaller medial temporal lobes (MTL) volumes, and MTL volume mediated the relationship between ApOE genotype and everyday memory performance. These everyday memory tasks measure genetically determined cognitive decline that can occur prior to a clinical diagnosis of dementia. Further, these tasks are easily administered and may be a useful clinical tool in identifying ε4 carriers who may be at risk for MTL atrophy and further cognitive decline that is a common characteristic of the earliest stages of Alzheimer's disease.

Getting completely turned around: how disorientation impacts subjective straight ahead.

In manipulating a pointer to indicate subjective straight ahead (SSA), participants were more variable after a series of whole-body rotations in conjunction with external sensory blockade than after external sensory blockade alone. The variability of reported SSA did not increase consequent to a temporal delay matched to the time taken by the rotation procedure. These results suggest that an observer's egocentric reference frame is more complex and less stable than has previously been thought.

Event segmentation ability uniquely predicts event memory.

Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segment activity into meaningful events a unique predictor of subsequent memory, or is the relationship between event perception and memory accounted for by general cognitive abilities? Two hundred and eight adults ranging from 20 to 79years old segmented movies of everyday events and attempted to remember the events afterwards. They also completed psychometric ability tests and tests measuring script knowledge for everyday events. Event segmentation and script knowledge both explained unique variance in event memory above and beyond the psychometric measures, and did so as strongly in older as in younger adults. These results suggest that event segmentation is a basic cognitive mechanism, important for memory across the lifespan.

Medial temporal lobe volume predicts elders' everyday memory.

Deficits in memory for everyday activities are common complaints among healthy and demented older adults. The medial temporal lobes and dorsolateral prefrontal cortex are both affected by aging and early-stage Alzheimer's disease, and are known to influence performance on laboratory memory tasks. We investigated whether the volume of these structures predicts everyday memory. Cognitively healthy older adults and older adults with mild Alzheimer's-type dementia watched movies of everyday activities and completed memory tests on the activities. Structural MRI was used to measure brain volume. Medial temporal but not prefrontal volume strongly predicted subsequent memory. Everyday memory depends on segmenting activity into discrete events during perception, and medial temporal volume partially accounted for the relationship between performance on the memory tests and performance on an event-segmentation task. The everyday-memory measures used in this study involve retrieval of episodic and semantic information as well as working memory updating. Thus, the current findings suggest that during perception, the medial temporal lobes support the construction of event representations that determine subsequent memory.

Distraction shrinks space.

Research investigating how people remember the distance of paths they walk has shown two apparently conflicting effects of experience during encoding on subsequent distance judgments. By the feature accumulation effect, discrete path features such as turns, houses, or other landmarks cause an increase in remembered distance. By the distractor effect, performance of a concurrent task during path encoding causes a decrease in remembered distance. In this study, we ask the following: What are the conditions that determine whether the feature accumulation or the distractor effect dominates distortions of space? In two experiments, blindfolded participants were guided along two legs of a right triangle while reciting nonsense syllables. On some trials, one of the two legs contained features: horizontally mounted car antennas (gates) that bent out of the way as participants walked past. At the end of the second leg, participants either indicated the remembered path leg lengths using their hands in a ratio estimation task or attempted to walk, unguided, straight back to the beginning. In addition to response mode, visual access to the paths and time between encoding and response were manipulated to determine whether these factors would affect feature accumulation or distractor effects. Path legs with added features were remembered as shorter than those without, but this result was significant only in the haptic response mode data. This finding suggests that when people form spatial memory representations with the intention of navigating in room-scale spaces, interfering with information accumulation substantially distorts spatial memory.

Incorporating injured employee outcomes into physical and occupational therapists' practice: a controlled trial of the Worker-Based Outcomes Assessment System.

BACKGROUND: Work related musculoskeletal disorders (WRMSDs) remain costly. The Worker-Based Outcomes Assessment System (WBOAS) is an injury treatment improvement tool. Its purpose is to increase treatment effectiveness and decrease the cost of care delivered in Occupational Health Service clinics. METHODS: The study used a non-randomized (parallel cohort) control trial design to test the effects on injured employee outcomes of augmenting the standard care delivered by physical and occupational therapists (PT/OTs) with the WBOAS. The WBOAS works by putting patient-reported functional health status, pain symptom, and work role performance outcomes data into the hands of PT/OTs and their patients. Test clinic therapists were trained to incorporate WBOAS trends data into standard practice. Control clinic therapists delivered standard care alone. RESULTS: WBOAS-augmented PT/OT care did improve (p< or =.05) physical functioning and new injury/re-injury avoidance and, on these same dimensions, cost-adjusted outcome. It did not improve (p>.05) mental health or pain symptoms or return-to-work or stay-at-work success nor, on these same dimensions, cost-adjusted outcome. CONCLUSION: Training PT/OTs to incorporate patient-reported health status, pain symptom, and work role performance outcomes trends data into standard practice does appear to improve treatment effectiveness and cost on some (e.g. physical functioning) but not other (e.g. mental health, pain symptoms) outcomes.