Age-related changes in visual encoding strategy preferences during a spatial memory task.

Ageing is associated with declines in spatial memory, however, the source of these deficits remains unclear. Here we used eye-tracking to investigate age-related differences in spatial encoding strategies and the cognitive processes underlying the age-related deficits in spatial memory tasks. To do so we asked young and older participants to encode the locations of objects in a virtual room shown as a picture on a computer screen. The availability and utility of room-based landmarks were manipulated by removing landmarks, presenting identical landmarks rendering them uninformative, or by presenting unique landmarks that could be used to encode object locations. In the test phase, participants viewed a second picture of the same room taken from the same (0°) or a different perspective (30°) and judged whether the objects occupied the same or different locations in the room. We found that the introduction of a perspective shift and swapping of objects between encoding and testing impaired performance in both age groups. Furthermore, our results revealed that although older adults performed the task as well as younger participants, they relied on different visual encoding strategies to solve the task. Specifically, gaze analysis revealed that older adults showed a greater preference towards a more categorical encoding strategy in which they formed relationships between objects and landmarks.

Age-related differences in visual encoding and response strategies contribute to spatial memory deficits.

Successful navigation requires memorising and recognising the locations of objects across different perspectives. Although these abilities rely on hippocampal functioning, which is susceptible to degeneration in older adults, little is known about the effects of ageing on encoding and response strategies that are used to recognise spatial configurations. To investigate this, we asked young and older participants to encode the locations of objects in a virtual room shown as a picture on a computer screen. Participants were then shown a second picture of the same room taken from the same (0°) or a different perspective (45° or 135°) and had to judge whether the objects occupied the same or different locations. Overall, older adults had greater difficulty with the task than younger adults although the introduction of a perspective shift between encoding and testing impaired performance in both age groups. Diffusion modelling revealed that older adults adopted a more conservative response strategy, while the analysis of gaze patterns showed an age-related shift in visual-encoding strategies with older adults attending to more information when memorising the positions of objects in space. Overall, results suggest that ageing is associated with declines in spatial processing abilities, with older individuals shifting towards a more conservative decision style and relying more on encoding target object positions using room-based cues compared to younger adults, who focus more on encoding the spatial relationships among object clusters.

Novel Ultrasonographic Thickness and Strength Assessments of the Flexor Digitorum: A Reliability Analysis.

OBJECTIVES: Clinical conditions such as focal dystonia often require the assessment of atrophy and weakness of the finger muscles. However, due to a lack of well-established protocols, the current investigation focused on assessing the reliability of thickness and strength assessments of the flexor digitorum (FD) muscle, including both the superficialis and profundus components. As a secondary assessment, the reliability of the strength measurement of the extensor digitorum muscle was examined as well. METHODS: Different thickness measurements of the FD were taken via ultrasonography and averaged to estimate the mean thickness of the FD. Likewise, individual finger strength measurements taken by a custom-made finger pressure device were averaged to compute the mean strength of the flexor and extensor digitorum muscles. Test-retest reliability of the above measurements performed at two different time points (about 6 months apart) were examined on the right and left hands of 10 participants. RESULTS: Findings indicated excellent test-retest reliability (ICC > 0.92) for the mean thickness assessment of the FD and mean strength of the flexor and extensor digitorum for both dominant and non-dominant hands. The standard error of measurement was ≤4.3% for all three mean assessments, indicating high sensitivity. Likewise, the smallest detectable change was also sufficiently small for the mean thickness and mean strength of the flexor digitorum (≤5.1%) and moderately small (≤12%) for the strength of the extensor digitorum. CONCLUSIONS: Results indicated an excellent relative and absolute reliability, for both hands, for the mean thickness and strength assessments of the flexor digitorum muscle and for the mean strength of the extensor digitorum (measured for both hands). These measurements can be used for future investigations and can contribute to the establishment of more precise methods for assessing the muscles in the forearms which serve the hand.

Orientation-dependent spatial memories for scenes viewed on mobile devices.

We examined whether spatial representations for scenes experienced on the screens of mobile devices are orientation dependent and whether the type of movement (physical vs. simulated) during learning affects the encoding and the retrieval of spatial information. Participants studied a spatial layout depicted on a tablet and then carried out perspective-taking trials in which they localized objects from imagined perspectives. Depending on condition, participants either rotated the tablet along with their body or remained stationary and swiped with their finger on the screen to change their viewpoint within the scene. Results showed that participants were faster and more accurate to point to objects from an imagined perspective that was aligned than misaligned to their initial physical orientation during learning, suggesting that they had formed an orientation-dependent representation. Although no differences were found between movement conditions during pointing, participants were faster to encode spatial information with physical than simulated movement.

Integrating visuospatial information across distinct experiences.

In two experiments, we examined whether the presence of stable visual information and the confluence of the viewpoints would cause participants to integrate in a single memory representation spatial locations they encoded at different points in time. Participants studied from the same or from different viewpoints two layouts of objects within a common visually cluttered room. Then, they carried out a series of pointing trials that involved objects from either the same or different layouts. Results showed that participants were faster for within- than between-layout judgments when they had studied the two layouts from different viewpoints but were equally fast across the two types of judgment after studying the layouts from the same viewpoint (Experiment 1). This finding suggests that they integrated locations into a single representation only when encoding the layouts from the same viewpoint. However, when participants' memory for the layout studied first was refreshed prior to testing (Experiment 2), no difference in response time was found, suggesting that they had integrated all locations in a single representation before the beginning of testing.

Selection of macroreference frames in spatial memory.

Spatial memories are often hierarchically organized with different regions of space represented in unique clusters within the hierarchy. Each cluster is thought to be organized around its own microreference frame selected during learning, whereas relationships between clusters are organized by a macroreference frame. Two experiments were conducted in order to better understand important characteristics of macroreference frames. Participants learned overlapping spatial layouts of objects within a room-sized environment before performing a perspective-taking task from memory. Of critical importance were between-layout judgments thought to reflect the macroreference frame. The results indicate that (1) macroreference frames characterize overlapping spatial layouts, (2) macroreference frames are used even when microreference frames are aligned with one another, and (3) macroreference frame selection depends on an interaction between the global macroaxis (defined by characteristics of the layout of all learned objects), the relational macroaxis (defined by characteristics of the two layouts being related on a perspective-taking trial), and the learning view. These results refine the current understanding of macroreference frames and document their broad role in spatial memory.

Developmental changes in the mental transformation of spatial arrays.

An experiment was conducted to investigate the spatial memory and transformation of spatial relations in a sample of 7-, 9-, and 11-year-olds and to compare their performance with that of adults. Four pictures of animals were presented at different locations on the outline of a circle. Participants were instructed to memorize the array of locations and then, in a direct retrieval task, to reconstruct it from memory on a piece of paper that included only the circle outline. Then, in the transformation task, participants were asked to randomly place one of the animals at a new position around the circle and then to place the remaining three animals so that object-to-object locations were preserved. Results from the direct retrieval task showed that 7-year-olds were less accurate than older children and adults, whereas 9- and 11-year-olds showed comparable performance to each other and to adults in reconstructing the array. Results from the transformation task revealed that adults were more accurate than children and that 11-year-olds were more accurate than 7-year-olds. There was no difference between 9- and 11-year-olds. Overall, these findings suggest that the ability to perform spatial transformations (a) develops gradually during childhood and (b) has a steeper developmental slope than the simple retrieval of memorized spatial information.

Updating spatial relations to remote locations described in narratives.

In four experiments we examined whether sensorimotor encoding influences readers' reasoning about spatial scenes acquired through narratives. Participants read a narrative that described the geometry of a store and then pointed to the memorized locations of described objects from imagined perspectives. In Experiment 1, participants walked during learning towards the direction of every described object and then visualized these objects as being in the immediate environment. In Experiment 2 they rotated their body to the direction of the described objects instead of walking to them, while in Experiment 3 they only turned their heads towards the objects. In Experiment 4, we eliminated the instructions to visualize the objects altogether. Results from the first three experiments revealed a performance benefit for responding from the perspective that participants physically occupied at testing. However, results from Experiment 4 showed that only participants who, in a post-task questionnaire, indicated that they had linked the described environment to their immediate environment exhibited such a benefit. Findings indicate that (1) the physical change in orientation influences reasoning about described environments if the remote environments are linked to participants' sensorimotor framework and, (2) visualization instructions are sufficient to produce such a link.

What's so difficult with adopting imagined perspectives?

Research on spatial cognition suggests that transformation processes and/or spatial conflicts may influence performance on mental perspective-taking tasks. However, conflicting findings have complicated our understanding about the processes involved in perspective-taking, particularly those giving rise to angular disparity effects, whereby performance worsens as the imagined perspective adopted deviates from one's actual perspective. Based on data from experiments involving mental perspective-taking in immediate and remote spatial layouts, we propose here a novel account for the difficulty with perspective-taking. According to this account, the main difficulty lies in maintaining an imagined perspective in working memory, especially in the presence of salient sensorimotor information.

Cross-sensory reference frame transfer in spatial memory: the case of proprioceptive learning.

In three experiments, we investigated whether the information available to visual perception prior to encoding the locations of objects in a path through proprioception would influence the reference direction from which the spatial memory was formed. Participants walked a path whose orientation was misaligned to the walls of the enclosing room and to the square sheet that covered the path prior to learning (Exp. 1) and, in addition, to the intrinsic structure of a layout studied visually prior to walking the path and to the orientation of stripes drawn on the floor (Exps. 2 and 3). Despite the availability of prior visual information, participants constructed spatial memories that were aligned with the canonical axes of the path, as opposed to the reference directions primed by visual experience. The results are discussed in the context of previous studies documenting transfer of reference frames within and across perceptual modalities.

Egocentric updating of remote locations.

The study examined whether people update remote spatial locations in unfamiliar environments during physical movement. Participants learned a layout of objects from one perspective and carried out perspective-taking trials after physically rotating to a new perspective in either the same room as learning or in an adjacent room. Prior to rotation in the adjacent room participants were instructed to visualize the objects as being around them. Responses to perspective-taking trials involved either pointing or verbal labeling. In both testing environments, participants pointed more efficiently from imagined perspectives aligned with either the initial learning perspective or their current facing orientation than from a novel imagined perspective; this indicates that they had updated the encoded spatial relations during the physical rotation and treated remote objects as immediate. Differences in performance among perspectives were less pronounced for verbal labeling in both environments, suggesting that this response mode is more flexibly used from imagined perspectives.

Integrating spatial information across experiences.

The current study examined the potential influence of existing spatial knowledge on the coding of new spatial information. In the Main experiment, participants learned the locations of five objects before completing a perspective-taking task. Subsequently, they studied the same five objects and five additional objects from a new location before completing a second perspective-taking task. Task performance following the first learning phase was best from perspectives aligned with the learning view. However, following the second learning phase, performance was best from the perspective aligned with the second view. A supplementary manipulation increased the salience of the initial view through environmental structure as well as the number of objects present. Results indicated that the initial learning view was preferred throughout the experiment. The role of assimilation and accommodation mechanisms in spatial memory, and the conditions under which they occur, are discussed.

Collaborating in spatial tasks: how partners coordinate their spatial memories and descriptions.

We summarize findings from a study examining whether the availability of the conversational partner's spatial viewpoint influences the speaker's spatial memories, description strategies, their joint efficiency and accuracy on the task, as well as the partner's resulting spatial memories. In 18 pairs, Directors described to a misaligned Matcher arrays that they learned while either knowing their Matcher's viewpoint or not. Memory tests preceding descriptions revealed that Directors represented their Matcher's viewpoint when known in advance. Moreover, Directors adapted the perspective of their descriptions according to each other's cognitive demands, given their misalignment. The number of conversational turns pairs took to coordinate suggested that pairs' strategies were effective at minimizing their collective effort. Nonetheless, in terms of accuracy on the task, pairs reconstructed more distorted arrays the more partner-centered descriptions Directors used. The Directors' descriptions also predicted Matchers' facilitation for their own perspective in memory tests following the description. Together, these findings demonstrate that partners in collaborative spatial tasks adapt their respective memory representations and descriptions contingently with the aim of optimizing coordination.

The effect of visually filled reproductions on the reproduced durations of auditory intervals.

The present study examined how the perception of time is affected by the presence of a visual stimulus during the reproduction phase of an online time reproduction task. Participants were instructed to reproduce the durations of speed-altered speech snippets with either a picture or a blank screen presented during the reproduction phase. Results showed that fast speeches were reproduced as longer than slow ones, while the reproduced durations of short speeches were closer to the actual durations than were the long speeches. In addition, longer reproduced durations were observed in trials with a picture than in trials with a blank screen. These results provide clear evidence that postencoding information can influence the reproduction of previously encoded temporal intervals and are discussed in the context of attention allocation and its possible influence on an internal clock mechanism. Also, the study provides evidence that online testing is reliable for assessing biases in time perception, at least with time reproduction tasks.

Music and speech time perception of musically trained individuals: The effects of audio type, duration of musical training, and rhythm perception.

The perception of time is a subjective experience influenced by various factors such as individual psychology, external stimuli, and personal experiences, and it is often assessed with the use of the reproduction task that involves individuals estimating and reproducing the duration of specific time intervals. In the current study, we examined the ability of 97 musically trained participants to reproduce the durations of temporal intervals that were filled with music or speech stimuli. The results revealed a consistent pattern of durations being underestimated, and an association was observed between the duration of musical training and the level of accuracy in reproducing both music and speech tracks. In addition, speech tracks were overall reproduced more accurately, and as longer, than music tracks. Structural models suggested the presence of two, highly correlated, dimensions of time perception for speech and music stimuli that were related to the duration of musical training, but not with self-reported rhythm perception. The possible effects of arousal and pleasantness of stimuli on time perception are discussed within the framework of an internal clock model.

Biases in object location estimation: The role of rotations and translation.

Spatial memory studies often employ static images depicting a scene, an array of objects, or environmental features from one perspective and then following a perspective-shift-prompt memory either of the scene or objects within the scene. The current study investigated a previously reported systematic bias in spatial memory where, following a perspective shift from encoding to recall, participants indicated the location of an object farther to the direction of the shift. In Experiment 1, we aimed to replicate this bias by asking participants to encode the location of an object in a virtual room and then indicate it from memory following a perspective shift induced by camera translation and rotation. In Experiment 2, we decoupled the influence of camera translations and rotations and examined whether adding additional objects to the virtual room would reduce the bias. Overall, our results indicate that camera translations result in greater systematic bias than camera rotations. We propose that the accurate representation of camera translations requires more demanding mental computations than camera rotations, leading to greater uncertainty regarding the location of an object in memory. This uncertainty causes people to rely on an egocentric anchor, thereby giving rise to the systematic bias in the direction of camera translation.

Effectiveness of Virtual Reality Vs Guided Imagery on mood changes in cancer patients receiving chemotherapy treatment: A crossover trial.

PURPOSE: To test whether Virtual Reality (VR) can benefit cancer patients from their interaction with an immersive environment, on their mood and their biophysical parameters, compared to those who will experience a Guided Imagery (GI) intervention. METHODS: This was a randomized crossover trial with 50 cancer patients on active chemotherapy treatment, who were randomized to one of two treatment sequences VR-GI or GI-VR. Patients were assessed for Mood Changes, using POMS questionnaire, for three symptoms (Nausea, Pain and Feeling Sick), using three questions from FACT-G questionnaire, and Bio-physical parameters (Blood Pressure, Heart Rate, Oxygen Saturation). Linear Mixed Effect Models were used for the statistical analysis. RESULTS: Patients experienced a better effect of mood state, for all the sub-scales of mood, after the VR intervention compared to GI, regardless of the sequence (p < 0⋅05). No effectiveness was found for Nausea, Pain and Feeling Sick symptoms. Statistically significant improvements were found on the Bio-physical parameters for the VR intervention (p < 0⋅05). CONCLUSION: VR intervention based on mood induction strategies is a feasible and effective procedure for promoting positive mood in cancer patients during chemotherapy. Ways to integrate such innovative technologies in clinical practice need to be explored by health care professionals. TRIAL REGISTRATION NUMBER: NCT02392728.

Alignment Effects in Spatial Perspective Taking from an External Vantage Point.

In three experiments, we examined, using a perceptual task, the difficulties of spatial perspective taking. Participants imagined adopting perspectives around a table and pointed from them towards the positions of a target. Depending on the condition, the scene was presented on a virtual screen in Virtual Reality or projected on an actual screen in the real world (Experiment 1), or viewed as immediate in Virtual Reality (Experiment 2). Furthermore, participants pointed with their arm (Experiments 1 and 2) vs. a joystick (Experiment 3). Results showed a greater alignment effect (i.e., a larger difference in performance between trials with imagined perspectives that were aligned vs. misaligned with the orientation of the participant) when executing the task in a virtual rather than in the real environment, suggesting that visual access to body information and room geometry, which is typically lacking in Virtual Reality, influences perspective taking performance. The alignment effect was equal across the Virtual Reality conditions of Experiment 1 and Experiment 2, suggesting that being an internal (compared to an external) observer to the scene induces no additional difficulties for perspective taking. Equal alignment effects were also found when pointing with the arm vs. a joystick, indicating that a body-dependent response mode such as pointing with the arm creates no further difficulties for reasoning from imagined perspectives.

Are Spatial Memories for Familiar Environments Orientation Dependent?

In one experiment we examined the organizational structure of spatial memories for familiar environments, comparing it directly with that for unfamiliar environments. Participants in the familiar condition pointed from imagined perspectives towards objects in their own rooms and their performance was compared to that of matched controls in an unfamiliar condition who carried out the same task after studying the same rooms in immersive Virtual Reality. In both conditions, participants were faster and more accurate in pointing from imagined perspectives that were aligned with the geometry of the room (vs. not aligned), suggesting the presence of orientation-dependent representations. Whereas in the unfamiliar condition pointing performance was best along a single axis, performance in the familiar condition was about equal across all 4 orientations that were aligned with the geometric structure of the room. Moreover, performance in the familiar condition was influenced by the orientation from which participants started to preview the room prior to testing; in contrast, in the unfamiliar condition performance was not influenced by the orientation from which encoding started. This finding suggests that post-encoding situational factors (e.g., the starting orientation from which an environment is previewed) can prime the accessibility of information in well-established long-term spatial memories.

Virtual Reality and Symptoms Management of Anxiety, Depression, Fatigue, and Pain: A Systematic Review.

In recent years, virtual reality (VR) has become an interesting alternative to traditional exposure-based therapies for many symptoms. VR involves immersion in a computer-generated virtual environment that minimizes avoidance and facilitates emotional processing. The objective of this systematic review is to evaluate evidence on the intervention effect of VR on anxiety, depression, fatigue, and pain. The research strategy of this systematic review included three electronic databases (MEDLINE/PubMed, Cochrane Library, and ScienceDirect) based on predetermined inclusion and exclusion criteria. Published quantitative studies from 2000 to 2020 were identified, which examined the effect of VR intervention on four different symptoms related to symptoms experienced by cancer patients. Quality assessments, data extractions, and analysis were completed on all included studies. A total of 882 titles and abstracts were screened, and 23 studies were included in the review. The studies were grouped according to the symptoms: anxiety and depression, fatigue, and pain. The review showed that VR intervention is more effective compared with the control (i.e., standard care) for anxiety, depression, fatigue, and pain. VR can reduce effectively these symptoms in different contexts and diseases, including cancer. The evidence suggests that there is value in exploring this intervention as a potential crossover treatment for these symptoms in patients. This study contributes to evidence that distraction is an effective symptom management mechanism. The findings are congruent with the theoretical framework, supporting the premise that VR, as an emotion-focused distraction intervention, decreases the severity of these symptoms.