“Active” and “passive” learning of three-dimensional object structure within an immersive virtual reality environment

We used a fully immersive virtual reality environment to study whether actively interacting with objects would effect subsequent recognition, when compared with passively observing the same objects. We found that when participants learned object structure by actively rotating the objects, the objects were recognized faster during a subsequent recognition task than when object structure was learned through passive observation. We also found that participants focused their study time during active exploration on a limited number of object views, while ignoring other views. Overall, our results suggest that allowing active exploration of an object during initial learning can facilitate recognition of that object, perhaps owing to the control that the participant has over the object views upon which they can focus. The virtual reality environment is ideal for studying such processes, allowing realistic interaction with objects while maintaining experimenter control.     

Long-term spatial clustering in free recall

We explored the influence of space on the organisation of items in long-term memory. In two experiments, we asked our participants to explore a virtual environment and memorise discrete items presented at specific locations. Memory for those items was later on tested in immediate (T1) and 24 hours delayed (T2) free recall tests, in which subjects were asked to recall as many items as possible in any order. In experiment 2, we further examined the contribution of active and passive navigation in recollection dynamics. Results across experiments revealed a significant tendency for participants to consecutively recall items that were encountered in proximate locations during learning. Moreover, the degree of spatial organisation and the total number of items recalled were positively correlated in the immediate and the delayed tests. Results from experiment 2 indicated that the spatial clustering of items was independent of navigation types. Our results highlight the long-term stability of spatial clustering effects and their correlation with recall performance, complementing previous results collected in immediate or briefly delayed tests.     

Effects of active navigation on object recognition in virtual environments.

We investigated the importance and efficiency of active and passive exploration on the recognition of objects in a variety of virtual environments (VEs). In this study, 54 participants were randomly allocated into one of active and passive navigation conditions. Active navigation was performed by allowing participants to self-pace and control their own navigation, but passive navigation was conducted by forced navigation. After navigating VEs, participants were asked to recognize the objects that had been in the VEs. Active navigation condition had a significantly higher percentage of hit responses (t (52) = 4.000, p < 0.01), and a significantly lower percentage of miss responses (t (52) = -3.763, p < 0.01) in object recognition than the passive condition. These results suggest that active navigation plays an important role in spatial cognition as well as providing an explanation for the efficiency of learning in a 3D-based program.     

The effect of pointing on spatial working memory in a 3D virtual environment

Pointing to locations can either help or hinder people's ability to recall spatial information. Prior research has focused on two‐dimensional spatial memory and pointing in real world tasks. The effect of pointing on three‐dimensional spatial memory in virtual environments remains unexplored. We examine this effect by comparing participants' recall when they point to and memorize a series of three‐dimensional locations using a gesture interface, and when they only passively view and memorize the spatial array. Thirty‐three participants completed 50 trials in both conditions. The results reveal that pointing has a negative effect on memory in the three‐dimensional virtual environment. These findings held across memory in the x–y plane of the computer screen as well as memory in the virtual third dimension. When they pointed during encoding, participants also responded more slowly, suggesting a higher cognitive load. Thus, active pointing may cause interference when users are simultaneously performing spatial memorization tasks.     

Memory bias in obsessive-compulsive disorder (OCD).

There is a memory bias associated with depression, and good reason to expect a memory bias associated with anxiety. However, the results of studies reported to date have been ambiguous. Accordingly, an experiment was conducted to assess memory for contamination in people with different types of anxiety. Memory for contaminated stimuli among participants who met DSM-IV criteria for obsessive-compulsive disorder (OCD) and indicated a fear of contamination (n = 10) was compared to memory in a group of anxious controls (n = 10), and in undergraduate students (n = 20). Participants were shown 50 objects, 25 of which were contaminated by the experimenter and 25 which were touched but not contaminated. They then completed a neuropsychological memory assessment, after which the participants were asked to recall all of the objects touched by the experimenter. They were then asked to approach each object and to rate their anxiety about touching it. Finally, participants were asked about their perceptions of the cleanliness of each object. The OCD group had better memory for contaminated objects than for clean ones. Neither control group showed such a bias. Neuropsychological test scores indicated that this bias is not the result of differences in general memory ability. The results are discussed in terms of the memory-deficit theory of OCD and of behavioural and cognitive approaches to understanding the role of information processing in fear and anxiety.     

Distance underestimation in virtual space is sensitive to gender but not activity-passivity or mode of interaction.

Four groups of undergraduates (half of each gender) experienced a movement along a corridor containing three distinctive objects, in a virtual environment (VE) with wide-screen projection. One group simulated walking along the virtual corridor using a proprietary step-exercise device. A second group moved along the corridor in conventional flying mode, depressing a keyboard key to initiate continuous forward motion. Two further groups observed the walking and flying participants, by viewing their progress on the screen. Participants then had to walk along a real equivalent but empty corridor, and indicate the positions of the three objects. All groups underestimated distances in the real corridor, the greatest underestimates occurring for the middle distance object. Males' underestimations were significantly lower than females' at all distances. However, there was no difference between the active participants and passive observers, nor between walking and flying conditions.     

Tests enhance retention and transfer of spatial learning

Many studies have reported that tests are beneficial for learning (e.g., Roediger & Karpicke, 2006a). However, the majority of studies on the testing effect have been limited to a combination of relatively simple verbal tasks and final tests that assessed memory for the same material that had originally been tested. The present study explored whether testing is beneficial for complex spatial memory and whether these benefits hold for both retention and transfer. After encoding a three-dimensional layout of objects presented in a virtual environment, participants completed a judgment-of-relative-direction (JRD) task in which they imagined standing at one object, facing a second object, and pointed to a third object from the imagined perspective. Some participants completed this task by relying on memory for the previously encoded layout (i.e., the test conditions), whereas for others the location of the third object was identified ahead of time, so that retrieval was not required (i.e., the study condition). On a final test assessing their JRD performance, the participants who learned through test outperformed those who learned through study. This was true even when corrective feedback was not provided on the initial JRD task and when the final test assessed memory from vantage points that had never been practiced during the initial JRD.     

Walking through doorways causes forgetting: active and passive interaction

ABSTRACT

The current study explored the location updating effect when people passively interacted with an environment. This was assessed experimentally by having one person actively navigate through a virtual environment while picking up and putting objects down. A second person passively viewed the movement. Both participants responded to memory probes for objects they encountered. Probes appeared when the active participant moved halfway across a room or immediately after moving into a new room. Consistent with previous research, a location updating effect was found. That is, memory was worse following a shift to a new room. This effect was found for both active and passive participants but was smaller for the passive group. Thus, the shift from one event to another causes information to be harder to remember, reinforcing the importance of event cognition in memory. However, the more involved a person is in the interactive event, the more pronounced the effects.     

The use of virtual reality for episodic memory assessment: effects of active navigation

Episodic memory was assessed using Virtual Reality (VR). Forty-four (44) subjects visualized a target virtual apartment containing specific objects in each room. Then they visualized a second virtual apartment comprised of specific objects and objects shared by the two apartments. Subjects navigated in the virtual apartments in one of the following two conditions: active and passive. Four main episodic memory components were scored from the VR exposures: (1) learning effect; (2) active forgetting effect; (3) strategies at encoding and at retrieval; and (4) false recognitions (FRs). The effect of navigation mode (active vs. passive) on each memory component was examined. Active subjects had better learning and retrieval (recognition hits) performances compared to passive subjects. A beneficial effect of active navigation was also observed on the source-based FR rates. Active subjects made fewer source-based FRs compared to passive subjects. These overall results for the effect of active navigation are discussed in terms of the distinction between item-specific and relational processing.     

Gender differences in object location memory in a real three-dimensional environment

In this preliminary study we investigate gender differences in object location memory. Our purpose is to extend the results about object location memory obtained in laboratory settings to a real 3-D environment and to further distinguish the specific components involved in this kind of memory by considering the strategies adopted to perform the task. To do this, we join the three-level model of spatial representations (landmark, route, and survey) proposed by Siegel and White (1975) with the three subcomponents of spatial memory (what, where, and what + where) identified by Postma and De Haan (1996). We adopted the object relocation task devised by Postma and De Haan (1996), adapted to a real environment. Seven common objects were placed on the floor of a cylindrical room. Sixty-four males and 64 females were asked to memorize the spatial layout. Next, the experimenter moved the objects to a different position along with seven new objects and the participants had to relocate the original objects to their initial positions. In line with Postma, Izendoorn, and De Haan (1998), we found no gender difference in object recognition, and in recalling absolute distance and categorical spatial relations; however males were better than females in recalling the distance between objects and the size of the layout. Overall, the data show a male advantage in some components of spatial cognition closely linked to the encoding of the metric structure of the spatial relationships at both route and survey level.     

物体相似性对空间表征的影响：来自眼动的证据

以三维场景图片为实验材料,采用眼动追踪技术,通过两个实验考察了对称场景中物体相似性对空间表征的影响。结果表明：（1）无相似物体条件下,场景本身的内在结构对空间表征有重要影响,对称轴方向可以作为空间表征参照方向;（2）存在部分相似物体条件下,物体的相似性会影响空间表征参照方向的选择,并且相似物体方向也是空间表征的参照方向之一。     

Forgetting in spatial memories acquired in a virtual environment

This study examined forgetting in spatial memories acquired in a virtual environment. In the two experiments, participants learned the locations of eight objects. In Experiment 1, the objects were presented as photographs in either a laboratory or in an equivalent virtual environment. Irrespective of learning condition, accuracy of recall of the locations was found to deteriorate after a retention interval of approximately 1 week. In Experiment 2, following virtual learning, three groups of participants performed a series of non‐spatial tasks of low, intermediate or high difficulty. The tasks were presented in a retention interval of 2 hours. A comparison of recall accuracy before and after presentation of the interference tasks indicated that that the groups were not differentially affected by the difficulty of the retroactive interference tasks. However, the groups differed in their subjective assessment of the mental workload involved in the tasks. The results are discussed with reference to a prominent theory of forgetting. Copyright © 2007 John Wiley & Sons, Ltd.     

Age-related differences in visual search in dynamic displays

The authors examined the ability of younger and older adults to detect changes in dynamic displays. Older and younger adults viewed displays containing numerous moving objects and were asked to respond when a new object was added to the display. Accuracy, response times, and eye movements were recorded. For both younger and older participants, the number of eye movements accounted for a large proportion of variance in transient detection performance. Participants who actively searched for the change performed significantly worse than did participants who employed a passive or covert scan strategy, indicating that passive scanning may be a beneficial strategy in certain dynamic environments. The cost of an active scan strategy was especially high for older participants in terms of both accuracy and response times. However, older adults who employed a passive or covert scan strategy showed greater improvement, relative to older active searchers, than did younger adults. These results highlight the importance of individual differences in scanning strategy in real-world dynamic, cluttered environments.     

Working memory capacity and retrieval limitations from long-term memory: An examination of differences in accessibility

In two experiments, the locus of individual differences in working memory capacity and long-term memory recall was examined. Participants performed categorical cued and free recall tasks, and individual differences in the dynamics of recall were interpreted in terms of a hierarchical-search framework. The results from this study are in accordance with recent theorizing suggesting a strong relation between working memory capacity and retrieval from long-term memory. Furthermore, the results also indicate that individual differences in categorical recall are partially due to differences in accessibility. In terms of accessibility of target information, two important factors drive the difference between high- and low-working-memory-capacity participants. Low-working-memory-capacity participants fail to utilize appropriate retrieval strategies to access cues, and they also have difficulty resolving cue overload. Thus, when low-working-memory-capacity participants were given specific cues that activated a smaller set of potential targets, their recall performance was the same as that of high-working-memory-capacity participants.     

Facilitated pointing to remembered objects in front: Evidence for egocentric retrieval or for spatial priming?

Recent spatial memory theories propose that long-term spatial memories are retrieved egocentrically. One source of evidence comes from imagined perspective taking, in which participants learn an object layout, later imagine standing at one object and facing a second (orienting) object, and then point to a third (target) object from the imagined perspective. Pointing is faster for target objects in the anterior than in the posterior half of imaginal space. This “front facilitation” is consistent with asymmetric sensory and biomechanical body properties (favoring the anterior half of body space), supporting claims of egocentric retrieval. However, front facilitation might actually result from spatial priming: Proximity differences might cause orienting objects to prime target objects more in the anterior than in the posterior half of imagined space. Using a modified perspectivetaking task that unconfounded front facilitation and spatial priming, two experiments identified separate influences of front facilitation and spatial priming when participants imagined perspectives within the surrounding environment or a remote environment.     

Effects of aging and encoding instructions on emotion-induced memory trade-offs

The effects of emotion on memory are often described in terms of trade-offs: People often remember central, emotional information at the expense of background details. The present experiment examined the effects of aging and encoding instructions on participants' ability to remember the details of central emotional objects and the backgrounds on which those objects were placed. When young and older adults passively viewed scenes, both age groups showed strong emotion-induced trade-offs. They were able to remember the visual details as well as the general theme of the emotional object, but they had difficulties remembering the visual specifics of the scene background. Age differences emerged, however, when participants were given encoding instructions that emphasized elaborative encoding of the entire scene. With these instructions, young adults overcame the trade-offs (i.e., they no longer showed impairing effects of emotion), whereas older adults continued to show good memory for the emotional object but poor memory for its background. These results suggest that aging impairs the ability to flexibly disengage attention from the negative arousing elements of scenes, preventing the successful encoding of nonemotional aspects of the environment.     

Dynamic search and working memory in social recall

What are the mechanisms underlying search in social memory (e.g., remembering the people one knows)? Do the search mechanisms involve dynamic local-to-global transitions similar to semantic search, and are these transitions governed by the general control of attention, associated with working memory span? To find out, we asked participants to recall individuals from their personal social networks and measured each participant's working memory capacity. Additionally, participants provided social-category and contact-frequency information about the recalled individuals as well as information about the social proximity among the recalled individuals. On the basis of these data, we tested various computational models of memory search regarding their ability to account for the patterns in which participants recalled from social memory. Although recall patterns showed clustering based on social categories, models assuming dynamic transitions between representations cued by social proximity and frequency information predicted participants' recall patterns best-no additional explanatory power was gained from social-category information. Moreover, individual differences in the time between transitions were positively correlated with differences in working memory capacity. These results highlight the role of social proximity in structuring social memory and elucidate the role of working memory for maintaining search criteria during search within that structure.     

Further exploration memory bias in compulsive washers

The aim of the present study was to replicate Radomsky and Rachman's findings on memory bias in obsessive-compulsive disorder (OCD), using the same procedure but an increased sample size, more specific control groups, and a full analysis of contamination attribution data. Sixteen OCD-washers, 16 OCD-checkers, 16 social phobic patients and 16 non-anxious controls were presented with 50 'clean' or 'dirty' objects. After this incidental encoding phase, participants were asked to freely recall the objects, to rate their anxiety when almost touching each object, and, finally, to attribute each object to one of the two contamination conditions ('clean' or 'dirty'). Verbal episodic memory was also assessed with the California Verbal Learning Test. The results indicate that, contrary to Radomsky and Rachman's findings, OCD-washers did not differ from the other participants in their memory for 'clean' and 'dirty' objects. However, the OCD-washers recalled more accurately the 'dirty' source of contamination than the 'clean' source. This result was specific to the OCD-washers, and suggests a memory bias for contextually threatening information. The differences between our findings and those published by Radomsky and Rachman's are discussed.     

Spatial reasoning with external visualizations: what matters is what you see, not whether you interact

Three experiments examined the effects of interactive visualizations and spatial abilities on a task requiring participants to infer and draw cross sections of a three-dimensional (3D) object. The experiments manipulated whether participants could interactively control a virtual 3D visualization of the object while performing the task, and compared participants who were allowed interactive control of the visualization to those who were not allowed control. In Experiment 1, interactivity produced better performance than passive viewing, but the advantage of interactivity disappeared in Experiment 2 when visual input for the two conditions in a yoked design was equalized. In Experiments 2 and 3, differences in how interactive participants manipulated the visualization were large and related to performance. In Experiment 3, non-interactive participants who watched optimal movements of the display performed as well as interactive participants who manipulated the visualization effectively and better than interactive participants who manipulated the visualization ineffectively. Spatial ability made an independent contribution to performance on the spatial reasoning task, but did not predict patterns of interactive behavior. These experiments indicate that providing participants with active control of a computer visualization does not necessarily enhance task performance, whereas seeing the most task-relevant information does, and this is true regardless of whether the task-relevant information is obtained actively or passively.     

Spatial exploration patterns determine navigation efficiency: trade-off between memory demands and distance travelled

A total of 41 participants explored a novel square-shaped environment containing five identical boxes each hiding a visually distinct object. After an initial free exploration the participants were required to locate the objects first in a predetermined and subsequently in an optional order task. Two distinct exploration strategies emerged: Participants explored either along the main axes of the room (axial), or in a more spatially spread, circular pattern around the edges of the room (circular). These initial exploration strategies influenced the optimality of spatial navigation performance in the subsequent optional order task. The results reflect a trade-off between memory demands and distance efficiency. The more sequential axial strategy resulted in fewer demands on spatial memory but required more distance to be travelled. The circular strategy was more demanding on memory but required less subsequent travelling distance. The findings are discussed in terms of spatial knowledge acquisition and optimality of strategy representations.