Unhindered Spatial Processing During Route Memorization is Required to Maximize Both Spatial and Verbal Route Knowledge

To successfully remember a route in a physical environment, individuals are believed to process and store both verbal and spatial information of that route. The present study tested whether both spatial and verbal contents are necessary to form an effective route memory. For that purpose, route learning was performed in three concurrent task conditions (spatial, verbal and control) and appraised at two moments in time, via three route memory tests (spatial, verbal and spatial–verbal). Results showed that route memory generally improved across time and that spatial information was remembered better than verbal information. The concurrent spatial condition resulted in lower retention scores of both spatial and verbal route knowledge. These results suggest that effective spatial processing forms a scaffold without which long‐term retention lacks detail of both spatial and verbal route knowledge. It is discussed how these findings add to understanding spatial memory of routes. Copyright © 2013 John Wiley & Sons, Ltd.     

Partner Orientation and Speaker's Knowledge as Conflicting Parameters in Language Production

Two parameters of language production, the partner model and the mentally represented knowledge about a spatial constellation, are investigated with respect to their influence on spatial reference. At issue is whether the verbally expressed point of view in route directions is primarily influenced by the needs of the partner or by the underlying mental representation of the speaker stemming from his or her own experience with an object. Two experiments in which participants (N = 90) were asked to produce a set of route directions are reported. The experimental situation was such that the point of view of the speaker did not correspond to the point of view of the partner. The results show that more participants localize from their own point of view than from the point of view of the partner. Discussion centers on the fact that speakers do not always behave in a truly partner-oriented manner.     

Working memory in spatial knowledge acquisition: Differences in encoding processes and sense of direction

This study examined how different components of working memory are involved in spatial knowledge acquisition for good and poor sense‐of‐direction (SOD) people. We employed a dual‐task method, and asked participants to learn routes from videos with verbal, visual and spatial interference tasks and without any interference. Results showed that participants with a good SOD encoded landmarks and routes verbally and spatially, and integrated knowledge about them into survey knowledge with the support of all three components of working memory. In contrast, participants with a poor SOD encoded landmarks only verbally, and tended to rely on the visual component of working memory in the processing of route knowledge. Based on the results, a possible model for explaining the differences in spatial knowledge acquisition and SOD was proposed. Copyright © 2010 John Wiley & Sons, Ltd.     

Learning from maps: the role of visuo‐spatial working memory

The involvement of visuo‐spatial working memory (VSWM) in map learning was tested. While learning a map, participants were asked either to perform or abstain from a secondary interference task. Learning of the map was assessed by means of three different tasks (landmark positioning, pointing, route finding), each tapping a different type of spatial knowledge, namely, relative position knowledge, absolute position knowledge and route knowledge. Results showed that VSWM supports learning of absolute landmark positions but not learning of relative landmark positions. Moreover, VSWM appears to be involved in route learning. Copyright © 2007 John Wiley & Sons, Ltd.     

Route and survey processing of topographical memory during navigation

We investigated the characteristics of route and survey processing of a unique complex virtual environment both at the behavioral and brain levels. Prior to fMRI scanning, participants were trained to follow a route and to learn the spatial relationships between several places, acquiring both route and survey knowledge from a ground-level perspective. During scanning, snapshots of the environment were presented, and participants were required to either indicate the direction to take to follow the route (route task), or to locate unseen targets (survey task). Data suggest that route and survey processing are mainly supported by a common occipito-fronto-parieto-temporal neural network. Our results are consistent with those gathered in studies concerning the neural bases of route versus survey knowledge acquired either from different perspectives or in different environments. However, rather than arguing for a clear distinction between route and survey processing, “mixed” strategies are likely to be involved when both types of encoding take place in the same environment.     

Stepping Into a Map: Initial Heading Direction Influences Spatial Memory Flexibility

Learning a novel environment involves integrating first‐person perceptual and motoric experiences with developing knowledge about the overall structure of the surroundings. The present experiments provide insights into the parallel development of these egocentric and allocentric memories by intentionally conflicting body‐ and world‐centered frames of reference during learning, and measuring outcomes via online and offline measures. Results of two experiments demonstrate faster learning and increased memory flexibility following route perspective reading (Experiment 1) and virtual navigation (Experiment 2) when participants begin exploring the environment on a northward (vs. any other direction) allocentric heading. We suggest that learning advantages due to aligning body‐centered (left/right/forward/back) with world‐centered (NSEW) reference frames are indicative of three features of spatial memory development and representation. First, memories for egocentric and allocentric information develop in parallel during novel environment learning. Second, cognitive maps have a preferred orientation relative to world‐centered coordinates. Finally, this preferred orientation corresponds to traditional orientation of physical maps (i.e., north is upward), suggesting strong associations between daily perceptual and motor experiences and the manner in which we preferentially represent spatial knowledge.     

A comparison of methods for estimating directions in egocentric space

A central issue for researchers of human spatial knowledge, whether focused on perceptually guided action or cognitive-map acquisition, is knowledge of egocentric directions, directions from the body to objects and places. Several methods exist for measuring this knowledge. We compared two particularly important methods, manual pointing with a dial and whole-body rotation (body heading), under various conditions of sensory or memory access to targets. In two experiments, blindfolded body rotation resulted in the greatest variability of performance (variable error), while the manual dial resulted in greater consistent bias (constant error). The variability of performance with body rotation was no greater than that of the dial when subjects' memory loads for directions to targets was reduced by allowing them to peek at targets in between trials, point to concurrent auditory targets, or point with their eyes open. In both experiments, errors with the manual dial were greater for directions to targets that were further from the closest orthogonal axis (ahead, behind, right, left), while errors with body rotation with restricted perceptual access were greater for directions to targets that were further from an axis straight ahead of subjects. This suggests that the two methods will produce evidence of different organizational frameworks for egocentric spatial knowledge. Implications for the structures and processes that underlie egocentric spatial knowledge, and are involved in estimating directions, are discussed, as is the value of decomposing absolute errors into variable and constant errors.     

Egocentric and allocentric navigation strategies in Williams syndrome and typical development

Recent findings suggest that difficulties on small‐scale visuospatial tasks documented in Williams syndrome (WS) also extend to large‐scale space. In particular, individuals with WS often present with difficulties in allocentric spatial coding (encoding relationships between items within an environment or array). This study examined the effect of atypical spatial processing in WS on large‐scale navigational strategies, using a novel 3D virtual environment. During navigation of recently learnt large‐scale space, typically developing (TD) children predominantly rely on the use of a sequential egocentric strategy (recalling the sequence of left–right body turns throughout a route), but become more able to use an allocentric strategy between 5 and 10 years of age. The navigation strategies spontaneously employed by TD children between 5 and 10 years of age and individuals with WS were analysed. The ability to use an allocentric strategy on trials where spatial relational knowledge was required to find the shortest route was also examined. Results showed that, unlike TD children, during spontaneous navigation the WS group did not predominantly employ a sequential egocentric strategy. Instead, individuals with WS followed the path until the correct environmental landmarks were found, suggesting the use of a time‐consuming and inefficient view‐matching strategy for wayfinding. Individuals with WS also presented with deficits in allocentric spatial coding, demonstrated by difficulties in determining short‐cuts when required and difficulties developing a mental representation of the environment layout. This was found even following extensive experience in an environment, suggesting that – unlike in typical development – experience cannot contribute to the development of spatial relational processing in WS. This atypical presentation of both egocentric and allocentric spatial encoding is discussed in relation to specific difficulties on small‐scale spatial tasks and known atypical cortical development in WS.     

Active and passive contributions to spatial learning

It seems intuitively obvious that active exploration of a new environment will lead to better spatial learning than will passive exposure. However, the literature on this issue is decidedly mixed—in part, because the concept itself is not well defined. We identify five potential components of active spatial learning and review the evidence regarding their role in the acquisition of landmark, route, and survey knowledge. We find that (1) idiothetic information in walking contributes to metric survey knowledge, (2) there is little evidence as yet that decision making during exploration contributes to route or survey knowledge, (3) attention to place–action associations and relevant spatial relations contributes to route and survey knowledge, although landmarks and boundaries appear to be learned without effort, (4) route and survey information are differentially encoded in subunits of working memory, and (5) there is preliminary evidence that mental manipulation of such properties facilitates spatial learning. Idiothetic information appears to be necessary to reveal the influence of attention and, possibly, decision making in survey learning, which may explain the mixed results in desktop virtual reality. Thus, there is indeed an active advantage in spatial learning, which manifests itself in the task-dependent acquisition of route and survey knowledge.     

Detrended windowed (lag one) autocorrelation: A new method for distinguishing between event-based and emergent timing

Previous research on route directions largely considers the case when a knowledgeable route-giver conveys accurate information. In the real world, however, route information is sometimes inaccurate, and directions can lead navigators astray. We explored how participants respond to route directions containing ambiguities between landmarks and turn directions, forcing reliance on one or the other. In three experiments, participants read route directions (e.g., To get to the metro station, take a right at the pharmacy) and then selected from destinations on a map. Critically, in half of the trials the landmark (pharmacy) and turn (right) directions were conflicting, such that the participant had to make a decision under conditions of uncertainty; under these conditions, we measured whether participants preferentially relied upon landmark- versus direction-based strategies. Across the three experiments, participants were either provided no information regarding the source of directions (Experiment 1), or told that the source of directions was a GPS device (Experiment 2), or a human (Experiment 3). Without information regarding the source of directions, participants generally relied on landmarks or turn information under conditions of ambiguity; in contrast, with a GPS source participants relied primarily on turn information, and with a human source on landmark information. Results were robust across gender and individual differences in spatial preference. We discuss these results within the context of spatial decision-making theory and consider implications for the design and development of landmark-inclusive navigation systems.     

Individual Differences in the Encoding Processes of Egocentric and Allocentric Survey Knowledge

This study examined how different components of working memory are involved in the acquisition of egocentric and allocentric survey knowledge by people with a good and poor sense of direction (SOD). We employed a dual‐task method and asked participants to learn routes from videos with verbal, visual, and spatial interference tasks and without any interference. Results showed that people with a good SOD encoded and integrated knowledge about landmarks and routes into egocentric survey knowledge in verbal and spatial working memory, which is then transformed into allocentric survey knowledge with the support of all three components, distances being processed in verbal and spatial working memory and directions in visual and spatial working memory. In contrast, people with a poor SOD relied on verbal working memory and lacked spatial processing, thus failing to acquire accurate survey knowledge. Based on the results, a possible model for explaining individual differences in spatial knowledge acquisition is proposed.     

Organization in audition by similarity in rate of change: Evidence from tracking individual frequency glides in mixtures

In audition, sound energy is assigned to separate auditory “streams” following principles of organization that closely parallel the visual gestalt principles that guide the perception of distinct forms or objects. Metzger (1934) provided evidence for organization in vision based on similarity in the velocity of moving forms. If two dots approach one another along one spatial dimension, they may appear to cross and continue beyond their meeting point if their velocities differ; otherwise, they usually appear to change direction abruptly and retrace their movements. If an analogous auditory principle exists, with rate of change in frequency substituted for velocity of movement, two frequency glides that sweep through the same frequency range in opposite directions should be able to perceptually cross if their rates of change differ; otherwise, they should usually appear to change direction and retrace the same frequency region. Four experiments provided data in support of this hypothesis, and the results were consistent across experiments with varying stimuli and methods of presentation. When properties of the stimuli favored organization according to a principle of frequency proximity, the effect of a principle of rate similarity was attenuated but still evident.     

Visuo‐spatial working memory in navigation

Two experiments employed dual task techniques to explore the role of working memory in route learning and subsequent route retrieval. Experiment 1 involved contrasting performance of two groups of volunteers respectively learning a route from a series of map segments or a series of visually presented nonsense words. Both groups performed learning and recognition under articulatory suppression or concurrent spatial tapping. Both concurrent tasks had an overall disruptive effect on each learning task. However, spatial tapping disrupted route recognition rather more than did articulatory suppression, while the nonsense word recognition was impaired more by articulatory suppression than by concurrent spatial tapping. Experiment 2 again used dual task methodology, but explored route learning by asking volunteers to follow the experimenter through the winding streets of a medieval European town centre. Retrieval involved following the same route while the experimenter followed and noted errors in navigation. Overall the results partially replicated those of Experiment 1 in that both concurrent tasks interfered with route learning. However, volunteers with high spatial ability appeared more affected by the concurrent spatial tapping task, whereas low spatial subjects appeared more affected by the concurrent articulatory suppression task. Results are interpreted to suggest that different aspects of working memory are involved in learning a route from a map with a greater emphasis on visuo‐spatial resources, but in tasks set in real environments where many cues of a varied nature are available, only high spatial ability subjects appear to rely heavily upon the visuospatial component of working memory. Copyright © 2002 John Wiley & Sons, Ltd.     

How do individuals with Williams syndrome learn a route in a real‐world environment?

Individuals with Williams syndrome (WS) show a specific deficit in visuo‐spatial abilities. This finding, however, derives mainly from performance on small‐scale laboratory‐based tasks. This study investigated large‐scale route learning in individuals with WS and two matched control groups (moderate learning difficulty group [MLD], typically developing group [TD]). In a non‐labelling and a labelling (verbal information provided along the route) condition, participants were guided along one of two unfamiliar 1‐km routes with 20 junctions, and then retraced the route themselves (two trials). The WS participants performed less well than the other groups, but given verbal information and repeated experience they learnt nearly all of the turns along the route. The extent of improvement in route knowledge (correct turns) in WS was comparable to that of the control groups. Relational knowledge (correctly identifying spatial relationships between landmarks), compared with the TD group, remained poor for both the WS and the MLD group. Assessment of the relationship between performance on the large‐scale route‐learning task and that on three small‐scale tasks (maze learning, perspective taking, map use) showed no relationship for the TD controls, and only a few non‐specific associations in the MLD and WS groups.     

Differentiated forgetting rates of spatial knowledge in humans in the absence of repeated testing

Spatial knowledge, necessary for efficient navigation, comprises route knowledge (memory of the landmarks along a route) and survey knowledge (map-like). Available data on the retention in humans of spatial knowledge show that this does not decline systematically over months or years. Here, two groups of participants elaborated route and survey knowledge during navigation in a complex virtual environment before performing route and survey tasks. Both groups were tested 5 minutes after learning and 3 months later, while one group was also tested 1 week and 1 month later (repeated testing). Performance was similar in both groups on the first testing session, remained stable in the repeated tested group, but decreased in the non-repeated tested group, especially on route tasks. These results are the first to reveal a substantial and selective decline of spatial knowledge, occurring only if there is no possibility of reactivating knowledge along repeated testing.     

Differentiated forgetting rates of spatial knowledge in humans in the absence of repeated testing

Spatial knowledge, necessary for efficient navigation, comprises route knowledge (memory of the landmarks along a route) and survey knowledge (map-like). Available data on the retention in humans of spatial knowledge show that this does not decline systematically over months or years. Here, two groups of participants elaborated route and survey knowledge during navigation in a complex virtual environment before performing route and survey tasks. Both groups were tested 5 minutes after learning and 3 months later, while one group was also tested 1 week and 1 month later (repeated testing). Performance was similar in both groups on the first testing session, remained stable in the repeated tested group, but decreased in the non-repeated tested group, especially on route tasks. These results are the first to reveal a substantial and selective decline of spatial knowledge, occurring only if there is no possibility of reactivating knowledge along repeated testing.