- Top of page
- 1. Introduction
- 2. Method
- 3. Results
- 4. Discussion
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.
- Top of page
- 1. Introduction
- 2. Method
- 3. Results
- 4. Discussion
Spatial knowledge acquired from the environment is fundamental to human lives and has been extensively studied from a variety of viewpoints. One of the issues that has consistently attracted researchers’ interest concerns the types of knowledge about large-scale spaces (Siegel & White, 1975). Landmark knowledge is knowledge about discrete objects or scenes; route knowledge consists of sequences of landmarks and actions; and survey knowledge is configurational, map-like knowledge. Importantly, in survey knowledge, the layout of the environment is represented, with separate landmarks or routes being integrated with each other. Thus, the acquisition of survey knowledge is considered an elaborate step in the microgenesis of spatial knowledge (Montello, 1998).
In discussing the structure of mentally represented environments, the issue of spatial frames of reference bears particular importance, because the acquisition of survey knowledge requires separately acquired information being integrated in a common frame of reference. Egocentric frames of reference specify locations with respect to the body (e.g., front-back-left-right), and allocentric frames of reference define spatial relations with respect to external objects or cardinal directions (Klatzky, 1998). The important point here is whether the representations are tied to the viewer’s position and orientation. That is, although survey knowledge can be represented either egocentrically or allocentrically, the latter is more flexible or sophisticated. Sholl (1996) described this transition as the knowledge development from self-to-object relations to object-to-object relations. Recognizing the importance of these issues for human spatial cognition, this research aims to examine how people with varied spatial aptitudes differ in the understanding and processing of the two types of survey relations from the horizontal, traveler’s perspective.
We note that this type of “horizontal” learning differs from “vertical” learning in important ways. For example, in map learning, the layout of places can be seen from above and allocentric relations may be acquired first, and then transformed into egocentric relations when necessary (e.g., Thorndyke & Hayes-Roth, 1982). Although not the focus of this research, the relationship between map learning and working memory is an important research topic (e.g., Coluccia, 2008; Coluccia, Bosco, & Brandimonte, 2007; Meilinger & Knauff, 2008).
Past research has shown that people have difficulties in estimating allocentric directions and distances (Avraamides, Loomis, Klatzky, & Golledge, 2004; McNamara, Rump, & Werner, 2003; Ruggiero & Iachini, 2006) and that there are large individual differences in the structure and processes of mental representations of the environment in relation to the environmental-learning aptitude called sense of direction (SOD; Kozlowski & Bryant, 1977). People with a good SOD tend to do better on tasks that require configurational understanding of environments (Hegarty, Richardson, Montello, Lovelace, & Subbiah, 2002; Ishikawa & Montello, 2006) and to use allocentric frames of reference to describe environments (e.g., Hund & Padgitt, 2010; MacFadden, Elias, & Saucier, 2003).
To examine the reason for these differences, it should be insightful to look into the encoding processes of information from the environment, on which this research is focused. People with a good and poor SOD may differ in the processing of information in working memory (e.g., Baddeley & Hitch, 1974; Baeyens & Bruyer, 1999; Courtney, Ungerleider, Keil, & Haxby, 1996), which in turn may affect the nature of acquired mental representations. Baddeley (2003) argued that although visuospatial working memory seems to be important for spatial orientation and geographic knowledge, there is still little work on this topic.
Concerning the relationships between environmental learning and working memory, Garden, Cornoldi, and Logie (2002) and Meilinger, Knauff, and Bülthoff (2008) found that verbal and spatial working memory are involved in the acquisition of landmark and route knowledge. Because these studies lacked the consideration of survey knowledge and visual working memory, Wen, Ishikawa, and Sato (2011) examined the involvement of three different components of working memory in the acquisition of three types of spatial knowledge, in relation to participants’ SOD. They showed that people 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, people 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, failing to acquire survey knowledge.
In the Wen et al. (2011) study, however, survey knowledge was not examined through detailed configurational measures (only sequential or “topological” accuracy of sketch maps was examined), nor was it examined through separate analyses of egocentric and allocentric survey relations. Furthermore, the role of the visual component of working memory remains to be clarified. These issues led us to conduct the present research. Also, in the past studies of the effect of verbal interference (Pouliot & Gagnon, 2005) and visual impairments (e.g., Rieser, Hill, Talor, Bradfield, & Rosen, 1992; Thinus-Blanc & Gaunet, 1997), the roles of the three components of working memory have not been examined separately, nor has an understanding of egocentric and allocentric survey relations been studied from an individual difference perspective in detail.
On the basis of these research backgrounds, we examined how the verbal, visual, and spatial components of working memory are involved in the acquisition of egocentric and allocentric survey knowledge by people with a good and poor SOD. Here, egocentric survey knowledge refers to the understanding of self-to-object relations tied to a specific viewpoint, and allocentric survey knowledge refers to the understanding of object-to-object relations. We used a dual-task method, in which participants learned routes with and without a concurrent task and then were tested on their understanding of egocentric and allocentric survey relations, so that we could examine which components of working memory are involved in survey learning.
We constructed several hypotheses to be tested in this research. On the basis of past studies of spatial microgenesis, reference frames, and SOD, we hypothesized (a) that people would do better on egocentric than on allocentric survey tasks; (b) that people with a better SOD would do better on both egocentric and allocentric survey tasks; and (c) that people with a good SOD would acquire at least a certain level of allocentric survey knowledge, whereas people with a poor SOD would fail to acquire accurate survey knowledge, either egocentric or allocentric.
On the basis of past studies about spatial learning and working memory, we hypothesized (d) that people with a poor SOD would have difficulties with spatial processing, and thus rely on other components of working memory; (e) that people with a good SOD, in contrast, would process information about the environment spatially; and (f) that the involvement of visual working memory would be greater for the acquisition of allocentric than egocentric survey knowledge, as the former might be facilitated by mentally “envisioning” the whole layout.