Individual and Strategy Differences in an Allocentric-Heading Recall Task.

Individual and Strategy Differences in an Allocentric-Heading Recall Task Heather Burte (burte@psych.ucsb.edu) Department of Psychological & Brain Sciences, UCSB Santa Barbara, CA 93106 USA Mary Hegarty (hegarty@psych.ucsb.edu) Department of Psychological & Brain Sciences, UCSB Santa Barbara, CA 93106 USA Abstract Participants estimated allocentric headings using pictures of familiar buildings around a college campus, in an allocentric- heading recall task. A weak relationship between sense-of- direction and accuracy, an alignment effect, and a novel relationship between strategy and accuracy were found. These results demonstrate that sense-of-direction and strategy use differentially affect accuracy across heading disparities. Our findings suggest that individual differences and strategy differences need to be incorporated into current hypotheses regarding allocentric-heading – specifically, into the animal- model hypothesis. Keywords: allocentric heading; sense of direction; heading- recall; strategy; egocentric and allocentric reference frames. Introduction People characterize their ability to move effectively through environmental-scale spaces, such as neighborhoods or cities, by referring to their ‘sense-of-direction’. Kozlowski and Bryant (1977) found that people’s ratings of their sense-of- direction (or SOD) correlated with accuracy in distance, direction, and time estimation tasks. Since then, research has either focused on how to assess SOD or how SOD correlates with performance in environmental-scale spatial tasks (e.g., Hegarty et al., 2002). However, the field is lacking insights into the underlying causes of the vast individual differences found in environmental-scale spatial cognition. Research on SOD has typically focused on strategy differences in navigation or on individual differences in learning novel environments. In terms of strategy differences, individuals with a poor SOD tend to prefer route strategies and those with a good SOD tend to prefer survey strategies (Prestopnik & Roskos-Ewoldsen, 2000). In terms of individual differences, there are large individual differences in the rates and accuracy with which individuals can learn novel environments and these differences are related to self-reported SOD (Ishikawa & Montello, 2006). To date, little research has focused on strategy and individual differences in manipulating one’s knowledge of familiar environments; however, manipulating one’s spatial knowledge is essential for wayfinding and route planning. Research that has used familiar environments tends to focus on two tasks: egocentric pointing (pointing from one’s current location towards a landmark) and judgments of relative direction (pointing from an imagined location and orientation towards another landmark) (e.g. Kozlowski & Bryant, 1977; Hegarty et al., 2002). These studies found significant correlations between SOD and task performance, but have not investigated strategy differences. The strategies identified during navigation, namely route and survey strategies, are not necessarily relevant in all spatial knowledge manipulation tasks (such as egocentric pointing and judgments of relative direction tasks). Therefore, research is needed to uncover the strategies used in spatial knowledge manipulation tasks – specifically, in environmental-scale spaces. In contrast, research on strategy differences has tended to utilize small-scale tasks. Kozhevnikov and Hegarty (2001) found that when people complete judgments of relative direction tasks, while viewing a map, they use either perspective-taking or mental rotation strategies. They found individual differences in performance, which were related to SOD, and they identified two strategies, which were separable abilities. The goal of this paper is to investigate the individual and strategy differences that exist within manipulating one’s environmental-scale spatial knowledge. To do so, we will focus on one task, the allocentric-heading recall task (Sholl, Kenny, & DellaPorta, 2006), which requires participants to manipulate their spatial knowledge of a familiar place. Sholl et al. (2006) developed the allocentric-heading recall task to reveal the architecture of a proposed human head-direction system. They argued that SOD is a single- faceted construct related to the performance of a head- direction system in humans, and they assumed that this system operated similarly to the head-direction system found in rats (Ranck, 1984). In rats, each head-direction cell fires maximally to one angle of difference between the rat’s facing direction and a reference direction grounded in the environment. In other words, head-direction cells respond to allocentric headings and not directions based on the axis of the body (or egocentric headings). Sholl et al. proposed that the human head-direction system operates similarly to that of rats and that the human head-direction system is the neural mechanism underlying self-reported SOD. We will refer to this the animal-model hypothesis. In the allocentric-heading recall task, participants view photographs of a familiar environment, identify the direction from which the photographs were taken, and then rotate in their chair to reproduce the direction. Initial studies (Sholl et al., 2006) revealed an alignment effect. Specifically, when a participant is facing the same direction as that from which the photograph was taken, participants