Spatial thinking refers to the mental process of encoding, representing, and using spatial information, such as shapes, locations, and movements of objects. Spatial information also includes the spatial relations between objects, and spatial relations between us and others when we navigate in an environment. Spatial thinking influences people’s daily life, from STEM achievement (science, technology, engineering, and mathematics), to everyday tasks such as assembling furniture and using navigational aids (like Google Maps). Large-scale spatial (navigation) ability is partially dissociated from small-scale spatial ability, such as mental rotation. However, the associations and dissociations between different aspects of large-scale spatial ability (e.g., environmental learning, pointing, wayfinding, and spatial perspective-taking) are still unclear. Performance on one large-scale spatial task does not necessarily predict another. In this dissertation, three lines of research show how individual differences, environmental features, and embodiment influence constructing “cognitive maps” and cognitive processes underlying different tasks.
“Cognitive maps” or configural environmental knowledge is commonly measured by having people point to unseen locations (judgments of relative direction) or navigate efficiently in the environment (shortcutting). Some people can estimate directions accurately, while others point randomly. Similarly, some people take shortcuts not experienced during learning, while others mainly follow learned paths. Notably, few studies have directly tested the correlation between pointing and shortcutting performance. In the first line of the research (Chapter II), I compared pointing and shortcutting in two experiments, one using desktop virtual reality (VR) (N = 57) and one using immersive VR (N = 48). Participants learned a new environment by following a fixed route and were then asked to point to unseen locations and navigate to targets by the shortest path. Participants’ performance was clustered into two groups using K-means clustering. One (lower ability) group pointed randomly and showed low internal consistency across trials in pointing, but were able to find efficient routes, and their pointing and shortcutting scores were not correlated. The others (higher ability) pointed accurately, navigated by efficient routes, and their pointing and shortcutting scores were correlated. These results suggest that with the same egocentric learning experience, the correlation between pointing and shortcutting depends on participants’ learning ability, internal consistency, and discriminating power of the measures. Inconsistency and limited discriminating power can lead to low correlations and mask factors driving human variation. Some people (with high spatial ability) could form accurate map-based knowledge, which enabled them to judge directions and take shortcuts. In contrast, the others (with low spatial ability) only acquired graph-based knowledge, enabling them to take shortcuts but with poor pointing performance.
Task performance in my first line of research (Chapter II) varied not only across participants but also across trials, which was highlighted by the internal inconsistency of the measures. Specifically, on each trial, landmarks involved near the graph boundary (i.e., distant from other landmarks) may be easy for people to orient themselves to. Learning experiences, such as ordinal positions of landmarks on a learning route, may make the earlier landmarks more memorable than later ones (i.e., learning sequence effect). To understand how these features drove the variance across trials, in the second line of research (Chapter III), the same navigation paradigm was used. Two of the three studies used desktop virtual reality (VR) (Ns = 53, 57), and one used immersive VR (N = 48). People pointed more accurately, and their paths were more direct if their starting landmark was far from the other landmarks, even without seeing the physical global boundaries of the environment. People took more novel efficient routes when targeting landmarks distant from the other landmarks. The graph boundary effect, not the learning sequence effect, impacted performance in this paradigm, suggesting that even at the early stage of forming cognitive maps, spatial knowledge goes beyond the linear sequence of the landmarks. These studies highlight the importance of examining spatial features of testing trials based on the environmental structure and learning experiences used in a research paradigm, which reveals properties of “cognitive maps” and underlying cognitive processes carried out by participants.
The results of my second line of research (Chapter III) suggested the most critical cognitive process in the pointing task is imagining their facing orientation before estimating target directions. Spatial perspective-taking ability is related to this orientation ability, which is the ability to imagine how a landmark or scene would appear from a perspective different from one’s current physical viewpoint. Importantly, in daily life, navigation takes place in a three-dimensional (3D) space; consulting maps for navigation involves the movement of human bodies through space, and people often need to map the perspective indicated by a top-down, external representation to their current surroundings to guide their movements to goal locations. In the third line of research (Chapter IV), I developed a viewpoint transformation task (iVTT) using immersive virtual reality (VR) technology. In the iVTT, people physically walked to a goal location in a virtual environment, using a first-person perspective, after taking the perspective indicated by a map. Comparing this task with a computerized version of a popular paper-and-pencil perspective-taking task (SOT: Spatial Orientation Task), the results indicated that the SOT is highly correlated with angle production error but not distance error in the iVTT. Overall angular error in the iVTT was higher than in the SOT. People utilized intrinsic body axes (front/back axis or left/right axis) similarly in the SOT and the iVTT, although there were some minor differences. These results suggest that the SOT and the iVTT capture common variance and cognitive processes, but are also subject to unique sources of error caused by different cognitive processes. The iVTT provides a new immersive VR paradigm to study perspective-taking ability in a space encompassing human bodies, and advances our understanding of perspective taking in the real world.
These studies, as a whole, show that navigation ability is multifaceted. How task-specific and environment-specific variances influence individual differences in large-scale spatial thinking calls for more systematic research. Analyses of psychometric properties, largely under-reported in spatial cognition, can advance our understanding of individual differences and cognitive processes for complex spatial tasks.
