From Scattering Dots to Cognitive Maps: Contributions of visual features in localization and cognitive mapping

• Author / Creator

  Zhou, Ruojing

• Localizing oneself and other objects in an environment is important in everyday life. Various visual features available in our surroundings can serve as spatial cues to support accurate localization. Encoding individual locations can be achieved by establishing a vector between a target location and a reference point chosen from the environmental features (e.g., the school is one kilometer north of my home). Representations of individual locations can further be integrated to compose a unified representation, which allows inferring novel spatial relations among the locations (i.e., a vector between two points). Such metric representations are referred to as cognitive maps (e.g., Tolman, 1948) and we refer to the integration process as cognitive mapping. Three sets of studies were carried out to investigate the contributions of different types of visual cues, mainly surface-based boundary cues (e.g., walls or river banks) and discrete-object-based landmark cues (e.g., buildings or trees), in encoding individual locations and cognitive mapping of the locations, respectively. The studies in Chapter 2 demonstrated a more accurate cognitive map of multiple locations derived from learning locations relative to a single landmark than to a circular boundary. The studies in Chapter 3 revealed two factors that impeded cognitive mapping relative to a circular boundary: 1) that the boundary provided multiple reference points for encoding individual locations, leading to a more complex integration process of single-location representations whereas the integration process was relatively easier when the locations were all encoded relative to the single landmark which served as the common reference point; 2) that participants’ knowledge of the spatial relations among the chosen reference points from the boundary was limited, leading to less accurate cognitive maps. The results of the studies in Chapter 3 suggest that people might represent a bounded space in a fragmented fashion rather than in a global fashion. Given the inconsistent roles of a boundary in encoding individual locations (the boundary advantage) and in cognitive mapping, the studies in Chapter 4 investigated two potential factors contributing to the relative preference for the boundary cue in goal localization, mainly the perceived stability of an environmental feature and the distinctiveness of the potential reference points provided by the environmental feature. An overshadowing effect of landmark-related learning over boundary-related learning was observed when the perceived relative stability of the landmark array was increased; however the distinctiveness alone was insufficient to increase the cue reliance upon the landmark array. The results challenged the incidental characteristic of boundary-related learning. We postulate that boundary-related learning might also be subject to a reference-point selection process at the initial stage of goal localization, during which the usefulness of various environmental features are evaluated based on the navigation task and more learning resource would be assigned to the more “informative” feature selected as the reference points for encoding locations. In sum, our work has demonstrated an inferior role of a boundary cue in forming cognitive maps and the susceptibility of the boundary to the cue competition from other environmental features. We propose the segmentation hypothesis and the vector-addition model to conceptualize localization and cognitive mapping relative to a boundary cue.

• Subjects / Keywords

  • Localization
  • Boundaries
  • Landmarks
  • Cognitive map

• Graduation date

  Fall 2016

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3CZ32G3M

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.