The research program described in this dissertation updates the knowledge base concerning human navigation and presents new methods for investigating selection and use of cognitive navigational strategies. Four experiments were designed to answer questions about the effects of environmental and experiential factors on cognitive mapping and selection of navigation strategies. Humans are thought to navigate using two different reference frames often referred to as “world based” and “person based”. These reference frames correspond to two probable cognitive/memory systems respectively labelled “allocentric” for the formation and use of cognitive maps of the environment, and “egocentric” for navigation by stimulus response or guidance. Different navigational strategies are associated with the two systems. Allocentric strategies rely on the presence of a stable environmental structure containing a number of more distal, relational stimuli whereas egocentric strategies rely only on the presence of simple, local cues (cue-based egocentric) or on body movements (response-based egocentric). The experiments tested navigation behaviour and strategy selection using virtual environment analogues of an animal model, the Morris water maze. Adaptations included, 1) the Place maze biasing participants toward the use of an allocentric strategy, 2) the Cue maze (and Floor Cue maze) biasing participants toward the use of an egocentric strategy, and 3) the Dual-strategy maze that has no bias because participants can choose to utilize either an allocentric or egocentric strategy. Experiment 1 was a behavioural study testing 101 university students in the Place maze and Floor Cue maze, with and without the opportunity to explore the environment before testing. The experiment showed for the first time that exploration is necessary for allocentric but not for egocentric navigation, suggesting that prior exploration is important for cognitive mapping. Experiment 2 outlined a novel and reliable eye tracking method for differentiating strategy use in the Place and Cue mazes. Eye movements were measured during the first orientation second of behavioural trials to differentiate allocentric from egocentric strategy use. Experiment 3 employed the established eye tracking method to test the effects of experience on strategy selection. Participants were trained in either the Place maze or the Cue maze and then tested in the Dual-strategy maze. A strategy probe trial was introduced at the end of testing to indicate whether participants had selected an allocentric or an egocentric strategy. Training experience had a strong behavioural effect on later strategy selection at the end of testing. Furthermore the effect of experience occurred independently of the gender of participants. However, the experience effect was only briefly shown using eye tracking measures. Experiment 4 was a successful feasibility study showing that eye tracking measures can be utilized to measure navigational strategy use in survivors of traumatic brain injury. Together these experiments may indicate that strategies are not innate or within the person but rather are interactions of the person with the environment. / Graduate
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/4317 |
| Date | 22 November 2012 |
| Creators | Lee, Sharon |
| Contributors | Skelton, Ronald William |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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