The use of foveal vision in route-selection and the roles of viewing distance and attention

Deijs, M. (2013) The use of foveal vision in route-selection and the roles of viewing distance and attention. thesis, Human Movement Sciences.

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Abstract

Although previous research has shown that foveal vision is purposefully employed in functional motor tasks, selectivity of gaze in tasks in which the object of visual attention is not specified, is not yet well understood. This study investigates selectivity of gaze behavior in a route-selection task and the roles of viewing distance and attention. Gaze tracking data and position data were collected from eleven healthy adults (22.4 ± 2.4 years) walking towards a goal through a 10.40 x 3.60 meter environment containing 40 obstacles, free to select their own route. In single-task (ST) conditions, subjects only performed the walking-task, and in dual-task (DT) conditions subjects simultaneously performed an arithmetic dual-task. Frame-by-frame video-analysis revealed that the major portion of fixations was made on task-relevant locations (i.e., obstacles, path and goal region). People seem to select their route based on perceiving of spaces that allow an obstacle free passage, rather than on perceiving obstructions, indicated by the larger amount of fixation time spent on path locations (50± 12% forST; 44 ± 22 % for DT) than on obstacles (25 ± 8 % for ST; 19 ± 9 % for DT). A very high number of fixations on obstacles (82 ± 11 %) and path (82 ± 13 %) was bordering to the eventually chosen route under ST conditions, but this specificity of fixations decreased as a result of the DT (70 ± 23 % for obstacles; 70 ± 18 % for path). Fixation distances were larger for obstacle fixations (5.4 m, averaged over STand DT) than path fixations (4.7 m), and larger for non-bordering fixations (6.8 m for obstacle; 5.4 for path) than bordering fixations (5.2 m for obstacle; 4.6 m for path), suggesting that employment of foveal vision becomes slightly less selective at larger fixation distances. The results provide insight into selective employment of gaze for action-choices, showing that fixation patterns are purposefully employed in route-selection and that fixations are selectively related to the eventually chosen route, but that specificity declines with larger viewing distances and selectivity is partially under attentional control.

Item Type:	Thesis (Thesis)
Supervisor name:	Supervisor: and Otter, dr. A.R. den and Center for Human Movement sciences, University Medical Cente and Groningen, The Netherlands
Faculty:	Medical Sciences
Date Deposited:	25 Jun 2020 10:57
Last Modified:	25 Jun 2020 10:57
URI:	https://umcg.studenttheses.ub.rug.nl/id/eprint/1720

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