For Efficient Navigational Search, Humans Require Full Physical Movement, but Not a Rich Visual Scene

Abstract

During navigation, humans combine visual information from their surroundings with body-based information from the translational and rotational components of movement. Theories of navigation focus on the role of visual and rotational bodybased information, even though experimental evidence shows they are not sufficient for complex spatial tasks. To investigate the contribution of all three sources of information, we asked participants to search a computer generated "virtual" room for targets. Participants were provided with either only visual information, or visual supplemented with body-based information for all movement (walk group) or rotational movement (rotate group). The walk group performed the task with nearperfect efficiency, irrespective of whether a rich or impoverished visual scene was provided. The visual-only and rotate groups were significantly less efficient, and frequently searched parts of the room at least twice. This suggests full physical movement plays a critical role in navigational search, but only moderate visual detail is required.

Visual search and foraging compared in a large-scale search task

“…However, these errors were comparatively small in number (14 participants made no errors at all), and there was no relationship between the display size and the number of revisits made by the remaining participants. This is in line with the findings of Gilchrist et al (2001) and Ruddle and Lessels (2006), who both report fewer revisit errors during large-scale search tasks.…”

“…latency, number of visits) was found to correlate strongly with short-term spatial memory measures, but not with age or general intelligence. Revisit behaviour was also measured by Ruddle and Lessels (2006) in a virtual reality (VR) task, where participants searched for multiple targets hidden in an array of boxes. Movement was varied by condition, with participants searching whilst seated at a monitor, standing stationary whilst wearing a VR headset, and actively walking through the virtual display.…”

“…This means that it is not possible to compare large-scale search with efficient or 'parallel' (Treisman and Gelade 1980) visual search behaviour, or to address the visually guided nature of search. Serial inspection of potential target locations in large-scale search (Gilchrist et al 2001;Ruddle and Lessels 2006;Smith et al 2005) is more akin to inefficient visual search behaviour, especially in visual search tasks where target complexity necessitates fixation of individual items (e.g. Klein and MacInnes 1999;Gilchrist and Harvey 2000).…”

“…Perhaps more fundamentally, explicit comparisons between visual search and large-scale search have not taken place in the same context or the same experiment. Ruddle and Lessels (2006) compared different groups on a monitor-based and full-body search, although they did not focus on visually guided aspects of search, and Gilchrist et al (2001) compared large-scale search profiles to previously reported visual search data in different tasks.…”

The development of path integration: Combining estimations of distance and heading

“…Existing accounts (such as those of: Gollege et al, 1985;Siegel & White, 1975) primarily focus of the use of landmarks and the formation of cognitive maps, with no place for idiothetic representations of movement in space. This is despite other accounts of the fundamental role of proprioception in cognitive mapping (Gallistel, 1990), along with clear empirical demonstrations that self-motion cues scaffold landmark learning (Müller and Wehner, 2010) and route learning (Ruddle and Lessels, 2006). One reason why path integration has not previously been incorporated into theories of navigational development may be that it had mostly been explored and characterised in closed biological systems, such as continuous online vector summation in the desert ant (Wehner & Srinivasan, 1981).…”