Chunking in spatial memory.

Abstract

In order to gain insight into the nature of human spatial representations, the current study examined how those representations are affected by blind rotation. Evidence was sought on the possibility that whereas certain environmental aspects may be updated independently of one another, other aspects may be grouped (or chunked) together and updated as a unit. Participants learned the locations of an array of objects around them in a room, then were blindfolded and underwent a succession of passive, whole-body rotations. After each rotation, participants pointed to remembered target locations. Targets were located more precisely relative to each other if they were (a) separated by smaller angular distances, (b) contained within the same regularly configured arrangement, or (c) corresponded to parts of a common object. A hypothesis is presented describing the roles played by egocentric and allocentric information within the spatial updating system. Results are interpreted in terms of an existing neural systems model, elaborating the model's conceptualization of how parietal (egocentric) and medial temporal (allocentric) representations interact. Keywords spatial memory; spatial updating; egocentric; allocentric; chunking On the basis of perceptual experience with the immediate environment, humans and other animals construct internal representations of the landmarks, boundaries, and objects that make up that environment. Evidence of these persisting internal representations is provided by the ability to locate objects and landmarks in the absence of ongoing perceptual support (e.g., Kosslyn, Ball, & Reiser, 1978;McNamara, 1986) and by neurophysiological data (e.g., Burgess & O'Keefe, 1996;Cressant, Muller, & Poucet, 1997;Ekstrom et al., 2003). As an organism navigates through the environment, these internal representations are updated to reflect the changing relationship between the organism and its surroundings (e.g., Müller & Wehner, 1988;Philbeck, Loomis, & Beall, 1997;Rieser, 1989;Waller, Montello, Richardson, & Hegarty, 2002). In the current study, we examined errors that accrue over this spatial updating process for evidence that a representation of a room-sized environment may be composed of "chunks," each of which contains location information for a different part of that environment.Correspondence concerning this article should be addressed to Jesse Sargent, who is now at the Department of Psychology, Washington University in St. Louis, Campus Box 1125, One Brookings Drive, St. Louis, MO 63130-4899. jsargent@artsci.wustl.edu. NIH Public Access NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptPrevious work provides a precedent for the possibility that this type of chunking might occur in spatial memory. Brockmole (2003a, 2003b) provided evidence that as humans navigate through larger environments (e.g., college campuses), they only actively update spatial aspects of the subenvironment (e.g., room) currently inhabited. Thus, it appears that spatial memory for larger environm...

Building a cognitive map by assembling multiple path integration systems

“…For example, Wang and Spelke (2000;Sargent, Dopkins, Philbeck, & Chichka, 2010;Waller & Hodgson, 2006;Xiao, Mou & McNamara, 2009) asked people to learn multiple target objects in a room. They then pointed to these targets before and after disorientation.…”

Spatial updating according to a fixed reference direction of a briefly viewed layout

“…A large body of evidence, however, indicates that humans have allocentric representations of objects’ locations in memory (e.g., Burgess, Spiers, & Paleologou, 2004; Greenauer & Waller, 2010; Holmes & Sholl, 2005; Mou & McNamara, 2002; Mou, Xiao, & McNamara, 2008; Sargent, Dopkins, Philbeck, & Chichka, 2010). Allocentric representations have been determined according to two criteria.…”

Getting completely turned around: how disorientation impacts subjective straight ahead

“…On each trial in the OC condition, the participant experienced an orientation challenge and then used the pointer to indicate SSA. The orientation challenge was similar to that used by Sargent, Dopkins, Philbeck, and Chichka (2010). The challenge included seven sequential rotations: 200 degrees clockwise (C), 100 degrees counterclockwise (CC), 40 degrees CC, 100 degrees C, 90 degrees CC, a filler rotation, and finally a return to the starting heading.…”