Anders Böök

Cognitive Mapping of Large-Scale Environments: The Interrelationship of Action Plans, Acquisition, and Orientation

A theory about the acquisition and use of cognitive maps of largescale everyday environments is presented. The basic assumptions of the theory are (1) peoples behavior in social and physical environments is determined by action plans, and, if the execution of such action plans requires traveling, plans for how to travel, termed travel plans, are formed and executed; (2) the cognitive maps of large-scale and medium-scale environments acquired are adapted to facilitate movement and travel, and contain information about destinations for travel, spatial information, and travel instructions; (3) cognitive maps are initially acquired in connection with the formation of travel plans and, at the later stages of acquisition, the execution of travel plans (requiring active monitoring) constitutes a more important set of conditions for acquisition. The principles of internal representation of the cognitive map are also discussed.

The spatiotemporal sequencing of everyday activities in the large-scale environment

Abstract Choices of where to carry out everyday activities in large-scale environments were conceptualized as a process of forming ‘travel plans’, and, to test a model of how such plans are formed, three experimental simulations of a planning task were performed in the laboratory. In Experiment 1, subjects (high school students) were found to choose a shortest route to travel between a number of actual, familiar locations in a town by first choosing the order between the locations that minimized straight-line (Euclidean) distances, then choosing the shortest paths between the locations in the constrained order. The order choices were, in Experiment 2, found to be made by minimizing distance locally rather than globally, except in some cases when ‘spatial configurations’ of the locations were discovered. Both the results of this experiment and of Experiment 3 suggested that such discoveries were facilitated by a simultaneous representation of the locations which was possible when they were positions on a display, committed to short-term memory or available for perceptual inspection, but to a less extent when they were actual locations.

Memory for the spatial layout of the everyday physical environment: Factors affecting rate of acquisition

Abstract That a memory representation of the spatial layout of a large-scale environment may be acquired very fast was shown in two experiments in which subjects (48 undergraduates and high-school students) were taken on tours through a residential area with which they were unfamiliar. Memory for the path traversed was almost perfect after the first trial, as indicated by almost perfect recall of the order in which a number of designated landmarks had been passed. Memory for the locations of the same landmarks appeared to reach an asymptotic level after the second of three trials. The memory representation of the locations were however not perfectly accurate, thus the asymptotic level might have been an acquisition plateau. The rate of acquisition was slightly faster for subjects driven in a car slowly through the area than for those who walked the same path. Men tended to improve slightly faster than women if they were driven by car but there were no other sex differences. Finally, the acquired memory representation appeared to be resistant to forgetting. Re-learning after a one-week retention interval was faster and rate of learning was not negatively affected whether the trials were massed or distributed with one week in between. The results are discussed in terms of hypotheses concerning the order in which different types of information about spatial layouts (landmarks, paths, and locations) are acquired. The bearing of the results on the question of why memory representations of the spatial layout are often found to be distorted is also discussed.

Maintenance of orientation during locomotion in unfamiliar environments.

Accuracy of maintenance of orientation during locomotion in unfamiliar environments was investigated by a laboratory procedure in two experiments. In a dark room, subjects were directed to a starting point, shown a target consisting of a point light on the floor, and required to walk straight by following a moving light line (1.18 m/sec) to a stopping point 1.4 to 11.0 m away. From the stopping point, the subjects numerically estimated the direction and distance to the target, which by then was out of sight. In contrast to control conditions with the target visible, the constant and variable errors were larger, and the constant errors varied with locomotion distance in a way that suggested proportional displacements of the target in the same direction as the subjects walked. Forgetting may in part account for the errors, but the main factor was assumed to be accumulated errors in recurrent central processing of the sensory information received about locomotion distance and target location.

Is elevation encoded in cognitive maps

Abstract Two experiments examined whether differences in elevation of the terrain are encoded in cognitive maps of outdoor environments. In Experiment 1, two groups of subjects who had travelled a varying number of times between a set of locations made direct estimates in metres of the differences in elevation between the locations. The results showed that subjects in both groups had knowledge of elevation but those for whom the terrain was less familiar tended to exaggerate the differences. In Experiment 2, decision times were measured of responses to the question whether one location is below or above another one. Neither for subjects who were more, nor for subjects who were less familiar with the terrain, did the decision times vary with the distances between the locations, thus failing to support the hypothesis that differences in elevation are retrieved by a process of ‘mental travel’.

Processing of information about location during locomotion: effects of amount of visual information about the locomotor patterns.

How maintenance of orientation during locomotion in unfamiliar environments is accomplished was investigated by presenting subjects (n = 32) a target in different locations in a dark room, having them walk linearly behind a moving light line (1.12 m/sec.), and from a stopping point 12 and 22.6 m away, numerically estimate direction and distance to the target. An equal number of subjects was assigned to each of 2 × 2 treatment levels: the starting point either visible or invisible from the stopping point and the target either visible only from the starting point or throughout each trial. In the conditions with invisible targets there were mainly negative effects of the visible starting point, partially the same as those previously obtained for a concurrent task during locomotion. The results suggested that maintenance of orientation is achieved by recurrent central processing of information, which if postponed leads to impaired performance mainly because forgetting occurs.

Maintenance of environmental orientation during body rotation.

The accuracy with which orientation is maintained in unfamiliar environments during body rotation was investigated by showing subjects (n = 16) a target in different directions (15° to 60° relative to the direction faced), then after varied retention intervals (7 to 14 sec.) requiring them to rotate their bodies 0° to 75° and, having completed rotation, to estimate numerically the direction to the target which by then was out of sight. By contrast to a perceptual baseline condition in which the target was visible, the subjects overestimated the target direction by an amount which increased linearly with the angle of body rotation. This overcompensation differed from the larger undercompensation that had been observed previously for straight walking, which suggested that different mechanisms produced the errors.