ARTICLE. Klatzky, Roberta L.; Loomis, Jack M.; Beall, Andrew C.; Chance, Sarah S.; Golledge, Reginald G. Spatial updating of self-position and orientation during real, imagined, and virtual locomotion. Psychological Science. 1998 Jul. 9 (4): p. 293-298 Language: English. Pub type: Empirical Study

ABSTRACT: Two studies investigated updating of self-position and heading during real, imagined, and simulated locomotion. 50 college students were exposed to a 2-segment path with a turn between segments; they responded by turning to face the origin as they would if they had walked the path and were at the end of the 2nd segment. The conditions of pathway exposure included physical walking, imagined walking from a verbal description, watching another person walk, and experiencing optic flow that simulated walking, with or without a physical turn between the path segments. If Subjects failed to update an internal representation of heading, but did encode the pathway trajectory, they should have overturned by the magnitude of the turn between the path segments. Such systematic overturning was found in the description and watching conditions, but not with physical walking. Simulated optic flow was not by itself sufficient to induce spatial updating that supported correct turn responses.

ARTICLE. Richardson, Anthony E.; Montello, Daniel R.; Hegarty, Mary Spatial knowledge acquisition from maps and from navigation in real and virtual environments. Memory & Cognition. 1999 Jul. 27 (4): p. 741-750 Language: English. Pub type: Empirical Study

ABSTRACT: In this study, the nature of the spatial representations of an environment acquired from maps, navigation, and virtual environments (VEs) was assessed. Participants first learned the layout of a simple desktop VE and then were tested in that environment. Then, participants learned two floors of a complex building in one of three learning conditions: from a map, from direct experience, or by traversing through a virtual rendition of the building. VE learners showed the poorest learning of the complex environment overall, and the results suggest that VE learners are particularly susceptible to disorientation after rotation. However, all the conditions showed similar levels of performance in learning the layout of landmarks on a single floor. Consistent with previous research, an alignment effect was present for map learners, suggesting that they had formed an orientation-specific representation of the environment. VE learners also showed a preferred orientation, as defined by their initial orientation when learning the environment. Learning the initial simple VE was highly predictive of learning a real environment, suggesting that similar cognitive mechanisms are involved in the two learning situations.

ARTICLE. Beall, Andrew C.; Loomis, Jack M. Visual control of steering without course information. Perception. 1996. 25 (4): p. 481-494 Language: English. Pub type: Empirical Study

ABSTRACT: In an experiment, with 6 graduate students, involving a computer-driven driving simulator, observers attempted to steer a straight path while subjected to lateral perturbing forces. When only bearing and its time derivative, motion parallax, were available, performance fell off as expected with the optical gain of motion parallax as the preview distance of the viewing aperture was varied. When splay angle and its time derivative, splay rate, were added to the display, performance generally improved and remained relatively constant with changing distance of the viewing aperture, as expected because of the constant optical gain of splay rate. Making course information available by adding point features to both displays improved steering performance only in the motion-parallax conditions.

ARTICLE. Fukusima, Sergio S.; Loomis, Jack M.; Da Silva, Jose A. Visual perception of egocentric distance as assessed by triangulation. Journal of Experimental Psychology: Human Perception & Performance. 1997 Feb. 23 (1): p. 86-100 Language: English. Pub type: Empirical Study

ABSTRACT: journal abstract Two triangulation methods for measuring perceived egocentric distance were examined. In the triangulation-by-pointing procedure, the observer views a target at some distance and, with eyes closed, attempts to point continuously at the target while traversing a path that passes by it. In the triangulation-by-walking procedure, the observer views a target and, with eyes closed, traverses a path that is oblique to the target; on command from the experimenter, the observer turns and walks toward the target. Two experiments using pointing and 3 using walking showed that perceived distance, averaged over observers, was accurate out to 15 m under full cue conditions. For target distances between 15 and 25 m, the evidence indicates slight perceptual underestimation. Results also show that observers, on average, were accurate in imaginally updating the locations of previously viewed targets.

ARTICLE. Loomis, Jack M.; da Silva, Jose A.; Fujita, Naofumi; Fukusima, Sergio S. Visual space perception and visually directed action. Journal of Experimental Psychology: Human Perception & Performance. 1992 Nov. 18 (4): p. 906-921 Language: English. Pub type: Empirical Study

ABSTRACT: The results of 2 types of experiments are reported. In 1 type, Subjects matched depth intervals on the ground plane that appeared equal to frontal intervals at the same distance. The depth intervals had to be made considerably larger than the frontal intervals to appear equal in length, with this physical inequality of equal-appearing intervals increasing with egocentric distance of the intervals (4-22 min). In the other type of experiment, Subjects viewed targets lying on the ground plane and then, with eyes closed, attempted either to walk directly to their locations or to point continuously toward them while walking along paths that passed off to the side. Performance was quite accurate in both motoric tasks, indicating that the distortion in the mapping from physical to visual space evident in the visual matching task does not manifest itself in the visually open-loop motoric task.

ARTICLE. Loomis, Jack M.; Klatzky, Roberta L.; Philbeck, John W.; Golledge, Reginald G. Assessing auditory distance perception using perceptually directed action. Perception & Psychophysics. 1998 Aug. 60 (6): p. 966-980 Language: English. Pub type: Empirical Study

ABSTRACT: Three experiments investigated auditory distance perception under natural listening conditions in a large open field. Targets varied in egocentric distance from 3 to 16 m. By presenting visual targets at these same locations on other trials, we were able to compare visual and auditory distance perception under similar circumstances. In some experimental conditions, observers made verbal reports of target distance. In others, observers viewed or listened to the target and then, without further perceptual information about the target, attempted to face the target, walk directly to it, or walk along a two-segment indirect path to it. The primary results were these. First, the verbal and walking responses were largely concordant, with the walking responses exhibiting less between-observer variability. Second, different motoric responses provided consistent estimates of the perceived target locations and, therefore, of the initially perceived distances. Third, under circumstances for which visual targets were perceived more or less correctly in distance using the more precise walking response, auditory targets were generally perceived with considerable systematic error.

ARTICLE. Loomis, Jack M.; Beall, Andrew C. Visually controlled locomotion: Its dependence on optic flow, three-dimensional space perception, and cognition. Ecological Psychology. 1998. 10 (3-4): p. 271-285 Language: English. Pub type: Empirical Study

ABSTRACT: J. J.Gibson (see record 1998-03373-001) and his followers have emphasized the role of optic flow in the control of locomotion. In recent years much research has been devoted to the visual control of aiming and braking, mainly in connection with terrestrial locomotion. The goal of this article is to broaden the topic empirically and theoretically. At the empirical level, the authors argue that there are a number of visually controlled maneuvers that need to be addressed for their own sake, for they involve more than can be learned from research on aiming and braking. At the theoretical level, they argue that optic flow needs to be supplemented by other explanatory primitives, including the actor's perception of three-dimensional spatial layout and the actor's cognitive representations of the spatial envelope and plant dynamics of his or her body or vehicle.

ARTICLE. Philbeck, John W.; Loomis, Jack M.; Beall, Andrew C. Visually perceived location is an invariant in the control of action. Perception & Psychophysics. 1997 May. 59 (4): p. 601-612 Language: English. Pub type: Empirical Study

ABSTRACT: Experimental evidence is provided that perceived location is an invariant in the control of action, by showing that different actions are directed toward a single visually specified location in space (corresponding to the putative perceived location) and that this single location, although specified by a fixed physical target, varies with the availability of information about the distance of that target. 16 adult observers in 2 conditions varying in the availability of egocentric distance cues viewed targets at 1.5, 3.1, or 6.0 m and then attempted to walk to the target with eyes closed using 1 of 3 paths; the path was not specified until after vision was occluded. The observers stopped at about the same location regardless of the path taken, providing evidence that action was being controlled by some invariant, ostensibly visually perceived location. That it was indeed perceived location was indicated by the manipulation of information about target distance--the trajectories in the full-cues condition converged near the physical target locations, whereas those in the reduced-cues condition converged at locations consistent with the usual perceptual errors found when distance cues are impoverished.