Viewing distance and estimates of duration

28 students reproduced the durations of 12- and 18-sec. intervals, which were defined by a moving stimulus on a computer monitor. The monitor was viewed from a distance of either .4 or 2.5 m. Temporal reproductions were significantly greater for the far than for the near distance conditions. Results are considered from the perspective of the change models of timing.     

Magnitude estimates for electrical pulses: evidence for two neural mechanisms

The hypothesis that there are two neural mechanisms for electrocutaneous stimulation--one that is sensitive to low current and is adaptive to repeated stimulation and another that is responsive to high current and is less adaptive--was tested in a control and four main experiments. In the main experiments, magnitude estimates obtained for single electrical pulses (of 2-msec duration) were described by a simple power function for each combination of high- and low-current levels and 10 trial blocks. The results were: (1) The slope of the power function for low current was steeper than was that for high current; (2) for low current, the intercept of the power function decreased with increasing block, whereas for high current, it remained constant over blocks; (3) this decrease of the intercept for low current disappeared when judgmental blocks were separated by a rest period of 8 min; (4) the modulus did not affect the slope; (5) for a large modulus combined with low current, the intercept decreased rapidly over trial blocks, whereas for a small modulus combined with high current, the intercept increased over trial blocks. The first four findings support the two-mechanism hypothesis, but the last one may also be interpretable in terms of the regression to absolute scale values.     

Effects of route traveled on the distance estimates of children and adults

Second graders, sixth graders, and adults walked about an experimental environment containing seven stimulus locations and three large barriers. Each individual learned the environment while traveling along a prescribed route. The environment was constructed such that 12 of the interlocation distances represented the factorial combination of route (traveled vs not traveled), barrier (absent vs present), and distance (4-, 6-, and 8-ft). After criterial performance in learning the environment, each person gave distance estimates of the 12 critical distances. In general, the estimates of the length of routes that were traveled, were long and had no intervening barrier were more accurate than the estimates of the length of routes which were not traveled, were short, and had intervening barriers to prevent direct travel. In addition, for 4- and 6-ft distances, subjects overestimated barrier present paths which were not traveled relative to the other three estimates for each distance (barrier present traveled, barrier absent traveled, barrier absent not traveled). These findings emphasize the generative nature of the construction of spatial representations and suggest that functional distance, or ease of travel, does not influence this construction in a simple manner. Results are discussed in terms of the ability to coordinate spatial information with general knowledge of spatial relationships.     

The effects of movement direction and hemispace on estimates of distance traveled

BACKGROUND/HYPOTHESIS: The degree of attention directed to a stimulus and the presence of anisometric representations can alter the perception of the magnitude of a stimulus. We wanted to learn if normal right-handed subjects' estimates of distance traveled are influenced by the right-left direction or hemispace of movements. METHODS: We had blindfolded participants estimate the distance their arm was moved in a rightward or leftward direction, in right and left hemispace. Since we wanted subjects to estimate the distance traveled rather than compute the distance between the start and finish points, the subjects' arms were passively moved in sinusoidal trajectories at a constant speed. RESULTS: Subjects estimated leftward movements as longer than rightward movements, but there was no effect of hemispace. COMMENTS/CONCLUSIONS: People often attend more to novel than routine conditions and therefore participants might have overestimated the distance associated with leftward versus rightward movement because right-handed people more frequently move their right hand in a rightward direction and learn to read and write using rightward movements. Thus, leftward movements might be more novel and more attended than rightward movements and this enhanced directional attention might have influenced estimates of magnitude (distance).     

Location and distance estimates by blind and sighted children

Blindfold normal, blindfold autistic and congenitally blind children made reproduction location and distance estimates of an arm movement. For each task they first experienced a standard vertical movement of a predetermined extent. In the test tasks which followed, they either reproduced the movement exactly, reproduced the end point although commencing from a different starting position, or reproduced the same distance from a different starting point. Sighted normal children and blind children performed very similarly on both the reproduction and the location task. However on distance reproduction, the blind children underestimated the longer distances more markedly than did the normals. Autistic children resembled the blind in their attempts to reproduce the longer distances. In addition they had a tendency to overshoot over short distances in all tasks.     

Role of vision and kinesthesis in location and distance estimates

Three experiments were conducted to investigate the visual/kinesthetic coding characteristics of two movement informations, i.e., location and distance. The first experiments used matching task procedures, the second experiment used visual augmentation and reduction procedures and the third experiment made use of an ischemic nerve block procedure. The findings' of the first experiment indicated a clear kinesthetic coding for distance information. Results suggest a kinesthetic coding for location cue, with the presence of vision (alone) on both phases of movements improving its accuracy. The second experiment ruled out a visual coding of distance cue and indicated a kinesthetic representation of location cue. Again, simultaneous presence of vision (only at the time of criterion movement) enhanced its performance. The third experiment confirmed a kinesthetic signalling of distance cue. Location cue, in conditions of the third experiment did not get influenced. Probably, muscle receptors in relation with central commands can handle location information. A multiple coding for location information is suggested.     

Statistical inference based on latent ability estimates

The quality of approximations to first and second order moments (e.g., statistics like means, variances, regression coefficients) based on latent ability estimates is being discussed. The ability estimates are obtained using either the Rasch, or the two-parameter logistic model. Straightforward use of such statistics to make inferences with respect to true latent ability is not recommended, unless we account for the fact that the basic quantities are estimates. In this paper true score theory is used to account for the latter; the counterpart of observed/true score being estimated/true latent ability. It is shown that statistics based on the true score theory are virtually unbiased if the number of items presented to each examinee is larger than fifteen. Three types of estimators are compared: maximum likelihood, weighted maximum likelihood, and Bayes modal. Furthermore, the (dis)advantages of the true score method and direct modeling of latent ability is discussed.     

Magnitude estimates of cold pressor pain: effects of suggestions, cognitive strategy, and tolerance

Pain magnitude when subjects immersed an arm in ice water was assessed by means of a magnitude estimation procedure during baseline and posttest sessions. Before the posttest session, subjects either received or did not receive an analgesic suggestion. Best-fit functions were linear, though power fits were also good. Analgesic suggestions had no effect on the rate of change in pain intensity. When subjects were classified as copers or catastrophizers on the basis of written testimony, pain intensity increased more rapidly for catastrophizers than for copers during the posttest session but not during the baseline session. Subjects who kept their arm immersed for more than 240 s were classified as high in tolerance. High-tolerance subjects experienced a slower rate of growth in pain intensity than low-tolerance subjects. Theoretical implications of the results are discussed.     

Adaptation in distance perception based on oculomotor cues

Accommodation and convergence primarily serve to adjust the eyes to the distance of the object viewed, but, once made, these oculomotor adjustments serve as cues for the object’s distance. Experiments are reported that show that the relation between oculomotor adjustments and the distances they signify can be changed by adaptation to glasses that cause alteration in the oculomotor adjustments with which objects are viewed. This changed relation manifested itself in marked alterations of size perception. Wearing, for 30 min, glasses that caused a change in accommodation and convergence corresponding to a smaller object distance and equivalent to 1.5 lens diopters caused subsequent mean size increases that ranged from 50% to 65%. Adaptation to glasses that changed oculomotor adjustments in the same amount but in the opposite direction resulted in decreases in perceived sizes that varied from 18% to 40%, dependent on the distance of the test object. These were the results of size estimates obtained before and after the adaptation period under conditions where only accommodation and convergence served as cues for distance. A newly developed test of size perception was also used, in which S adjusted the size of the projected image of an array of familiar objects on a screen until the size of the objects appeared normal. Again, such adjustments were made before and after the adaptation period, and size differences were obtained that were in the direction to be expected of adaptation and varied in amount between 12% and 33%, dependent on the distance of the screen. The reason for the different amounts of size change measured by the two kinds of tests was investigated.     

Using verbal and blind-walking distance estimates to investigate the two visual systems hypothesis

Verbal estimates of egocentric distance are usually too short at distances greater than several meters, yet blindfolded walking to previously viewed targets can be surprisingly accurate. We present evidence from three experiments for the existence of two visual pathways with differentencodings of perceived egocentric distance. We found that (1) blind-walking estimates of egocentric distance are consistently more accurate than verbal reports; (2) an indoor versus outdoor environment selectively influences verbal reports; and (3) wearing prism lenses, which displace the visual field vertically, selectively influences the blind-walking estimates. We interpret these results in terms of the two visual systems hypothesis.     

The nature of adaptation in distance perception based on oculomotor cues

In previous work by the senior authors, brief adaptation to glasses that changed the accommodation and convergence with which objects were seen resulted in large alterations in size perception. Here, two further effects of such adaptation are reported: alterations in stereoscopic depth perception and a change when distance is represented by a response of S’s arm. We believe that the three effects are manifestations of one primary effect, an alteration of the relation between accommodation and convergence on the one hand and the distance they represent in the nervous system (registered distance) on the other. This view was supported by the results of two experiments, each of which demonstrated that the alterations in stereoscopic depth perception could be obtained after adaptation periods which had provided no opportunity to use stereoscopic vision, and that the adaptation effect was larger for depth perception than for size perception when it was obtained under the same conditions; the latter finding was expected if both effects resulted from the same change in registered distance. In three of the five experiments here reported, the variety of cues that could represent veridical distance during the adaptation period was limited. In one condition of adaptation, only the pattern of growth of the retinal images of objects that S approached and the kinesthetic cues for S’s locomotion served as cues to veridical distance. In two other conditions S remained immobile. In one of these, only the perspective distortion in the projection of the scene that S viewed mediated veridical distance, and in the other one familiar objects of normal size were successively illuminated in an otherwise totally dark field, conditions from which opportunities to use stereoscopic vision were again absent. After exposure to each of these adaptation conditions, adaptive changes in perceived size and larger ones in perceived stereoscopic depth were obtained. Because we found that familiar size may serve as the sole indicator of veridical distance in an adaptation process, we concluded that it can function as a perceptual as distinguished from an inferential cue to distance.     

Global-scale location and distance estimates: common representations and strategies in absolute and relative judgments

The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although participants were relative experts, their latitude estimates revealed the presence of psychologically based regions with large gaps between them and a tendency to stretch North America southward toward the equator. The distance estimates revealed the same properties in the representation recovered via multidimensional scaling. Though the aggregated within- and between-regions distance estimates were fitted by Stevens's law (S. S. Stevens, 1957), this was an averaging artifact: The appropriateness of a power function to describe distance estimates depended on the regional membership of the cities. The authors conclude that plausible reasoning strategies, combined with regionalized representations and beliefs about the location of these relative to global landmarks, underlie global-scale latitude and distance judgments.     

分数的数量表征

分数数量表征已成为当前数学认知研究的重要主题之一。基于该领域近10年来的研究发现, 总结了分数数量表征研究的新进展。首先概述分数数量表征的发展, 然后着重介绍分数数量的不同表征方式并系统分析制约数量表征的任务及背景因素。此外, 还深入探究了分数数量表征与整数、小数数量表征的区别与联系。未来研究者应注意在分数数量表征的个体差异、跨文化以及干预等方面加强考察。     

Correcting distance estimates by interacting with immersive virtual environments: effects of task and available sensory information

The tendency to underestimate egocentric distances in immersive virtual environments (VEs) is not well understood. However, previous research (A. R. Richardson & D. Waller, 2007) has demonstrated that a brief period of interaction with the VE prior to making distance judgments can effectively eliminate subsequent underestimation. Here the authors examine the mechanism underlying the effect of VE interaction and the conditions that may give rise to it. In Experiment 1, after interacting with an immersive VE, participants tended to overestimate distances in the physical world, indicating that the interaction involved a recalibration of the perceptual-motor system. Experiment 2 demonstrates that visual information is not necessary (and that body-based information is necessary) during the interaction period for it to have a positive effect on subsequent distance estimation accuracy. Experiment 3 illustrates that the interaction task does not need to be goal directed in order to be effective.