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Role of selected encoding strategies on short-term retention of kinesthetic information.

30 volunteer subjects were required to use either a counting encoding strategy or an imagery encoding strategy to facilitate recall of information from short-term storage. Subjects were also required to use two reproducation cues in combination with two encoding strategies. Analysis indicated no differences between the accuracy at recall of subjects using imagery or counting strategies of encoding, nor was the predicted interaction between encoding strategies and reproduction cue supported.

Cues↗

Effect of familiar size on judgments of relative size and distance.

Carlson and Tassone (1971) found that for far viewing distances a person was judged taller in objective size, smaller in apparent size, and more distant than a board of the same size and at the same distance as the person. The purpose of this experiment was to replicate Carlson and Tassone's findings for near viewing distances. Subjects compared to size and distance of familiar and unfamiliar objects viewed from a distance of 5.3 m. The two objects were judged equal in both apparent and objective size and the familiar object was judged as more distant than the unfamiliar object. It is suggested that the distance results can best be explained in terms of the detail pattern cue rather than the familiar size cue to relative distance.

Adolescent↗

Estimation of distance and Preferred State Theory.

This paper describes the application of Preferred State Theory to provide quantitative predictions of a variety of psychological effects, including the prothetic-metathetic distinction, and the expected form of the matching functions between physical stimuli and the estimates produced by magnitude and category subjective estimation methods. The subjective distance from a midwestern university campus to each of 24 American cities was judged by 157 male and female undergraduates. It was hypothesized on the basis of the theory that subjects would process short geographical distances as a metathetic continuum and longer distances as a prothetic continuum. This hypothesis was supported for the method of category judgments but not for the method of magnitude estimation. Based on the theory, the matching functions between physical and subjective distances for short distances were expected to be more nearly linear than for long distances for both judgment methods. The data do not support this hypothesis for either method.

Adolescent↗

Head tip, cue to object elevation and location: implications for the blind.

Sighted subjects can accurately direct a light-beam source mounted on their head to the position of their hand on a vertical or horizontal scale by tipping their head in the up-down dimension. A blind person might be trained to utilize head-tip cues for location of objects in space. If he scanned his environment vertically (by tipping his head) with a horizontal inear array of photosensitive elements, presence of an object at a given position and elevation could be signalled to him by a small light attached to the object.

Acoustic Stimulation↗

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 X 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.

Distance Perception↗

Use of musical scales to display distance to objects in an electronic travel aid for the blind.

An electronic travel aid for the blind has been designed which displays distance to objects in terms of the eight notes of the musical scale. Experiments are described which determine the relationship between the efficacy of various tonal displays and the musical sophistication of the subjects. In particular it is shown that the accuracy of predicting the end of a scale, and hence a collision with an object, is a function of familiarity with the scale. That this accuracy is a function of musical sophistication receives only partial support. As expected, the ascending and descending versions of a scale are, in general, equally effective but, unexpectedly, the hypothesis that the accuracy of predicting the end of a tonal sequence would be an inverse function of the sequence length is confirmed only in the case of one scale, the Ionian or Major scale.

Blindness↗

Complexity of context and orientation of figure in the corridor illusion.

12 subjects judged the magnitude of the corridor illusion as two independent variables were manipulated, complexity of context and orientation of the target figures. The contexts included a complete corridor, one with vertical elements deleted, and one having but two converging lines. Figures embedded within these contexts were thin black lines oriented either vertically or horizontally. Although the context had a significant effect upon the magnitude of the illusion, orientation of the judged lines did not. These results suggest that it is legitimate to use the corridor illusion to illustrate size-distance relationships.

Adult↗

Practice variability and longer and short retention intervals.

This experiment compared the effect of different practice schedules on distance and direction errors in a blindfolded two-dimensional movement. The three experimental groups, (a) criterion target only, (b) varied targets (not criterion), (c) single target (not criterion) and one control group (rested), were tested immediately after the "practice" session without knowledge of results and were tested again after a 1-wk. retention interval. The distance data demonstrated little difference among the three experimental groups, but all three groups were significantly better than the control group. However, there was little difference in errors of direction among the groups. While the data for distance support a schema interpretation of movement control, the data for direction appear to reflect the concept of a visual-spatial map being used to guide movements.

Distance Perception↗

Simultaneous investigation of effects of distance of projection and object size on object reception by children in grade 1.

This study examined simultaneously the effects of distance of projection (4-, 6-, and 8-horizontal ft.) and object size (6-, 8.5-in., and 10-in. diameter balls) on object reception by children in the first grade. 6 boys and 6 girls were randomly assigned to each of the 3 distances (36 subjects total). Each subject was administered 36 trials, 12 attempted catches with each ball size at their assigned distance. All balls were projected by a device designed to control accuracy as well as the angle of projection for projections to each distance. Each attempted each was evaluated by a 5-point scale (r = .96). Trials, sex, distance of projection, ball size, and related interactions were examined using a conventional analysis of variance. Ball size was the only significant main effect, but the interaction between ball size and sex was also significant. Post hoc analysis indicated that the 10-in. ball gave significantly more catching success than the 8.5- or the 6-in. ball. Although more success in catching was achieved with the larger ball sizes, no difference in catching was attributable to the varying distances. The sequences for catching success according to ball size at each distance were not significantly different.

Child↗

Scaling apparent distance in a large open field: presence of a standard does not increase the exponent of the power function.

Apparent distance in a large open field was scaled by the method of magnitude estimation with or without a standard distance present. The presence of the standard did not increase the exponent of the power law. The average exponent of the power function relating judged to physical distance was .87. The results are consistent with those of other studies showing that apparent distance is a decelerating function of actual distance in a natural outdoor setting.

Adolescent↗

Scales for subjective distance in a large open field from the fractionation method: effects of type of judgment and distance range.

By means of the method of fractionation, scales for subjective distance were derived from five different types of judgment accomplished with two ranges of distance estimated in a large open field. It was found (a) that the scales for subjective distance are to a considerable extent influenced by ways of obtaining the judgments, (b) that the scales are relatively uninfluenced by range of distance, (c) that the exponents of the scales for egocentric distances are different from those for exocentric distances, (d) that the functions for egocentric distances are slightly decelerated but for exocentric distances slightly accelerated, and (e) that the average exponent for all subjects was 0.98.

Adolescent↗

Effect of presentation time and Gestalt principles of proximity, similarity, and closure on perceptual accuracy.

The present study investigated Gestalt principles of proximity, similarity and closure. 32 subjects reproduced distances between dots and lines. Two stimulus exposure times were used. Time was significant for proximity, similarity, and closure. Type of distance estimated was significant for proximity and closure and the interaction of time and type of distance was significant for similarity. Most accurate estimations were consistently found for fast exposure times, and internal distances were estimated more accurately than external distances.

Adult↗

Scaling apparent distance in a large open field: some new data.

Judged distance in a large open field, scaled by the method of magnitude estimation, is related to physical distance by a power function with an exponent smaller than unity. The exponents obtained with two ranges of distance were not affected by the availability of a standard. The mean exponent for all 80 individual power functions was 0.86, with a standard deviation of 0.11.

Adolescent↗

Individual differences in distance estimation: comparison of judgments in the field with those from projected slides of the same scenes.

This study was designed to determine the comparative accuracy with which trained and untrained observers could judge distances to a target and to assess the correspondence of those judgments with other judgments, by the same observers, from photographic slides of the same target and scene at identical viewing distances. 9 experienced and 15 untrained observers estimated distances ranging from 600 to 1550 m in 50-m increments. Photographic slides were made of the target at each distance and, 1 mo. later, observers made the same judgments from the slides. It was found that averages of the group's judgments in the field very closely approximated true target distances. However, judgments of the individual observers were so erratic and inaccurate as to render questionable the interpretation of those averages. In addition, while the averages of the group indicated that judgments from two-dimensional slides could be substituted fro three-dimensional real-world judgments, detailed analysis of the individual observers' performances dramatically contradicted this conclusion.

Discrimination Learning↗

Stability of individual psychophysical functions for perceived distance in natural indoor and outdoor settings.

Exp. 1 examined correlations of the power functions exponents for individual observers, for apparent distance in a natural indoor setting, obtained for a group of 9 observers over 5 experimental sessions separated by intersession intervals that varied from 1 day to 9 mo. Stable individual differences in the exponent of the psychophysical power law were shown. Intercorrelations of subjects' exponents were positive and reliable with 1 day between sessions and 9 mo. In Exp. 2 the estimates of apparent distance were made by 5 independent groups of 10 observers each, tested and retested at different intersession intervals. There were 5 intervals of 1 day to 9 mo. Fair temporal stability of psychophysical power function exponents was observed in most groups. In Exp. 3 psychophysical power functions were obtained from magnitude estimates of apparent distance in a natural outdoor setting. The same 10 observers were tested and then retested after 1 day and again after 1 yr. Significant correlations for both intersessions intervals indicated consistent and persisting individual differences. Taken together Exps. 1, 2, and 3, regardless of the environment in which distance estimates were performed, clearly demonstrate that power functions are repeatable, enduring, and characteristic of individuals. In addition, the mean exponents were in reasonable agreement with other reported apparent distance exponents obtained in both settings.

Adult↗