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At least 757 records · Page 42Linked to original sources
PubMed1975

Effect of changes in fin-length on apparent shaft-length and depth in the Müller-Lyer illusion.

Müller-Lyer figures with outgoing fins were back illuminated and apparent shaft-length and depth were both judged by 20 undergraduates. With the angle between the fins constant, progressive increases in fin-length produced first an increase in the apparent shaft-length and then a decrease. Changes in fin-length, however, had no significant effect on apparent depth. These data were interpreted as inconsistent with an account of the Müller-Lyer illusion in terms of perspective theory, since the latter predicts systematic changes in perceived shaft-length to be associated with systematic changes in perceived depth.

Adolescent↗
PubMed1975

Perception of curves.

In 4 experiments, in which 66 subjects participated, the perception of 6 types of curved contours in two-dimensional shapes was studied. Random polygons and their curvilinear transformations were presented for detection under low-luminance contrast conditions, oddity-type discrimination problem solving, tachistoscopic identification, and identification involving visual acuity in distance vision. In all experiments curvature affected perception at statistically significant levels, but the extent of this effect was a function of (1) the locus and direction of curvature, (2) the level of compactness-jaggedness of the figure, and (3) the nature of perceptual task. Shapes with acute corners were more easily perceived than shapes with curved corners. Within these two classes of shapes, those with convex sides were perceived as having greater curvedness than those with concave contours. However, the degree to which curvature affected response was determined primarily by the nature of the perceptual task.

Cues↗
PubMed1976

Performance of retarded and nonretarded adolescents when processing relevant and irrelevant information.

The information-processing performance of 12 retarded and 12 nonretarded adolescents was compared. Using reaction time keys each subject classified color words, secondary color words, non-color words, non-sense syllables, and stick figures according to the color of ink in which each stimulus was presented. Reaction time of the nonretarded subjects was significantly faster than that of retarded subjects; color words and secondary color words significantly interfered with processing performance as measured by correct reaction time. The results indicate that the Stroop task interferes with response initiation rather than memory retrieval and that the locus of interference for retarded and nonretarded subjects is equivalent.

Adolescent↗
PubMed1977

Response-selection processes in paranoid and nonparanoid schizophrenia.

Previous research (Marshall, 1973) has shown that the most pronounced component of deficit on a choice reaction time task among a mixed schizophrenic sample involved response-selection processes. Other evidence has indicated that paranoids may be more deficient in this respect than nonparanoids. Hence, it was hypothesized that the former subgroup of schizophrenics would display response-selection deficit while the latter subgroup would display either less or no deficit. Response-selection processes were re-examined using the CRT paradigm with comparisons carried out among paranoid and nonparanoid schizophrenics and a group of nonschizophrenic controls. Results indicated that only the paranoid schizophrenics displayed abnormally retarded response-selection operations, the nonparanoid schizophrenics being nonsignificantly discriminable from the controls. It was suggested that past evidence of CRT response-selection deficit among mixed schizophrenics might have been attributable primarily to the performance of the paranoids, whose performance appears to be adversely affected by an increase in the number of dimensions relevant to response selection.

Association↗
PubMed1977

Within-modal and cross-modal reliabilities of two laterality tests among left handers.

20 left handers were administered four repeat testing of a dichotic listening task and a verbal visual half-field task. Scores on the dichotic task were reliable between Days 1 and 4 while visual half-field performance did not stabilize until two testing sessions. Left handers showed a clear right channel, superiority of the right visual half field for the verbal material. No significant cross-model reliabilities were observed. It was also found that, in comparison to right handers, left handers show more variability in channel/visual half field than right handers on the same procedures.

Auditory Perception↗
PubMed1978

Role of two-dimensional surface characteristics in pictorial depth perception.

The purpose of the present experiment was to test the hypothesis that flat surface information for the plane of projection is the essential difference between ordinary and pictorial perception. Adults were asked to make relative size judgments of pairs of squares and triangles placed and pictured at various distances. The conditions were: real scene controls, life-size slides and prints, and real scenes viewed through clear glass, textured glass, a screen and a 50-mm lens. The error rate was significantly lower with real scenes than with either slides or prints which did not differ. The control data for real scenes were used for comparison to test for the effects of interposed flat surfaces on size judgments of real scenes. Viewing real scenes through either a clear glass pane or a 50-mm lens increased the error rate two and one-half times that of the controls for real scenes. Neither textured glass nor a screen significantly affected error rate. Results were interpreted as supporting the hypothesis that information about a flat surface for the plane of projection is the critical variable determining the special character of picture perception.

Depth Perception↗
PubMed1979

Examination stress and performance on a color-word interference test.

Interference observed in the Stroop color-word task is influenced by various characteristics of the words employed. 38 students in their final year, approaching examinations, were asked to name the colors of words associated with this theme. These words produced greater delay than a control set, and those students who were most anxious about the examinations experienced most interference. This effect might be more generally employed in stress research, providing a performance-based index of reaction to issues or situations which are potential sources of anxiety.

Arousal↗
PubMed1979

Concurrent validity of a children's version of the Stroop Color-Word Test: the Fruit Distraction Test.

To assess the concurrent validity of the Fruit Distraction Test, the Stroop Color-Word Test and the Fruit Distraction Test were administered to two groups of boys aged 12 yr. (N = 63) and 8 yr. (N = 52). Partial correlations, with IQ controlled, based on time and error scores derived from both tests, provided no convincing evidence that the Fruit Distraction Test is a valid downward extension of the Stroop.

Child↗
PubMed1980

Effects of multi-chromatic and achromatic targets and darts on throwing.

This study determined the effects of achromatic and multichromatic targets and darts on throwing. Subjects were 56 college men assigned to one of four dart-and-target throwing conditions as follows: white target--white darts, white target--multi-colored darts, multi-colored target--white darts, and multi-colored target--multi-colored darts. Subjects threw from 20 ft. using an overhand throwing pattern. The main effect of target color and the interaction of target color and dart color were significant. The results indicated that white backgrounds are superior to colored backgrounds. Also, the interactions of colored darts against a white background produced the best combination for performance. In target tasks which depend upon response-produced feedback, color of figures and background interact apparently to affect motor performance.

Adolescent↗
PubMed1980

Depth perception in moving line patterns.

By means of a computer system, the two-dimensional projections of a three-dimensional random wire figure, rotated clockwise (CW) or counterclockwise (CCW) about the vertical axis, were produced and displayed on a CRT. Generally the stimulus display appeared as an object rotating in depth, changing direction of movement frequently from clockwise rotation to counterclockwise, and vice versa. In the experiment, the three subjects observed the displays of three different types of projection, two polar projections and a parallel one. They were instructed to judge the direction of the seen motion and asked to report it using the button-switches. Both duration of the rotation perceived in either direction and frequency of the apparent reversals between those two were measured from the output sheets of a pen-recorder. The results showed the effects of the type of projection. (1) The veridical motions were perceived more continuously and durably in the polar projections than in the parallel one, (2) the opposite relation was found with the nonveridical motions, and (3) the reversals of moving direction were seen more frequently in the parallel projection than in the polar ones.

Adult↗
PubMed1983

Depth perception and subjective contours.

A distinction can be made between subjective lines and edges, and subjective lines of the Kennedy-type which suppress (are epistatic to) illusory depth defined by differences of shade.

Cues↗
PubMed1983

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↗
PubMed1985

Role of visual richness in picture recognition memory.

25 fourth graders, 21 eighth graders, and 21 college students were shown slides of objects presented as color photographs, black-and-white photographs, simple outline drawings, or printed words. After an 8-wk. delay, students were asked to discriminate the study slides from similar distractor slides. No significant differences were found among the types of pictures. Recognition of black-and-white photographs was superior to words.

Adolescent↗