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At least 865 records · Page 48Linked to original sources
PubMed1980

Is the Vando Scale a valid measure of perceptual reactance?

A test of the validity of the Vando Scale of perceptual reactance was made by correlating Vando Scale scores with objective pain tolerance, subjective discomfort, distortion in estimation of duration of discomfort, and assertiveness. 84 college women participated in an ice water-tolerance task. Higher scores associated with less subjective discomfort, greater time distortion and reduced submissiveness. Objective tolerance was not correlated with scale scores. It was concluded that the Vando Scale has relatively low construct validity and may be very sensitive to the demand characteristics of the research situation.

Adolescent↗
PubMed1981

Binocular pattern stabilization by afterimage technique: reliability of children's time-dependent judgments of chromatic features.

To investigate visual afterimage technique as a means of producing retinally stabilized pattern, children's judgments of time-dependent shifts in chromatic appearance of random-dot configurations were twice examined within a 3-wk. interval. 13 subjects, aged 7 to 12 yr., were very consistent (r = .93) in their test-retest response times. This supports the belief that after image procedures can be developed as a reliable means of studying developmental aspects of stabilized pattern perception.

Child↗
PubMed1989

Fixed set in the perception of size in relation to lightness.

When control subjects compared the sizes of two circles of different lightness, the lightness-size illusion was observed, i.e., the darker circle was perceived to be smaller. However, after experimental subjects were shown a large, light circle and a smaller, darker circle repeatedly, the subjective size of the dark circle increased. It decreased after repeated exposures to a small, light circle and a large, dark one. These changes in perception were assumed to be contrast effects produced by an experimentally fixed set and were similar to changes observed when the same method was previously applied by this author to the size-weight illusion. Despite differences in modality and dimension of perception, every application of the fixed-set method resulted in analogous patterns. When the situation of the set-fixing experiment and that of the critical experiment were similar to each other, the fixed set was activated more and greater contrast effects were produced.

Adaptation, Physiological↗
PubMed1991

Effects of tryptophan depletion on Poggendorff illusion, corner Poggendorff illusion, and attention.

The effects of a tryptophan-free amino acid mixture on Poggendorff illusion, corner Poggendorff illusion, and attention were investigated with 12 male subjects who ingested either a balanced amino acid mixture or a tryptophan-free mixture, the latter known to cause a marked depletion of brain tryptophan and serotonin. No significant difference between the two mixtures on the perceptual illusions was found.

Adult↗
PubMed1993

An investigation of the color-affect hypothesis in Exner's comprehensive system.

The color-affect hypothesis states that color responses on the Rorschach provide information regarding an individual's emotional life. The present study explored the several color-affect interpretive hypotheses in Exner's popular Comprehensive System by using a theory-relevant measure of affective modulation inferred from 32 undergraduates' behavior in an emotionally salient dyadic interaction. Subjects designated as high affective modulators (n = 6) and low affective modulators (n = 10) according to Exner's theory were not significantly different on a discrepancy score measure of affective modulation. It is suggested that Rorschach color scores may be insensitive to the more subtle forms of affective modulation present in less emotionally disordered individuals. Further research is suggested and caution is advised for clinicians assessing affective modulation styles in less severely disturbed patients based on traditional color-affect interpretive theory.

Adolescent↗
PubMed1994

Collinearity judgment as a function of induction angle.

The misalignment which is seen in the Poggendorff illusion can be studied with better control by using a configuration which has only two line segments. Two experiments were conducted in which subjects judged collinearity of a test segment, this judgment being subjected to a biasing influence from a second (induction) segment. Exp. 1 held the test segment at one of three orientations relative to the observer (30 degrees, 45 degrees, and 60 degrees) and systematically varied the orientation of the induction segment in 15 degrees increments through the range of possible positions. The orientation of the page relative to the observer was varied as well. Exp. 2 varied the test segment through a greater range of angles and sampled more levels of induction segment orientation. Analysis indicated that projection errors follow orderly rules similar in kind to but different in magnitude from those observed for the Tilt Illusion, most notably, (a) misprojection is greatest when the orientation of the interfering line is similar to that of the line segment being projected and (b) the strength of this influence decreases as the relative angle becomes orthogonal. Also, the orientation of the segment being projected relative to the observer serves to modulate the strength of the basic induction effect. These perceptual interactions are discussed in relation to neural models for orientation selectivity.

Adult↗
PubMed1995

Information on location in visual persistence: effects of temporal delay and duration of exposure on report of dot location.

This study of location information involved in information persistence used the partial-report paradigm. Six subjects were asked on 144 trials to recall positions of dots presented in a display. The subjects were instructed to maintain only information on location (but not on identity information) of the presented dots until a partial-report cue was introduced. The effects of display duration (50, 200, and 350 msec.) and cue delay (interval between the display offset and the onset of the partial-report cue: 50, 250, and 500 msec.) were examined. Analysis showed effect of cue delay on partial-report performance decreased as the duration of display increased so performance was negatively affected by the cue delay only when the subject was exposed to the presented dots for 50 msec. Contrarily, partial-report performance did not decline much for a 200-msec. duration and showed little variation in a 350-msec. duration, even though the cue delay increased. Consequently, the decay of the information on location mediating partial-report performance about dots varies with duration of display.

Adult↗
PubMed1995

Visual scotoma and visual afterimages: some evidence that the perceived visual afterimage may not be a purely retinal phenomenon: a single case study.

Observations of the differential appearance and behaviour of a deliberately induced visual scotoma and a patterned visual afterimage are reported. Although a retinal scotoma behaves like a visual afterimage in some ways, there are sufficient differences to suggest that the perceived visual afterimage may not be just the simple consequence of prolonged retinal stimulation.

Afterimage↗
PubMed1975

Figural after-effects of Köhler and Wallach reinterpreted.

A theory of perception is extended to figural after-effects which has been used already to rationalize the illusory phenomena of static visual illusions, fluctuating figures and visual illusions of motion. The theory proposes three laws of perception. All of the extensive observations of Köhler and Wallach are rationalized under these laws embodying the present theoretical orientation. The theory maintains that the experience of perception occurs only during the interaction of forces introduced by a pattern with the forces characteristic of the brain in order to produce the greatest equilibrium within the two systems of forces. A pattern is not reproduced in the brain. A pattern produces a system of forces. Neither the image of the pattern nor its forces impinging on the nervous system produce the perceptual experience. It is during the process of interaction of the forces of the pattern with the forces of the brain and only during this interaction that perception is experience. This interaction is a constant process to integrate the incompatibilities existing between the two system of forces.

Brain↗
PubMed1987

Palinopsia and visual allesthesia.

Two cases of palinopsia are reported. The first patient had palinopsia and visual allesthesia secondary to an occipital calcified cysticercus. Symptoms were more prominent during treatment for his parasitic infection. The second case was a patient with long standing vascular headaches associated for many years with episodes of visual persistence; he had a right occipital lobe infarct; he reported deformation of images, illusion of movement and macropsia in his left homonymous hemianoptic visual field. Different hypotheses for explaining palinopsia have been proposed. An analysis of our cases does not prove or disprove any of the current hypotheses. However, the current hypotheses do not necessarily contradict each other. Implications of the two cases reported are analyzed.

Adult↗