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Results for “Perceptual Distortion”

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PubMed1983

Effects of suggestibility and hypnosis on accurate and distorted retrieval from memory.

Research investigated the hypothesis inferred from the theorizing of Loftus that suggestibility is related to the tendency to incorporate incorrect information into memory when this information has been subtly introduced after the to-be-remembered events have occurred. Specifically, it was predicted that if level of suggestibility is theoretically relevant to subjects' acceptance of misleading information, then more subjects who are highly hypnotically suggestible than those with a low level of hypnotic suggestibility will incorporate the incorrect information into memory. Hypnotic as compared with waking instruction should enhance this distortion effect by providing a context of testing in which subjects are readily prone to respond positively to suggestions. Eight independent groups of 12 subjects were tested. Separate groups of subjects of high and low suggestibility were presented with misleading or neutral information about a wallet-snatching incident and tested for memory under either waking or hypnotic instruction. Analysis of subjects' memory distortions indicated that suggestibility plays a somewhat different role than has been argued previously. The magnitude of distortion that was observed varied according to the stimulus features that were studied, but hypnotic suggestibility was not associated with the distortion effect. Despite the fact that hypnosis did not enhance recall in any way, subjects were frequently confident that distorted memories recovered under hypnosis were accurate.

Female↗
PubMed1996

Distorted self-perceptions: divergent self-reports as statistical outliers in the multimethod assessment of children's social-emotional adjustment.

The influence of statistical outliers among older children's self-reports was investigated in the context of a multitrait-multimethod validation of the Weinberger Adjustment Inventory (Weinberger, 1991). Self, teacher, and peer ratings in 6th-grade classrooms (N = 155) provided evidence of the convergent and discriminant validity of distress (i.e., anxiety, depression, low self-esteem, and low well-being) and self-restraint (i.e., impulse control, suppression of aggression, consideration of others, and responsibility) as superordinate dimensions of adjustment. However, a few children were statistical outliers whose self-reports starkly contradicted others' perceptions. These nonrepresentative cases notably affected the validity coefficients for the entire sample and seemed to identify children with potentially clinically significant distortions in their self-perceptions.

Affective Symptoms↗
PubMed1979

An exploration of perception of body boundary, personal space, and body size in elderly persons.

A study of 108 elderly persons using the Body Distortion Questionnaire and the personal space simulation technique test did not support hypotheses that elderly persons with a large personal space will have a larger distortion of body boundary, a larger perception of large body size, a smaller perception of small body size, a larger distortion of body size, and a larger body distortion than elderly persons with a small personal space. The analyses with one-tail t tests showed elderly persons with a small personal space have a larger perception of large body size and a larger distortion of body size than elderly persons with a large personal space. When the extremes of personal space were used the results were the same. Males have a larger personal space and greater distortion of skin perceptions than females.

Aged↗
PubMed1982

Auditory distortion.

The auditory system responds to pulsatile energy flow from the environment. Compression and rarefaction of gaseous molecular mass is transduced into electromechanical forms, in order to produce an effect at the cortical level. For energy input to have consistent meaning, transduction must preserve information coded within the pattern of energy flow. Distortion, or alteration of the original form, occurs in many ways throughout the chain of generation/transmission/reception/interpretation. Parameters of energy flow are discussed, and distortion of each parameter is presented in a context which permits the development of a distortion-based analysis of common clinical problems in otolaryngology.

Acoustics↗
PubMed2003

Misleading postevent information and flashbulb memories.

The aim of this study was to create the conditions of a real discussion concerning the past in an experimental setting and examine their effect on subsequent recollections of important autobiographical events. A total of 55 adults described two episodes twice. The first episode was a typical news reception event and the second one represented a private event of particular personal significance. In between the two recall sessions, participants from the experimental group viewed two films. The first was a short televised account of the two events; the second was a corresponding videotaped description of the personal experiences of a middle-aged man. In addition, participants were asked to imagine what he had been talking about. Most of the participants from the experimental group incorporated elements of the man's description into their own subsequent accounts. In spite of this, they rated the accuracy of their post-test memories as very high. The implications for understanding distortion mechanisms in flashbulb memories are discussed.

Adult↗
PubMed1996

Visual search performance with complete and incomplete visual lobe areas.

A simulation study of the effects of visual lobe shape and search strategy on search performance is reported. Using a homogeneous pattern search task that did not dictate eye fixation movements (as in reading), three basic categories of strategy and two lobe shapes were tested. Random strategies with controlled overlap of lobe areas, representing various degrees of memory, were found to produce better performance (faster search times with equal or better detection rates) than either a completely random strategy or systematic strategies with various degrees of controlled visual lobe area overlap. The controlled overlap random strategies were far better able to compensate for non-optimum interfixation distances and distortion of visual lobe shape than systematic strategies.

Attention↗
PubMed1988

Reliability and accuracy of self-report of a new body-image measure.

The present study investigated the reliability and accuracy of the Body-image Distortion Questionnaire, a paper-and-pencil self-report measure. Forty male and 41 female college students completed the questionnaire on each of two occasions 21 days apart. During the second session, height, weight, and body build were measured. Results indicated that the questionnaire is a reliable and accurate measure of body-image distortion.

Adolescent↗
PubMed2002

A three-dimensional nonlinear active cochlear model analyzed by the WKB-numeric method.

A physiologically based nonlinear active cochlear model is presented. The model includes the three-dimensional viscous fluid effects, an orthotropic cochlear partition with dimensional and material property variation along its length, and a nonlinear active feed-forward mechanism of the organ of Corti. A hybrid asymptotic and numerical method combined with Fourier series expansions is used to provide a fast and efficient iterative procedure for modeling and simulation of the nonlinear responses in the active cochlea. The simulation results for the chinchilla cochlea compare very well with experimental measurements, capturing several nonlinear features observed in basilar membrane responses. These include compression of response with stimulus level, two-tone suppressions, and generation of harmonic distortion and distortion products.

Animals↗
PubMed1981

The many illusions of the Müller-Lyer: comparisons of the wings-in and wings-out illusions and manipulations of standard and dot forms.

The assumed role of peripheral distortion mechanisms in both wings-in and wings-out Müller-Lyer illusions was investigated by requiring subjects to reproduce the central extent of standard Müller-Lyer figures and dot variations. Illusory magnitude of the line and dot variations was also examined with increasing wing length and wing angle. A reduction in the overestimation for the wings-out illusion occurred with the removal of intersecting lines; the dot variations evidenced a significant overestimation effect. In contrast, no reliable decrease in underestimation was found with the removal of intersecting lines in the wings-in illusion, and both standard and dot variations were significantly underestimated. These results support a conclusion that the wings-in and wings-out Müller-Lyer illusions are two distinct illusions, and may be differentially determined at the loci of distortion within the visual system. Parallel changes in illusory magnitude were noted with configural manipulations of standard and dot wings-out illusions. However, standard and dot forms of the wings-in illusion were not equivalently affected by equivalent configural manipulations, which suggests that they are different illusions. Thus, the use of the wings-in dot variation to separate empirically peripheral from non-peripheral distortion mechanisms may be ill-advised.

Discrimination Learning↗
PubMed1983

Brightness induction and the Café Wall illusion.

The Café Wall illusion is a distortion illusion in which the parallel lines of a chessboard-like figure consisting solely of parallel and perpendicular line elements appear to converge in alternating rows, creating a wedge distortion similar to that of the well-known Zöllner illusion. Gregory and Heard have formulated an explanation for the Café Wall illusion which relies upon the operation of a 'border-locking mechanism' in the visual system. The results of the present experiment suggest an alternative explanation in which the operation of brightness induction within the mortar regions of the Café Wall produces a series of 'twisted cords' or slanted line elements akin to those of the Fraser or Zöllner figures. A series of such 'twisted cords' is shown to be capable of itself to produce an illusory convergence like that of the Café Wall. Manipulations of the luminance of discrete regions in the mortar lines of the Café Wall, designed either to augment or cancel the effects of brightness induction in the production of these slanted line elements, are successful in enhancing or reducing, respectively, the wedge distortion of this visual illusion.

Adult↗
PubMed1973

Monocular spatial distortions induced by marked accommodation.

Contraction of the ciliary muscle during marked accommodation causes the leading edge of the retina to advance as much as 0.5 centimeter. Near the posterior pole of the eye, the upward and downward extensional strains on the retina should be reasonably balanced. In the horizontal meridian an asymmetry is introduced because of the nasal location of the optic nerve head. Observers were asked to bisect the space between two parallel lines while fixating a movable line lying near the midpoint of the two lines. The test was conducted with the target far from and near the subject, in the horizontal and vertical meridians, and was repeated with accommodation paralyzed by a cycloplegic agent. Marked accommodation induced significant spatial distortions in the horizontal meridian. The effect is largely retinal.

Accommodation, Ocular↗
PubMed1997

A re-examination of body image distortion: evidence against a sensory explanation.

OBJECTIVE: This study was designed to assess female bulimic and control subjects' sensitivity to changes in their own and a model's body. METHOD: A video distortion camera was employed. Each subject (20 bulimics, 20 controls) compared a constant image of her undistorted body with 180 separate images of her body at various distortion levels (-16%, -12%, -8%, -4%, 0%, 4%, 8%, 12%, 16%) using the method of constant stimuli. The procedure was repeated using prerecorded images of a model. RESULTS: Bulimics and controls were equally adept at detecting increases and decreases in the model's body and at detecting decreases in their own bodies. Bulimics, however, detected increases in their own bodies less well than controls. DISCUSSION: The data provide evidence against a purely sensory/perceptual explanation of body image distortion.

Adult↗
PubMed2005

Cognitive distortions about sex and sexual offending: a comparison of sex offending girls, delinquent girls, and girls from the community.

Cognitive distortions about sexual offending were examined in 11 girls who committed sexual offenses, 12 girls who committed non-sexual criminal offenses, and 21 girls with no history of sexual of non-sexual offending. Participants responded to 12 vignettes that described sexual contact between an adolescent girl and a younger boy. The vignettes varied with respect to the sexual contact portrayed and the victim's response. Girls who had sexually offended were more likely to endorse statements reflecting the belief that the offender in a sexually aggressive vignette was not responsible for initiating the sexual contact. In addition, when the victim's response to the sexual contact was clearly negative, and the degree of contact was more serious, girls who had sexually offended demonstrated more distorted beliefs about the victim than the other two groups. Similarities and differences between the current findings and studies of distorted thinking in male sexual offenders are discussed.

Adolescent↗