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Results for “Perceptual Distortion”

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At least 829 records · Page 46Linked to original sources
PubMed1981

Visual motion cues in prismatic adaptation: evidence of two separate and additive processes.

The present study was based on the assumption that there are two visual channels which provide separate contributions to visuo-motor recalibration following prismatic displacement of the visual field. The functional properties of the two channels were assumed to conform to predictions from the two motion-analyzing systems models of visual motion perception. The results of the present study confirmed the predictions of the model. Whatever the type of illumination (continuous or stroboscopic) central vision utilizes only cues provided by visual exposure of the arm pointing to a stationary target. Peripheral vision utilizes only cues from visual exposure of the arm freely moving against the homogeneous background but this can be prevented by stroboscopic illumination. In peripheral vision, movement cues provided by exposure of a passively moved arm are not processed. In contrast, the processing of visual cues in central vision is unaffected by whether the movements are active or passive, provided that a stationary target is present. The effects of the two channels may be additive or competitive depending on the conditions. Experimental and theoretical implications are discussed.

Cues↗
PubMed1990

Object superiority: a comparison of complete and part probes.

Previous research on object superiority effects has shown that certain contexts enhance the recognition of an object part. However, those contexts would not normally be called objects. The present study discusses object superiority within more general issues of object recognition. By using what we call 'complete' probes, superiority effects were extended to exposure durations much longer than those used in previous research. Experiments 1 and 2 found that complete probes gave stable superiorities at 250 msec and even 2-sec stimulus exposures. These object superiority effects were found for both objects (faces and chairs) investigated. Experiment 3 showed that object superiorities established with complete probes were not necessarily greater than those for part probes. The experiments stress the role of spatial arrangement of object parts in accessing stored information. It is argued that a successful match of a structural description to a representation in long-term memory influences stimulus processing by allowing the formation of higher level features.

Adult↗
PubMed1992

An experimental study of the effect of mood on body size perception.

The study presented is an experimental investigation of the effect of mood on body size perception. Female students estimated their body size and indicated their degree of dissatisfaction with their body size before and after the induction of a negative or positive mood state. Compared with women who received the positive induced mood, the induction of low mood led to greater disturbances in body size perception in the form of a tendency to overestimate their body size more and significantly greater dissatisfaction with their body size. Furthermore, among the women who received the negative mood condition, compared with those with little or no concern with their body shape, for those with such concerns the induction of low mood led to greater disturbances in body size perception in the form of overestimating their body size significantly more and a tendency towards greater dissatisfaction with their body size. These findings suggest that depressed mood may play an important role in determining the extent of disturbance in body size perception in clinical populations.

Adult↗
PubMedDate not supplied

Correcting faulty appraisals of obsessional thoughts.

Cognitive techniques are becoming more widely established in the treatment of obsessive-compulsive disorder (OCD). This paper extends previous work by van Oppen and Arntz (1994, Behaviour Research and Therapy, 33, 79-87) on overestimation of threat and excessive responsibility by discussing other types of appraisals that may be involved in OCD, particularly when overt compulsions are absent. Examples are given of types of intervention that may be useful to correct faulty appraisals concerning the overestimation of the importance of thoughts such as thought-action fusion, excessive responsibility, perfectionistic concerns such as the need for absolute certainty, and expectations about anxiety and its consequences.

Arousal↗
PubMed1976

Striate cortex ablation and spatial vision.

Normal and visually decorticate rats were trained to orient to a luminous target. All subjects reached the same criterion of orientation accuracy, but operated subjects required more training and exhibited greater response latency throughout testing. To determine if visually decorticate subjects located the target according to the retinal position of its image, or only by sampling luminous flux density at different points in space, field-displacing wedge prisms were placed before the subjects' eyes to laterally displace the retinal locus of the target image without affecting luminous flux information. Prism imposition shifted orientation toward the virtual target position for all subjects. In a second study, translucent plastic was place over the subjects' eyes to disrupt the retinal topography and location of the target image while again leaving luminoux flux unaffected as a potential cue. All animals showed a dramatic and complete disruption of target localization once the diffusing material was applied. The data were considered as support for the hypothesis that 'spatial' vision survives visual decortication.

Animals↗
PubMed1991

Newborns' preferential tracking of face-like stimuli and its subsequent decline.

Goren, Sarty, and Wu (1975) claimed that newborn infants will follow a slowly moving schematic face stimulus with their head and eyes further than they will follow scrambled faces or blank stimuli. Despite the far-reaching theoretical importance of this finding, it has remained controversial and been largely ignored. In Experiment 1 we replicate the basic findings of the study. In Experiment 2 we attempt a second replication in a different maternity hospital, and extend the original findings with evidence suggesting that both the particular configuration of features, and some aspects of the features themselves, are important for preferential tracking in the first hour of life. In Experiment 3 we use a different technique to trace the preferential tracking of faces over the first five months of life. The preferential tracking of faces declines during the second month. The possible causes and consequences of this observation are discussed.

Attention↗
PubMedDate not supplied

A direct comparison of the defense mechanisms of nondepressed people and depressed psychiatric inpatients.

This report presents a direct comparison of defensive styles (as measured by the Defense Mechanisms Inventory [DMI]) in a sample of depressed psychiatric inpatients and samples of nondepressed male and female normative groups. Consistent with the "depressive realism" literature, nondepressed men and women were more likely than their depressed counterparts to bias their perceptions in an overly cheerful, optimistic direction. Counternormative sex differences were also found. Depressed men were more likely to use internalizing defenses and depressed women were more likely to use externalizing defenses than their respective nondepressed comparison groups. Overall, as has been speculated, there was a relationship within depressed subjects between depression severity and the amount of negatively biased self-perception.

Adult↗
PubMed1991

Toward implementation of a flexible hearing aid measurement system.

An evaluation of a computerized hearing aid measurement system was performed with input and output compression hearing aids stimulated using high-quality audio equipment. The results of the computer measurements were compared to those from a manual technique using conventional laboratory instrumentation. The results from the computerized and manual methods matched very closely. However, the computer system was found to be considerably more flexible than conventional instrumentation and was much easier to use.

Equipment Design↗