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PubMed1991

Body-size judgments and eye movements associated with looking at body regions in obese and normal weight subjects.

Eye movements of 20 male and 20 female obese and nonobese subjects were monitored during two body-size estimation tasks using a computer-based video technology. Analysis indicated no differences in body-size estimation between subjects using the staircase method. All subjects slightly underestimated body size; however, obese subjects were more sensitive than normal-weight subjects in detecting size distortion when a signal-detection task was employed. Eye-movement data indicated subjects looked longest at the chest, followed by waist, head, thighs, and calves/feet, in both the staircase and the signal-detection methods. Women viewed the waist region longer than men. On a signal-detection task subjects were better at detecting body-size distortion when viewing the body from the back than from front or profile.

Adolescent↗
PubMed1993

Memory for position and dynamic representations.

Memory for the position of an object is biased. When asked to judge whether an object has changed its position with respect to a position shown a few milliseconds before, observers tend to detect the displacement more often when the displacement is not in the expected direction (downward for a falling object). The hypothesis proposed by Freyd (1983, 1987) states that the internal representation of an object is intrinsically dynamic. Therefore, the forces perceived as acting on the object affect the representation. Quantitative predictions of this model were tested in three experiments by measuring memory distortion for the position of an object on an inclined plane. Angle of inclination and retention interval were varied. The results for different inclinations support the physical model. The time course of the memory distortion suggests a new view about the relation between this phenomenon and very short-term memory.

Adult↗
PubMed2000

"Danger is lurking everywhere". the relation between anxiety and threat perception abnormalities in normal children.

The present study examined the relation between anxiety and depression and threat perception abnormalities. Children were exposed to stories describing social situations. Some of the stories were ambiguous (i.e., these stories contained information that could be interpreted as threatening) whereas other stories were non-threatening (i.e., these stories contained no obvious trace of threat). From children's responses to the stories, several threat perception indices were derived. Children's level of anxiety and depression were assessed by means of self-report questionnaires. Results indicated that high levels of anxiety were accompanied by a high frequency of threat perception, high ratings of threat, a high frequency of threatening interpretations, high levels of negative feelings and cognitions, and an early detection of threat. Interestingly, significant associations between anxiety and threat perception abnormalities were not only observed in response to ambiguous stories but also in relation to non-threatening scenarios. Furthermore, depression was also connected with threat perception distortions. Even when controlling for anxiety levels, depression remained significantly related to threat frequency, threat ratings, and threat thresholds.

Adolescent↗
PubMed2002

Thought-shape fusion in anorexia nervosa: an experimental investigation.

Cognitive biases and cognitive distortions have been implicated as important factors in the development and maintenance of many disorders. The concept of thought-shape fusion (TSF) in eating disorders was developed by Shafran, Teachman, Kerry, and Rachman (British Journal of Clinical Psychology 38 (1999) 167) as a variant of thought-action fusion, described by Shafran, Thordarson and Rachman (Journal of Anxiety Disorders 10 (1996) 379). TSF occurs when thinking about eating certain types of food increases a person's estimate of their shape and/or weight, elicits a perception of moral wrongdoing, and/or makes the person feel fat. Shafran et al. (1999) examined both the psychometric and experimental properties of TSF in an undergraduate sample. This paper reports an extension of this work to a clinical group (N=20) of patients with anorexia nervosa. After completing a set of relevant questionnaires, participants were asked to think about a food which they considered extremely fattening. They were then asked to write out the sentence, "I am eating--.", inserting the name of the fattening food in the blank. After being asked to rate their anxiety, guilt, feelings about their weight, morality, etc., participants were given the opportunity to neutralize their statement in any way they chose. The majority of the participants neutralized in ways consistent with the findings of Shafran et al. (1999). The results are discussed in terms of cognitive-behavioural formulations of eating disorders, and of the influence of cognitive biases and cognitive distortions on the processing of information relevant to food, weight and shape in anorexia nervosa.

Adult↗
PubMed1991

Concordance between two measures of dream bizarreness.

To assess the level of concordance between two published measures of dream bizarreness, 100 randomly selected dreams from 93 college students were scored for primary process using the Auld, Goldenberg, and Weiss scale and for dream distortion using Zepelin's scale. This analysis yielded a strong relationship between these measures, indicating adequate concurrent validity for the content analysis of the construct of dream bizarreness.

Adult↗
PubMed1996

Influence of preconception on body image.

The purpose of this study was to establish whether preconceived body images influence quantitative perceptions of body shape. 59 healthy female subjects were subdivided into four groups by amount of activity and body mass index. The body shape of the same person, dressed differently to appear like a model, a student, and a cook, was classified by reference to an adiposity scale based on line drawings. A significant difference was shown between the representations of the types of occupation, with the model viewed consistently as the slimmest and the cook as the fattest. The obese women classified all three occupational groups as slimmer than the nonobese, and the active groups as slimmer than the inactive. The implications of this work relate to a better understanding of body-image distortion, to treatment for eating disorders, and a recognition that people retain preconceived perceptions developed on the basis of experience.

Adult↗
PubMed1978

Face-form frames.

Face-form frames may be appropriate for sunglasses but present many problems if used for prescription lenses especially when the power is strong. Angling the lenses affects the power and location of the cylinder axis and makes it difficult to attain the right P.D. The problems of mounting the lenses in the frame are magnified. Angling also generates unwanted sphere and cylinder in the periphery as well as distortion. These effects can be measured and even calculated ahead of time and cannot be dismissed lightly. The increased field of view is not needed.

Automobile Driving↗
PubMed1996

Psychotic experiences induced in deluded patients using distorted auditory feedback.

The effect of hearing immediate auditory feedback of their own voice distorted in pitch was examined in 21 patients with a diagnosis of schizophrenia. Patients frequently reported that they heard a voice "speaking when I speak" and often attributed this "other" voice to an external agent: "I think it's an evil spirit speaking when I speak." The frequency of making these ''other''attributions was significantly related to degree of pitch distortion (rho = 0.62, P <.01) and to current severity of delusions (rho = 0.62, P <.01). However, the relationship with hallucinations was not significant (rho = 0.40) and there was no relationship with negative features such as psychomotor retardation. We conclude that the "hallucination-like" reports elicited by our paradigm resulted from an interaction between an unusual perceptual experience (distorted auditory feedback) and an abnormal mechanism for belief formation present in deluded patients. This formulation suggests a close relationship between delusions and hallucinations.

Journal Article↗
PubMed1991

Time distortion--a comparison of hypnotic induction and progressive relaxation procedures: a brief communication.

Hypnotic experiences are frequently associated with alteration in temporal perception. 24 male and 24 female Ss were asked to estimate the interval associated with hypnotic, relaxation, or control procedures. Only the group that received the hypnotic condition displayed significant distortions in time estimations. These were primarily underestimations (temporal constriction or "time loss") compared to the more normal distributions of estimations for the other 2 groups of Ss. The hypnotic treatment explained about 35% of the variance in the absolute distortion of time estimates. The present study demonstrates that subjective distortions of time experience during a hypnotic procedure are more than an artifact of deep relaxation or instruction.

Adult↗
PubMed1997

Influence of magnitude of horizontal and vertical deformation on preference for morphed faces.

The purpose of this study was to assess whether the magnitude of the extreme horizontal or vertical deformations of morphed facial features influenced judgments of acceptability or preference of the facial soft tissue profile. Twelve judges responded to 5 changing features of 2 faces with clinically divergent malocclusions under 3 stimulus conditions, i.e., the magnitudes of the distortions were biased in the direction of preferred change, equally distorted in both directions and opposite to preferred change. For each condition, judges responded by pressing a mouse button when the feature became "acceptable" and releasing it when no longer acceptable and by pressing the button when the most pleasing distortion appeared. A small significant shift in the mean acceptability and preference was found for some features. Differences between the faces, however, remained constant, indicating that magnitude of distortion has little effect on acceptability or preference for changes in soft-tissue profiles.

Adolescent↗
PubMed2003

Pulling faces: an investigation of the face-distortion aftereffect.

After adaptation to a face distorted to look unnaturally thin or fat, a normal face appears distorted in the opposite direction (Webster and MacLin 1999 Psychonomic Bulletin & Review 6 647-653). When the adapting face is oriented 45 degrees from vertically upright and the test face 45 degrees in the opposite direction, the axis of perceived distortion changes with the orientation of the face. The magnitude of this aftereffect shows a reduction of approximately 40% from that found when both adapting and test faces are tilted identically. This finding suggests that to a large degree the aftereffect is mediated not by low-level retinotopic (image-based) visual mechanisms but at a higher level of object-based processing. Aftereffects of a similar magnitude are obtained when adapting and test images are both either upright or inverted, or for an upright adapter and an inverted test; but aftereffects are smaller when the adapter is inverted and the test upright. This pattern of results suggests that the face-distortion aftereffect is mediated by object-processing mechanisms including, but not restricted to, configurational face-processing mechanisms.

Adaptation, Psychological↗
PubMedDate not supplied

Visuomotor adaptation in normal aging.

Visuomotor adaptation to a gradual or sudden screen cursor rotation was investigated in healthy young and elderly subjects. Both age groups were equally divided into two subgroups; one subgroup was exposed to 11.25 degrees step increments of visual feedback rotation, every 45 trials (up to a total of 90 degrees), whereas a second subgroup was subjected to 90 degrees rotation from the onset of exposure. Participants performed discrete, horizontal hand movements to virtual targets in four randomized directions. Targets appeared on a computer screen in front of them, and a board prevented vision of the hand at all times. Differential effects of aging on visuomotor adaptation were found, depending on the time course of the visual distortion. In both age groups, early exposure to the sudden visual feedback distortion resulted in typical spiral-like trajectories, which became straighter by late exposure. However, the final adaptation level was reduced in the aged group, although the aftereffects were similar. When subjects were exposed to the gradual distortion, no statistically significant differences in measures of adaptation with advancing age were found. In this case, both age groups appeared to adapt equally. However, after removal of the distortion, elderly subjects showed reduced aftereffects as compared with the young group. These findings suggest differential effects of aging on adaptation to gradual versus sudden visual feedback distortions, and may help to explain the conflicting results obtained in previous visuomotor adaptation studies.

Adaptation, Physiological↗
PubMed2004

Robust and accurate fundamental frequency estimation based on dominant harmonic components.

This paper presents a new method for robust and accurate fundamental frequency (F0) estimation in the presence of background noise and spectral distortion. Degree of dominance and dominance spectrum are defined based on instantaneous frequencies. The degree of dominance allows one to evaluate the magnitude of individual harmonic components of the speech signals relative to background noise while reducing the influence of spectral distortion. The fundamental frequency is more accurately estimated from reliable harmonic components which are easy to select given the dominance spectra. Experiments are performed using white and babble background noise with and without spectral distortion as produced by a SRAEN filter. The results show that the present method is better than previously reported methods in terms of both gross and fine F0 errors.

Adult↗
PubMed1986

Body-image distortion and dissatisfaction in university students.

The present study investigated body-image distortion and body-image dissatisfaction for a sample of 75 male and 75 female university students, in relation to personality variables implicated in the literature, such as sex-role orientation, self-esteem, locus of control, and depression. Women perceived their weight deviation from the norm at over 15% above their actual deviation, whereas men distorted less than 1%. In a multiple regression analysis, none of the personality measures correlated significantly with body-image distortion; however, sex of subject accounted for 25% of its variance. Body dissatisfaction was significantly associated with low self-esteem, externality, depression, and distortion. The relationship between body-image distortion and dissatisfaction, although significant, was surprisingly small. Apparently, these two aspects of body-image disturbance represent quite distinct constructs.

Adolescent↗
PubMed1986

Phoneme boundaries in normal and hearing-impaired ears.

Two experiments are reported which explore variables that may complicate the interpretation of phoneme boundary data from hearing-impaired listeners. Fourteen synthetic consonant-vowel syllables comprising a/ba-da-ga/ continuum were used as stimuli. The first experiment examined the influence of presentation level and ear of presentation in normal-hearing subjects. Only small differences in the phoneme boundaries and labeling functions were observed between ears and across presentation levels. Thus monaural presentation and relatively high signal level do not appear to be complicating factors in research with hearing-impaired listeners, at least for these stimuli. The second experiment described a test procedure for obtaining phoneme boundaries in some hearing-impaired listeners that controlled for between-subject sources of variation unrelated to hearing impairment and delineated the effects of spectral shaping imposed by the hearing impairment on the labeling functions. Labeling data were obtained from unilaterally hearing-impaired listeners under three test conditions: in the normal ear without any signal distortion; in the normal ear listening through a spectrum shaper that was set to match the subject's suprathreshold audiometric configuration; and in the impaired ear. The reduction in the audibility of the distinctive acoustic/phonetic cues seemed to explain all or part of the effects of the hearing impairment on the labeling functions of some subjects. For many other subjects, however, other forms of distortion in addition to reduced audibility seemed to affect their labeling behavior.

Adolescent↗
PubMed1996

Two sources of acoustic distortion products from the human cochlea.

The amplitude and phase of both stimulus-frequency and distortion-product emissions have been measured in healthy human ears. In some ears it is possible to model acoustic distortion products (DPs) generated by low-to-moderate stimulus levels as the vector sum of two components originating from distinct regions of the cochlea, one from the f2 place and the other, with a longer delay, from the distortion product place. The phase lag of the more delayed DP component is slightly greater than that of stimulus frequency emissions (SFEs) measured in the same ears.

Acoustics↗
PubMed2003

Assessment of hearing and hearing disorders in rock/jazz musicians.

The aim of this study was to assess hearing and hearing disorders among rock/jazz musicians. One hundred and thirty-nine (43 women and 96 men) musicians participated. The results are based on pure-tone audiometry and questionnaire responses. According to our definition of hearing loss, tinnitus, hyperacusis, distortion and/or diplacusis as hearing disorders, we found disorders in 74%, of the rock/jazz musicians studied. Hearing loss, tinnitus and hyperacusis were most common, and the latter two were found significantly more frequently than in different reference populations. The women showed bilateral, significantly better hearing thresholds at 3-6 kHz than the men. Hyperacusis, and the combination of both hyperacusis and tinnitus, were found to be significantly more frequent among women than among men. Hearing loss and tinnitus were significantly more common among men than among women. It is important to evaluate all kinds of hearing problems (other than hearing loss) in musicians, since they represent an occupational group especially dependent on optimal, functional hearing. On the basis of our results, we suggest that hearing problems such as tinnitus, hyperacusis, distortion and/or diplacusis should, in addition to hearing loss, be defined as hearing disorders.

Acoustic Stimulation↗