Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Form Perception”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1977

Body locus and form perception.

Forms were drawn on the palms, forearms, or biceps of 42 subjects, with vision excluded. Subjects were then required to make a visual match to the drawn forms. It was expected that the accuracy of form recognition would be a direct function of the sensitivity of the receptor surface. Thus the palm was expected to yield more accurate form recognition than the forearm or bicep. Form recognition was significantly worse on the forearm than on other skin locations. The adequacy of a skin surface as an information transducer does not appear to be a simple function of cutaneous sensitivity since there was no significant difference in the accuracy of form recognition between the palm and bicep.

Arm↗
PubMed1977

Physiognomic form perception: a comparison of normal and schizophrenic subjects.

The following reports the findings of a study that tested the hypothesis that schizophrenics--contrary to what has been suggested in the literature--are deficient, rather than superior, in perception of physiognomic properties. The Physiognomic Form Perception Test (RFPT), developed for the purpose and found reliable, was administered to 19 normal and 19 schizophrenic Sc. Results were in support of the hypothesis: normal Ss scored significantly higher than schizophrenics (t = 3.01, p less than .01). In addition, a qualitative analysis of verbalizations showed, as predicted, that schizophrenics gave significantly fewer "physiognomic-expressive" responses and significantly more of those rated "associations-rationalizations," as well as more "personalized and self-referent" responses.

Adolescent↗
PubMed1992

Achromatic form perception is based on luminance, not brightness.

Two figures were examined, one a subjective disk and the other a cup whose shape was revealed by shadows. The figures were presented in a single color on a background of a different color, and the observers adjusted the radiance of one color until, in the first case, the vividness of the subjective contour reached a minimum (minimum subjective contour) or, in the second case, the impression of depth that is due to shadows disappeared (shadow disappearance). The results for these two tasks followed the data for minimum flicker matches (made with the same stimuli) much more closely than those for direct brightness matching. We therefore claim that achromatic form perception in general and subjective contour and shadow perception in particular are based on the intensity dimension measured by flicker photometry, not on that measured by brightness matching. Finally, in agreement with these findings, bleaching of short-wavelength sensitive cones did not affect settings for subjective contours, shadows, or flicker photometry but did affect brightness matching.

Color Perception↗
PubMed1978

An automated apparatus for the study of central variables in tactile form perception.

An apparatus which employs standard behavioral programming equipment is described. It enables the experimenter to program in advance with variables as auditory and visual instructional cues, delay intervals, and response mode, and to monitor response latency automatically. The apparatus is easily constructed, easily operated, and markedly increases the control of variables in tactile form perception experiments.

Computers↗
PubMed1977

Physiognomic form perception: mature or immature?

The hypothesis that physiognomic perception, rather than being an immature mode, characterizing, in particular, children, primitives, and schizophrenics, is, instead, a basic mode, was tested. Children of both Eastern and Western parentage in Grades 3, 5, 6, and 11 were given the Physiognomic Form Perception Test, an instrument specially developed for testing physiognimic perception. No decrease with age in such perception was noted. Although there was a tendency for scores to increase with age for girls of Eastern origin, in general the scores do not increase with age. Physiognomic perception is apparently not acquired. Sex differences were not significant.

Adolescent↗
PubMed1977

Form perception in stumptail macaques following posterior parietal and lateral frontal lesions.

Monkeys with bilateral posterior parietal and lateral frontal ablations were compared with normal animals on a series of four tests for their ability to relate elements of a visual pattern on the basis of the Gestalt principle of proximity. The operated animals showed no clear impairment on these tests of perceptual grouping. The three groups of monkeys were then trained to discriminate two faces and tested for generalisation to different views of the same faces. The pariental-operated monkeys showed less generalisation than the other animals to lateral mirror-images of the training stimuli, but more generalisation to inverted mirror-images. It is concluded that any deficit in "gestalt" perception following such lesions must be at a relatively high level.

Animals↗
PubMed1975

Visual form perception in deficient and normal readers as a function of age and orthographic-linguistic familiarity.

The present investigation directly assessed the hypothesis that poor readers sustain no basic disorder in visual-spatial functioning. In order to extend pervious results to younger children, the performance of poor and normal readers from both the second and sixth grades was compared. Adopting the format of an earlier investigation, a visual recall task was employed as the dependent variable, and it was predicted that poor readers would perform as well as normals with stimuli taken from Hebrew, an unfamiliar orthography. Accordingly, non-Hebrew poor and normal readers were compared with normal readers learning Hebrew on the production of varying length Hebrew words. As anticipated, children in the non Hebrew reader groups performed comparably on this task, but the performance of these subjects was inferior to that of children in the Hebrew groups. The data support the contention that visual perceptual disorder is an unlikely source of reading disability.

Age Factors↗
PubMed1975

Color and form perception on the Rorschach as a function of eye color.

Recent research had demonstrated that dark-eyed individuals are more reactive than light-eyed people. The present paper investigated one area of reactivity, ease of emotional arousal. The hypothesis that dark-eyed male subjects (n equals 40) would show greater ease of arousal than light-eyed male subjects (n equals 40) was tested using color and form responses on the Rorschach as dependent measures. The predicted interaction was significant; light-eyed subjects gave relatively more form responses, but dark-eyed subjects gave relatively more color responses. Implications for future research and application were discussed.

Arousal↗
PubMed1977

Subjective and objective symmetry in perception of form.

A new quantitative measure of the physical symmetry of 2-dimensional shapes is proposed which relates it to the proportion of translational and rotational (TR) overlap between a figure and its mirror image. Category ratings of the apparent vertical symmetry of distorted diamond figures correlate highly with this measure while it is also an important contributor in the prediction of the apparent symmetry and geometricity of random polygons.

Choice Behavior↗
PubMed1979

Dichhaptic perception of forms by normal adults.

Dichhaptic perception of nonsense forms was examined in familial righthanders. In Exp. 1, 15 males and 15 females performed similarly, obtaining a non-significant right-hand superiority with a 5-sec. memory interval between presentation of stimuli and their choice-recognition response. Individual differences in Block Design scaled scores but not State or Trait anxiety were related to hand performance for both sexes. One strategy on a questionnaire was related to performance of males. Exp. 2 was a replication with the memory interval removed. A significant right-hand superiority was obtained and different strategies were related to performance of males and females.

Adolescent↗
PubMed1979

Influence of movement activities on shape recognition and retention.

Three groups of 4-yr.-old children were asked to complete a form perception assessment instrument prior to, 1 hr. after, and 1 wk. following a treatment. Group 1 participated in a movement-based form perception program, while Group 2 was instructed using a traditional classroom method. A third group which acted as control participated in unrelated movement activities. A repeated-measures analysis of variance gave a main effect of tests and an interaction of groups X tests. Group 2 displayed significantly higher performance on the posttest than Group 1; however, after 7 wk. the performance of Group 2 had decreased to a level below that of Groups 1 and 3, which remained stable.

Child, Preschool↗
PubMed1978

The perception of solid form in early infancy.

Day and McKenzie determined the rate of habituation of fixation of young infants to repeated visual presentations of a cube. They found the habituation rate to be the same when the stimulus orientation changed between presentations as when it was fixed, and they interpreted this as evidence of shape constancy. However, a failure to discriminate between cubes in different orientations is only evidence of shape constancy if the infant can at the same time discriminate the cube from other cubelike forms. The experiment described here contrasted the rate of habituation of fixation of 12-week-old infants to a homogenous stimulus series (a cube presented in different orientations) with the rates of habituation to various heterogeneous series, in each of which a cube was alternated with some other solid. It was found that, while the infant could distinguish a cube from a photograph of a cube and a concave solid (an L-form), there was no evidence of discrimination between the cube and either a wedge or a truncated pyramid. The results imply limits to the young infants capacity to resolve solid form.

Discrimination Learning↗
PubMed1976

[The significance of the CNS for the physiology of hearing (author's transl)].

Some general aspects of auditory perception (funnelling, contrast, pattern recognition, form perception, methodological limitations) are discussed in the first part of this presentation. The modern concept of the hydrodynamics of the inner ear, including electronic modelling of the function of the basilar membrane is their dealth with. For the encoding and decoding processes of the auditory system the different grades of intensity function at the different neuronal levels is compared with that of the envelope of the basilar membranes deflection. The influence of the efferent system is discussed. In a third section of the paper some new results from our department are reported concerning the single unit activity at geniculate level recorded from the awake cat by means of a telemetric system. Neurophysiological correlates to vowel- and consonant detectors and their relations to be the phonem recognition of speech could be demonstrated. Finally, the most recent state of objective audiometry is discussed (DC-potentials, simultaneous records of electrocochleogram and cortically evoked activity, relations to EEG's power spectrum, and brains changes in vigilance) with a view of future approaches to ERA.

Animals↗
PubMed1977

Global detection of symmetry.

Two experimental approaches examined observers' ability to characterize shape symmetry based upon the information obtained within a single fixation. Exp. I tested observers' ability to discriminate among three levels of symmetry on the basis of a 25-msec. presentation. Results indicated that identification accuracy was higher for symmetrical and asymmetrical shapes than for mixed shapes, which contained both symmetrical and asymmetrical components. Exp. II tested observers' ability to detect a given level of symmetry by means of a signal-detection approach. Symmetrical shapes were detected better than asymmetrical shapes. Detectability of mixed shapes was lower than that for both symmetrical and asymmetrical shapes. The results of Exps. I and II demonstrate that observers can characterize shape symmetry on the basis of information available within a single fixation. The data are supportive of the hypothesis that a global response to the over-all configuration of the shape serves to facilitate form perception.

Discrimination, Psychological↗
PubMed1975

Newborn infant attention to form of contour.

Human neonates selectively fixated patterns with curved rather than straight contours when the outermost contours differed in this form variable and when quantitative variables were controlled. The presence from birth of a discrimination ability basic to later form perception was evidenced.

Attention↗
PubMed1979

Visual acuity functions and pattern discrimination in the destriate cat.

The study provides evidence that the cat is capable of processing visual information of some detail after removal of area 17 and most of area 18. This postoperative discrimination of complex spatial stimuli is not based on the use of such cues as luminance differences or local flux cues. From the deficits which follow extensive lesions of areas 17-18, it appears as though these cortices participate in the detection of fine details. We found a modest increase in the threshold of grating acuity, moderate loss in orientation acuity and extensive deficit in a task requiring topographic alignment of contours (vernier offset). Further evidence for the substantial preservation of spatial vision in the destriate cat is provided by experiments which show that perceptual grouping of rectilinear arrays of figural elements (dots or line segments) into obliquely oriented rows is largely unaffected by the lesion, even when the grouping is initiated by near-threshold proximity cues. Since grouping effects are felt to be involved in the organization of the visual field into the figure-ground dichotomy, these results indicate that the neural mechanisms subserving the initial stage of form perception lie outside of areas 17 and 18. Consistent with the increased acuity thresholds of destriate cats, these animals have deficits in several pattern discriminations that require fine-grained spatial analysis The results suggest that areas 17-18 serve as a high-spatial frequency analyzer, but are not essential to pattern and form recognition.

Animals↗