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Results for “Size Perception”

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PubMed1977

Field dependence and the role of visual frameworks in the perception of size.

The extent to which apparent size is relationally determined has been studied by Rock and Ebenholtz and by Wenderoth, who came to widely differing conclusions as to the magnitude of this phenomenon. In both studies, a large range of individual differences was observed. In the present study, an attempt was made to account for variations in the influence of visual contexts on the perception of size by relating them to the cognitive style dimension of field dependence/independence. In two situations, relativelyfield-dependent observers made size judgments which were influenced by a frame surrounding the target figure, while relatively field-independent observers made size judgments which were influenced by a frame surrounding the target figure, while relatively field-independent observers tended to be less influenced by the frame, making their judgments approximate the retinal size of the target. The results suggest that assessment of the magnitude of the relational determination of apparent size must consider the cognitive style of the observers as well as situational variations.

Field Dependence-Independence↗
PubMed1982

A given visual field location has a wide range of perceptive field sizes.

Increment thresholds were measured at the intersections of a modified Hermann Grid at several retinal locations and at photopic, mesopic and scotopic adaptation levels. On a concentric perceptive field explanation of the illusion, these results suggest that a broad distribution of perceptive field sizes exists at each visual field location. The peak of this distribution lies close to the previously reported perceptive field size at that location. As the adaptation level decreases, the distribution shifts upwards in size. At scotopic levels lateral inhibition only occurs for large stimuli. The size distribution can be used to account for the spatial extent of some contrast phenomena.

Adaptation, Ocular↗
PubMed1983

Shifts in perceived size as a function of contrast and temporal modulation.

It has been suggested that perceived size depends upon the distribution of responses among a localized population of different size-tuned mechanisms. If so, then manipulations which alter this distribution should also affect perceived size. We therefore studied the effects of luminance contrast and mode of temporal presentation on size perception. Both manipulations produce significant shifts in perceived size. The results suggest that at least two factors contribute to the size percept. For small and intermediate size patterns, perceived size depends primarily on the local distribution of size-tuned mechanism responses, whereas for wide patterns, the spatial distribution of mechanism responses plays a major role.

Humans↗
PubMed1986

Young children's knowledge about visual perception: projective size and shape.

Although recent research indicates that an increased sensitivity to visual appearances develops around 4 or 5 years of age, evidence from perceptual studies suggests that certain types of appearances, that is, projective size and shape, are not noticed or understood until at least 7. 4 experiments investigated preschool children's knowledge of the projective size--distance and projective shape--orientation relationships. In Experiment 1, 3- and 4-year-olds were asked whether an object should be moved farther or nearer in order to increase or decrease its apparent size. 4-year-olds performed significantly better than chance, but 3-year-olds did not. Experiment 2 showed that 3-year-olds are able to perceive projective size changes, indicating that although they do not fully understand the projective size-distance relationship, the necessary perceptual information is potentially available to them. In Experiment 3, 3- and 4-year-olds were asked to indicate how a circular object should be rotated to make it appear either circular or elliptical. Again, 4-year-olds performed significantly better than chance, but 3-year-olds did not. Again also, the results of Experiment 4 indicate that although 3-year-olds are not aware of the projective shape-orientation relationship, they are capable of attending to changes in projective shape. Thus, the constraints on children's knowledge of the projective size-distance and projective shape-orientation relationships seem to be at least partly cognitive rather than wholly perceptual. These results are interpreted as further evidence for the acquisition of level 2 percept knowledge during early childhood.

Child Development↗
PubMed2005

Relating particles and texture perception.

Practically all foods contain particles. It has been suggested that the presence of particles in food may affect the perception of sensory attributes. In the present study we investigated the effect of size and type (hardness and shape) of particles added to a CMC based vanilla custard dessert. The two types of particles included in the study were silica dioxide and polystyrene spheres, varying in size from 2 to 230 microm. Eighteen trained adults participated in the study. They rated the sensation of 17 sensory flavour and texture attributes on a 100-point visual analogue scale (VAS). The results indicate that the addition of particles increased the sensation of roughness attributes and decreased the ratings of a number of presumably favorable texture attributes (smoothness, creamy, fatty and slippery) significantly. These effects increased with increasing particle size up to 80 microm. Roughness ratings deceased for larger particles sizes. Surprisingly, even particles of 2 microm had significant effects: they increased perceived rough lip-tooth feel, and decreased slippery lip-tooth feel and smoothness of the product. The affected attributes had previously been related to lubricative properties of foods. Particles added to semi-solid foods with relatively low levels of fat seem to counteract the lubricating effects of the fat resulting in increased oral friction. In a separate study on size perception the silica dioxide particles were used. By sampling the stimuli between the tongue and palate, subjects rated the size of the particles on a 100-point scale in comparison to anchor stimuli containing no particles and particles of 250 microm. The perceived particle size significantly increased for larger particles. Furthermore, perceived particle size was negatively correlated with roughness ratings. Thus, subjects who were sensitive and perceived the particles as being relatively large reported the same stimuli to have less rough after-feel. In conclusion, particles added to a product induce large effects on texture sensations, and texture sensation is related to individual size perception.

Adult↗
PubMed1982

The effect of familiar size at familiar distances.

The effect of familial size as a distance cue was tested with familiar objects at familiar distances. Experiment 1 showed that there were no uncontrolled distance cues available and that in their absence the retinal image did not affect depth or size perception. Under these conditions, size and distance judgments were essentially indeterminate and independent of each other. In experiment 2 a paradigm was employed which allowed a direct determination of whether equivalent changes either in size of a familiar object or in its true distance produced equivalent changes in its perceived distance. The results showed that there were no uncontrolled distance cues, and that subjects perceived the familiar object as having its familiar size. Moreover, changing the retinal image of the objects had almost exactly the same effect on their perceived distance as did changing their true distance. Hence, familial size does effectively govern the perception of distance when there are no competing cues.

Cues↗
PubMed2005

Multitrait-multimethod investigation of a novel body image measurement technique.

A multitrait-multimethod (MTMM) matrix was used to evaluate validity evidence for a digital image manipulation (DIM) body image measurement technique in young women. One hundred one young women completed the DIM procedure and the Thompson and Gray (1995) Contour Drawing Rating Scale to measure self-ideal discrepancy and size perception accuracy components of body image. Seven-day test-retest reliability was acceptable (R = .81-.95). Convergent validity for self-ideal discrepancy was higher (r = .74) than the corresponding heterotrait, monomethod coefficients (r = .46, r = .23) and heterotrait-heteromethod coefficients (r = .18, r = .12). However, the convergent validity coefficient for size perception accuracy was r = .12. The pattern of correlations in the MTMM matrix met the criteria of Campbell and Fiske (1959) for validity of these procedures to measure self-ideal discrepancy but not size perception accuracy. The DIM procedure addresses some of the criticisms associated with figure-rating scales, such as unrepresentativeness of the figures, scale coarseness, and restriction of range in responses. DIM, therefore, represents a realistic, valid alternative to figure-rating scales for measuring self-ideal discrepancy.

Adolescent↗
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↗
PubMed1997

Social categorization and perceptual judgment of size: when perception is social.

Social knowledge may affect not only people's thoughts and judgments but also their actual perceptions of physical magnitude. The physical magnitude of a stimulus is perceived in a relative way, comparing the magnitude of the target with surrounding context stimuli. Because similar objects invite comparison processes more easily than dissimilar objects ("similarity breeds comparability"), social knowledge can affect judgments of physical magnitude by determining what is perceived as (dis) similar. In Experiment 1, the authors show that social categorizations that are based on physical cues (e.g., gender) may affect the magnitude of perceptual contrast effects (the Ebbinghaus illusion). More important, in Experiment 2, the influence of social categorizations that have no physical bases is shown to affect the magnitude of perceptual contrast effects. Implications of these findings for theories of social knowledge effects are discussed.

Attention↗
PubMed1985

Organizational size and perceptions in a residential treatment program.

Centralization of a residential mental health treatment program from three small houses to one large facility provided a naturally occurring opportunity to study the effect of organizational size on the perceptions held by clients and staff. Quantitative data were repeatedly collected on their perceptions of themselves, the organization as a whole, and subgroups within the organization during their involvement in both the small and large social contexts. Results of repeated measures analyses of variance provided considerable support for the theoretically derived hypotheses of heightened anxiety, self-impoverishment, more negative views of the psychosocial environment, and greater psychological distance in the large organizational context.

Adult↗
PubMed1993

Theoretical and empirical considerations on the relation between 'body image', body scheme and somatosensation.

The authors first discuss possible interactions between the hitherto neglected neurophysiological and neuropsychological factors and the traditionally accepted cognitive and affective factors in 'body image' formation. They then report on a study of the relation between body size perception (video distortion technique, image marking procedure, kinaesthetic size estimation apparatus) and somatosensation (thermal, pain and vibration thresholds) in young women. Included in the study were questionnaires on eating behaviour and motivation, body attitude or body satisfaction, and depressive mood and thoughts. Neither the somatosensory nor the questionnaire variables explained the difference between 'overestimators' and 'underestimators' of body size. However, these variables did explain the difference between 'good perceivers' and 'poor perceivers' (degree of deviation from actual body size) in the video distortion technique, with a somewhat larger contribution by the somatosensory variables. The latter finding, although clearly preliminary, should stimulate further investigations of the relationship between somatosensory variables and body size perception.

Adult↗