Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SIZE 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 973 records · Page 54Linked to original sources
PubMed1982

The axis feature: illusionary effects on children's judgments of length.

The effect of the position of lines on length estimation was investigated. 40 5-yr.-olds were asked to compare the two arms of an L-shaped figure presented inside circular frames of different diameters. For each figure one of the arms was on the axis, that is, the diameter, and the other arm was perpendicular to that axis. In making perceptual judgments about the relative length of two lines the children tended to describe the on-axis line as longer than the off-axis line. This illusion which, presumably, reflects a perceptual force induced by the characteristics of the structural pattern, supports the context model of visual anomalies.

Child↗
PubMed1984

Effect of luminance on perceptual alternation of ambiguous patterns.

The perceptual alternation of the Necker cube, in its stationary phase, is studied as a function of the stimulus luminance down to the extreme condition in which the cones are completely inactivated so that the pattern of neural excitation reaching the primary visual cortex is very different from the normal one. No evident effect of luminance was found under passive observation either on the reversal rate or on the features of data distributions. Moreover, the complementary situation in which perception is based only on the cones does not affect the phenomenon either. These results permit the assumption that the perceptual alternation in its stationary phase, is a passive and automatic process, that is affected neither by a satiation of the first levels of the visual system nor by the psychological attitude of the subject consequent on dazzling the retina.

Discrimination Learning↗
PubMed1987

The horizontal-vertical illusion: independence of line bisection and a comparison line.

Undergraduate students in social science and architecture did not differ in their accuracy of adjusting the vertical lines of L and inverted-T figures to be equal to a 1-in. horizontal line (the adjustment task) or in producing a 1 in. long line in the vertical or horizontal plane on a blank sheet of paper (the production task). In the adjustment task vertical lines were made significantly shorter than the horizontal comparison line and the shortening of the vertical line was significantly greater for the inverted-T than for the L-figure. In the production task lines drawn in the horizontal plane did not differ significantly from 1 inch but those drawn in the vertical plane were significantly shorter than 1 inch. Further, the magnitude of this error was equal to that obtained with the inverted-T figure. These results demonstrate that, while line bisection (the bisection of the horizontal by the vertical in the inverted-T figure) contributes to the horizontal-vertical illusion, the illusion clearly exists in the absence of a comparison line and can be accounted for as an overestimation of the vertical line.

Adult↗
PubMed1989

Effect of intershaft wing removal on the Mueller-Lyer illusion as a function of judgment task.

Two methods were used to measure the Mueller-Lyer illusion. In the comparison procedure, subjects showed the difference between the lengths of the shafts; in the independent-judgment procedure they showed the length of each shaft individually. With both methods, one part of the figure was placed above the other and wings were removed from one part, either between or outside the two shafts. Removing the wings in the intershaft space reduced the illusion more than removing the wings outside the two parts of the figure with the comparison procedure but not with the independent-judgment procedure. The wings in the intershaft space contribute to the illusion, but only when the figure is considered as a whole.

Attention↗
PubMed1994

Apparent depth threshold for the Benussi effect.

Using the single staircase psychophysical method, the apparent depth threshold for the Benussi effect was determined for 5 observers. The threshold occurred at an eccentricity of 2r/3, where r equals the radius of the larger circle expressed in millimeters.

Depth Perception↗
PubMed1982

Lateralization of concrete and abstract characteristics analysis in the animal brain.

The experiments were performed on 92 white Wistar rats. Motion-food technique for working out conditioned reflexes was used. The following models were used: reflexes to correlation, transfer of conditioned reflexes, invariant recognition of visual images. Cortex inactivation was achieved by means of spreading depression. Sufficiently crude reflexes to the correlation of geometrical figure area or straight line segment lengths in animal populations were shown to be equally impaired after right and left hemisphere inactivation. In forming conditioned reflexes to the area correlation of some other figures or their accumulations, as well as finer reflexes to the correlation of segment lengths, right hemisphere inactivation led mainly to the impairment of concrete stimuli characteristics, and left hemisphere inactivation to that of abstract ones. Conditioned reflex transfer to other geometrical figures was mainly impaired after left hemisphere inactivation. Invariant recognition of visual images was more impaired after left than after right hemisphere inactivation. The results obtained suggest that in animals the right hemisphere mainly analyses concrete stimuli characteristics, whereas the left one analyses their abstract characteristics.

Animals↗
PubMed1991

The effect of lightness contrast on the colored Müller-Lyer illusion.

Two subjects estimated the length of the central line in red and blue Müller-Lyer figures that were viewed both foveally and parafoveally. The illusion figures were defined by either lightness and hue differences between figure and ground or by a hue difference alone. For both subjects, the figures defined solely by hue produced larger illusions. Since depth-cue scaling and other cognitive factors did not cause the enlargement, it was concluded that the robust, hue-produced illusions resulted from contour interactions generated within parvocellular channels that are specialized for coding color.

Adult↗
PubMed1994

Cross-modal compatibility effects with visual-spatial and auditory-verbal stimulus and response sets.

Within the visual-spatial and auditory-verbal modalities, reaction times to a stimulus have been shown to be faster if salient features of the stimulus and response sets correspond than if they do not. Accounts that attribute such stimulus-response compatibility effects to general translation processes predict that similar effects should occur for cross-modal stimulus and response sets. To test this prediction, three experiments were conducted examining four-choice reactions with (1) visual spatial-location stimuli assigned to speech responses, (2) speech stimuli assigned to keypress responses, and (3) symbolic visual stimuli assigned to speech responses. In all the experiments, responses were faster when correspondence between salient features of the stimulus and response sets was maintained, demonstrating that similar principles of translation operate both within and across modalities.

Auditory Perception↗
PubMed1992

The slippery context effect in psychophysics: intensive, extensive, and qualitative continua.

When subjects gave magnitude estimates of 500- and 2500-Hz tones at various SPLs, they judged a 500-Hz tone of 60 dB to be as loud as a 2500-Hz tone of 57 dB in one context (low SPLs at 500 Hz, high SPLs at 2500 Hz), but as loud as a 2500-Hz tone at 40 dB in another context (high SPLs at 500 Hz, low at 2500 Hz) (Marks, 1988). Such shifts in matches derived from judgments of multidimensionally varying stimuli are termed slippery context effects. The present set of seven experiments showed that slippery effects were absent from judgments of pitch of tones at different loudnesses, duration of tones at different pitches, and length of lines at different colors, though a small effect emerged in judgments of duration of tones and lights. Slippery context effects were substantial when subjects gave magnitude estimates of loudness of 500- and 2500-Hz tones under conditions in which the pitch at each trial either was cued visually beforehand or could be known through the regular stimulus sequence, and with instructions to make absolute magnitude estimates. The results are consistent with the view that slippery context effects occur automatically and "preattentively."

Attention↗
PubMed1976

Visual recognition memory for large and small binary pictures.

Recognition memory for pictures was tested using matrices of 0s and 1s as stimuli in two experiments. In the first experiment dimensionality of matrices was varied (5 X 5 and 10 X 10 matrices). The results showed better recognition memory for 10 X 10 matrices. The second experiment investigated the importance of certain areas, such as center or surround, using 10 X 10 matrices only. The results suggested that neither center nor surround is given unusual weight.

Attention↗
PubMed1979

[Features of thought formation in schizophrenic children].

The paper deals with problems related to the onthogenetic formation of a special type of the pathological cognitive activity. Such activity was expressed in disturbances of selective actualization of knowledge based on the past experience. Experimental psychological studies were performed in children from 5--14 years of age, with slowly progressive forms of schizophrenia. The data obtained indicate an acceleration (in comparison to normal children of the same age) in the development of thinking operations, demonstrate in a capability to generalize additive signs and relations. The results obtained also suggest that the capability to generalize subject properties hierarchied according to the degree of social priority, is formed by other regularities and is retarded in schizophrenic children in comparison to normal children of the same age.

Adolescent↗