Visual angle and apparent size of objects in peripheral vision

Measurements of apparent size were obtained by distance adjustment of a peripherally viewed stimulus to produce a match to a foveally viewed standard. As eccentricity increased, the peripheral stimulus was adjusted at distances of progressively greater visual angle, indicating that a continuous diminution in apparent size occurs with increased eccentricity. This effect was found to be stable for several conditions of illumination and for changes in the light adaptive state of S. Apparent size diminution and apparent distance increase were also found for familiar objects viewed in an open field.     

Figural after-effects and apparent size

Sutherland (1954) obtained results which suggest that when the retinal size of test and inspection figures is equal, the direction of the FAE may be determined by the relative apparent sizes of the two figures. Other investigators have reproduced this result when exactly the same conditions were used: when the conditions were changed the result was not obtained. In the present paper these results are discussed and an attempt is made to determine why the effect is not obtained with small variations in the experimental conditions. It is further shown that some FAE phenomena cannot be explained by the two main existing theories; these phenomena could be explained if some analysis of the stimulus is being performed before the stage of the nervous system at which the process underlying FAEs occurs. Some recent physiological evidence (Hubel and Wiesel, 1959) supports this hypothesis. If this hypothesis is correct, it is likely that further work on FAEs determined by apparent size may help to throw light on the physiological mechanisms underlying size constancy, and some further experiments are suggested.     

The representation of moving 3-D objects in apparent motion perception

In the present research, we investigated the depth information contained in the representations of apparently moving 3-D objects. By conducting three experiments, we measured the magnitude of representational momentum (RM) as an index of the consistency of an object’s representation. Experiment 1A revealed that RM magnitude was greater when shaded, convex, apparently moving objects shifted to a flat circle than when they shifted to a shaded, concave, hemisphere. The difference diminished when the apparently moving objects were concave hemispheres (Experiment 1B). Using luminance-polarized circles, Experiment 2 confirmed that these results were not due to the luminance information of shading. Experiment 3 demonstrated that RM magnitude was greater when convex apparently moving objects shifted to particular blurred convex hemispheres with low-pass filtering than when they shifted to concave hemispheres. These results suggest that the internal object’s representation in apparent motion contains incomplete depth information intermediate between that of 2-D and 3-D objects, particularly with regard to convexity information with low-spatial-frequency components.     

Aesthetic preferences in the size of images of real-world objects

Konkle and Oliva (in press, Journal of Experimental Psychology: Human Perception and Performance) found that the preferred ('canonical') visual size of a picture of an object within a frame is proportional to the logarithm of its known physical size. They used within-participants designs on several tasks, including having participants adjust the object's size to 'look best'. We examined visual size preference in 2AFC tasks with explicit aesthetic instructions to choose: "which of each pair you like best". We also used both within- and between-participants conditions to investigate the possible role of demand characteristics. In experiments 1 and 2, participants saw all possible image pairs depicting the same object at six different sizes for twelve real-world objects that varied in physical size. Significant effects of known physical size were present, regardless of whether participants made judgments about a single object (the between-participants design) or about all objects intermixed (the within-participants design). Experiment 3 showed a reduced effect when the amount of image detail present at different visual sizes was kept constant by posterizing the images. The results are discussed in terms of ecological biases on aesthetic preferences.     

Figural after-effects, retinal size, and apparent size

The results of earlier experiments on the question of whether figural after-effects are affected by apparent as opposed to retinal size are shown to be inconclusive. A new hypothesis is proposed namely that both factors may be responsible for producing figural aftereffects, and four experiments have been made to test it. Situations were used in which the apparent sizes of the figures were determined by the size-constancy effect. It was found that where retinal sizes of test and inspection figures are the same and apparent sizes are different, figural after-effects in the direction which would be predicted on the basis of apparent sizes are obtained. It was further shown that where retinal and apparent sizes are in conflict, whether a figural after-effect is seen or not, and the direction of the figural after-effect, depends upon the balance between these two factors.     

Conceptual information about size of objects in nouns

Two experiments provide evidence that information about the real-life size of objects is elicited by nouns. A priming paradigm was used with a category membership verification task. The results showed that targets were responded to faster when preceded by a same-size prime, and that large entities were processed faster than small ones. Overall, our results significantly extend previous work on perceptual information elicited by concepts (e.g., Zwaan & Yaxley, 2004) and, in particular, on size information (e.g., Rubinstein & Henik, 2002) by means of a size-unrelated paradigm.     

Temporal restriction in apparent motion of two objects by presenting multipartite subframes

Two experiments tested whether proper perception of motion can be realized with a multipartite subframe stimulus. In order to elucidate the constructive processes of visual motion, two motion stimuli were used which differed according to their hierarchical levels of reference. It was found that: (a) stable motion was perceived so long as the temporal interval between the neighboring frames comprising several subframes was held between 30 and 120 ms; (b) visual unification of subframes was properly achieved independently of the number of subframes insofar as the temporal constraint mentioned above was satisfied; (c) when stimuli consisted of two motions of different hierarchical level of reference, perception of the higher-level motion required the prior perception of the lower-level motion.     

High-intensity sound increases the size of visually perceived objects

The effect of audiovisual interactions on size perception has yet to be examined, despite its fundamental importance in daily life. Previous studies have reported that object length can be estimated solely on the basis of the sounds produced when an object is dropped. Moreover, it has been shown that people typically and easily perceive the correspondence between object sizes and sound intensities. It is therefore possible that auditory stimuli may act as cues for object size, thereby altering the visual perception of size. Thus, in the present study we examined the effects of auditory stimuli on the visual perception of size. Specifically, we investigated the effects of the sound intensity of auditory stimuli, the temporal window of audiovisual interactions, and the effects of the retinal eccentricity of visual stimuli. The results indicated that high-intensity auditory stimuli increased visually perceived object size, and that this effect was especially strong in the peripheral visual field. Additional consideration indicated that this effect on the visual perception of size is induced when the cue reliability is relatively higher for the auditory than for the visual stimuli. In addition, we further suggest that the cue reliabilities of visual and auditory stimuli relate to retinal eccentricity and sound intensity, respectively.     

The relation between size and apparent heaviness

Attention, Perception, & Psychophysics - A formula for the size-weight illusion was derived from the Stevens and Rubin (1970) finding that heaviness functions form a family of power functions...     

A further investigation of apparent size and retinal size as determinants of the figural after-effect

A figure which is more distant from the eye than another but subtends the same visual angle is usually seen as the larger. This phenomenon is called perceptual size constancy. Experiments have been reported which show that sometimes the apparent and sometimes the retinal sizes of the stimulus figures determine the direction of the figural after-effect. These experiments are reviewed and two further experiments are reported. In the first experiment two types of stimulus figure (discs and annuli) which subtended a visual angle of 1° 36' resulted in figural after-effects, the direction of which would have been predicted by the retinal sizes of the figures. In the second experiment larger figures were used which subtended a visual angle of about 4° and which were the same as those used by Sutherland (1954). In this experiment the after-effects were generally in a direction which would have been expected if apparent size determined the direction of the after-effect. In the interpretation of the results attention is drawn to the “Central Tendency Effect” which has been observed in size judgements of stimulus figures of varying size. Two hypotheses are suggested; one is that the true figural aftereffect has been obscured by the “Central Tendency Effect” in successive judgements, and the other is that time error in successive judgements of size is essentially a figural aftereffect. Some supportive evidence for the latter hypothesis is reported. It is concluded that apparent size is not a critical determinant of the figural after-effect.     

Optic array determinants of apparent distance and size in pictures

This study explored whether special mechanisms are operative in picture perception to correct for the distortion that occurs when pictures are viewed from the wrong station point. Five photographs were taken of a layout composed of two same-sized dolls positioned at different distances on a flat untextured ground. Perspective differences existed between the photographs as a function of varying the distance of the camera to the layout. Each picture was viewed from five station points along the normal by 12 adults who estimated the relative magnitude of the depth interval between the dolls and judged whether the rear doll was objectively smaller, larger, or the same size as the front doll. No evidence was found of a compensation mechanism operating to stabilize the pictured layout. Distance and size judgments were affected in a manner that was consistent with what would occur if an actual layout and the conditions under which it were viewed were similarly transformed.     

Perceived size of familiar objects and the theory of off-sized perceptions

In three experiments, I examined the claim (Gogel, 1969; Gogel & Newton 1969)that familiar objects viewed under reduced stimulus conditions frequently appear to be off-sized (i.e., larger or smaller.than normal). In Experiments 1 and 2, I presented images ofdifferent familiar objects, one at a time, at distances of .1. and 2 m from the observers. The images were normal-, large-, or small-sized versions of familiar objects, and the observers judged the perceived size of each object rela.tive to its familiar normal size. In Experiment 3, I presented normal-, large-, and small-sized versions of thesame familiar object at physical distances of 1 and 2 m. The pattern of size results was similar across the three experiments. In general, normal-sized objects appeared normal to small-sized at the 1-mdistance and small-sized at the 2-mdistance; small-sized objects appeared small-sized at the 1-m distance and even smaller at the 2-m distance; and large-sized objects appeared normal- to large-sized at the 1-m distance and normal- to small-sized at the 2-m distance. The distance results of Experiment 3 indicated that familiar size was an effective determinant of reported distance. These results are consistent with Gogel’s theory of off-sized perceptions and, more generally, with the claim that familiar size is not an important determinant of perceived size.     

Target size and luminance in apparent brightness of the peripheral visual field.

Four target sizes between 15 and 120 min. of arc with six luminance levels covering the range between 398.1 and 1.26 cd/m2 in steps of .5 log units were presented to 0, 20, 40, 60, and 80 degrees nasal retinal loci. In both peripheral and foveal viewing, magnitude estimates to apparent brightness judged by 12 Ss changed as a function of target size and luminance. The exponent of the power function was not dependent on retinal loci but on target size. However, when target size increased, the apparent brightness was slightly greater with peripheral viewing than with foveal viewing.