"Assimilation Theory and the Ponzo Illusion: Quantitative Predictions": Erratum.

Reports an error in "Assimilation theory and the Ponzo illusion: Quantitative predictions" by A. W. Pressey, N. Butchard and L. Scrivner (Canadian Journal of Psychology Revue Canadienne de Psychologie, 1971[Dec], Vol 25[6], 486-497). A corrected formula is provided. (The following abstract of the original article appeared in record 1972-10045-001.) Predicted that the ponzo illusion would increase, and then decrease as angle of the oblique arms increased, on the basis of assimilation theory. A reversed illusion was predicted when the angle was very obtuse. 4 orientations of the ponzo illusion were employed. In these the apex pointed to the top, bottom, left, and right. A different orientation was used on each of 4 sessions separated by a minimum of 1 day. The order was randomized for each of 9 men and 6 women ss. Both predictions were verified. Data suggest a change in the attentive field postulate of assimilation theory, and a general formula was derived to obtain a numerical estimate of illusion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The bicycle illusion: Sidewalk science informs the integration of motion and shape perception.

The authors describe a new visual illusion first discovered in a natural setting. A cyclist riding beside a pair of sagging chains that connect fence posts appears to move up and down with the chains. In this illusion, a static shape (the chains) affects the perception of a moving shape (the bicycle), and this influence involves assimilation (averaging) rather than opposition (differentiation). These features distinguish the illusion from illusions of motion capture and induced motion. The authors take this bicycle illusion into the laboratory and report 4 findings: Na?ve viewers experience the illusion when discriminating horizontal from sinusoidal motion of a disc in the context of stationary curved lines; the illusion shifts from motion assimilation to motion opposition as the visual size of the display is increased; the assimilation and opposition illusions are dissociated by variations in luminance contrast of the stationary lines and the moving disc; and the illusion does not occur when simply comparing two stationary objects at different locations along the curved lines. The bicycle illusion provides a unique opportunity for studying the interactions between shape and motion perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relations entre la notion et la perception de la vitesse relative chez l'enfant.

Administered 2 tasks bearing on the perception and concept of relative velocity to 7-, 9-, 11-, and 13-yr-old children (24 at each age level). The perceptual task presented an illusion created by the movement of a target on a moving background, while the conceptual task was a modified version of Piaget's technique. In each task the 2 movements involved were either in the same (MS) or in the opposite direction. It was found that the illusion appeared earlier than the corresponding concept under the MS condition. The possibility of a retroactive effect of the concept on the percept is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of hypnotic age regression on the magnitude of the Ponzo illusion: A replication.

Partially replicated M. Parrish, R. Lundy, and the Liebowtiz's (see record 1970-03085-001) study on the effect of hypnotic age regression on the magnitude of the Ponzo and Poggendorff illusions. The Ponzo illusion was presented to 4 male and 4 female undergraduates under 3 conditions: waking, regressed to age 9, and regressed to age 5. Unlike the previous study, there were no significant difference in the magnitude of the illusion across the 3 conditions. It is concluded that hypnotic age regression does not affect the magnitude of the Ponzo illusion. It is suggested that age regression is a questionable tool for investigating developmental aspects of perception. (27 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ontogenetic changes in two forms of the Muller-Lyer illusion in normal and retarded subjects.

Forms A (arrowheads pointing out) and B (arrowheads pointing in) of the Muller-Lyer illusion were administered to normal and retarded Ss to study possible changes in illusion strength in either or both forms. It was found that only Form A changed in strength when (a) age was varied from 8-18 yrs in normal children and (b) when the illusion was presented repeatedly over 8 trials for normal and retarded children. These findings conflict with perceptual theories which assume that both forms of the illusion change with these manipulations. A control condition was also presented and its utility is discussed. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A motion illusion from two-dimensional periodic patterns

The spatial properties of a motion illusion (the Ouchi illusion) that occurs in a stationary pattern were examined by means of a variety of two-dimensional periodic patterns (formed by multiplying pairs of various one-dimensional periodic functions). In two experiments, observers rated the magnitude of the illusion. The results showed that (1) patterns having large energy and steep saddle-shaped contrast gradients tended to generate stronger illusions, (2) the composite pattern made up of the sum of the fundamental and harmonic components exhibited a stronger illusion than either the fundamental or the harmonic pattern, (3) patterns possessing an element orientation and phase shift similar to those of a rectangular checkerboard, and with element sizes of 15-50 min in width and 4-8 min in height yielded a larger illusion, (4) equiluminant colors largely abolished the effect, and (5) blurring the boundary between the test and surround did not reduce the illusion. Interactions between spatially overlapping ON and OFF units was discussed as a possible underlying cause of this phenomenon.     

Size illusion, distance illusion, and terrestrial passage: Comment on Reed.

Comments on C. F. Reed's (see record 1985-29807-001) terrestrial-passage theory, in which it is assumed that the moon's failure to increase in visual subtense while elevating is accounted for strictly by perceptual distancing. This allows a formal account of the moon distance illusion, but at the expense of a compelling explanation of the moon size illusion. In order to explain the distance illusion, Reed also assumes that all objects, regardless of their perceived altitude, are perceived to start from a common point at the horizon. Several alternative applications of Reed's terrestrial-passage foundation to the actual illusions are suggested. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

锥面密封油套管特殊螺纹接头密封面过盈量计算

根据厚壁圆筒的弹性力学原理,对油套管锥面密封形式特殊螺纹接头的密封面过盈量设计进行了理论推导,根据第四强度理论,在保证密封面不屈服的条件下,得出密封面理论最大过盈量.利用得到的公式对密封结构参数进行了计算分析,结果表明,密封面角取10°～30°、台肩角取5 °～20°,为接头设计的理想范围.对实际加工接头进行标准试验,对比试验值与计算值,发现实际过盈量为计算最大过盈量的0.7～0.9倍,研究成果为接头密封面设计提供了理论依据.     

Assimilation of traumatic experiences and physical-health outcomes: Cautions for the Pennebaker paradigm.

This study reports an application of the assimilation model, a theory of psychotherapeutic change, to an analogue study in which 43 students were asked to write for 20 minutes a day for 4 days ("Pennebaker paradigm") about a traumatic experience. Contrary to expectations based on previous research, participants who showed the greatest change in assimilation level and achieved the highest levels of assimilation during the study subsequently had more health-center visits than participants whose assimilation was less. Qualitative exploratory work suggested that there may be negative consequences of exposing traumatic experiences in the absence of supportive therapy to contain and fully integrate the experiences. A more measured approach to the benefits of brief exposition of traumatic experiences may be warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Levels of perceptual processing in the development of visual illusions.

Used illusion decrement to explore the relative contributions of structural factors and cognitive processing factors to the commonly found age differences in the magnitude of the Muller-Lyer illusion. A total of 160 7-, 9-, 11-, and 21-yr-olds judged the standard Brentano form and a dot form of the illusion for 5 trials at 30-sec intervals. The initial illusion magnitudes for the Brentano form showed the usual decrease with age; however, the age trend for the dot form was considerably weaker. For both configurations, the initial age trends completely disappeared over the 2.5-min testing session. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The target in the celestial (moon) illusion.

The visual conditions sufficient to produce the celestial (moon) illusion do not produce it for all presumably suitable celestial targets. For most observers, the illusion is complete for the moon: Apparent visual angle and apparent physical size are inverse functions of elevation, but apparent distance is a direct function. These features of the illusion are attenuated for star clusters and absent for star pairs. Although, in accordance with modern theories of the illusion, the visual terrain may be necessary for the celestial illusion, it is not sufficient; the visual target itself apparently must display particular features. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constraints on the processing of rolling motion: The curtate cycloid illusion.

When a wheel rolls along a flat surface, a point on its perimeter traces a cycloid trajectory, forming a sequence of adjacent semicircle-like scallops. However, when mentally visualizing this point's trajectory, participants erroneously describe the point's path as looping back on itself between each scallop or phase of the cycloid, a phenomenon called the curtate cycloid illusion. The studies supported the hypothesis that the curtate cycloid illusion occurs because the cognitive system sometimes does not have sufficient resources for simultaneously processing 2 components of the motion: its translation and its rotation about its current instant center. Four experiments using computer-animated rolling wheels found that participants who were high in spatial ability were less susceptible to the curtate cycloid illusion than were low-spatial participants, that high-spatial participants were not susceptible to the illusion if they could control the animated wheel display, and that the illusion was substantially decreased if the opportunity to compute instant centers was reduced. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Moon illusion in pictures: A multimechanism approach.

The existence of the moon illusion in pictorial representations was demonstrated in 6 experiments. Ss either judged the size of the moon in pictures, depicted as on the horizon or high in the sky, or drew horizon and elevated moons. The horizon moon was consistently judged to be larger than the elevated moon, independent of the angle at which the pictures are viewed. The distance paradox usually observed with the moon illusion (horizon moon apparently closer than the elevated moon) also exists in pictures. The magnitude of both size and distance effects depends on the salience of depicted depth cues. The pattern of results suggests that the moon illusion is caused by several interacting mechanisms and that use of pictorial stimuli may allow the separation of various cognitive from physiological contributions to the illusion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"The tenacity of historical misinformation: Titchener did not invent the Titchener illusion": Correction.

Reports an error in the original article by G. Burton ( History of Psychology, 2001[Aug], Vol 4[3], pp. 228-244). In this article, the author asserted that a motivation textbook by R. C. Beck (see record 1979-32908-000) falsely listed a monkey as one of the objects in which L. Albert was tested for generalization of his supposed fear of fuzzy objects. In fact, Beck accurately indicated that the monkey was used during the pretest to determine Albert's preexisting fears; Beck did not claim that the monkey was used during the generalization phase. (The following abstract of this article originally appeared in record 2001-07674-002.) Some well-known psychological "facts" are actually false, but dispelling them is difficult. One such false fact is that Titchener introduced the illusion depicting a circle ringed by smaller circles, which appears larger than an equivalent circle surrounded by larger circles. A review of contemporary sources indicates that Ebbinghaus probably introduced this illusion in the 1890s, although not in any explicit publication, and Titchener neither had nor asserted any authorship of this figure. There are also 3 other illusions that are sometimes labeled the Ebbinghaus illusion... (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depth cues and constancy scaling in the horizontal-vertical illusion: The bisection error.

Analysis of the horizontal-vertical illusion in terms of possible depth cues allows the prediction of a bisection illusion in which the length of the lower portion of the vertical is underestimated relative to the length of the upper segment. Significant variations in illusion magnitude as a function of line length and angle of inclination indicates that height in the plane is the depth cue which is evoking inappropriate size constancy scaling. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The octave illusion revisited: Suppression or fusion between ears?

The octave illusion occurs when each ear receives a sequence of tones alternating by 1 octave but with the high and low tones in different ears. Most listeners perceive these stimuli as a high pitch in one ear alternating with a low pitch in the other ear. D. Deutsch and P. L. Roll (1976) interpreted this phenomenon as evidence for a what-where division of auditory processing caused by sequential interactions between the tones. They argued that the pitch follows the frequency presented to the dominant ear but is lateralized toward the higher frequency component. This model was examined in 4 experiments. Results indicate that the perceived pitch approximates the fundamental frequency and that the illusion does not depend on sequential interactions. The octave illusion may arise from an interaction between dichotic fusion and binaural diplacusis rather than from suppression as proposed by Deutsch. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A jittered squares illusion and a proposed mechanism

A new visual illusion is reported in which randomly positioned squares that are perfectly aligned with the horizontal and vertical appear slightly rotated about their midpoints ('jittered') relative to each other. Possible mechanisms for the illusion have been explored in a series of three experiments. Experiment 1 showed that, unlike the Münsterberg illusion, the Jittered Squares illusion persists at isoluminance. Experiment 2 indicated that the degree of rotation from vertical and horizontal, of rows and columns of squares in which the edges of individual squares remain perfectly aligned with vertical and horizontal, changes the perceived strength of the illusion such that the strongest effect is found at rotations of +/- 10 degrees to +/- 15 degrees. Experiment 3 revealed that the illusion is dependent upon the spatial extent of the gaps between the squares, such that it becomes weaker as the separation increases. On the basis of the findings it is suggested that the jittering results from the extraction of obliquely oriented contours by an integrator mechanism when the difference in orientation, between the edges of the individual squares and the global orientation of a contour made up of a number of edges of individual squares, is not too dissimilar. It is proposed that a mechanism such as simultaneous orientation contrast between these global contours and the vertical and horizontal edges of the individual squares causes the squares to appear rotated away from the orientation of the extracted contours, leading to the perceived jittering.     

Terrestrial passage theory of the moon illusion.

Reviews theories of the celestial, or moon, illusion and asserts that they have neglected geometric characteristics of movement along and above the surface of the earth. It is suggested that the illusion occurs because the characteristics of terrestrial passage are attributed to celestial passage. In terrestrial passage, the visual angle subtended by an object changes discriminably as an essentially invariant function of elevation above the horizon. In celestial passage, by contrast, change in visual angle is indiscriminable at all elevations. If a terrestrial object gains altitude, its angular subtense fails to follow the expansion projected for an orbital course: Angular diminution or constancy is equivalent to distancing. On the basis of terrestrial projections, a similar failure of celestial objects in successive elevations is also equivalent to distancing. It is argued that the illusion occurs because of retinal image constancy, not—as traditionally stated—despite it. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grouping and assimilation in perception, memory, and conditioning.

A group-assimilation theory hypothesizes that a Gestalt-like group is associated with assimilation among the parts of the group. Assimilation is an increase in the perceived or sensed similarity of 1 part to a 2nd part. Assimilation occurs for traditional parts such as color but also occurs for salience. The theory accounts for key outcomes in perception, memory, and conditioning. An important hypothesis is that traditional assimilation and salience assimilation tend to have opposing effects on identification. The traditional assimilation of a target to a 2nd part frequently impairs the target's identification. In contrast, the assimilation of a less salient target to a more salient 2nd part increases the salience of the target and thus improves the target's identification. The corresponding hypothesis that 2 groups are associated with contrast between those parts that belong to different groups is also considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)