Sex differences in susceptibility to the Poggendorff illusion

This study presents experimental results indicating that there are sex differences in the susceptibility to a geometric optical illusion. Participants (57 male and 39 female undergraduate students) performed 3 trials on a test involving the Poggendorff illusion. Analysis indicated that the magnitude of the illusion diminished significantly with each trial and that the percent perceived error was significantly larger for women than for men. This finding is consistent with the numerous studies which have indicated better visuospatial abilities for men than for women.     

Lack of sex differences with the Baldwin illusion

Responses of college students (16 men and 16 women) to the Baldwin illusion showed a significant effect for size of square but not for sex. Findings are consistent with those reported previously by Porac, Coren, Girgus, and Verde for adults and for the oldest group of children tested by Pressey and Wilson.     

The geometric illusion and induced differences in perceived time

Just as circle-size induces differences in the perceived extent of a line which interconnects the circles of the Baldwin illusion, it is demonstrated that circle-size induces differences in the perceived duration of a time interval which intervenes between circles of different sizes.     

Local and global visual mechanisms underlying individual differences in the rod-and-frame illusion

The role of local and global visual mechanisms in individual differences in the rod-and-frame (RF) effect was investigated. Field-dependent and field-independent observers, selected on the basis of Witkin and Asch’s (1948) classical procedure, were submitted to the small RF test (Coren & Hoy, 1986). Four frame tilts and two gap sizes were used. As expected, direct effects (i.e., rod settings in the direction of frame tilt) were observed at small degrees of frame tilt, while indirect effects (i.e., rod settings in the direction opposite that of frame tilt) were observed at larger frame tilts. Fielddependent observers showed larger direct effects in the case of the small gap. Indirect effects were comparable in both field-dependent and field-independent subjects, regardless of gap size. Following the model proposed by Wenderoth and Johnstone (1987), these findings indicate that low-level visual mechanisms, responsible for local orientation interactions, have a different gain in fielddependent and field-independent individuals. In contrast, global visual mechanisms, presumably acting     

Acquisition and retention of perceptual learning and the horizontal-vertical illusion.

The present study examined procedure-specific differences in the acquisition and retention of perceptual learning using four forms of the Horizontal-Vertical illusion. Training to criterion was conducted using intertrial feedback, continued visual inspection, or yoked-control procedures. Retention of perceptual learning was assessed at posttraining intervals ranging from 1 minute to 1 month. Subjects trained with feedback achieved criterion in fewer trials and showed greater accuracy and short-term retention of perceptual learning on the inverted-T figure and the 1-in. vertical line-production task. The present results show that the correction of inaccurate strategic factors most likely represents the temporary acquisition of compensatory strategies that facilitate performance on simple perceptual-motor skills tasks.     

Sex differences in the Poggendorff illusion: identifying the locus of the effect

Extensive research has identified individual differences associated with sex in a range of visual task performances, including susceptibility to visual illusions. The aim of this study was to identify the locus of sex differences within the context of the Poggendorf illusion. 79 women and 79 men participated within a mixed factorial design. Analyses indicated that sex differences were only present in the stimulus context with the full inducing element present. This finding replicates recent research and provides qualifying evidence as to the locus of the effect. The findings are discussed within the functional framework of perceptual processes involved in extrapolating 3-dimensional characteristics from 2-dimensional visual stimuli.     

How the Thatcher illusion reveals evolutionary differences in the face processing of primates

Face recognition in humans is a complex cognitive skill that requires sensitivity to unique configurations of eyes, mouth, and other facial features. The Thatcher illusion has been used to demonstrate the importance of orientation when processing configural information within faces. Transforming an upright face so that the eyes and mouth are inverted renders the face grotesque; however, when this “Thatcherized” face is inverted, the effect disappears. Due to the use of primate models in social cognition research, it is important to determine the extent to which specialized cognitive functions like face processing occur across species. To date, the Thatcher illusion has been explored in only a few species with mixed results. Here, we used computerized tasks to examine whether nonhuman primates perceive the Thatcher illusion. Chimpanzees and rhesus monkeys were required to discriminate between Thatcherized and unaltered faces presented upright and inverted. Our results confirm that chimpanzees perceived the Thatcher illusion, but rhesus monkeys did not, suggesting species differences in the importance of configural information in face processing. Three further experiments were conducted to understand why our results differed from previously published accounts of the Thatcher illusion in rhesus monkeys.     

Individual differences and informal learning in the workplace

Informal learning is important in today's dynamic and competitive business environment. However, research on informal learning is limited and largely anecdotal. Based on theory and research on training and development and positive psychology, this study examined the influence of individual differences including the Big Five personality dimensions, generalized self-efficacy, and zest on informal learning. One hundred eighty managers from an organization that owns and operates casual theme restaurants completed online measures of individual differences and informal learning approximately one year apart. The results demonstrated that each of the individual differences had a significant relationship with informal learning. However, zest was the only significant predictor of informal learning when all of the individual differences were considered together. The implications of the results for research and practice are discussed.     

Individual differences and informal learning in the workplace

Informal learning is important in today's dynamic and competitive business environment. However, research on informal learning is limited and largely anecdotal. Based on theory and research on training and development and positive psychology, this study examined the influence of individual differences including the Big Five personality dimensions, generalized self-efficacy, and zest on informal learning. One hundred eighty managers from an organization that owns and operates casual theme restaurants completed online measures of individual differences and informal learning approximately one year apart. The results demonstrated that each of the individual differences had a significant relationship with informal learning. However, zest was the only significant predictor of informal learning when all of the individual differences were considered together. The implications of the results for research and practice are discussed.     

Individual differences in the rubber-hand illusion: Predicting self-reports of people's personal experiences

Can we assess individual differences in the extent to which a person perceives the rubber-hand illusion on the basis of self-reported experiences? In this research, we develop such an instrument using Rasch-type models. In our conception, incorporating an object (e.g., a rubber hand) into one's body image requires various sensorimotor and cognitive processes. The extent to which people can meet these requirements thus determines how intensely people experience and, simultaneously, describe the illusion. As a consequence, individual differences in people's susceptibility to the rubber-hand illusion can be determined by inspecting reports of their personal experiences. The proposed model turned out to be functional in its capability to predict self-reports of people's experiences and to reliably assess individual differences in susceptibility to the illusion. Regarding validity, we found a small, but significant, correlation between individual susceptibility and proprioceptive drift. Additionally, we found that asynchrony, and tapping rather than stroking the fingers constrain the experience of the illusion.     

Cultural differences in the predictors of depression

This study examined a number of psychosocial factors thought likely to contribute to depression among ethnic Korean and Caucasian students. As hypothesized, Koreans (n = 61) were more depressed than Caucasians (n = 69). Stepwise multiple regression analysis revealed different models for predicting depression in the two groups. Value orientations, a neglected element in the prevailing stress paradigm, contributed substantially to variation in depression, especially among Koreans. Two measures of parental values and three coping strategies accounted for a striking 44% of the variance in Korean youths' depression. Perceived parental traditionalism, the strongest predictor, was associated with higher depression; and perceived parental modernism, with lower depression. For Caucasians, in contrast, only 13% of the variance in depression could be accounted for; and the two significant predictors were academic stress and respondents' own modern values (the latter associated with fewer symptoms). The findings of this study argue for greater attention to the importance of values in studying adaptation to stress.     

Visual field differences in the magnitude of the Oppel-Kundt illusion vary with processing time

Three experiments were performed to investigate hemispheric differences in susceptibility to the Oppel-Kundt illusion presented tachistoscopically to the two visual hemifields. Experiment 1 used a successive comparison mode, in which 16 undergraduate students indicated whether the second of two successive extents looked shorter or longer than the first. Experiment 2 (20 under-graduates) and Experiment 3 (1 commissurotomy patient) required judgments of two extents presented simultaneously. The first experiment found no significant visual field differences, although females were more susceptible than males. In the second experiment, the illusion magnitude was greater in the left visual field, and in the third experiment, it was greater in the right visual field. Post hoc analyses resolve the conflicting results and show that in all three experiments, the susceptibility of the right hemisphere declined more than that of the left hemisphere during illusion processing. An interpretation is offered in terms of two parallel processes, one that is fast, uses feature extraction, and is performed more effectively in the left hemisphere, and one that is slow, uses visuospatial analysis to compute distances between parts of the illusion figure, and is performed more effectively in the right hemisphere.     

Cultural and sex differences in touch avoidance

250 male and female respondents from American, Mediterranean, Near Eastern, and Far Eastern cultures completed a self-report measure of touch-avoidance. Confirmatory factor analysis indicated factors for opposite-sex and same-sex touch-avoidance. These factors were used as dependent variables in a 4 x 2 (culture by sex) multivariate analysis of variance which yielded a significant interaction of culture by sex on opposite-sex touch-avoidance and a main effect of the respondents' sex on same-sex touch-avoidance.