Accentuation effects and illusory change in exemplar-based category learning

Examined the hypothesis that information enhancing category differences receives greater weight in estimates of category means than information that reduces such differences. In the first experiment, subjects estimated the cumulative means of test scores of two groups of students. The experimental manipulation involved a gradual shift of the true mean of one group either towards or away from the true mean of the other group. As predicted, changes of estimates were larger when the two means became more dissimilar than when they became more similar. The second experiment involved otherwise identical procedures, but the variance in one category was increased while the mean remained stable. Subjects perceived an illusory change of the mean away from the comparison category. It is suggested that accentuation effects of this kind may limit the reduction of social stereotypes.     

Inhibited power motivation and persuasive communication: a lens model analysis

The authors tested the hypothesis that after motive arousal, individuals with an inhibited power motive (IPM) would excel at a persuasive task and explored the behavioral strategies IPM individuals use to that purpose. Sixty-eight participants presented their point of view on a controversial subject to another person. Power motivation and inhibition were both assessed by a picture-story test. Prior to their presentation, half of the participants imaginatively explored the ensuing task. The other half was assigned to a no-imagery control condition. Lens model analysis of videotaped presentations revealed that IPM participants in the imagery condition were judged to be the most persuasive of all participants. This interactive effect of power motivation, inhibition, and imagery condition was accounted for by three behavioral cues: verbal fluency, gesturing, and eyebrow lifts. No comparable effects emerged among no-imagery participants.     

Local contextual cuing in visual search

Previous research has indicated that covariations between the global layout of search displays and target locations result in contextual cuing: the global context guides attention to probable target locations. The present experiments extend these findings by showing that local redundancies also facilitate visual search. Participants searched for randomly located targets in invariant homogenous displays, i.e., the global context provided information neither about the location nor about the identity of the target. The only redundancy referred to spatial relations between the targets and certain distractors: Two of the distractors were frequently presented next to the targets. In four of five experiments, targets with frequent flankers were detected faster than targets with rare flankers. The data suggest that this local contextual cuing does not depend on awareness of the redundant local topography but needs the redundantly related stimuli to be attended to.     

Visual analogue scales for mode-independent measurement in self-administered questionnaires

Previous research has shown evidence for mode differences between computer-assisted self-administered interviews (CASI) and paper-and-pencil interviews, especially in the case of sensitive questions. Some of these differences are explained by higher degrees of self-disclosure for CASI than for paper-and-pencil interviews, due to the more private situation with CASIs. This analysis examines the existence of different degrees of self-disclosure for CASI versus paper-and-pencil questionnaires and whether these differences can be reduced by the use of a specific response format. Judgments of items on a self-control scale with discrete 5-point (Likert-type) scales are compared with judgments on continuous visual analogue scales (VAS). Because a categorization effect for Likert-type items is assumed when pressure for social desirability is present, it is hypothesized that VAS compared to Likert-type response formats are less sensitive to mode differences.     

Eye vergence is susceptible to the hollow-face illusion

When an observer looks at a hollow mask of a face, a normal convex face is often perceived [the hollow-face illusion--Gregory 1973, in Illusion in Nature and Art (London: Duckworth) pp 49-96]. We show that in exploring an illusory face, the eyes converge at the illusory and not at the real distances of fixated targets like the tip of the nose. The 'vergence error' appears even though the resulting disparities of the two retinal images of the target provide feedback that would allow an immediate correction. It is presumably the success of recognising a familiar object (a face) which overrides the correction of convergence. This suggests that the brain strives for a congruency of eye vergence and distance perception.     

The Chinese Version of the Revised Creativity Domain Questionnaire (CDQ‐R): First Evidence for its Factorial Validity and Systematic Association with the Big Five

The present study examines the factor structure of a Chinese version of the Revised Creativity Domain Questionnaire (CDQ‐R; Kaufman, Waterstreet, Ailaouni, Whitcomb, Roe, & Riggs, 2009) as well as its relation to Big Five personality traits within a Chinese sample (N = 787). Analyses indicate the appropriateness of the Chinese version of the CDQ‐R in terms of internal consistency, factorial validity as well as convergent and divergent validity concerning the Big Five personality factors. Revealing some culture‐specific variation, confirmatory factor analysis indicated a slight superiority of a five‐factor model for this Chinese sample over the existing four‐factor model established with American samples. This higher level of differentiation in terms of one factor of the creativity domain could be explained on the basis of the specific characteristics of the Chinese culture.     

Extending JAGS: A tutorial on adding custom distributions to JAGS (with a diffusion model example)

We demonstrate how to add a custom distribution into the general-purpose, open-source, cross-platform graphical modeling package JAGS (“Just Another Gibbs Sampler”). JAGS is intended to be modular and extensible, and modules written in the way laid out here can be loaded at runtime as needed and do not interfere with regular JAGS functionality when not loaded. Writing custom extensions requires knowledge of C++, but installing a new module can be highly automatic, depending on the operating system. As a basic example, we implement a Bernoulli distribution in JAGS. We further present our implementation of the Wiener diffusion first-passage time distribution, which is freely available at https://sourceforge.net/projects/jags-wiener/.     

Application of the rubber hand illusion paradigm: comparison between upper and lower limbs

The “rubber hand illusion (RHI)” is a perceptual illusion, which allows the integration of artificial limbs into the body representation of a person by means of combined visual and tactile stimulation. The illusion has been frequently replicated but always concerning the upper limbs. The present study verified an analog illusion that can be called the “rubber foot illusion” (RFI). In a conjoint experiment using both a rubber hand and a rubber foot, brushstrokes were applied to the respective real and rubber limb placed alongside the real one. However, only the artificial limb’s handling was visible. The brushstrokes were given either synchronously, with a delay of ±0.5 s, or without tactile stimulation of the real limb. Questionnaire data and the proprioceptive drift towards the rubber limb (determined by calling on the subjects to show where they locate their unseen limb) defined the illusion strength. Results revealed that the illusion was induced in both limbs with comparable strength, but only in the synchronous condition.