Perceived path of oblique motion: horizontal-vertical and stimulus-orientation effects

Subjects adjusted the path of moving stimuli to produce apparent slopes of 45 degrees with respect to horizontal. The stimulus was either a single moving dot or a vertical or horizontal bar. In separate experiments either the stimuli were tracked or fixation was maintained on a stationary fixation target positioned 8 deg to the right of the center of stimulus motion. In both experiments the selected path slopes were in general more horizontal than 45 degrees. This pattern indicates that subjects overestimate the vertical component of motion along an oblique path, and is interpreted as a manifestation of the spatial anisometropy generally termed the 'horizontal-vertical illusion'. Additionally, paths selected for horizontal bars were more vertical than those for vertical bars. This finding is interpreted in the context of a previous report of the influence of stimulus orientation on perceived velocity.     

Longitudinal Associations Between Delinquent Behaviour of Friends and Delinquent Behaviour of Adolescents: Moderation by Adolescent Personality Traits

In this longitudinal study, we examined whether personality traits (parent‐rated Big Five personality traits) render some adolescents more susceptible than others to delinquent behaviour of friends, predicting rank‐order changes in adolescents' self‐reported delinquent behaviour. We examine susceptibility to both perceived (reported by adolescents) and self‐reported (reported by friends) delinquent behaviour of friends. Participants in this two‐wave study were 285 Dutch adolescents and their best friends. The adolescents (50% girls) were 15.5 years old on average (SD = 0.8 years), and their best friends (N = 176; 58% girls) were 15.1 years old (SD = 1.5 years). Perceived (but not self‐reported) delinquency of friends predicted a stronger increase in adolescent delinquency 1 year later, especially among adolescents low or average on conscientiousness. Emotional stability, agreeableness, extraversion and openness did not moderate associations between delinquency of friends and delinquency of adolescents. Our findings show that low conscientiousness serves as a risk factor, increasing vulnerability to perceived delinquent behaviour of friends, while high conscientiousness serves as a protective factor, increasing resilience to perceived delinquent behaviour of friends. Our findings also show that adolescents are susceptible to, and differ in susceptibility to, friends' delinquent behaviour as they perceive it—not to delinquent behaviour as reported by friends themselves. Copyright © 2015 European Association of Personality Psychology     

Circular vection is independent of stimulus eccentricity

The sensation of self-rotation induced by viewing a surround rotating about the observer's vertical axis (circular vection or CV) was investigated with equal-area stimuli located in either the central, the mid-peripheral, or the far-peripheral visual field. Magnitude estimation responses indicated greater CV with larger stimulus area, but no significant differences in CV sensations as a function of stimulus eccentricity. This pattern of results does not support the belief that CV is dominated by peripheral stimulation when equal-area stimuli are compared.     

Stepwise Latent Class Models for Explaining Group-Level Outcomes Using Discrete Individual-Level Predictors

Explaining group-level outcomes from individual-level predictors requires aggregating the individual-level scores to the group level and correcting the group-level estimates for measurement errors in the aggregated scores. However, for discrete variables it is not clear how to perform the aggregation and correction. It is shown how stepwise latent class analysis can be used to do this. First, a latent class model is estimated in which the scores on a discrete individual-level predictor are used to construct group-level latent classes. Second, this latent class model is used to aggregate the individual-level predictor by assigning the groups to the latent classes. Third, a group-level analysis is performed in which the aggregated measures are related to the remaining group-level variables while correcting for the measurement error in the class assignments. This stepwise approach is introduced in a multilevel mediation model with a single individual-level mediator, and compared to existing methods in a simulation study. We also show how a mediation model with multiple group-level latent variables can be used with multiple individual-level mediators and this model is applied to explain team productivity (group level) as a function of job control (individual level), job satisfaction (individual level), and enriched job design (group level).     

Explanatory,Multilevel Person-Fit Analysis of Response Consistency on the Spielberger State-Trait Anxiety Inventory

Self-report measures are vulnerable to concentration and motivation problems, leading to responses that may be inconsistent with the respondent's latent trait value. We investigated response consistency in a sample (N = 860) of cardiac patients with an implantable cardioverter defibrillator and their partners who completed the Spielberger State-Trait Anxiety Inventory on five measurement occasions. For each occasion and for both the state and trait subscales, we used the l ^p _z person-fit statistic to assess response consistency. We used multilevel analysis to model the between-person and within-person differences in the repeated observations of response consistency using time-dependent (e.g., mood states) and time-invariant explanatory variables (e.g., demographic characteristics). Respondents with lower education, undergoing psychological treatment, and with more post-traumatic stress disorder symptoms tended to respond less consistently. The percentages of explained variance in response consistency were small. Hence, we conclude that the results give insight into the causes of response inconsistency but that the identified explanatory variables are of limited practical value for identifying respondents at risk of producing invalid test results. We discuss explanations for the small percentage of explained variance and suggest alternative methods for studying causes of response inconsistency.