Separating response‐execution bias from decision bias: Arguments for an additional parameter in Ratcliff's diffusion model

Diffusion model data analysis permits the disentangling of different processes underlying the effects of experimental manipulations. Estimates can be provided for the speed of information accumulation, for the amount of information used to draw conclusions, and for a decision bias. One parameter describes the duration of non‐decisional processes including the duration of motor‐response execution. In the default diffusion model, it is implicitly assumed that both responses are executed with the same speed. In some applications of the diffusion model, this assumption will be violated. This will lead to biased parameter estimates. Consequently, we suggest accounting explicitly for differences in the speed of response execution for both responses. Results from a simulation study illustrate that parameter estimates from the default model are biased if the speed of response execution differs between responses. A second simulation study shows that large trial numbers (N>1,000) are needed to detect whether differences in response‐execution times are based on different execution times.     

Implicit and explicit self-esteem in the context of internet addiction

Previous research has repeatedly found that people suffering from some clinical disorders (e.g., bulimia nervosa, depression) possess low explicit (i.e., conscious, deliberate) self-esteem while at the same time displaying high implicit (i.e., unconscious, automatic) self-esteem. This phenomenon has been termed damaged self-esteem and was proposed to be an indicator of psychological distress. Although Internet addiction has been found to be associated with low levels of explicit self-esteem, as well as with high levels of psychological distress, its relation to implicit self-esteem has, to our knowledge, not been investigated thus far. We therefore hypothesized that the phenomenon of damaged self-esteem could also be found amongst people suffering from Internet addiction, and conducted two studies using the Initial Preference Task as a measure of implicit self-esteem. As expected, we found that individuals scoring high on Internet addiction possess low explicit and high implicit self-esteem. This effect was, however, only found for the first name initial of the Initial Preference Task, leading to the conclusion that first and last name initials might tap into different parts of implicit self-esteem.     

Hierarchical Multinomial Processing Tree Models: A Latent-Class Approach

Multinomial processing tree models are widely used in many areas of psychology. Their application relies on the assumption of parameter homogeneity, that is, on the assumption that participants do not differ in their parameter values. Tests for parameter homogeneity are proposed that can be routinely used as part of multinomial model analyses to defend the assumption. If parameter homogeneity is found to be violated, a new family of models, termed latent-class multinomial processing tree models, can be applied that accommodates parameter heterogeneity and correlated parameters, yet preserves most of the advantages of the traditional multinomial method. Estimation, goodness-of-fit tests, and tests of other hypotheses of interest are considered for the new family of models. The author thanks Bill Batchelder, Edgar Erdfelder, Thorsten Meiser, and Christoph Stahl for helpful comments on a previous version of this paper. The author is also grateful to Edgar Erdfelder for making available the data set analyzed in this paper.     

Two types of serial dependence in visual working memory

Stimulus representations in working memory depend on memory traces of past stimuli both from previous trials and from the current trial. However, it is unclear whether the same or different mechanisms underlie this serial dependence across and within trials. We directly contrasted estimates of bias for pairs of immediately successive stimuli across and within trials. In each trial, participants memorized two consecutive motion direction stimuli (S1 and S2) and after a short delay were cued to report one of them. We found serial dependence across trials: The current S1 was attracted towards the preceding S2 when the latter had been cued for report. In contrast, within the same trial S2 was repulsed from S1. In addition, repulsion within a trial occurred for a broader range of motion direction differences between stimuli than attraction across trials. A second experiment in which 25% of trials did not require a response demonstrated that across‐trial attraction did not depend on whether the previous S2 actually had to be reported. Our findings provide evidence for two types of serial dependence operating across and within trials. They support the notion of different mechanisms integrating or segregating current from similar past memory contents depending on their task relevance.     

Average Effects Based on Regressions with a Logarithmic Link Function: A New Approach with Stochastic Covariates

Psychometrika - Researchers often use regressions with a logarithmic link function to evaluate the effects of a treatment on a count variable. In order to judge the average effectiveness of the...     

Does attitude acquisition in evaluative conditioning without explicit CS-US memory reflect implicit misattribution of affect?

Research that dissociates different types of processes within a given task using a processing tree approach suggests that attitudes may be acquired through evaluative conditioning in the absence of explicit encoding of CS-US pairings in memory. This research distinguishes explicit memory for the CS-US pairings from CS-liking acquired without encoding of CS-US pairs in explicit memory. It has been suggested that the latter effect may be due to an implicit misattribution process that is assumed to operate when US evocativeness is low. In the present research, the latter assumption was supported neither by two high-powered experiments nor by complementary meta-analytic evidence, whereas evocativeness exerted an influence on explicit memory. This pattern of findings is inconsistent with the view that CS-liking acquired without encoding of CS-US pairs in explicit memory reflects an implicit misattribution process at learning. Hence, the underlying learning process is awaiting further empirical scrutiny.     

Decision noise: An explanation for observed violations of signal detection theory

In signal detection theory (SDT), responses are governed by perceptual noise and a flexible decision criterion. Recent criticisms of SDT (see, e.g., Balakrishnan, 1999) have identified violations of its assumptions, and researchers have suggested that SDT fundamentally misrepresents perceptual and decision processes. We hypothesize that, instead, these violations of SDT stem from decision noise: the inability to use deterministic response criteria. In order to investigate this hypothesis, we present a simple extension of SDT—the decision noise model—with which we demonstrate that shifts in a decision criterion can be masked by decision noise. In addition, we propose a new statistic that can help identify whether the violations of SDT stem from perceptual or from decision processes. The results of a stimulus classification experiment—together with model fits to past experiments—show that decision noise substantially affects performance. These findings suggest that decision noise is important across a wide range of tasks and needs to be better understood in order to accurately measure perceptual processes.     

‘Automatic’ evaluation? Strategic effects on affective priming

Two studies examined strategic effects on affective priming. Extending prior research by Klauer and Teige-Mocigemba [Klauer, K. C., & Teige-Mocigemba, S. (2007). Controllability and resource dependence in automatic evaluations. Journal of Experimental Social Psychology, 43, 648-655], the influence of different control strategies on a priming measure of prejudice was assessed. In both studies, a short stimulus onset asynchrony between prime and target (275 ms) was implemented along with considerable time pressure. In Study 1, participants could strategically eliminate priming effects with attitudinal prime categories (Arabs and liked celebrities) represented by several exemplars per category while priming effects for control categories remained intact. In Study 2, two strategies (payoff and faking) were induced to motivate participants to respond particularly fast and accurately to incongruent targets. Both strategies were successful in counteracting the usual priming effects, while leaving priming effects for non-targeted primes intact. We consider the role of so-called implementation intentions in accounting for the present findings.     

Rechtliche Grundlagen der psychosomatischen Rehabilitation Auswirkungen auf die Psychotherapeut-Patient-Beziehung

The legal foundation of psychosomatic rehabilitation, which amounts to more than half of all inpatient psychotherapies performed in Germany, includes the duty of the patient to cooperate, the pre-condition that there is a chance for increasing or restoring patient’s ability to work, and the obligation for therapists, to perform a socio-medical rating of patient's ability to work as well as a judgement about his/her credibility concerning the asserted handicaps and disabilities. All this has an influence on the relationship between psychotherapist und patient and leads to problems in the treatment especially of those patients, who wish to retire. For the psychotherapist not only counter—transferences may be difficult to handle but also role conflicts resulting above all from the challenge being simultaneously psychotherapist and medical expert, who has to rate patient's ability for work and his credibility. To keep capacity of acting, the psychotherapist should reflect these issues and make them transparent for the patient. Sufficient supervision is very important. This will not only improve patient's, but also pension scheme's profit.