Processing order in dual-task situations: The “first-come,first-served” principle and the impact of task order instructions

When two overlapping tasks are processed, they hit a bottleneck at a central processing stage that prevents simultaneous processing of the two tasks. Thus far, however, the factors determining the processing order of the tasks at the bottleneck are unknown. The present study was designed to (re)investigate whether the arrival times of the two tasks at the central bottleneck are a key determinant of the processing order (cf. Sigman & Dehaene, 2006). To this end, we implemented a visual–auditory dual task with a random stimulus order, in which we manipulated arrival time by prolonging the initial, perceptual processing stage (stimulus analysis) of the visual task and compared the effects of this manipulation with those of one impacting the central bottleneck stage of the visual task. Additionally, we implemented two instruction conditions: Participants were told to respond either in the order of stimulus presentation or in the order they preferred. The manipulation of the visual perception stage led to an increase in task response reversals (i.e., the response order was different from the order of stimulus presentation), whereas there was no such increase when the bottleneck stage was manipulated. This pattern provides conclusive evidence that the processing order at the bottleneck is (at least in part) determined by the arrival times of the tasks at that point. Reaction time differences between the two instruction conditions indicated that additional control processes are engaged in determining task processing order when the participants are expressly told to respond in the order of stimulus presentation.     

Source consistency, distinctiveness, and consensus: the three dimensions of the Kelley ANOVA model in persuasion

Based on a conceptual analysis and existing research, the authors propose that the three source dimensions specified in the ANOVA model play similar roles in persuasion as other source characteristics (e.g., expertise). Two studies test assumptions derived from this approach regarding the effects of different combinations of consistency and consensus (Study 1) and distinctiveness and consensus (Study 2). Combinations resulting in contradictory (vs. similar) inferences regarding message validity should affect judgmental confidence and, consequently, affect message scrutiny. Study 1 shows that, as predicted, high consistency/low consensus and low consistency/high consensus (incongruent combinations) lead to higher desired confidence and more extensive message elaboration than high consistency/high consensus and low consistency/low consensus (congruent combinations). Similarly, Study 2 reveals heightened message scrutiny given incongruent (vs. congruent) combinations of distinctiveness and consensus. Results are discussed with respect to majority/minority influence processes and multiple source characteristics.     

: Applicants' experiences with discrimination explain their reactions to algorithms in personnel selection

Algorithms might prevent prejudices and increase objectivity in personnel selection decisions, but they have also been accused of being biased. We question whether algorithm-based decision-making or providing justifying information about the decision-maker (here: to prevent biases and prejudices and to make more objective decisions) helps organizations to attract a diverse workforce. In two experimental studies in which participants go through a digital interview, we find support for the overall negative effects of algorithms on fairness perceptions and organizational attractiveness. However, applicants with discrimination experiences tend to view algorithm-based decisions more positively than applicants without such experiences. We do not find evidence that providing justifying information affects applicants—regardless of whether they have experienced discrimination or not.     

The Effects of Tai Chi Chuan Relaxation and Exercise on Stress Responses and Well-Being: An Overview of Research

The rationale of this article is to review, analyze, and discuss studies concerning the role of Tai Chi in stress management and well-being, linking those studies to research on exercise, yoga, and relaxation with regard to physiological and psychological wellness. All studies reported in PsychLit and Medline between 1996 and 1999 directly related to the subject, plus other studies relevant for the analysis, are addressed in this review. Studies reviewed in this article characterize Tai Chi as a form of moderate exercise. Although Tai Chi may not be suitable for achieving aerobic fitness, it may enhance flexibility and overall psychological well-being. Cognitively, there are indications that Tai Chi exercise may lead to improvements in mood. However, it is not clear whether the positive effects of Tai Chi are due solely to its relaxation and meditation component, or whether they are the consequence of various peripheral factors, since it is known that stress reduction often occurs when we indulge in activities we find pleasurable and satisfying. An important finding is that all studies on the benefits of Tai Chi for senior adults have revealed positive results.     

A Social Problem-Solving Model of Adherence to HIV Medications.

HIV medication adherence remains a challenge and limits the degree to which treatment benefit can be maximized. This study tested an explanatory model of HIV medication adherence using a social problem-solving (SPS) framework. Associations of SPS with adherence are hypothesized to be direct and/or indirect via psychological health. HIV+ adults were interviewed using validated measures of SPS, psychological health, and antiretroviral therapy (ART) medication adherence. Structural equation modeling (SEM) techniques were used to test hypothesized relationships and to evaluate overall fit of the model to the data. SEM supported an indirect association (but not direct) of SPS on adherence via psychological health among the 545 HIV+ adults included in the analyses. Overall, the findings resulted in a model of adherence that offered very good fit to the data and correctly classified 97% of the cases as adherent versus nonadherent. Results support the use of SPS as a conceptual framework for understanding adherence to ART. Findings offer rationale and direction for SPS interventions to enhance adherence by improving psychological health. Such approaches, if effective, have the potential to positively impact psychological well being and adherence, thereby maximizing clinical benefit from treatment, which is linked to lower mortality from AIDS.     

Combining EEG,MIDI, and motion capture techniques for investigating musical performance

This article describes a setup for the simultaneous recording of electrophysiological data (EEG), musical data (MIDI), and three-dimensional movement data. Previously, each of these three different kinds of measurements, conducted sequentially, has been proven to provide important information about different aspects of music performance as an example of a demanding multisensory motor skill. With the method described here, it is possible to record brain-related activity and movement data simultaneously, with accurate timing resolution and at relatively low costs. EEG and MIDI data were synchronized with a modified version of the FTAP software, sending synchronization signals to the EEG recording device simultaneously with keypress events. Similarly, a motion capture system sent synchronization signals simultaneously with each recorded frame. The setup can be used for studies investigating cognitive and motor processes during music performance and music-like tasks—for example, in the domains of motor control, learning, music therapy, or musical emotions. Thus, this setup offers a promising possibility of a more behaviorally driven analysis of brain activity.     

Facial electromyography reveals dissociable affective responses in social and non-social cooperation

While economic standard theory explains cooperation in terms of rational decision-making, empirical studies suggest that humans have social preferences for cooperating with others. We investigated the specificity of these social preferences for interactions with human, relative to non-human, agents in a prisoner’s dilemma game. To obtain insights into emotional processes during cooperation, we measured activity of the corrugator supercilii muscle as indicator of spontaneous emotional responding during cooperation. After unreciprocated defection (free-riding), participants switched more often to a cooperative strategy and showed increased corrugator activity (suggesting more negative emotional responses) when playing with a human relative to a computer. This suggests that humans have a specific preference for cooperating with other humans and that cooperation may be promoted by unpleasant affect in response to the outcome of one’s own “free-riding”.     

Reminders of an agentic ingroup buffer disease uncontrollability

Chronic illness has negative impacts beyond those on physical health. In particular, because it is often experienced as uncontrollable, chronic illness might reduce people's general sense of personal control and, subsequently, personal well-being. Drawing on recent theory and research, we proposed and tested in four experiments (N_total = 1323) a potential buffer to these negative effects: thinking about an agentic social ingroup in one's life. In Study 1, patients suffering from a chronic illness that was either high or low in medical disease controllability were asked either to think about an agentic ingroup or a personal issue. Low perceived disease-related control was associated with low perceived personal control only when participants' personal self, but not when their ingroup, was salient. In three follow-up vignette studies, we asked participants to take the perspective of a person who suffered from a health problem of low medical disease controllability and attended a self-help group that was described as either high or low in agency. The findings supported the predicted buffering effect: participants who reflected on a target suffering from a low control disease thought that the target would experience more personal control when the agentic (vs. the nonagentic) self-help group was salient. These findings suggest ingroups can serve as a source of personal control in the context of health-related threats to the extent that they are perceived as agentic. Thus, focusing on agentic properties of (health-related) ingroups might be a promising novel strategy when designing effective group-based interventions to cope with chronic illness.     

Task switching: effects of practice on switch and mixing costs

In the task-switching paradigm, mixing costs indicate the performance costs to mix two different tasks, while switch costs indicate the performance costs to switch between two sequentially presented tasks. Applying tasks with bivalent stimuli and responses, many studies demonstrated substantial mixing and switch costs and a reduction of these costs as a result of practice. The present study investigates whether extensive practice of a task-switching situation including tasks with univalent stimuli eliminates these costs. Participants practiced switching between a visual and an auditory task. These tasks were chosen because they had shown eliminated performance costs in a comparable dual-task practice study (Schumacher et al. Psychol Sci 12:101–108, 2001). Participants either performed the tasks with univalent responses (i.e., visual-manual and auditory-verbal stimulus–response mappings) or bivalent responses (i.e., visual-manual and auditory-manual stimulus–response mappings). Both valence conditions revealed substantial mixing and switch costs at the beginning of practice, yet, mixing costs were largely eliminated after eight practice sessions while switch costs were still existent.