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”.     

Reconciling justificatory internalism and content externalism

At first pass, internalism about justification is the view that there is no justificatory difference without an internal difference. Externalism about mental content is the view that there are differences in mental content without an internal difference. Assuming (complete) mental contents are the primary bearers of justificatory features, the two views are in obvious tension. The goal of this paper is to determine how the tension is best resolved.     

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.     

Emotional response to musical repetition

Two experiments examined the effects of repetition on listeners' emotional response to music. Listeners heard recordings of orchestral music that contained a large section repeated twice. The music had a symmetric phrase structure (same-length phrases) in Experiment 1 and an asymmetric phrase structure (different-length phrases) in Experiment 2, hypothesized to alter the predictability of sensitivity to musical repetition. Continuous measures of arousal and valence were compared across music that contained identical repetition, variation (related), or contrasting (unrelated) structure. Listeners' emotional arousal ratings differed most for contrasting music, moderately for variations, and least for repeating musical segments. A computational model for the detection of repeated musical segments was applied to the listeners' emotional responses. The model detected the locations of phrase boundaries from the emotional responses better than from performed tempo or physical intensity in both experiments. These findings indicate the importance of repetition in listeners' emotional response to music and in the perceptual segmentation of musical structure.     

Professional values and their development among trainees in psychoanalytic psychotherapy1

Forty-six psychotherapy students in three groups at one training institute for psychoanalytic psychotherapy in Sweden were asked to fill out a questionnaire about important influences on their professional development during their three-year training and afterwards. The questionnaire was distributed on three occasions during the training program and on one later occasion. Twenty-one students responded to the questionnaire on all four occasions. Working with patients in therapy, getting supervision, and participating in personal psychotherapy were viewed as the three most important influences on the students. The importance attributed to specialist literature and technical skills seemed to increase over time during the training, while the influences of experiences in personal life and personal qualities decreased. These changes in reported views were reversed in the initial years after graduation. Concerning assets, the students valued the ability to be containing and emphatic as the most important, but in their first years as licensed psychotherapists assigned more importance to the ability to create contact. The training program led to a change over time in a higher rating for the importance of technical and methodological attributes and less emphasis on personal characteristics and experiences. Most of the changes reported during training tended to be reversed afterwards.     

The Use of the MacAndrew Alcoholism Scale in Detecting Substance Abuse and Antisocial Personality

We evaluated the hypothesis that characterological factors, particularly antisocial personality, influence scores on the MacAndrew Alcoholism Scale (MAC). Using the Washington University research criteria to establish diagnoses, the following subgroups were defined: subjects who received no psychiatric diagnoses; subjects who received diagnoses other than alcoholism, drug dependence, or antisocial personality; and subjects who received a diagnosis of alcoholism, drug dependence, and/or antisocial personality, alone or in combination with other psychiatric diagnoses. The highest MAC scores were obtained by subjects diagnosed as having antisocial personality without alcoholism or drug dependence and subjects diagnosed with antisocial personality, drug dependence, and alcoholism. Alcoholics without antisocial personality or drug dependence, and subjects with other psychiatric diagnoses scored lowest. Although higher MAC scores were obtained by males, MAC scores greater than 24 correctly classified the greatest number of males and females as alcoholic, drug dependent and/or antisocial. These findings are interpreted as consistent with MacAndrew's reinterpretation of the scale as assessing a dimension of personality, rather than solely a tendency to addiction.     

Setting things straight: A comparison of measures of saccade trajectory deviation

In eye movements, saccade trajectory deviation has often been used as a physiological operationalization of visual attention, distraction, or the visual system’s prioritization of different sources of information. However, there are many ways to measure saccade trajectories and to quantify their deviation. This may lead to noncomparable results and poses the problem of choosing a method that will maximize statistical power. Using data from existing studies and from our own experiments, we used principal components analysis to carry out a systematic quantification of the relationships among eight different measures of saccade trajectory deviation and their power to detect the effects of experimental manipulations, as measured by standardized effect size. We concluded that (1) the saccade deviation measure is a good default measure of saccade trajectory deviation, because it is somewhat correlated with all other measures and shows relatively high effect sizes for two well-known experimental effects; (2) more generally, measures made relative to the position of the saccade target are more powerful; and (3) measures of deviation based on the early part of the saccade are made more stable when they are based on data from an eyetracker with a high sampling rate. Our recommendations may be of use to future eye movement researchers seeking to optimize the designs of their studies.     

Concurrent deployment of visual attention and response selection bottleneck in a dual-task: Electrophysiological and behavioural evidence

Visual attention and response selection are limited in capacity. Here, we investigated whether visual attention requires the same bottleneck mechanism as response selection in a dual-task of the psychological refractory period (PRP) paradigm. The dual-task consisted of an auditory two-choice discrimination Task 1 and a conjunction search Task 2, which were presented at variable temporal intervals (stimulus onset asynchrony, SOA). In conjunction search, visual attention is required to select items and to bind their features resulting in a serial search process around the items in the search display (i.e., set size). We measured the reaction time of the visual search task (RT2) and the N2pc, an event-related potential (ERP), which reflects lateralized visual attention processes. If the response selection processes in Task 1 influence the visual attention processes in Task 2, N2pc latency and amplitude would be delayed and attenuated at short SOA compared to long SOA. The results, however, showed that latency and amplitude were independent of SOA, indicating that visual attention was concurrently deployed to response selection. Moreover, the RT2 analysis revealed an underadditive interaction of SOA and set size. We concluded that visual attention does not require the same bottleneck mechanism as response selection in dual-tasks.     

Telling things apart: the distance between response keys influences categorization times

People use spatial distance to talk and think about differences between concepts, and it has been argued that using space to think about different categories provides a scaffold for the categorization process. In the current study, we investigated the possibility that the distance between response keys can influence categorization times in binary classification tasks. In line with the hypothesis that distance between response keys can facilitate response selection in a key-press version of the Stroop task, our results showed that responses on incongruent Stroop trials were significantly facilitated when participants performed the Stroop task with response keys located far apart, compared with when they performed the task with response keys located close together. These results support the idea that the spatial structuring of response options facilitates categorizations that require cognitive effort, and that people can incorporate environmental structures such as spatial distance in their thought processes. Keeping your hands apart might actually help to keep things apart in your mind.