Inferences from memory: strategy- and exemplar-based judgment models compared

What are the cognitive processes underlying people's inferences from memory? To provide an answer, the exemplar-based approach to predicting people's inferences is tested against the strategy-based approach. Exemplar models assume that people make inferences about objects by retrieving similar objects from memory. In contrast, the strategy-based approach assumes that people select cognitive strategies that make inferences based on abstracted knowledge and information the inference situation provides. In Experiment 1, in which dichotomous feedback on the level of pair-comparisons was provided, almost all participants were classified as using a simple lexicographic strategy. In Experiment 2, in which continuous feedback for single objects was provided, most participants were classified as using a compensatory strategy. Both experiments suggest that the strategy-based approach is more suitable for predicting people's inferences from memory than the exemplar-based approach. The strategy-based approach shows how people adapt to inference situations by selecting different cognitive strategies.     

Inter-manual transfer and practice: Coding of simple motor sequences

Previous research suggests that movements are represented early in practice in visual-spatial coordinates/codes, which are effector independent, and later in practice in motor coordinates/codes (e.g., joint angles, activation patterns), which are effector dependent. In the present experiments, the task was to reproduce 1.3 s patterns of elbow flexions and extensions. An inter-manual transfer paradigm was used in Experiment 1 and an inter-manual practice paradigm was used in Experiment 2. The present results clearly indicated a strong advantage of effector transfer when the motor coordinates available during acquisition were reinstated (Experiment 1) and demonstrate that inter-manual practice with the same motor coordinates results in enhanced retention performance relative to transfer and practice where the same visual-spatial coordinates are used. These results demonstrate that the more effective movement code (motor or visual-spatial) is dependent on the movement sequence characteristics (e.g., difficulty, number of elements, and mode of control [preplanned or on-line]). These results are also interesting because they indicate, contrary to previous findings with more complex movement sequences, that an effective motor code can be developed relatively early in practice for rapid movement sequences.     

Conditionals Right and Left: Probabilities for the Whole Family

The fact that the standard probabilistic calculus does not define probabilities for sentences with embedded conditionals is a fundamental problem for the probabilistic theory of conditionals. Several authors have explored ways to assign probabilities to such sentences, but those proposals have come under criticism for making counterintuitive predictions. This paper examines the source of the problematic predictions and proposes an amendment which corrects them in a principled way. The account brings intuitions about counterfactual conditionals to bear on the interpretation of indicatives and relies on the notion of causal (in)dependence.     

A model of working memory capacity in the radial-arm maze task

The radial arm maze is one of the most commonly used tests for assessing working memory in laboratory animals. However, to date, there exists no quantitative method of estimating working memory capacity from performance on this task. Here, we present a mathematical model of performance on the radial arm maze from which we can derive estimates of capacity. We derive explicit results for the two most commonly used measures of performance as functions of number of arms in the maze and memory capacity, assuming a uniform random search. We simulate random non-uniform search strategies. Comparing our model to previous experiments, we show that our model predicts a working memory capacity in the range of 3-9 at the level of performance observed in these experiments. This estimate is within the typical estimate of human working memory capacity. Performance of rats on large mazes (e.g. 48 arms) has been used as evidence that the working memory capacity of rats may be significantly larger than that of humans. We report that memory capacity in the range 3-9 is sufficient to explain the performance of rats in very large radial mazes. Furthermore, when we simulate non-uniform random search strategies observed in the experiments, the resulting estimates do not differ significantly from those assuming a uniform random search. We conclude that a list-based model of working memory with modest capacity is more powerful than previously expected.     

Emotionally controlled decision-making and a gene variant related to serotonin synthesis in women with borderline personality disorder

The Iowa Gambling Task (IGT) was used to examine (i) social decision-making in women with borderline personality disorder (BPD), and (ii) the relationship between impaired decision-making and the tryptophan hydroxylase-1 (TPH-1) gene, involved in serotonin synthesis. Forty-two women with BPD and a history of suicide attempts were genotyped, and the frequency of a TPH-1 haplotype previously uniquely associated with BPD was calculated. The BPD group scored significantly lower than a control group in the IGT. Furthermore, the TPH-1 haplotype displayed a significantly higher frequency in BPD participants with impaired decision making, compared to BPD participants with normal scores. These findings suggest that impaired decision-making as determined by the IGT is a feature of BPD and may be (i) associated with serotonin dysfunction, and (ii) possibly relevant for suicidal behavior.     

Assessment of self-conscious emotions: a Swedish psychometric and structure evaluation of the Test of Self-Conscious Affect (TOSCA)

The Test of Self-Conscious Affect (TOSCA) is a well-established scenario-based questionnaire assessing self-conscious emotions, such as shame and guilt, which have been shown to be differentially associated with a variety of functional, motivational, behavioral and health outcomes. The aim of this study was to evaluate the psychometric properties and internal structure of a Swedish version of TOSCA in a sample of 361 healthy adults. The psychometric properties and internal consistency of the Swedish version were at level with the original US TOSCA version for shame, guilt and detachment. The internal structure of the Swedish version was acceptable for shame, guilt and detachment but contained shortcomings in assessment of externalization.     

Internet addiction among Norwegian adults: a stratified probability sample study

Most Norwegians are Internet users. We conducted a stratified probability sample study (Norway, 2007, age-group 16–74 years, N = 3,399, response rate 35.3%, 87.1% Internet users) to assess the prevalence of Internet addiction and at-risk Internet use by the Young Diagnostic Questionnaire (YDQ). The prevalence of Internet addiction (YDQ score 5–8) was 1.0% and an additional 5.2% were at-risk Internet users (YDQ score 3–4). Internet addiction and at-risk Internet use was strongly dependent on gender and age with highest prevalences among young males (16–29 years 4.1% and 19.0%, 30–39 years 3.3% and 10.7%). Logistic regression showed that male gender, young age, university level education, and an unsatisfactory financial situation were factors positively associated with "problematic Internet use" (at-risk and addicted use combined). Time spent on the Internet and prevalence of self-reported sleeping disorders, depression, and other psychological impairments increased linearly with YDQ score. Problematic Internet use clearly affects the lives of many people.     

How to handle anxiety: The effects of reappraisal, acceptance, and suppression strategies on anxious arousal

It has been suggested that reappraisal strategies are more effective than suppression strategies for regulating emotions. Recently, proponents of the acceptance-based behavior therapy movement have further emphasized the importance of acceptance-based emotion regulation techniques. In order to directly compare these different emotion regulation strategies, 202 volunteers were asked to give an impromptu speech in front of a video camera. Participants were randomly assigned to one of three groups. The Reappraisal group was instructed to regulate their anxious arousal by reappraising the situation; the Suppression group was asked to suppress their anxious behaviors; and the Acceptance group was instructed to accept their anxiety. As expected, the Suppression group showed a greater increase in heart rate from baseline than the Reappraisal and Acceptance groups. Moreover, the Suppression group reported more anxiety than the Reappraisal group. However, the Acceptance and Suppression groups did not differ in their subjective anxiety response. These results suggest that both reappraising and accepting anxiety is more effective for moderating the physiological arousal than suppressing anxiety. However, reappraising is more effective for moderating the subjective feeling of anxiety than attempts to suppress or accept it.