Observing repetitive finger movements modulates response times of auditorily cued finger movements

Our motor and perceptual representations of actions seem to be intimately linked and the human mirror neuron system (MNS) has been proposed as the mediator. In two experiments, we presented biological or non-biological movement stimuli that were either congruent or incongruent to a required response prompted by a tone. When the tone occurred with the onset of the last movement in a series, i.e., it was perceived during the movement presentation, congruent biological stimuli resulted in faster reaction times than congruent non-biological stimuli. The opposite was observed for incongruent stimuli. When the tone was presented after visual movement stimulation, however, no such interaction was present. This implies that biological movement stimuli only affect motor behaviour during visual processing but not thereafter. These data suggest that the MNS is an "online" system; longstanding repetitive visual stimulation (Experiment 1) has no benefit in comparison to only one or two repetitions (Experiment 2).     

Association between polymorphisms in the dopamine transporter gene and depression: evidence for a gene-environment interaction in a sample of juvenile detainees

Previous research has generated examples of how genetic and environmental factors can interact to create risk for psychopathology. Using a gene-by-environment (G x E) interaction design, we tested whether three polymorphisms in the dopamine transporter gene (DAT1, also referred to as SLC6A3, located at 5p15.33) interacted with maternal parenting style to predict first-onset episodes of depression. Participants were male adolescents (N= 176) recruited from a juvenile detention center in northern Russia. As hypothesized, one of the polymorphisms (rs40184) moderated the effect of perceived maternal rejection on the onset of major depressive disorder, as well as on suicidal ideation. Further, this G x E interaction was specific to depression; it did not predict clinically significant anxiety. These results highlight the need for further research investigating the moderating effects of dopaminergic genes on depression.     

An impoverished machine: Challenges to human learning and instructional technology

Many of the limitations to human learning and processing identified by cognitive psychologists over the last 50 years still hold true, including computational constraints, low learning rates, and unreliable processing. Instructional technology can be used in classrooms and in other learning contexts to address these limitations to learning. However, creating technological innovations is not enough. As part of psychological science, the development and assessment of instructional systems should be guided by theories and practices within the discipline. The technology we develop should become an object of research like other phenomena that are studied. In the present article, I present an informal account of my own work in assessing instructional technology for engineering thermodynamics to show not only the benefits, but also the limitations, in studying the technology we create. I conclude by considering several ways of advancing the development of instructional technology within the SCiP community, including interdisciplinary research and envisioning learning contexts that differ radically from traditional learning focused on lectures and testing.     

The philosophy of simulation: hot new issues or same old stew?

Computer simulations are an exciting tool that plays important roles in many scientific disciplines. This has attracted the attention of a number of philosophers of science. The main tenor in this literature is that computer simulations not only constitute interesting and powerful new science, but that they also raise a host of new philosophical issues. The protagonists in this debate claim no less than that simulations call into question our philosophical understanding of scientific ontology, the epistemology and semantics of models and theories, and the relation between experimentation and theorising, and submit that simulations demand a fundamentally new philosophy of science in many respects. The aim of this paper is to critically evaluate these claims. Our conclusion will be sober. We argue that these claims are overblown and that simulations, far from demanding a new metaphysics, epistemology, semantics and methodology, raise few if any new philosophical problems. The philosophical problems that do come up in connection with simulations are not specific to simulations and most of them are variants of problems that have been discussed in other contexts before. An erratum to this article can be found at     

Development and validation of the Inventory of Depression and Anxiety Symptoms (IDAS)

The authors describe a new self-report instrument, the Inventory of Depression and Anxiety Symptoms (IDAS), which was designed to assess specific symptom dimensions of major depression and related anxiety disorders. They created the IDAS by conducting principal factor analyses in 3 large samples (college students, psychiatric patients, community adults); the authors also examined the robustness of its psychometric properties in 5 additional samples (high school students, college students, young adults, postpartum women, psychiatric patients) who were not involved in the scale development process. The IDAS contains 10 specific symptom scales: Suicidality, Lassitude, Insomnia, Appetite Loss, Appetite Gain, Ill Temper, Well-Being, Panic, Social Anxiety, and Traumatic Intrusions. It also includes 2 broader scales: General Depression (which contains items overlapping with several other IDAS scales) and Dysphoria (which does not). The scales (a) are internally consistent, (b) capture the target dimensions well, and (c) define a single underlying factor. They show strong short-term stability and display excellent convergent validity and good discriminant validity in relation to other self-report and interview-based measures of depression and anxiety.     

Latent structure of anxiety: taxometric exploration

Taxometrics is a statistical tool that can be used to discern categories from continua. Taxometric analyses (MAXCOV and MAXEIG) were conducted in a large nonclinical sample (N=1,215) to determine whether extreme anxiety forms a distinct psychopathological category, an anxiety taxon. Anxiety was operationalized with self-report measures of subjective anxiety, anxious cognitive style, physiological arousal, and anxiety-related impairment. Procedures consistently identified a taxon with a prevalence of approximately 11%. Examination of the taxon's convergent and discriminant validity revealed that it reflects general distress rather than physiological arousal. Taxon membership showed some evidence of incremental validity.     

Updating in working memory: a comparison of good and poor comprehenders

In this research, we examined the relation between reading comprehension and success in a working memory updating task. We tested the hypotheses that poor comprehenders' deficiencies are associated with a specific difficulty in the working memory updating process, particularly in controlling for information that is no longer relevant. In the first experiment, groups of poor and good comprehenders, ages 8-11 years, were administered a working memory updating task. In the second experiment a year later, a subgroup of participants involved in the first experiment was tested with a different updating task. In both experiments, poor comprehenders had less accurate recall performance and made more intrusion errors than did good comprehenders. Moreover, distinguishing intrusion errors on the basis of their permanence in memory, we found that poor comprehenders were more likely to intrude items that were maintained longer in memory than were good comprehenders. This type of error predicted reading comprehension abilities better than did working memory recall. This suggests that the relation between reading comprehension and working memory is mediated by the ability to control for irrelevant information.