Response times seen as decompression times in Boolean concept use

This paper reports a study of a multi-agent model of working memory (WM) in the context of Boolean concept learning. The model aims to assess the compressibility of information processed in WM. Concept complexity is described as a function of communication resources (i.e., the number of agents and the structure of communication between agents) required in WM to learn a target concept. This model has been successfully applied in measuring learning times for three-dimensional (3D) concepts (Mathy and Bradmetz in Curr Psychol Cognit 22(1):41-82, 2004). In this previous study, learning time was found to be a function of compression time. To assess the effect of decompression time, this paper presents an extended intra-conceptual study of response times for two- and 3D concepts. Response times are measured in recognition phases. The model explains why the time required to compress a sample of examples into a rule is directly linked to the time to decompress this rule when categorizing examples. Three experiments were conducted with 65, 49, and 84 undergraduate students who were given Boolean concept learning tasks in two and three dimensions (also called rule-based classification tasks). The results corroborate the metric of decompression given by the multi-agent model, especially when the model is parameterized following static serial processing of information. Also, this static serial model better fits the patterns of response times than an exemplar-based model.     

Clinical practice as natural laboratory for psychotherapy research: a guide to case-based time-series analysis

Both researchers and practitioners need to know more about how laboratory treatment protocols translate to real-world practice settings and how clinical innovations can be systematically tested and communicated to a skeptical scientific community. The single-case time-series study is well suited to opening a productive discourse between practice and laboratory. The appeal of case-based time-series studies, with multiple observations both before and after treatment, is that they enrich our design palette by providing the discipline another way to expand its empirical reach to practice settings and its subject matter to the contingencies of individual change. This article is a user's guide to conducting empirically respectable case-based time-series studies in a clinical practice or laboratory setting.     

Empathic deficits and alexithymia in trauma-related impulsive aggression

Our long term interest is to develop a developmental model of impulsive aggression based on a confluence of social, psychological and biological features. This approach incorporates neurobiological research, which has identified language processing deficits as a unique characteristic of impulsive aggressors and extends it to include emotional deficits. As an initial test of this hypothesis, we examined whether empathy and alexithymia were associated with impulsive aggression. Regressions were performed to explore the associations among impaired empathy, alexithymia, impulsive aggression, verbal and physical general aggression. Among impulsive aggressive veterans (n = 38) recruited from a VA trauma clinic, alexithymia predicted impulsive aggression and empathic deficits predicted verbal aggression. Neither emotional awareness deficit predicted general physical aggression in this middle-aged sample. Results suggested that empathic deficits were associated with general verbal aggression, but alexithymia was uniquely associated with impulsive aggression. Consideration of alexithymia in impulsive aggression has implications for its etiology, prevention and treatment. Published in 2008 by John Wiley & Sons, Ltd.     

Myopic biases in competitions

In three studies using both laboratory and field data, we show that the focal competitor’s strengths and weaknesses feature more prominently in predictions of the outcomes of future competitions than do the strengths and weaknesses of the opponents. People are more confident when their own side is strong, regardless of how strong the competition is. We show that this effect is driven by the fact that people have better information about their own side than the other side, in part because they preferentially seek out information about their own side. Implications for theories of decision making in competitive settings are discussed.     

The role of impulsivity in actual and problematic use of the mobile phone

Several authors have investigated the risks arising from the growth in mobile phone use (e.g. debts incurred by young people). The aims of the present study are (1) to validate a new questionnaire assessing problematic mobile phone use: the Problematic Mobile Phone Use Questionnaire (PMPUQ), and (2) to investigate the relationships between the PMPUQ and the multi‐faceted construct of impulsivity. With these aims, 339 subjects were screened using the PMPUQ and the UPPS Impulsive Behaviour Scale (UPPS) which assesses four distinct components associated with impulsive behaviours (urgency, lack of premeditation, lack of perseverance and sensation seeking). The results showed that the PMPUQ has an acceptable fit and assesses four different dimensions of problematic mobile phone use (prohibited use, dangerous use, dependence, financial problems). While each facet of impulsivity played a specific role in mobile phones use, urgency appeared to be the strongest predictor of problematic use. Copyright © 2008 John Wiley & Sons, Ltd.     

Awareness of action: Inference and prediction

This study investigates whether the conscious awareness of action is based on predictive motor control processes, or on inferential "sense-making" process that occur after the action itself. We investigated whether the temporal binding between perceptual estimates of operant actions and their effects depends on the occurrence of the effect (inferential processes) or on the prediction that the effect will occur (predictive processes). By varying the probability with which a simple manual action produced an auditory effect, we showed that both the actual and the predicted occurrence of the effect played a role. When predictability of the effect of action was low, temporal binding was found only on those trials where the auditory effect occurred. In contrast, when predictability of the effect of action was high, temporal binding occurred even on trials where the action produced no effect. Further analysis showed that the predictive process is modulated by recent experience of the action-effect relation. We conclude that the experience of action depends on a dynamic combination of predictive and inferential processes.     

Environmental cue saliency influences the vividness of a remote spatial memory in rats

The Morris water maze is frequently used to evaluate the acquisition and retrieval of spatial memories. Few experiments, however, have investigated the effects of environmental cue saliency on the strength or persistence of such memories after a short vs. long post-acquisition interval. Using a Morris water maze, we therefore tested in rats the effect of the saliency of distal cues on the vividness of a recent (5 days) vs. remote (25 days) memory. Rats trained in a cue-enriched vs. a cue-impoverished context showed a better overall level of performance during acquisition. Furthermore, the probe trials revealed that the rats trained and tested in the cue-impoverished context (1) spent less time in the target quadrant at the 25-day delay, and (2) swam shorter distances in the target area, with fewer crossings at both 5- and 25-day delays, as compared to their counterparts trained and tested in the cue-enriched context. Thus, the memory trace formed in the cue-enriched context shows better resistance to time, suggesting an implication of cue saliency in the vividness of a spatial memory.     

Distress, coping, and blogging: comparing new myspace users by their intention to blog.

New Myspace.com users (N = 134, mean age 24.5 years) completed a questionnaire about their intent to blog and several psychosocial variables. Intending bloggers scored higher on psychological distress, self-blame, and venting and scored lower on social integration and satisfaction with number of online and face-to-face friends. Intending bloggers may view this activity as a potential mechanism for coping with distress in situations in which they feel inadequately linked with social supports.     

Small and large number processing in infants and toddlers with Williams syndrome

Previous studies have suggested that typically developing 6‐month‐old infants are able to discriminate between small and large numerosities. However, discrimination between small numerosities in young infants is only possible when variables continuous with number (e.g. area or circumference) are confounded. In contrast, large number discrimination is successful even when variables continuous with number are systematically controlled for. These findings suggest the existence of different systems underlying small and large number processing in infancy. How do these develop in atypical syndromes? Williams syndrome (WS) is a rare neurocognitive developmental disorder in which numerical cognition has been found to be impaired in older children and adults. Do impairments of number processing have their origins in infancy? Here this question is investigated by testing the small and large number discrimination abilities of infants and toddlers with WS. While infants with WS were able to discriminate between 2 and 3 elements when total area was confounded with numerosity, the same infants did not discriminate between 8 and 16 elements, when number was not confounded with continuous variables. These findings suggest that a system for tracking the features of small numbers of object (object‐file representation) may be functional in WS, while large number discrimination is impaired from an early age onwards. Finally, we argue that individual differences in large number processing in infancy are more likely than small number processing to be predictive of later development of numerical cognition.