Reliability conducive measures of coherence

A measure of coherence is said to be truth conducive if and only if a higher degree of coherence (as measured) results in a higher likelihood of truth. Recent impossibility results strongly indicate that there are no (non-trivial) probabilistic coherence measures that are truth conducive. Indeed, this holds even if truth conduciveness is understood in a weak ceteris paribus sense (Bovens & Hartmann, 2003, Bayesian epistemology. New York, Oxford: Oxford University Press; Olsson, 2005, Against coherence: Truth probability and justification. Oxford: Oxford University Press). This raises the problem of how coherence could nonetheless be an epistemically important property. Our proposal is that coherence may be linked in a certain way to reliability. We define a measure of coherence to be reliability conducive if and only if a higher degree of coherence (as measured) results in a higher probability that the information sources are reliable. Restricting ourselves to the most basic case, we investigate which coherence measures in the literature are reliability conducive. It turns out that, while a number of measures fail to be reliability conducive, except possibly in a trivial and uninteresting sense, Shogenji’s measure and several measures generated by Douven and Meijs’s recipe are notable exceptions to this rule.     

The transportability of multisystemic therapy to Sweden: short-term results from a randomized trial of conduct-disordered youths

This randomized clinical trial assessed the effectiveness of multisystemic therapy (MST) for 156 youths who met the diagnostic criteria for conduct disorder. Sweden's 3 largest cities and 1 small town served as the recruiting area for the study. A mixed factorial design was used, with random allocation between MST and treatment as usual groups. Assessments were conducted at intake and 7 months after referral. With an intention-to-treat approach, results from multiagent and multimethod assessment batteries showed a general decrease in psychiatric problems and antisocial behaviors among participants across treatments. There were no significant differences in treatment effects between the 2 groups. The lack of treatment effect did not appear to be caused by site differences or variations in program maturity. MST treatment fidelity was lower than that of other studies, although not clearly related to treatment outcomes in this study. The results are discussed in terms of differences between Sweden and the United States. One difference is the way in which young offenders are processed (a child welfare approach vs. a juvenile justice system approach). Sociodemographic differences (e.g., rates of poverty, crime, and substance abuse) between the 2 countries may also have moderating effects on the rates of rehabilitation among young offenders. (PsycINFO Database Record (c) 2008 APA, all rights reserved).     

Capacity limitations and the detection of correlations: comment on Kareev (2000)

Y. Kareev (2000) argued that the limited capacity of working memory may be an adaptive advantage for the early detection of useful correlations. His analysis indeed suggests that the optimal sample size is close to G. A. Miller's (1956) "magical number 7 +/- 2." The authors point out logical and statistical limitations of Y. Kareev's (2000) analysis, including that it neglects that the adaptive value is not determined by the hit rate but by the posterior probability of hit and that only signal trials are considered. The authors' analysis demonstrates that when these limitations are corrected for, the alleged benefit for small samples does not occur, and larger samples imply considerable improvement in the detection of correlations.     

The role of social cognition in emotion

Although recent research has shown that social cognition and emotion engage overlapping regions of the brain, few accounts of this overlap have been offered. What systems might be commonly or distinctively involved in each? The close functional relationship between social cognition and emotion might be understood in terms of a central role for mental state attribution in the understanding, learning and regulation of emotion. In each of these cases, mental state attributions might be supported by either stimulus-driven or more reflective processes.     

Exemplars in the mist: the cognitive substrate of the representativeness heuristic

The idea that people often make probability judgments by a heuristic short-cut, the representativeness heuristic, has been widely influential, but also criticized for being vague. The empirical trademark of the heuristic is characteristic deviations between normative probabilities and judgments (e.g., the conjunction fallacy, base-rate neglect). In this article the authors contrast two hypotheses concerning the cognitive substrate of the representativeness heuristic, the prototype hypothesis (Kahneman & Frederick, 2002) and the exemplar hypothesis (Juslin & Persson, 2002), in a task especially designed to elicit representativeness effects. Computational modelling and an experiment reveal that representativeness effects are evident early in training and persist longer in a more complex task environment and that the data are best accounted for by a model implementing the exemplar hypothesis.     

Can exposure and acceptance strategies improve functioning and life satisfaction in people with chronic pain and whiplash-associated disorders (WAD)? A randomized controlled trial

Although 14% to 42% of people with whiplash injuries end up with chronic debilitating pain, there is still a paucity of empirically supported treatments for this group of patients. In chronic pain management, there is increasing consensus regarding the importance of a behavioural medicine approach to symptoms and disability. Cognitive behaviour therapy has proven to be beneficial in the treatment of chronic pain. An approach that promotes acceptance of, or willingness to experience, pain and other associated negative private events (e.g. fear, anxiety, and fatigue) instead of reducing or controlling symptoms has received increasing attention. Although the empirical support for treatments emphasizing exposure and acceptance (such as acceptance and commitment therapy) is growing, there is clearly a need for more outcome studies, especially randomized controlled trials. In this study, participants (N = 21) with chronic pain and whiplash-associated disorders were recruited from a patient organization and randomized to either a treatment or a wait-list control condition. Both groups continued to receive treatment as usual. In the experimental condition, a learning theory framework was applied to the analysis and treatment. The intervention consisted of a 10-session protocol emphasizing values-based exposure and acceptance strategies to improve functioning and life satisfaction by increasing the participants' abilities to behave in accordance with values in the presence of interfering pain and distress (psychological flexibility). After treatment, significant differences in favor of the treatment group were seen in pain disability, life satisfaction, fear of movements, depression, and psychological inflexibility. No change for any of the groups was seen in pain intensity. Improvements in the treatment group were maintained at 7-month follow-up. The authors discuss implications of these findings and offer suggestions for further research in this area.     

Demonstrator skill modulates observational aversive learning

Learning to avoid danger by observing others can be relatively safe, because it does not incur the potential costs of individual trial and error. However, information gained through social observation might be less reliable than information gained through individual experiences, underscoring the need to apply observational learning critically. In order for observational learning to be adaptive it should be modulated by the skill of the observed person, the demonstrator. To address this issue, we used a probabilistic two-choice task where participants learned to minimize the number of electric shocks through individual learning and by observing a demonstrator performing the same task. By manipulating the demonstrator’s skill we varied how useful the observable information was; the demonstrator either learned the task quickly or did not learn it at all (random choices). To investigate the modulatory effect in detail, the task was performed under three conditions of available observable information; no observable information, observation of choices only, and observation of both the choices and their consequences. As predicted, our results showed that observable information can improve performance compared to individual learning, both when the demonstrator is skilled and unskilled; observation of consequences improved performance for both groups while observation of choices only improved performance for the group observing the skilled demonstrator. Reinforcement learning modeling showed that demonstrator skill modulated observational learning from the demonstrator’s choices, but not their consequences, by increasing the degree of imitation over time for the group that observed a fast learner. Our results show that humans can adaptively modulate observational learning in response to the usefulness of observable information.     

Correcting Too Much or Too Little? The Performance of Three Chi-Square Corrections

This simulation study investigates the performance of three test statistics, T₁, T₂, and T₃, used to evaluate structural equation model fit under non normal data conditions. T₁ is the well-known mean-adjusted statistic of Satorra and Bentler. T₂ is the mean-and-variance adjusted statistic of Sattertwaithe type where the degrees of freedom is manipulated. T₃ is a recently proposed version of T₂ that does not manipulate degrees of freedom. Discrepancies between these statistics and their nominal chi-square distribution in terms of errors of Type I and Type II are investigated. All statistics are shown to be sensitive to increasing kurtosis in the data, with Type I error rates often far off the nominal level. Under excess kurtosis true models are generally over-rejected by T₁ and under-rejected by T₂ and T₃, which have similar performance in all conditions. Under misspecification there is a loss of power with increasing kurtosis, especially for T₂ and T₃. The coefficient of variation of the nonzero eigenvalues of a certain matrix is shown to be a reliable indicator for the adequacy of these statistics.