Altering the Shape of Punishment Distributions Affects Decision Making in a Modified Iowa Gambling Task

Neuroeconomics research has shown that preference for gambling is altered by the statistical moments (mean, variance, and skew) of reward and punishment distributions. Although it has been shown that altered means can affect feedback‐based decision making tasks, little is known if the variance and skew will have an effect on these tasks. To investigate, we systematically controlled the variance (high, medium, and low) and skew (negative, zero, and positive) of the punishment distributions in a modified version of the Iowa Gambling Task. The Iowa Gambling Task has been used extensively in both academic and clinical domains to understand decision making and diagnose decision making impairments. Our results show that decision making can be altered by an interaction of variance and skew. We found a significant decrease over trials in choices from the decks with high variance and asymmetrically skewed punishments and from the decks with low variance and zero skew punishments. These results indicate that punishment distribution shape alone can change human perception of what is optimal (i.e., mean expected outcome) and may help explain what guides our day‐to‐day decisions. Copyright © 2013 John Wiley & Sons, Ltd.     

Where are virtues?

Philosophical Studies - This paper argues that the question, ‘where are virtues?’ demands a response from virtue theorists. Despite the polarizing nature of debates about the relevance...     

Functional communication training: From efficacy to effectiveness

Functional communication training (FCT; Carr & Durand, 1985) is a common function‐based treatment in which an alternative form of communication is taught to reduce problem behavior. FCT has been shown to result in substantial reductions of a variety of topographically and functionally different types of problem behavior in children and adults (efficacy). The extent to which these reductions maintain in relevant contexts and result in meaningful changes in the lives of those impacted (effectiveness) is the focus of this paper. This review evaluates the degree to which FCT has been established as an evidence‐based practice in psychology (EBPP) according to the definition set out by the American Psychological Association's 2005 Presidential Task Force on Evidence‐Based Practice. Our review finds overwhelming evidence in support of FCT as an efficacious treatment but highlights significant limitations in support of its effectiveness. In order to also be recognized as an EBPP, future research on FCT will need to focus more closely on issues related to home, school, and community application, feasibility, consumer satisfaction, and more general and global changes for the individual.     

Adaptive spatial working memory assessments for aging pet dogs

Assessments for spatial working memory (SWM) in pet dogs that can detect age-related cognitive deficits in a single session may aid in diagnosing canine dementia and may facilitate translational research on Alzheimer’s disease in humans. Adaptive testing procedures are widely used in single-session assessments for humans with diverse cognitive abilities. In this study, we designed and deployed two up-down staircase assessments for SWM in which 26 pet dogs were required to recall the location of a treat hidden behind one of two identical boxes following delays of variable length. In the first experiment, performance tended to decline with age but few dogs completed the test (n?=?10). However, all of the dogs that participated in the second experiment (n?=?24) completed the assessment and provided reliable evidence of learning and retaining the task. Delay length and age significantly predicted performance supporting the validity of this assessment. The relationships between age and performance were described by inverted U-shaped functions as both old and young dogs displayed deficits in weighted cumulative-scores and trial-by-trial performance. Thus, SWM in pet dogs may develop until midlife and decline thereafter. Exploratory analyses of non-mnemonic fixation strategies, sustained engagement, inhibitory control, and potential improvements for future SWM assessments which adopt this paradigm are also discussed.

     

When is the Wilcoxon–Mann–Whitney procedure a test of location? Implications for effect-size measures

The Wilcoxon–Mann–Whitney procedure is invariant under monotone transformations but its use as a test of location or shift is said not to be so. It tests location only under the shift model, the assumption of parallel cumulative distribution functions (cdfs). We show that infinitely many monotone transformations of the measured variable produce parallel cdfs, so long as the original cdfs intersect nowhere or everywhere. Thus there are infinitely many effect sizes measured as shifts of medians, invalidating the notion that there is one true shift parameter and thereby rendering any single estimate dubious. Measuring effect size using the probability of superiority alleviates this difficulty.