Enhancing tolerance to delayed reinforcers: the role of intervening activities

Three participants with moderate to profound mental retardation were exposed to choices between an immediate small amount and a delayed larger amount of a preferred reinforcer. All participants initially showed a relatively high preference for the smaller reinforcer, suggesting impulsive choice making. However this preference reversed, suggesting self-control, when the larger reinforcer was available immediately and, over time, its delay was gradually increased. Results highlight the potential utility of incorporating concurrent activities into self-control training paradigms.     

Selective adult age differences in an age-invariant multifactor model of declarative memory

Confirmatory factor analysis was used to test competing models of declarative memory. Data from middle-aged participants provided support for a model comprised of 2 2nd-order (episodic and semantic memory) and 4 1st-order (recall, recognition, fluency, and knowledge) factors. Extending this model across young-old and old-old participants established support for age invariance. Tests of group differences showed an age deficit in episodic memory that was more pronounced for recall than for recognition. For semantic memory, there was an increase in knowledge from middle to young-old age and thereafter a decrease. Overall, the results support the view that episodic memory is more age sensitive than semantic memory, but they also indicate that aging has differential effects within these 2 forms of memory.     

The p-value fallacy and how to avoid it.

Null hypothesis significance tests are commonly used to provide a link between empirical evidence and theoretical interpretation. However, this strategy is prone to the "p-value fallacy" in which effects and interactions are classified as either "noise" or "real" based on whether the associated p value is greater or less than .05. This dichotomous classification can lead to dramatic misconstruals of the evidence provided by an experiment. For example, it is quite possible to have similar patterns of means that lead to entirely different patterns of significance, and one can easily find the same patterns of significance that are associated with completely different patterns of means. Describing data in terms of an inventory of significant and nonsignificant effects can thus completely misrepresent the results. An alternative analytical technique is to identify competing interpretations of the data and then use likelihood ratios to assess which interpretation provides the better account. Several different methods of calculating the likelihood ratios are illustrated. It is argued that this approach satisfies a principle of "graded evidence," according to which similar data should provide similar evidence.     

An evaluation of response allocations to concurrently available slot machine simulations

Gambling behavior often involves making choices between concurrently available game options. With regard to slot machine gambling, multiple games allow for choices to be made with respect to which game to play. The authors of the present study used a slot machine simulation created in Visual Basic. NET to examine gambling preference. The specific question addressed was whether gamblers prefer a smaller payout more often (averaging around every 10 spins) over a larger payout less often (averaging around every 50 spins). Two types of reinforcement were examined during the study: frequency of payouts and the amount of credits won. The results indicate that participants had a preference for a slot machine with the more frequent payout as opposed to one with more intermittent payout. These results support existing literature on theories of choice and provide a step toward understanding human gambling behavior.     

Psychological Adjustment and Knowledge About Hereditary Hemochromatosis in a Clinic-Based Sample: A Prospective Study

This study assessed psychological adjustment and quality of life relative to population-based norms and knowledge about hereditary hemochromatosis in a sample of 101 patients who attended a hemochromatosis clinic. Participants were assessed prior to their clinic visit, and two weeks and 12 months after attendance, using self-administered questionnaires. Mean Mental Health Component Scores from the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) (45.3, 95% CI 43.2, 47.4) were as compromised as those found amongst stroke victims (45.9, 95% CI 42.8, 49.0) who had participated in a national health survey. Recall of the genetic testing result was less than optimal, in that only 69.3% of those with genetic testing results knew whether they carried one or two mutations. This study demonstrates that patients would benefit from routine assessment of psychological distress and referral to mental health professionals of those whose levels of distress suggest a need for clinical intervention. Results also show that patients may benefit from strategies aimed at improving recall of genetic testing results.     

Not all triads are created equal: further support for the importance of visual and semantic proximity in object identification

Identification deficits were investigated in ELM, a temporal lobe stroke patient with category-specific deficits. We replicated previous work done on FS, a patient with category specific deficits as a result of herpes viral encephalitis. ELM was tested using novel, computer generated shapes that were paired with artifact labels. We paired semantically close or disparate labels to shapes and ELM attempted to learn these pairings. Overall, ELM's shape-label confusions were most detrimentally affected when we used labels that referred to objects that were visually and semantically close. However, as with FS, ELM had as many errors when shapes were paired with the labels "donut," "tire," and "washer" as he did when they were paired with visually and semantically close artifact labels. Two explanations are put forth to account for the anomalous performance by both patients on the triad of donut-tire-washer.     

Recreating Raven’s: Software for systematically generating large numbers of Raven-like matrix problems with normed properties

Raven’s Progressive Matrices is a widely used test for assessing intelligence and reasoning ability (Raven, Court, & Raven, 1998). Since the test is nonverbal, it can be applied to many different populations and has been used all over the world (Court & Raven, 1995). However, relatively few matrices are in the sets developed by Raven, which limits their use in experiments requiring large numbers of stimuli. For the present study, we analyzed the types of relations that appear in Raven’s original Standard Progressive Matrices (SPMs) and created a software tool that can combine the same types of relations according to parameters chosen by the experimenter, to produce very large numbers of matrix problems with specific properties. We then conducted a norming study in which the matrices we generated were compared with the actual SPMs. This study showed that the generated matrices both covered and expanded on the range of problem difficulties provided by the SPMs.     

Who Will Volunteer? Religiosity, Everyday Racism, and Social Participation Among African American Men

This study explores the relative importance of everyday racism, empathic concern, communalism, and religiosity as predictors of pro-social involvement (i.e., volunteerism and membership in political/social justice organizations) among a sample of African American men (N = 151). Church involvement emerged as a positive predictor of the likelihood that these men were involved in volunteer work as well as the number of hours that men dedicated to volunteer work. Communalism positively predicted the amount of time (in hours per year) that men were involved in volunteer work. Subjective religiosity and the stress of everyday racism were associated with a greater likelihood of being a member of a political–social justice organization. Implications of these findings are discussed.     

Exploring the utility of functional analysis methodology to assess and treat problematic verbal behavior in persons with acquired brain injury

Functional analyses were conducted on four adults with acquired brain injuries who regularly displayed instances of inappropriate verbal behavior including depressive, aggressive, suicidal, profane, and sexually inappropriate utterances. After the functional analysis yielded a maintaining variable for each participant, a function‐based intervention consisting of differential reinforcement of alternative verbal behavior was implemented. Results of the behavioral interventions show that instances of vocal behavior can be assessed and subsequently treated using the functional analysis methodology often reserved for nonverbal forms of behavior. The utility of functional analysis for assessing complex human behavior is discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

Exploring collaborative problem solving in adulthood

Collaborative problem solving occurs in situations in which two or more individuals cooperate in appraising, representing, and solving a variety of cognitive tasks. Collaborative groups are the context for much everyday cognitive activity in adulthood. Collaboration has been explored as a means through which older adults may maintain high levels of performance, perhaps compensating for individual-level cognitive and neurological decline. This study explored the effects of collaboration (group size) and adult age on solving both fixed- and unrestricted-alternatives 20 Questions tasks. Younger (M=24.3 years) and older (M=67.9 years) adults were randomly assigned to one of three homogeneous group size conditions: individuals, dyads, and tetrads. Results indicated some dissociation between individual-level performance (poorer for older adults) and collaborative performance (better for older adults). For the fixed-alternatives task, older adults produced more of the relatively inefficient hypothesis-scanning questions than did younger adults. In contrast, older collaborative groups produced more of the efficient constraint-seeking questions than hhpothesis-scanning questions, and an amount equivalent to that of younger adults. Overall performance for the difficult unrestricted-alternatives task was less efficient for both younger and older adults. The roles of task type, group characteristics, and adult age are discussed.