Heterogeneity of strategy use in the Iowa gambling task: A comparison of win-stay/lose-shift and reinforcement learning models

The Iowa gambling task (IGT) has been used in numerous studies, often to examine decision-making performance in different clinical populations. Reinforcement learning (RL) models such as the expectancy valence (EV) model have often been used to characterize choice behavior in this work, and accordingly, parameter differences from these models have been used to examine differences in decision-making processes between different populations. These RL models assume a strategy whereby participants incrementally update the expected rewards for each option and probabilistically select options with higher expected rewards. Here we show that a formal model that assumes a win-stay/lose-shift (WSLS) strategy—which is sensitive only to the outcome of the previous choice—provides the best fit to IGT data from about half of our sample of healthy young adults, and that a prospect valence learning (PVL) model that utilizes a decay reinforcement learning rule provides the best fit to the other half of the data. Further analyses suggested that the better fits of the WSLS model to many participants’ data were not due to an enhanced ability of the WSLS model to mimic the RL strategy assumed by the PVL and EV models. These results suggest that WSLS is a common strategy in the IGT and that both heuristic-based and RL-based models should be used to inform decision-making behavior in the IGT and similar choice tasks.     

Left-Right Differences on Timed Motor Examination in Children

Age-related change in the difference between left- and right-side speed on motor examination may be an important indicator of maturation. Cortical maturation and myelination of the corpus callosum are considered to be related to increased bilateral skill and speed on timed motor tasks. We compared left minus right foot, hand, and finger speed differences using the Revised Physical and Neurological Assessment for Subtle Signs (PANESS; Denckla, 1985 Denckla, M. B. 1985. Revised neurological examination for subtle signs. Psychopharmacology Bulletin, 21: 773–779. [PubMed], [Web of Science ®] , [Google Scholar]); examining 130 typically developing right-handed children (65 boys, 65 girls) ages 7–14. Timed tasks included right and left sets of 20 toe taps, 10 toe-heel alternation sequences, 20 hand pats, 10 hand pronate-supinate sets, 20 finger taps, and 5 sequences of each finger-to-thumb apposition. For each individual, six difference scores between left- and right-sided speeded performances of timed motor tasks were analyzed. Left-right differences decreased significantly with age on toe tapping, heel-toe alternations, hand pronation-supination, finger repetition, and finger sequencing. There were significant gender effects for heel-toe sequences (boys showing a greater left-right difference than girls), and a significant interaction between age and gender for hand pronation-supination, such that the magnitude of the left-right difference was similar for younger, compared with older girls, while the difference was significantly larger for younger, compared to older boys. Speed of performing right and left timed motor tasks equalizes with development; for some tasks, the equalization occurs earlier in girls than in boys.     

The wane of childhood amnesia for autobiographical and public event memories

We modified Bruce, Dolan, and Phillips-Grant's (2000) threshold procedure for determining the wane of childhood amnesia. In two experiments, undergraduates labelled childhood events (e.g., your first permanent tooth came in) as know or recollect memories and estimated their age at the event's occurrence. In both studies the estimated transition from mostly know memories to mostly recollect memories was roughly 4.7 years. This transition estimate was replicated in a sample of adults (ages 24-65 years) with both Bruce et al.'s event-generation task and the Experiment 1a questionnaire. By contrast, in two experiments a transition estimate of roughly 6 years was found for undergraduates' memories of public events (e.g., the Challenger explosion). The wane of childhood amnesia appears to occur around 4.7 years.     

Contents of Volume 138

Volume Contents

Contents of Volume 138     

Understanding the emotional past: relations between parent and child contributions in emotionally negative and nonnegative events

The past event conversations of 33 mothers with their 3-year-old children (18 girls and 15 boys) were selected from a larger sample based on their discussion of negative events. Negative events included both those that were negative in topic and those that contained negative incidents but were otherwise positively themed. Within-subjects comparisons were made between the negative events and a neutral or positive event. There were few differences in how mothers and their children talked about negative and nonnegative events. Children did include more interpretations (internal state and causal references) in their negative event conversations. For both event types, mothers who talked more about the past events had children who reported more. When maternal talkativeness was controlled, involving children in the negative event conversations through deflecting the conversational turn predicted children's total contributions and number of interpretations. Repeating information and requests for information while constraining the topic was negatively related to the number of details children reported for nonnegative past events. Conversations about minor negative experiences demonstrate that mothers can influence children's involvement in discussions and understanding of the past.     

Bullying and victimization among black and Hispanic adolescents

The prevalence of bullying and victimization by gender, grade level, and race/ethnicity was examined among a sample of low socioeconomic, Black and Hispanic 6th- to 12th-graders in a large urban school district in Texas. Bullying and victimization were measured using specific behaviors. Students were classified as bullies (7%), victims (12%), bully-victims (5%), or neither (76%), depending on the number and frequency of reported experiences. For specific types of bullying (e.g., spreading rumors, excluding others), 4.5%-9.4% of students reported participation. Specific types of victimization (e.g., being hit or pushed, picked on) ranged from 6%-12%. Gender differences were not observed for general bullying and victimization, but physical and some verbal types were more prevalent among males. Blacks were more likely to participate in bullying and victimization, and these experiences seemed to peak in the 9th grade. This study adds to the literature as few U.S. studies on both general and specific types of bullying have been conducted among low socioeconomic, racial/ethnic minority students in middle and high school.     

Cognitive behavioral therapy for compulsive buying disorder

To our knowledge, no psychotherapy treatment studies for compulsive buying have been published. The authors conducted a pilot trial comparing the efficacy of a group cognitive behavioral intervention designed for the treatment of compulsive buying to a waiting list control. Twenty-eight subjects were assigned to receive active treatment and 11 to the waiting list control group. The results at the end of treatment showed significant advantages for cognitive behavioral therapy (CBT) over the waiting list in reductions in the number of compulsive buying episodes and time spent buying, as well as scores on the Yale–Brown Obsessive Compulsive Scale—Shopping Version and the Compulsive Buying Scale. Improvement was well-maintained at 6-month follow-up. The pilot data suggests that a cognitive behavioral intervention can be quite effective in the treatment of compulsive buying disorder. This model requires further testing.     

Recruitment of first-generation Latinos in a rural community: the essential nature of personal contact

The purpose of this article is to report on the success of various recruitment activities for a behavioral observation study with Spanish-speaking Latino families in a rural community in the western United States. Recruitment activities are pivotal to research to research because the enormous impact to the quality of the sample and, thus, the quality of the answers to the questions posed by the research. Recruitment can be especially challenging for researchers working with ethnic minorities due to a historical legacy of mistreatment by researchers that has led to healthy reticence to participate in research investigations. The present research presented unique challenges in that the data collection (1) took place in a rural community, (2) sought participation of a recent immigrant population, and (3) required videotaping. Data were collected from 50 families in a western rural community. After multiple recruitment strategies were used, the research team learned that word of mouth and use of existing community resources were the most powerful recruitment strategies. However, participant reports suggest that the other recruitment strategies helped familiarize participants with the study and potentially strengthened the influence of word of mouth referrals. Important differences were found between the easy-to-recruit and the hard-to-recruit samples within this study that support engagement in multiple recruitment strategies.     

Mathematics learning disability in girls with Turner syndrome or fragile X syndrome

Two studies were carried out to examine the persistence (Study 1) and characteristics (Study 2) of mathematics learning disability (MLD) in girls with Turner syndrome or fragile X during the primary school years (ages 5-9 years). In Study 1, the rate of MLD for each syndrome group exceeded the rate observed in a grade-matched comparison group, although the likelihood of MLD persisting through the primary school years was comparable for all three groups. In Study 2, formal and informal math skills were compared across the syndrome groups, a normative group, and children from the normative group who had MLD. Few differences were observed between the Turner syndrome and normative groups. Despite having rote counting and number representation skills comparable to those in the normative group, girls with fragile X had difficulty with counting rules (e.g., cardinality, number constancy). However, this difficulty did not distingush them from the MLD group. Overall, counting skills appear to distinguish the Turner syndrome and fragile X groups, suggesting that the specificity of math deficits emerges earlier for fragile X than Turner syndrome.     

Overestimation of heights in virtual reality is influenced more by perceived distal size than by the 2-D versus 3-D dimensionality of the display

One important aspect of the pictorial representation of a scene is the depiction of object proportions. Yang, Dixon, and Proffitt (1999 Perception 28 445-467) recently reported that the magnitude of the vertical-horizontal illusion was greater for vertical extents presented in three-dimensional (3-D) environments compared to two-dimensional (2-D) displays. However, because all of the 3-D environments were large and all of the 2-D displays were small, the question remains whether the observed magnitude differences were due solely to the dimensionality of the displays (2-D versus 3-D) or to the perceived distal size of the extents (small versus large). We investigated this question by comparing observers' judgments of vertical relative to horizontal extents on a large but 2-D display compared to the large 3-D and the small 2-D displays used by Yang et al (1999). The results confirmed that the magnitude differences for vertical overestimation between display media are influenced more by the perceived distal object size rather than by the dimensionality of the display.