Delay of gratification: impulsive choices and problem behaviors in early and late adolescence

High school students were offered a monetary incentive for participating in research. They were given a choice between a smaller fee immediately or a larger fee one week later. Compared to students who delayed gratification, those who chose the immediate fee showed more self-regulatory deficits. They showed greater involvement with cigarettes, alcohol, and marijuana, had a poorer self-concept and underperformed academically. A replication study with middle-school students and different reward parameters yielded equivalent results. Younger adolescents who chose the immediate monetary incentive showed a similar pattern of problem behaviors as the high school students. The findings indicate that this simple choice-delay procedure yields an unobtrusive behavioral measure of self-regulation and offers a developmentally appropriate extension of the delay-of-gratification paradigm for use with older children and adolescents.     

Preference and resistance to change with constant- and variable-duration terminal links: independence of reinforcement rate and magnitude

Pigeons responded in a three-component multiple concurrent-chains procedure in which the variable-interval reinforcement schedules were the same across components but magnitudes differed across components. The terminal links were arranged either as a variable delay followed by presentation of a reinforcer ("variable duration") or as a fixed period of access to the schedule during which a variable number of reinforcers could be earned ("constant duration"). Relative reinforcement rate was varied parametrically across both types of conditions. After baseline training in each condition, resistance to change of terminal-link responding was assessed by delivering food during the initial links according to a variable-time schedule. Both preference and resistance to change were more sensitive to reinforcement-rate differences in the constant-duration conditions. Sensitivities of preference and resistance to change to relative reinforcement rate did not change depending on relative reinforcement magnitude. Taken together, these results confirm and extend those of prior studies, and suggest that reinforcement rate and magnitude combine additively to determine preference and resistance to change. A single structural relation linking preference and resistance to change describes all the data from this and several related studies.     

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.     

Path integration from optic flow and body senses in a homing task

We examined the roles of information from optic flow and body senses (eg vestibular and proprioceptive information) for path integration, using a triangle completion task in a virtual environment. In two experiments, the contribution of optic flow was isolated by using a joystick control. Five circular arenas were used for testing: (B) both floor and wall texture; (F) floor texture only, reducing information for rotation; (W) wall texture only, reducing information for translation; (N) a no texture control condition, and (P) an array of posts. The results indicate that humans can use optic flow for path integration and are differentially influenced by rotational and translational flow. In a third experiment, participants actively walked in arenas B, F, and N, so body senses were also available. Performance shifted from a pattern of underturning to overturning and exhibited decreased variability, similar responses with and without optic flow, and no attrition. The results indicate that path integration can be performed by integrating optic flow, but when information from body senses is available it appears to dominate.     

Intervening to improve communication between parents, teachers, and primary care providers of children with ADHD or at high risk for ADHD

This study examines interventions designed to improve communication between individuals who take care of children with ADHD. A teacher rating of 6,171 elementary school children identifies 1,573 children with ADHD or with high risk for ADHD. Parent interviews and information from teachers are collected on 243 children who are randomized into treatment and control conditions and followed for 39 months. The interventions consisted of group workshops and single one-on-one tutorials with parents, teachers, and providers about the evaluation and treatment of ADHD that stressed the need for communication between the three parties. There are few significant effects on communication that are short lived. Results suggest that the interventions are insufficient to cause significant increase in communication. Future attempts to improve parent-teacher-provider coordination should be continuing rather than single-session interventions.     

The influence of exploration mode, orientation, and configuration on the haptic Müller-Lyer illusion

We studied the impact of manner of exploration, orientation, spatial position, and configuration on the haptic Müller-Lyer illusion. Blindfolded sighted subjects felt raised-line Müller-Lyer and control stimuli. The stimuli were felt by tracing with the index finger, free exploration, grasping with the index finger and thumb, or by measuring with the use of any two or more fingers. For haptic judgments of extent a sliding tangible ruler was used. The illusion was present in all exploration conditions, with overestimation of the wings-out compared to wings-in stimuli. Tracing with the index finger reduced the magnitude of the illusion. However, tracing and grasping induced an overall underestimation of size. The illusion was greatly attenuated when stimuli were felt with the index fingers of both hands. Illusory misperception was not altered by the position in space of the Müller-Lyer stimuli. No effects of changes in the thickness of the line shaft were found, but there were effects of the length of the wing endings for the smaller, 5.1 cm stimuli. The theoretical and practical implications of the results are discussed.     

Task complexity and older adults' decision-making competence

This article reports progress in an ongoing research program examining older adults' decision-making competence (DMC). Using a theoretical framework that emphasizes the person-task fit in assessing DMC, the authors report the results of a study comparing older versus younger adults' decision performance on simple and complex tasks about health, finance, and nutrition. The authors hypothesized and found that increasing age and task complexity were related to greater comprehension errors and inconsistency in decision making. Hierarchical regression analyses showed that a large amount of age-related variance in performance on the decision tasks could be accounted for by exogenous social variables, health measures, basic cognitive skills, and attitudinal measures. The discussion emphasizes several directions for future research, including the need to validate the meaning of performance on these tasks for real-life decision processes.     

Item method directed forgetting diminishes false memory

Directed forgetting may reduce DRM false memory illusion by interfering with meaning processing. Participants were presented with a list composed of six 10-word semantically associated sub-lists, and they were either (a) asked to remember all list items of (b) asked to remember all associates from sub-lists and to forget all associates from other sub-lists. All participants were requested to recall and recognise list items. Although directed forgetting effects have been previously reported only for true responses in the DRM paradigm with the list method, we also found directed forgetting for false responses with the item method. Such forgetting instructions reduced both verbatim and meaning processing, decreasing both the intrusion and the false alarm rate. These results are consistent with two-process explanations of DRM false memories, such as fuzzy-trace theory, and add to our understanding of false memory editing.     

Exposure to Externalizing Peers in Early Childhood: Homophily and Peer Contagion Processes

Guided by a transactional model, we examined the predictors and effects of exposure to externalizing peers in a low-risk sample of preschoolers and kindergarteners. On the basis of daily observations of peer interactions, we calculated measures of total exposure to externalizing peers and measures of exposure to same- and other-sex externalizing peers. Analyses of predictors of externalizing peer exposure supported a homophily hypothesis for girls. Tests of peer contagion effects varied by sex, and exposure to externalizing peers predicted multiple problem behaviors for girls but not for boys. Sex differences were a function of childrens own sex, but not of peers sex. The study provides evidence of externalizing peer exposure effects in a low-risk sample of young children, notably for girls.Contributed equally to the conceptualization of this project