Category effects on stimulus estimation: Shifting and skewed frequency distributions

The category adjustment model (CAM) proposes that estimates of inexactly remembered stimuli are adjusted toward the central value of the category of which the stimuli are members. Adjusting estimates toward the average value of all category instances, properly weighted for memory uncertainty, maximizes the average accuracy of estimates. Thus far, the CAM has been tested only with symmetrical category distributions in which the central stimulus value is also the mean. We report two experiments using asymmetric (skewed) distributions in which there is more than one possible central value: one where the frequency distribution shifts over the course of time, and the other where the frequency distribution is skewed. In both cases, we find that people adjust estimates toward the category’s running mean, which is consistent with the CAM but not with alternative explanations for the adjustment of stimuli toward a category’s central value.     

Co-occurring disorders: a possible key to visual perceptual deficits in children with developmental coordination disorder?

A study was conducted to examine how visual perceptual functioning in children with DCD may be influenced by co-occurring learning problems such as reading disabilities (RD) and/or attention deficit hyperactivity disorder (ADHD). Participants included seven groups of children: 27 children with DCD only, 11 with ADHD only, 14 with RD only, 63 with DCD and at least one other disorder (i.e., DCD + ADHD, DCD + RD, DCD + ADHD + RD), and 73 typically developing controls. Visual perceptual skills were assessed using the Test of Visual Perceptual Skills (TVPS) and the Rey Osterreith Complex Figure (ROCF; copy and delayed recall). Children with DCD and at least one other disorder were found to have impairments on the TVPS compared to children with DCD only, ADHD only, and typically developing controls, particularly on subtests assessing visual memory. On the ROCF, children with DCD and at least one other disorder scored significantly lower than children with ADHD only or RD only. Children with DCD plus one other disorder were then subdivided into three groups: DCD + ADHD, DCD + RD, and DCD + ADHD + RD and compared to children with DCD only, ADHD only, and RD only. Results indicated that children with DCD + ADHD + RD had significant impairments on the TVPS compared to children with DCD only and children with ADHD only. On the ROCF, children with DCD + ADHD + RD scored significantly lower than all of the groups, except the DCD+RD group. These findings suggest that DCD on its own is not associated with visual perceptual problems; rather, it is the presence of co-occurring disorders that is a possible key to visual perceptual deficits in children with DCD. The number of co-occurring disorders present with DCD is associated with the severity of the visual perceptual dysfunction. Deficits in visual memory skills appear to be a specific area of difficulty for children with DCD and co-occurring RD and/or ADHD.     

Links between sex-related expectations about alcohol, heavy episodic drinking and sexual risk among young men in a shantytown in Lima, Peru

CONTEXT: Alcohol use is frequently identified as a contributor to risky sexual behaviors; however, research results are mixed. Given the conflicting evidence, researchers have focused on other factors, such as expectations about alcohol's effects that might help explain the relationship of alcohol use and risky sexual behaviors. METHODS: Cross-sectional data from 312 sexually experienced males aged 18-30 in a shantytown in Lima, Peru, were used in logistic regression models to identify associations of heavy episodic drinking and sex-related expectations about alcohol with sexual risk behaviors. RESULTS: Heavy episodic drinking was associated with having had two or more sexual partners and having had sex with a casual partner in the past year (odds ratios, 2.8 and 2.5, respectively). After controlling for alcohol consumption, sex-related expectations about alcohol were associated with these high-risk sexual behaviors, as well as with not using a condom at last sex (1.2) and not using a condom at last sex with a casual partner (1.3). CONCLUSION: Beliefs about the effect of alcohol on sexual performance could help explain links between alcohol consumption and risky sexual behavior not completely accounted for by the pharmacological effects of alcohol.     

Primacy or recency effects in forming inductive categories

Five experiments provide evidence for a primacy effect in the formation of inductive categories. Participants completed a category induction task in which they observed and reproduced a set of lines that varied in length but were serially ordered so that they increased or decreased in length. Subsequent estimates of the average of the distribution were systematically biased in the direction of stimuli encountered at the beginning of the induction task, suggesting that initially encountered stimuli exert greater weight in a category representation than do subsequent stimuli. We offer possible explanations for why this primacy effect might arise.     

Depression and internally directed aggression: genetic and environmental contributions

This study uses behavior genetic (BG) methodology to investigate Freud's theory of depression as aggression directed toward the self (1930) and the extent to which genetically and environmentally influenced aggressive tendencies contribute to depressive symptoms. Data from the Twin and Offspring Study in Sweden (TOSS) is used to demonstrate how, in estimating shared and unique environmental influences, BG methods can inform psychoanalytic theory and practice, particularly because of their shared emphasis on the importance of individual experience in development. The TOSS sample consists of 909 pairs of adult twins, their partners, and one adolescent child per couple. The Center for Epidemiologic Studies Depression Scale (Radloff 1977) was used to measure depressive symptoms and the Karolinska Scales of Personality (Schalling and Edman 1993) to measure internally directed aggression. Genetic analyses indicated that for both men and women, their unique experiences as well as genetic factors contributed equally to the association between internally directed aggression and depressive symptoms. These findings support Freud's theory that constitutionally based differences in aggression, along with individual experiences, contribute to a person's depressive symptoms. Establishing that an individual's unique, not shared, experiences and perceptions contribute to depressive symptoms and internally directed aggression reinforces the use of patient-specific treatment approaches implemented in psychoanalytic psychotherapy or psychoanalysis.     

A computational model of early argument structure acquisition

How children go about learning the general regularities that govern language, as well as keeping track of the exceptions to them, remains one of the challenging open questions in the cognitive science of language. Computational modeling is an important methodology in research aimed at addressing this issue. We must determine appropriate learning mechanisms that can grasp generalizations from examples of specific usages, and that exhibit patterns of behavior over the course of learning similar to those in children. Early learning of verb argument structure is an area of language acquisition that provides an interesting testbed for such approaches due to the complexity of verb usages. A range of linguistic factors interact in determining the felicitous use of a verb in various constructions —associations between syntactic forms and properties of meaning that form the basis for a number of linguistic and psycholinguistic theories of language. This article presents a computational model for the representation, acquisition, and use of verbs and constructions. The Bayesian framework is founded on a novel view of constructions as a probabilistic association between syntactic and semantic features. The computational experiments reported here demonstrate the feasibility of learning general constructions, and their exceptions, from individual usages of verbs. The behavior of the model over the timecourse of acquisition mimics, in relevant aspects, the stages of learning exhibited by children. Therefore, this proposal sheds light on the possible mechanisms at work in forming linguistic generalizations and maintaining knowledge of exceptions.     

Children's dietary recalls from three validation studies: types of intrusion vary with retention interval

Using previously collected data of fourth‐grade children observed eating school meals and then interviewed, we categorized intrusions (food items reported but not observed eaten) as stretches (on the child's tray) or confabulations (not on the child's tray). We investigated intrusions, confabulations, and stretches and the role of liking, at different retention intervals (morning interviews about the previous day's intake; evening interviews about that day's intake) and under different reporting‐ order prompts (forward; reverse). As retention interval between consumption and report increased, the likelihood (1) increased that reported items were intrusions, that reported items were confabulations and that intrusions were confabulations; and (2) was constant that reported items were stretches. Results concerning reporting‐order prompts were inconclusive. Liking ratings were higher for matches (reports of items observed eaten) than stretches, for confabulations than stretches, and for matches than omissions (unreported items observed eaten), but did not vary by retention interval or reporting‐order prompts. Copyright © 2007 John Wiley & Sons, Ltd.     

Intention to communicate BRCA1/BRCA2 genetic test results to the family.

Guided by the theory of planned behavior, this analysis explores the communication skills of women who had genetic testing for BRCA1 and BRCA2. The key outcome was intention to tell test results to adult first-degree relatives. The theory predicts that global and specific attitudes, global and specific perceived social norms, and perceived control will influence the communication of genetic test results. A logistic regression model revealed that global attitude (p < .05), specific social influence (p < .01), and perceived control (p < .05) were significant predictors of intention to tell. When gender and generation of relatives were added to the regression, participants were more likely to convey genetic test results to female than to male relatives (p < .05) and were also more likely to communicate test results to children (p < .01) or siblings (p < .05) than to parents. However, this association depended on knowing the relative's opinion of genetic testing. Intention to tell was lowest among participants who did not know their relative's opinion. These results extend the theory of planned behavior by showing that gender and generation influence intention when the relative's opinion is unknown.     

When Goals Conflict But People Prosper: The Case of Dispositional Optimism

Optimistic persistence in pursuing goals may have beneficial consequences such as protection against negative affect and greater likelihood of goal attainment, but persistence can also result in greater likelihood of goal conflict, which can have negative consequences. Two studies, one cross-sectional (N = 100) and one longitudinal (N = 77), found that optimism associated with higher goal conflict. However, objectively rated goal conflict did not significantly undermine adjustment, and when balance among goal value, expectancy, and conflict was considered, optimism associated with better balance. In turn, balance accounted for part of optimists' better goal progress over the course of a semester. Although goal conflict may have costs, these costs appear to be offset by accompanying benefits, particularly for optimists.