A Meta-Analysis of the Association Between Birth Weight and Attention Deficit Hyperactivity Disorder

A large body of work has investigated the association between birth weight and ADHD and has resulted in mixed findings with regard to the direction and magnitude of this association. Despite the vast amount of research on this topic, a comprehensive and systematic quantification of the association between birth weight and ADHD has yet to be undertaken. A meta-analysis of 88 unique studies (N?=?4,645,482) was conducted to quantify the overall effect size of birth weight on ADHD symptoms. Several variables were examined as moderators that may contribute to systematic variation in effect sizes. Overall, birth weight was found to have a small, but significant, association with ADHD symptoms such that individuals born at lower birth weights manifested greater symptoms of ADHD (r?=??0.15). Sample type, mean birth weight of the sample, geographic region, the informant of ADHD symptoms, ADHD symptom measurement method, and race were all found to contribute significantly to heterogeneity in effect sizes. Notably, several early life risk factors previously found to be associated with both ADHD and birth weight, gestational age and prenatal smoking exposure, were not found to contribute to heterogeneity in effect sizes. The findings of the current analyses align with the growing recognition that early life adversity contributes to neurodevelopmental difficulties, and the findings highlight the importance of a better understanding of the mechanisms underlying the association between early life risk factors and adverse neurodevelopmental sequela, such as that observed in ADHD.     

Semantic richness and word learning in children with autism spectrum disorder

Semantically rich learning contexts facilitate semantic, phonological, and articulatory aspects of word learning in children with typical development (TD). However, because children with autism spectrum disorder (ASD) show differences at each of these processing levels, it is unclear whether they will benefit from semantic cues in the same manner as their typical peers. The goal of this study was to track how the inclusion of rich, sparse, or no semantic cues influences semantic, phonological, and articulatory aspects of word learning in children with ASD and TD over time. Twenty‐four school‐aged children (12 in each group), matched on expressive vocabulary, participated in an extended word learning paradigm. Performance on five measures of learning (referent identification, confrontation naming, defining, phonetic accuracy, and speech motor stability) were tracked across three sessions approximately one week apart to assess the influence of semantic richness on extended learning. Results indicate that children with ASD benefit from semantically rich learning contexts similarly to their peers with TD; however, one key difference between the two groups emerged – the children with ASD showed heightened shifts in speech motor stability. These findings offer insights into common learning mechanisms in children with ASD and TD, as well as pointing to a potentially distinct speech motor learning trajectory in children with ASD, providing a window into the emergence of stereotypic vocalizations in these children.     

Understanding supplement use: an application of temporal self-regulation theory

Vitamin and mineral supplement use is increasing worldwide. As evidence of the effects of these practices are equivocal at best, it is important to determine why individuals engage in vitamin and mineral supplement use through the application of a theoretical framework. The aim of this study was to employ temporal self-regulation theory (TST) to establish the determinants of supplement use. A cross-sectional design was used with a sample of 121 individuals who consume vitamins or minerals as dietary supplements. Hierarchical regression analyses were conducted to determine the influence of intention, habit, self-control, and the interaction between intention and habit and self-control on the frequency of supplement use. The model accounted for a significant proportion of variance in behaviour (R² = .44) with intention and habit significantly related to supplement use. Self-control moderated the relationship between intention and behaviour indicating that intention was not related to behaviour when self-control was low. The TST model offers a satisfactory account of supplement use and provides avenues for interventions aimed at increasing safe and beneficial supplement use and decreasing potentially harmful supplement use.     

Personal and Professional Development for Judges: The Institute for Faculty Excellence

This interview study describes the role that participation in the Institute for Faculty Excellence in Judicial Education (IFEJE) played in the personal and professional development of four judges. Judicial education is a relatively new field of adult and continuing professional education. There is limited literature devoted to this area of study outside of the arena of substantive legal or judging topics. Interviews served as the primary data source for this study along with program evaluations, photographs, and e-mail correspondence from Institute participants. The findings revealed that the combined safe environment, challenges, and support participants experienced at the Institute and learning about adult learning helped them: feel less isolated in their work; stretch their normal work boundaries resulting in the completion of projects for which they had great passion; and benefited them as judges, supervisors, teachers, and in other social relationships.     

Person perception informs understanding of cognition during visual search

Does person perception—the impressions we form from watching others—hold clues to the mental states of people engaged in cognitive tasks? We investigated this with a two-phase method: In Phase 1, participants searched on a computer screen (Experiment 1) or in an office (Experiment 2); in Phase 2, other participants rated the searchers’ video-recorded behavior. The results showed that blind raters are sensitive to individual differences in search proficiency and search strategy, as well as to environmental factors affecting search difficulty. Also, different behaviors were linked to search success in each setting: Eye movement frequency predicted successful search on a computer screen; head movement frequency predicted search success in an office. In both settings, an active search strategy and positive emotional expressions were linked to search success. These data indicate that person perception informs cognition beyond the scope of performance measures, offering the potential for new measurements of cognition that are both rich and unobtrusive.     

Glucocorticoids are required for extinction of predator stress-induced hyperarousal

Background

The role of glucocorticoids in extinction of traumatic memories has not been fully characterized despite its potential as a therapeutic target for acquired posttraumatic stress disorder (PTSD). The predator stress paradigm allows us to determine whether glucocorticoids mediate the extinction of both context-dependent and context-independent fear memories.

Methods

Male C57BL/6J mice were exposed to a predator (cat) then repeatedly exposed to the predator stress context in the absence of the cat. Context-dependent (associative) fear memory was assessed as suppression of activity during re-exposure to the predator stress context without the cat (extinction trials). Context-independent fear (non-associative) was assessed seven days after extinction trials using measures of hyperarousal and anxiety-like behaviours in environments unlike the predator stress context. To assess the role of glucocorticoids, mice were injected with metyrapone (50 mg/kg) 90 min prior to extinction trials in predator stressed mice and context-dependent and context-independent fear memories were assessed. Finally, metyrapone-treated predator stressed mice were injected with corticosterone (5 or 10 mg/kg) immediately following extinction trials and context-dependent and context-independent fear memories were assessed.

Results

Repeated re-exposure to the predator stress context without the cat present extinguished context-dependent fear memory, and also reduced hyperarousal, a generalized, chronic PTSD-like symptom. We show that extinction of context-independent predator stress-induced hyperarousal is dependent on endogenous glucocorticoids during the extinction trials. Furthermore, the inhibition of extinction by metyrapone on startle amplitude was reduced by exogenous administration of corticosterone following extinction trials. Overall, these data implicate glucocorticoids in the extinction of hyperarousal, a core symptom of PTSD.     

Sound to meaning correspondences facilitate word learning

A fundamental assumption regarding spoken language is that the relationship between sound and meaning is essentially arbitrary. The present investigation questioned this arbitrariness assumption by examining the influence of potential non-arbitrary mappings between sound and meaning on word learning in adults. Native English-speaking monolinguals learned meanings for Japanese words in a vocabulary-learning task. Spoken Japanese words were paired with English meanings that: (1) matched the actual meaning of the Japanese word (e.g., “hayai” paired with fast); (2) were antonyms for the actual meaning (e.g., “hayai” paired with slow); or (3) were randomly selected from the set of antonyms (e.g., “hayai” paired with blunt). The results showed that participants learned the actual English equivalents and antonyms for Japanese words more accurately and responded faster than when learning randomly paired meanings. These findings suggest that natural languages contain non-arbitrary links between sound structure and meaning and further, that learners are sensitive to these non-arbitrary relationships within spoken language.     

Memory for noun pairs in the same or different underlying strings

A number of studies have shown that children learn noun pairs faster when they have been presented in a noun-verb-noun context than when they are presented in a noun-conjunction-noun context. Suzuki and Rohwer (1969) hypothesized that the underlying strings of sentences correspond to memory units, making it easier to recall two nouns from the same underlying string than from two different underlying strings. They reported that data from fifth graders supported this hypothesis but that data from college students did not. The experiments reported here were done to determine whether the hypothesis would be supported (a) if the test rate were faster than that used by Suzuki and Rohwer or (b) if sentences longer and more complex than those used by them were employed. The recall data accorded with some predictions derived from the hypothesis. However, data from Ss’ posttraining reports on how they learned the pairs suggest that Ss, particularly adults, often made up their own strings rather than using those provided, and raise the question of the adequacy of Suzuki and Rohwer’s procedure for testing this hypothesis, particularly in adults.     

Construct validity and case validity in assessment

Clinical assessment relies on both construct validity, which focuses on the accuracy of conclusions about a psychological phenomenon drawn from responses to a measure, and case validity, which focuses on the synthesis of the full range of psychological phenomena pertaining to the concern or question at hand. Whereas construct validity is grounded in understanding causal influences of a distinct phenomenon on responses to various measures and life contexts, case validity encompasses the joint influences of multiple phenomena on individuals' responses. Two sets of distinctions essential to understanding psychological phenomena, hence to understanding construct validity, are (a) implicit and explicit versions of personality constructs and (b) ability and personality as versions of constructs measured by performance tests presenting maximal and typical conditions, respectively. Since both implicit and explicit versions of constructs interface with maximal or typical performance conditions, case validity requires systematic inclusion of these distinctions in assessment protocols.