Intra-Individual Variability Among Children with ADHD on a Working Memory Task: An Ex-Gaussian Approach

Intra-individual variability on a computer-based working memory task was examined among 25 children/adolescents with ADHD and 24 typically developing peers. Participants completed the Visual Serial Addition Task (VSAT) and reaction time data were fit to an ex-Gaussian distribution. ADHD participants demonstrated significantly more variable performance than controls, and effects of working memory load were observed. Event rate, however, had no influence on group differences in performance. Follow-up correlations revealed associations between VSAT performance and ADHD symptomatology. This study supports intra-individual variability as a hallmark feature of ADHD beyond the domain of response inhibition and reinforces the need to consider variability in ADHD more broadly.     

Development of a Screening Instrument for Early Language Delay in Hong Kong Chinese: A Preliminary Study

Having language delay—one of the common neurodevelopmental difficulties during childhood—does not only imply an impairment in communication in the 1st few years of life. Previous studies have suggested that language problems have long-term implications for social, emotional, and intellectual development. Researchers have found that early identification and intervention of speech and language delay yields better treatment effects. However, unlike most of the motor developmental assessment tools, language assessment tools are not readily transferred across cultures because of the different linguistic features and the developmental stages of such features in a particular language or dialect. The present study presents an empirical example of the initial development of a culturally sensitive screening protocol, using vocabulary size as the indicator to minimize the effect of linguistic differences.     

The impact of mediodorsal thalamic lesions on olfactory attention and flavor perception

Olfactory attention may be important in generating odor-induced tastes - an arguably universal form of synesthesia - by ensuring that the taste concurrent is captured by the nose and olfaction, not by the mouth and gustation (oral-capture). To examine the role of olfactory attention in generating odor-induced tastes and oral capture we tested a small sample (n = 4) of participants with likely impairments in olfactory attention - individuals with mediodorsal thalamic nucleus (MDNT) lesions. These participants were compared to two sets of controls on tests of olfactory attention, oral capture, odor and flavor perception, and control tasks. MDNT participants demonstrated impaired olfactory attention and enhanced oral capture. Greater oral capture was associated with greater olfactory attentional impairment. These findings imply that olfactory attention may be important in attributing odor-induced tastes to the olfactory modality. However, unlike for visual binding and for the neurodevelopmental synesthesias, where attention may be necessary to demonstrate both phenomena, olfactory attention deficits did not impair flavor binding or the experience of odor-induced tastes.     

Unconscious and out of control: Subliminal priming is insensitive to observer expectations

We asked whether the influence of an invisible prime on movement is dependent on conscious movement expectations. Participants reached to a central target, which triggered a directional prime–mask arrow sequence. Participants were instructed that the visible arrows (masks) would most often signal a movement modification in a specific (biased) direction. Kinematic analyses revealed that responses to the visible mask were influenced by participants’ intentional bias, as movements were fastest when the more probable mask was displayed. In addition, responses were influenced by the invisible prime without regard to its relationship to the more probable mask. Analysis of the time of initial trajectory modifications revealed that both primes influenced responses in a similar manner after accounting for participants’ bias. These results imply that invisible stimuli automatically activate their associated responses and that unconscious priming of the motor system is insensitive to the conscious expectations of the participant making the pointing movements.     

Perceived Risk Following Melanoma Genetic Testing: A 2-Year Prospective Study Distinguishing Subjective Estimates from Recall

A major goal of predictive genetic testing is to alert people to their risk before illness onset; however, little is known about how risk perceptions change following genetic testing and whether information is recalled accurately over time. In the United States, a CDKN2A/p16 mutation confers 76 % lifetime risk of melanoma. Following genetic counseling and test reporting, subjective risk estimates and recall of counselor-provided risk estimates were assessed 5 times over the next 2 years among 60 adult members of 2 extended CDKN2A/p16 kindreds. No sustained changes from baseline in risk perceptions were reported. Unaffected carriers (n?=?15) consistently reported significantly lower subjective risk estimates (46 %) than they were actually given (76 %, p?<?0.001) or recalled having been given (60 %, p?<?0.001). Noncarriers’ (n?=?27) risk estimates decreased following results disclosure, but rebounded, with both subjective and recalled estimates subsequently exceeding what they were told by the counselor (both ps?<?0.001). Affected carriers’ (n?=?18) risk estimates for developing a new melanoma corresponded well to counselor-provided information (p?=?0.362). For all 3 patient groups, results were consistent across multiple risk measures and remained similar when demographic, phenotypic, and baseline behavioral contributors to melanoma risk were statistically controlled. These findings are consistent with other studies of risk perception, but additional studies of more diverse populations are needed to understand the reasons behind both the persistence of initial risk estimates and their divergence from information provided by the counselor during genetic counseling. Additionally, determining whether holding subjective risk perceptions that differ from counselor-provided information ultimately affects adherence to management recommendations will help guide the presentation of risk information in genetic counseling practice.     

Do college students drink more than their non-college-attending peers? Evidence from a population-based longitudinal female twin study

The association of college attendance with alcohol use and alcohol use disorders was examined in a population-based young adult female twin sample identified from a systematic search of birth records. College-attending women consumed a larger overall volume of alcohol than did their non-college-attending peers, but they were not more likely to be diagnosed with an alcohol use disorder. Significant associations between college attendance and alcohol involvement were probed using 3 different complementary research designs: multivariate cross-sectional analyses, longitudinal analyses of the precollege and college years, and cotwin-control analyses of twin pairs discordant for attending college. Although demographic and lifestyle characteristics accounted for most or all of the association between college attendance and alcohol involvement, there was 1 aspect of drinking behavior, occasionally consuming large quantities of alcohol, that remained significantly associated with college attendance even after controlling for these characteristics or for genetic and family background factors. These results are consistent with the conclusion that some aspect of the college experience may be an important environmental risk factor for this pattern of drinking among young adults.