Comorbid attention-deficit/hyperactivity disorder in borderline patients defines an impulsive subtype of borderline personality disorder

In order to examine the impulsive profile of a BPD sample with comorbid ADHD, adult patients who met criteria for BPD were assessed for ADHD with the CAADID and the WURS. A high rate of ADHD in the BPD sample was found, with sixty-nine (38.1%) BPD patients diagnosed as having comorbid adult ADHD. BPD-ADHD group had higher rates of general substance use disorder (59.4% vs. 38.4%), antisocial personality disorder (7.2% vs. 0.9%) and obsessive-compulsive personality disorder (21.7% vs. 6.3%). The BPD group without comorbid adult ADHD showed a higher rate of mood disorders (62.5% vs. 37.7%), panic disorders (54.5% vs. 23.1%) and benzodiazepine abuse (18.8% vs. 5.8%). Only in BPD patients without ADHD was comorbid avoidant personality disorder found. BPD patients could be distinguished in two clear subgroups related to the adult ADHD comorbidity. BPD-ADHD patients showed a more homogeneous and impulsive profile while BPD without ADHD comorbidity had more anxiety and depressive disorders.     

Genetic and environmental influences on girls' and boys' gender-typed and gender-neutral values

In this first investigation of genetic and environmental influences on children's values, 271 German twin pairs (50.2% boys) reported their values at ages 7-11 years using the Portrait Values Questionnaire (Schwartz & Rubel, 2005). We distinguished between gender-neutral (conservation vs. openness to change) and gender-typed (self-transcendence vs. self-enhancement) values. Boys differed from girls in the importance given to gender-typed benevolence, achievement, and power values. Gender-neutral values showed moderate (.34) and gender-typed values showed higher (.49) heritability, with nonshared environment and error accounting for the remaining variance. For both sexes, substantial genetic effects accounted for the importance children gave to their respective gender-stereotypical end of the self-transcendence versus self-enhancement dimension. However, dramatic sex differences emerged in the gender-atypical end of the distribution. For girls, low self-transcendence (high gender-atypical values) showed a large (.76) group heritability. For boys, gender-atypical values (high self-transcendence) showed no heritability and a modest (.10) shared environment effect.     

The time course of attentional focusing in dyslexic and normally reading children

A cue size procedure was used to evaluate the time course of visuo-spatial attention in dyslexic and normally reading children. When a stimulus target is presented inside a large cue vs a small cue the identification time is slower. In the present study two cue-target delays (100 and 500 ms) were used. Results showed a slower time course of attentional focusing in dyslexics vs normal readers. Indeed, dyslexics exhibited no cue size effect at a shorter cue-target delay (100 ms), while it was present at a longer cue-target delay (500 ms). In contrast, a cue size effect was found at both cue-target delays in normally reading children. These results further support the hypothesis of sluggish automatic focusing of visual attention in dyslexics. This impairment could be a consequence of a general magnocellular deficit demonstrated previously in dyslexics.     

Fetal Alcohol-Exposed Rats Exhibit Differential Response to Cholinergic Drugs on a Delay-Dependent Memory Task

Fetal alcohol exposure in human and rodents produces a number of cognitive deficits including impairments in learning and memory. Recent evidence in our laboratory has shown that fetal alcohol-exposed (FAE) rats respond differently to systemic administration of cholinergic drugs when tested for vigilance and locomotor activity. The present study examined the effects of muscarinic and nicotinic agonists and antagonists on memory performance in a delayed alternation task. Subjects were male offspring of Sprague-Dawley rats fed a 35% ethanol-derived caloric diet, pair-fed with sucrose, or chow-fed with lab chow during the last 2 weeks of gestation. Rats (3 months old) were food-deprived prior to training in the T-maze. Rats were first trained in the alternation task at no delay for five sessions. Rats were then trained at longer delays (20, 60, 180 s) until all groups showed similar performance for two consecutive sessions. Each animal was then tested following systemic injections of the cholinergic antagonists scopolamine and mecamylamine (60-s delay) and the cholinergic agonists pilocarpine and nicotine (180-s delay). Rats received saline injections on alternate days of testing. The results revealed that FAE rats exhibited no impairments in alternation performance at the no delay and 20-s delay, but showed impairments on both the 60- and 180-s delays during the initial sessions. However, with additional training, FAE rats showed performance similar to that of control groups at these delays. Following both pilocarpine and nicotine injections, control groups, but not the FAE group, showed significant memory enhancement in the alternation task. Following scopolamine injections, the FAE rats showed a significant impairment, while control groups showed a nonsignificant decrease in performance. All three groups showed impairments in the alternation task following administration of mecamylamine compared to saline treatment. These findings suggest that alterations in the cholinergic system in FAE rats may underlie some of the cognitive deficits observed with prenatal alcohol exposure.     

Forgetting and learning potentiation: dual consequences of between-session delays in cognitive skill learning

In the cognitive skill literature, between-session delays have been treated either as having a negligible effect on performance or as causing forgetting. In contrast, in the procedural skill literature, overnight between-session delays can result in performance gains. In 5 multi-session data sets, the author demonstrates that neither of these 2 models holds for the case of cognitive skill learning. Instead, the delay between sessions appeared to yield both forgetting and enhanced potential for new learning. Two candidate classes of explanation are considered, and implications for the empirical law of learning are discussed.     

The Care and Development of Children Living in Contexts of Poverty

Human development is determined by both genetic and environmental factors, especially during early childhood. Recently, research has indicated that the circumstances surrounding poverty can significantly influence children’s development. In this study, we aimed to measure the developmental level of children living in low-income, rural areas in northern Colombia. A total of 629 children (aged 0–5 years) were assessed using the Battelle Developmental Inventory. Results indicated that 17?% of the participants had a general developmental delay for their age group. This was especially true for scores on cognitive development (35.5?%) and communication (21.5?%). Moreover, the number of children with developmental delay increased at 6 months of age and continued to increase after 1 year in the communication and cognitive domains. The findings of this study suggest that impoverished social contexts—such as the one studied herein—offer opportunities that favor the development of the social domain, but restrict the development of the cognitive domain. Therefore, to promote cognitive development, individuals within children’s environment need to actively and intentionally stimulate them. Thus, there is a need for interventions that will improve environmental conditions; especially those that will help parents improve their caregiving practices and train educational staff to recognize and respond to the stimulation needs of children, especially those developmental domains that are affected by the environment.     

Genetic and environmental influences on religiousness: findings for retrospective and current religiousness ratings

Estimates of the degree of genetic and environmental influences on religiousness have varied widely. This variation may, in part, be due to age differences in the samples under study. To investigate the heritability of religiousness and possible age changes in this estimate, both current and retrospective religiousness were assessed by self-report in a sample of adult male twins (169 MZ pairs and 104 DZ pairs, mean age of 33 years). Retrospective reports of religiousness showed little correlation difference between MZ (r=.69) and DZ (r=.59) twins. Reports of current religiousness, however, did show larger MZ (r=.62) than DZ (r=.42) similarity. Biometric analysis of the two religiousness ratings revealed that genetic factors were significantly weaker (12% vs. 44%) and shared environmental factors were significantly stronger (56% vs. 18%) in adolescence compared to adulthood. Analysis of internal and external religiousness subscales of the total score revealed similar results. These findings support the hypothesis that the heritability of religiousness increases from adolescence to adulthood.     

Sex differences in early verbal and non‐verbal cognitive development

The present study of over 3000 2‐year‐old twin pairs used a sex‐limitation model to examine genetic and environmental origins of sex differences in verbal and non‐verbal cognitive ability. Girls scored significantly higher on both measures (p<0.0001), although gender only accounted for approximately 3% of the variance in verbal ability and 1% of the variance in non‐verbal cognitive ability. For the verbal measure boys showed greater heritability than girls. Also the twin‐pair correlation is significantly lower for opposite‐sex twins than for non‐identical same‐sex twins. This indicates that individual differences in verbal ability include some sex‐specific factors. Non‐verbal cognitive ability did not differ in aetiology for boys and girls. We conclude that genetic and environmental influences differ for girls and boys for early verbal but not non‐verbal development.     

Dramatic Increase in Heritability of Cognitive Development From Early to Middle Childhood: An 8-Year Longitudinal Study of 8,700 Pairs of Twins

ABSTRACT— The generalist genes hypothesis implies that general cognitive ability ( g ) is an essential target for understanding how genetic polymorphisms influence the development of the human brain. Using 8,791 twin pairs from the Twins Early Development Study, we examine genetic stability and change in the etiology of g assessed by diverse measures during the critical transition from early to middle childhood. The heritability of a latent g factor in early childhood is 23%, whereas shared environment accounts for 74% of the variance. In contrast, in middle childhood, heritability of a latent g factor is 62%, and shared environment accounts for 33%. Despite increasing importance of genetic influences and declining influence of shared environment, similar genetic and shared environmental factors affect g from early to middle childhood, as indicated by a cross-age genetic correlation of .57 and a shared environmental correlation of .65. These findings set constraints on how genetic and environmental variation affects the developing brain.     

Why aren't identical twins linguistically identical? Genetic, prenatal and postnatal factors

Results of twin studies clearly demonstrate that genetic factors play an important role in the rate of language acquisition and linguistic proficiency attained by normal and impaired children and adults [see Stromswold, K. (2001). The heritability of language: A review and meta-analysis of twin, adoption and linkage studies. Language, 77, 647-723.]. That said, twin-based heritability estimates for language rarely exceed .6 and monozygotic (MZ) twins (who are usually assumed to have identical genetic and environmental endowments) sometimes have very different linguistic profiles. In addition, twins are more likely to suffer linguistic delays and impairments than singletons. Postnatal factors, such as differences in linguistic input twins receive, are usually assumed to be the major reason for these findings. This paper discusses how genetic, epigenetic, and perinatal environmental factors can lower heritability estimates for language, cause MZ twins to be linguistically discordant, and increase the risk of language impairments in twins. We present results from our ongoing Perinatal Environment and Genetic Interaction (PEGI) study that suggest that perinatal environmental factors affect linguistic development more than postnatal factors, and that postnatal factors affect cognitive development more than perinatal factors. Because perinatal factors are overwhelming biological, whereas postnatal factors tend to be psychosocial (e.g., how and how much parents speak to their children), these results support nativist/biological theories of language and language development and call into question empiricist/emergentist theories. These results are also consistent with modularist theories of language. We end by suggesting new methods that can be used to tease apart the effects of prenatal and postnatal environment and to investigate how these factors interact with genetic factors.     

Unsignaled delay of reinforcement, relative time, and resistance to change

Two experiments with pigeons examined the effects of unsignaled, nonresetting delays of reinforcement on responding maintained by different reinforcement rates. In Experiment 1, 3-s unsignaled delays were introduced into each component of a multiple variable-interval (VI) 15-s VI 90-s VI 540-s schedule. When considered as a proportion of the preceding immediate reinforcement baseline, responding was decreased similarly for the three multiple-schedule components in both the first six and last six sessions of exposure to the delay. In addition, the relation between response rates and reinforcement rates was altered such that both parameters of the single-response version of the matching law (i.e., k and Re) were decreased. Experiment 2 examined the effects of unsignaled delays ranging from 0.5 s to 8.0 s on responding maintained by a multiple VI 20-s VI 120-s schedule of reinforcement. Response rates in both components increased with brief unsignaled delays and decreased with longer delays. As in Experiment 1, response rates as a proportion of baseline were affected similarly for the two components in both the first six and last six sessions of exposure to the delay. Unlike delays imposed between two stimulus events, the effects of delays between responses and reinforcers do not appear to be attenuated when the average time between reinforcers is longer. In addition, the disruptions produced by unsignaled delays appear to be inconsistent with the general finding that responding maintained by higher rates of reinforcement is less resistant to change.     

Temporal discounting and preference reversals in choice between delayed outcomes

Subjects chose between pairs of hypothetical amounts of money available after different delays. When smaller, more immediate amounts were selected over larger, more delayed amounts, the addition of a constant delay to both outcomes resulted in reversals of preference, contrary to the standard discounted utility model of economics. The delays at which preference reversed were determined for three pairs of amounts ($20 vs. $50, $100 vs. $250, and $500 vs. $1,250). The relation between the delay to the larger amount and the delay to the smaller amount at preference reversal was well fit by both linear and quadratic functions. Intercepts increased with amount, strongly suggesting that rate of discounting decreases with amount. The presence of significant negative curvature in the data from the majority of individual subjects poses problems for exponential and hyperbolic models of temporal discounting in self-control, both of which predict a linear relation between the delays to the larger and smaller amounts.     

Processing Speed Deficits in Attention Deficit/Hyperactivity Disorder and Reading Disability

The goal of the current study was to test whether deficits in processing speed (PS) may be a shared cognitive risk factor in reading disability (RD) and Attention Deficit/Hyperactivity Disorder (ADHD), which are known to be comorbid. Literature on ADHD and RD suggests that deficits on tasks with a speeded component are seen in both of these disorders individually. The current study examined a wide range of speeded tasks in RD, ADHD, comorbid RD+ADHD, and a control group to test whether RD and ADHD have similar profiles of PS deficits, and whether these deficits are shared by the two disorders. The results suggest that a general PS deficit exists in both clinical groups compared to controls, although children with RD demonstrate greater PS deficits than children with ADHD. Two tests (underadditivity and partial correlations) were conducted to test whether these PS deficits are shared. Since we found that PS deficits were underadditive in the comorbid group and that partialling PS reduced the correlation between RD and ADHD, it appears that PS is a shared cognitive risk factor that may help explain the comorbidity of these two disorders.     

Retribution and emotional regulation: The effects of time delay in angry economic interactions

Individuals driven by negative emotions often punish non-cooperators at a cost to themselves. The current research demonstrates that, although time delays can attenuate this effect, they can also produce unintended consequences. Five experiments investigated the effects of time delays and thought patterns on punishments in direct and third party interactions. The results show that time delays decreased punishment (Experiment 1) by reducing negative emotions (Experiments 2A and 2B). However, thought patterns during a delay were crucially important (Experiments 3A and 3B): People who engaged in a distraction task punished less; people who engaged in affective rumination punished more; and people who engaged in cognitive reappraisal were unaffected by a delay. These differences meant that, after a time delay, affective ruminators administered greater punishments than cognitive reappraisers or distracted individuals. Implications of these findings for managing punitive impulses via time delays are discussed.     

Delayed matching in the pigeon: Effect on performance of sample-specific observing responses and differential delay behavior

Pigeons were trained on a delayed matching-to-sample task with a 0-sec delay and then transferred to a 1-sec delay (Experiment 1) or were trained with mixed 0-sec/1-sec delays and then transferred to longer mixed delays up to 28 sec (Experiment 2). Four groups were distinguished by the nature of the observing response required to each sample color (red and blue). For Group NN pecks were allowed to neither color. For Group PcPc pecks were required to both colors. For Group PcN pecks were required to red but were not allowed to blue. For Group PcPt pecks were required at the center key in the presence of red, but at a key located directly above the center key in the presence of blue. The results of both experiments indicated significant effects of both Pecking vs Not Pecking, and Sample-Specific vs Sample-Independent Responding. At the longer delays individual differences in sample-specific delay behavior were a better predictor of performance than the behavior required in the presence of the sample.     

Common Genetic but Specific Environmental Influences for Aggressive and Deceitful Behaviors in Preadolescent Males

Although both aggressive (AGG) and deceitful behaviors (DEC) are symptoms of childhood conduct problems, few studies have examined common vs. specific etiological influences. Early intervention is encouraged for conduct problems and findings from genetically informative studies can suggest whether interventions should focus on conduct problems in general or groupings of conduct problems more specifically. Twin model-fitting analyses were conducted on same and different teacher ratings of AGG and DEC for 872 9-year old male twin pairs. Common genetic influences were found to underlie the susceptibility for both AGG and DEC. The same teacher ratings resulted in somewhat higher heritability estimates than different teacher ratings. Results also indicated stronger environmental effects for DEC as compared with AGG, with a significant shared environmental component for same teachers and a substantial non-shared environmental component for different teachers. Our data suggest that AGG and DEC share risk genes and environmental factors may differentiate these two types of conduct problems. Characterizing these specific environmental factors may be useful when developing interventions.     

The effect of age and sensation seeking on pedestrian crossing safety in a virtual reality street

A wide range of individual, interpersonal and environmental factors influence the safety of pedestrians crossing the street, including human development (children take more risks than adolescents and adults) and sensation seeking (individuals higher in sensation seeking have greater risk). The interaction between those two variables has not been carefully studied, however. Does the effect of sensation seeking on pedestrian safety vary across human development as cognitive and other skills improve? This study investigated the primary effects of age and sensation seeking, plus their joint effects, on pedestrian crossing in a virtual reality environment. 209 children (10–13 years old), adolescents (14–18 years old) and young adults (20–24 years old) screened to be high and low level in sensation seeking participated. A 3 (age group: child vs adolescent vs young adult) × 2 (sensation seeking: high vs low) × 2 (traffic condition: easy vs harder crossing) mixed factorial design was conducted. Three pedestrian safety outcomes – start delay, missed opportunities and dangerous crossings – were considered. Results showed that when the traffic condition was easier to cross within, the start delay to enter traffic gaps was significantly shorter for children than for adolescents and young adults. There were no significant differences across age groups when the traffic condition was harder to cross within. Pedestrians also missed more opportunities to cross the road when the traffic condition was harder to cross within. Pedestrians low in sensation seeking missed more opportunities to cross than those high in sensation seeking. All age groups had more dangerous crossings during the harder crossing scenario than in the easier one, and adolescents had more dangerous crossings than young adults or children. Finally, the results of hierarchical regression models predicting dangerous crossings showed that traffic condition had a significant predictive effect on children's dangerous crossing behavior, and both high sensation seeking and harder traffic conditions predicted adolescents’ dangerous crossing behavior. No included variables significantly predicted adults' dangerous crossing behavior. We conclude that both age and sensation-seeking contribute to pedestrian safety. The effect of sensation seeking does not vary widely by age group, but its effect on adolescents was somewhat stronger than in the other age groups studied.     

The problem of delayed causation in a video game: Constant, varied, and filled delays

A first-person shooter video game was adapted for the study of causal decision making within dynamic environments. The video game included groups of three potential targets. Participants chose which of the three targets in each group was producing distal explosions. The actual source of the explosion effect varied in the delay between the firing of its weapon and the effect (from 0 to 2 s), whether these programed average delays were constant or varied from shot to shot, and whether the delays were unfilled or filled with an auditory event. In Experiment 1, participants’ choice accuracy was highest with shorter delays, but there was no effect of filling the delay and some beneficial effect of varying the delay. These results were re-examined in Experiment 2 but with participants experiencing the same average delay for seven subsequent decisions before the next average delay was introduced. In this experiment, men showed a strong and consistent benefit of filling a delay whereas women did not. Participants’ behavior is considered within the context of a model that assumes that choice behavior is driven by experienced contiguity for the target and foils.     

Comorbid interpretation and expectancy bias in social anxiety and alcohol use

Background: In two studies, the present research examined whether being high in both social anxiety and alcohol use disorder symptoms is associated with a comorbid interpretation and expectancy bias that reflects their bidirectional relationship.

Design: Cross-sectional, quantitative surveys.

Methods: Measures of social anxiety and alcohol use disorder symptoms, as well as an interpretation and expectancy bias task assessing biases for social anxiety, drinking, and comorbid social anxiety and drinking.

Results: In Study 1 (N?=?447), individuals high (vs. low) in social anxiety had stronger social threat bias and individuals high (vs. low) in alcohol use disorder symptoms had stronger drinking bias. Those high in both social anxiety and alcohol use disorder symptoms endorsed interpretations and expectancies linking social interaction with alcohol use. Comorbid bias predicted membership into the high social anxiety/drinking group, even after taking into account single-disorder biases. In Study 2 (N?=?325), alcohol use disorder symptoms predicted drinking bias and social anxiety symptoms predicted social anxiety bias. Alcohol use disorder symptoms, social anxiety symptoms, and their interaction predicted comorbid interpretation and expectancy bias.

Conclusion: Results indicate unique cognitive vulnerability markers for persons with comorbid social anxiety and alcohol use disorder symptoms, which may improve detection and treatment of this serious comorbidity.