Response inhibition among early adolescents prenatally exposed to tobacco: an fMRI study.

Children prenatally exposed to tobacco have been found to exhibit increased rates of behavior problems related to response inhibition deficits. The present study compared the brain function of tobacco-exposed (n=7) and unexposed (n=11) 12-year-olds during a Go/No-Go response inhibition task using an event-related functional MRI (fMRI) design. Prenatal alcohol exposure, neonatal medical problems, environmental risk, IQ, current environmental smoke exposure, and handedness were statistically controlled. Tobacco-exposed children showed greater activation in a relatively large and diverse set of regions, including left frontal, right occipital, and bilateral temporal and parietal regions. In contrast, unexposed but not exposed children showed activation in the cerebellum, which prior research has indicated is important for attention and motor preparation. The diversity of regions showing greater activation among tobacco-exposed children suggests that their brain function is characterized by an inefficient recruitment of regions required for response inhibition.

Children's cognitive ability from 4 to 9 years old as a function of prenatal cocaine exposure, environmental risk, and maternal verbal intelligence.

This study examined the effects of prenatal cocaine exposure, environmental risk, and maternal verbal intelligence on children's cognitive ability. Gender and age were examined as moderators of potential cocaine exposure effects. The Stanford-Binet IV intelligence test was administered to 231 children (91 cocaine exposed, 140 unexposed) at ages 4, 6, and 9 years. Neonatal medical risk and other prenatal exposures (alcohol, cigarettes, and marijuana) were also examined for their unique effects on child IQ. Mixed models analysis indicated that prenatal cocaine exposure interacted with gender, as cocaine-exposed boys had lower composite IQ scores. Age at assessment did not moderate this relation, indicating that cocaine-exposed boys had lower IQs across this age period. A stimulating home environment and high maternal verbal IQ also predicted higher composite IQ scores. Cocaine-exposed boys had lower scores on the Abstract/Visual Reasoning subscale, with trends for lower scores on the Short-Term Memory and Verbal Reasoning subscales, as exposure effects were observed across domains. The findings indicate that cocaine exposure continues to place children at risk for mild cognitive deficits into preadolescence. Possible mechanisms for the Exposure x Gender interaction are discussed.

Preadolescent health risk behavior as a function of prenatal cocaine exposure and gender.

OBJECTIVE: To examine the effect of prenatal cocaine exposure on health risk behaviors during preadolescence. METHODS: The present study examined prenatal cocaine exposure, gender, and environmental risk as predictors of self-reported substance use, aggression, and a disregard for safety precautions on the Youth Risk Behavior Survey in a sample of 10.5 year olds (n = 154, including 60 who were prenatally exposed to cocaine). RESULTS: Gender tended to moderate the effects of prenatal cocaine exposure because exposure effects were found for boys but not girls. Boys who were prenatally exposed to cocaine reported engaging in more high-risk behavior. In examining individual outcomes, cocaine exposed boys had the highest scores for aggression, substance use, and a disregard for safety precautions, although these differences were significant only for the composite health risk behavior measure. CONCLUSIONS: The findings extend earlier work showing that prenatal cocaine exposure places boys at risk for problems of inhibitory control, emotional regulation, and antisocial behavior. Research is needed to examine whether the effects of prenatal cocaine on health risk behaviors persist into adolescence, when such behaviors tend to increase.

Reactivity and regulation in children prenatally exposed to cocaine.

Children prenatally exposed to cocaine may be at elevated risk for adjustment problems in early development because of greater reactivity and reduced regulation during challenging tasks. Few studies have examined whether cocaine-exposed children show such difficulties during the preschool years, a period marked by increased social and cognitive demands and by rapid changes in reactivity and regulation. The authors addressed this question by examining frustration reactivity and regulation of behavior during a problem-solving task in cocaine-exposed and -unexposed preschoolers. Participants were 174 4.5-year-olds (M age = 4.55 years, SD = 0.09). Frustration reactivity was measured as latency to show frustration and number of disruptive behaviors, whereas regulation was measured as latency to approach and attempt the problem-solving task and number of problem-solving behaviors. Results indicated that cocaine-exposed children took longer to attempt the problem-solving task but that cocaine-exposed boys showed the most difficulties: They were quicker to express frustration and were more disruptive. Effect sizes were relatively small, suggesting both resilience and vulnerabilities.

Early risk, attention, and brain activation in adolescents born preterm.

The relations among early cumulative medical risk, cumulative environmental risk, attentional control, and brain activation were assessed in 15-16-year-old adolescents who were born preterm. Functional magnetic resonance imaging found frontal, temporal, and parietal cortex activation during an attention task with greater activation of the left superior-temporal and left supramarginal gyri associated with better performance. Individual differences in early cumulative risk are related to patterns of brain activation such that medical risk is related to left parietal cortex activation and environmental risk is related to temporal lobe activation. The findings suggest that early risk is related to less mature patterns of brain activation, including reduced efficiency of processing and responding to stimuli.

Aggression at age 5 as a function of prenatal exposure to cocaine, gender, and environmental risk.

OBJECTIVE: To examine childhood aggression at age 5 in a multiple risk model that includes cocaine exposure, environmental risk, and gender as predictors. METHODS: Aggression was assessed in 206 children by using multiple methods including teacher report, parent report, child's response to hypothetical provocations, and child's observed behavior. Also examined was a composite score that reflected high aggression across contexts. RESULTS: Multiple regression analyses indicated that a significant amount of variance in each of the aggression measures and the composite was explained by the predictors. The variables that were independently related differed depending on the outcome. Cocaine exposure, gender, and environmental risk were all related to the composite aggression score. CONCLUSIONS: Cocaine exposure, being male, and a high-risk environment were all predictive of aggressive behavior at 5 years. It is this group of exposed boys at high environmental risk that is most likely to show continued aggression over time.

Antecedents of emotion knowledge: Predictors of individual differences in young children.

Individual differences in emotion knowledge were examined among 188 4-year-old, predominantly African American children. Cognitive ability and negative emotionality, maternal characteristics (parenting, verbal intelligence, and depressive symptoms), environmental risk, and child sex were examined as predictors of emotion knowledge. Regression analyses indicated that cognitively skilled children who resided in relatively low risk environments with verbally intelligent mothers possessed greater emotion knowledge. Proximal (4-year) child cognitive ability was a stronger predictor than distal (2-year) cognitive ability. Positive parenting at 4 years was correlated with child emotion knowledge, but this relation disappeared when parenting was examined in the context of other predictors. These findings highlight the potential role of child cognitive ability, along with environmental risk and maternal verbal intelligence, in children's emotion knowledge and demonstrate the importance of examining a variety of predictors for their unique contribution to emotion knowledge.

Does the Organization of Emotional Expression Change Over Time? Facial Expressivity From 4 to 12 Months.

Differentiation models contend that the organization of facial expressivity increases during infancy. Accordingly, infants are believed to exhibit increasingly specific facial expressions in response to stimuli as a function of development. This study tested this hypothesis in a sample of 151 infants (83 boys and 68 girls) observed in 4 situations (tickle, sour taste, arm restraint, and masked stranger) at 4 and 12 months of age. Three of the 4 situations showed evidence of increasing specificity over time. In response to tickle, the number of infants exhibiting joy expressions increased and the number exhibiting interest, surprise, and surprise blends decreased from 4 to 12 months. In tasting a sour substance, more infants exhibited disgust and fewer exhibited joy and interest expressions, and fear and surprise blends over time. For arm restraint, more infants exhibited anger expressions and anger blends and fewer exhibited interest and surprise expressions and surprise blends over time. In response to a masked stranger, however, no evidence of increased specificity was found. Overall, these findings suggest that infants increasingly exhibit particular expressions in response to specific stimuli during the 1st year of life. These data provide partial support for the hypothesis that facial expressivity becomes increasingly organized over time.

On Specifying Specificity: Facial Expressions at 4 Months.

Izard (2004/this issue) clarifies the position of differential emotions theory by proposing a distinction between hard and soft versions of event-emotion expression relations. We concur that the best design to examine situational specificity in facial expressions is one that utilizes multiple stimulus situations assessed over multiple occasions and ages. However, the problem of how to identify, a priori, a family of stimulus situations remains. We offer an example from our own recent work demonstrating how facial expressions and physiological indexes may converge to indicate the presence of a meaningful family of stimulus situations. Specifically, we found evidence for a family of frustrating, goal-blocking events that elicited expressions and cortisol responses indicative of anger at 4 months. Yet, individual differences exist in that these situations also elicited expressions and cortisol changes indicative of sadness. Identification of a more comprehensive set of such situations throughout infancy will allow researchers to more systematically examine the degree to which situational specificity of emotions is present.

Inhibitory motor control at five years as a function of prenatal cocaine exposure.

This study examined children's (n = 140, age 5 years) ability to inhibit a motor response as a function of prenatal cocaine exposure. We hypothesized that cocaine-exposed children would perform worse than unexposed children on the Contrary Tapping task. Results indicated that cocaine exposure, high environmental risk, male gender, and low child IQ each were related to poorer inhibitory control. An interaction indicated that cocaine effects were specific to children who lived in relatively low-risk environments. Cocaine-exposed children made an error sooner than unexposed children in low-risk environments but in the same trial as both exposed and unexposed children living in high-risk environments. Potential underlying mechanisms and the importance of examining cocaine exposure effects in the context of children's existing environment are discussed.

Children's intellectual and emotional-behavioral adjustment at 4 years as a function of cocaine exposure, maternal characteristics, and environmental risk.

The authors examined 223 children at age 4 years for the effects of prenatal cocaine exposure, exposure to other substances, maternal and environmental risk factors, and neonatal medical problems on IQ, externalizing problems, and internalizing problems. Regression analyses showed that maternal verbal IQ and low environmental risk predicted child IQ. Cocaine exposure negatively predicted children's overall IQ and verbal reasoning scores, but only for boys. Cocaine exposure also predicted poorer short-term memory. Maternal harsh discipline, maternal depressive symptoms, and increased environmental risk predicted externalizing problems. In contrast, only maternal depressive symptoms predicted internalizing problems. These findings indicate that early exposure to substances is largely unrelated to subsequent IQ or adjustment, particularly for girls.

Facial Expressivity at 4 Months: A Context by Expression Analysis.

The specificity predicted by differential emotions theory (DET) for early facial expressions in response to 5 different eliciting situations was studied in a sample of 4-month-old infants (n = 150). Infants were videotaped during tickle, sour taste, jack-in-the-box, arm restraint, and masked-stranger situations and their expressions were coded second by second. Infants showed a variety of facial expressions in each situation; however, more infants exhibited positive (joy and surprise) than negative expressions (anger, disgust, fear, and sadness) across all situations except sour taste. Consistent with DET-predicted specificity, joy expressions were the most common in response to tickling, and were less common in response to other situations. Surprise expressions were the most common in response to the jack-in-the-box, as predicted, but also were the most common in response to the arm restraint and masked-stranger situations, indicating a lack of specificity. No evidence of predicted specificity was found for anger, disgust, fear, and sadness expressions. Evidence of individual differences in expressivity within situations, as well as stability in the pattern across situations, underscores the need to examine both child and contextual factors in studying emotional development. The results provide little support for the DET postulate of situational specificity and suggest that a synthesis of differential emotions and dynamic systems theories of emotional expression should be considered.