Analyzing temporal patterns of infant sleep and negative affective behavior: a comparison between different statistical models

Objective

Variability in infant sleep and negative affective behavior (NAB) is a developmental phenomenon that has long been of interest to researchers and clinicians. However, analyses and delineation of such temporal patterns were often limited to basic statistical approaches, which may prevent adequate identification of meaningful variation within these patterns. Modern statistical procedures such as additive models may detect specific patterns of temporal variation in infant behavior more effectively.

Method

Hundred and twenty-one mothers were asked to record different behaviors of their 4–44 weeks old healthy infants by diaries for three days consecutively. Circadian patterns as well as individual trajectories and day-to-day variability of infant sleep and NAB were modeled with generalized linear models (GLMs) including a linear and quadratic polynomial for time, a GLM with a polynomial of the 8th order, a GLM with a harmonic function, a generalized linear mixed model (GLMM) with a polynomial of the 8th order, a generalized additive model, and a generalized additive mixed model (GAMM).

Results

The semi-parametric model GAMM was found to fit the data of infant sleep better than any other parametric model used. GLMM with a polynomial of the 8th order and GAMM modeled temporal patterns of infant NAB equally well, although the GLMM exhibited a slightly better model fit while GAMM was easier to interpret. Besides the well-known evening clustering in infant NAB we found a significant second peak in NAB around midday that was not affected by the constant decline in the amounts of NAB across the 3-day study period.

Conclusion

Using advanced statistical procedures (GAMM and GLMM) even small variations and phenomena in infant behavior can be reliably detected. Future studies investigating variability and temporal patterns in infant variables may benefit from these statistical approaches.     

Increased intraindividual variability is a marker of ADHD but also of dyslexia: a study on handwriting

It has been suggested that intraindividual variability (IIV) in neuropsychological tasks may be a specific characteristic of Attention-Deficit Hyperactivity Disorder (ADHD), but previous research has not thoroughly examined whether IIV also concerns academic performance or other types of developmental disabilities. The present study investigates the role of IIV in 15 children with ADHD without reading difficulties, 15 children with dyslexia without associated symptoms of ADHD, and 15 typically developing children (TDC) in a simple response time (SRT) task and in a skill more directly related with school learning—handwriting. Results show that children with ADHD and those with dyslexia have a greater IIV than the TDC in both tasks. However, the pattern of the relationship between IIV in SRT and handwriting was different in children with ADHD and dyslexia: the IIV in the handwriting task was found to depend on IIV in the SRT task only in children with dyslexia. These findings support the crucial role of IIV not only in ADHD but also in other developmental disabilities, but suggest that in children with ADHD it may present specific aspects related with motor control.     

Friendship factors and suicidality: common and unique patterns in Mexican American and European American youth

Research suggests a link between friendships and suicidality among U.S. youth, but this link has not been confirmed across ethnicities. The relationship between friendships and suicidality among Mexican American and European American adolescents was examined in this study. Specifically, the role of friendship problems (i.e., social isolation, poor quality friendships) and problematic friends (i.e., friends who were disconnected from school, delinquent friends) was explored. Participants were 648 community youth. Friends' school disconnection was related to Mexican American girls' suicidal ideation, while friends' delinquency was associated with European American youth suicidal behavior. Friendship factors were no longer associated with suicidality after controlling for suicidality correlates such as depression. These findings indicate that the relationship between friendships and suicidality varies by gender and ethnicity. They also suggest a dominant role of depression.     

Psychometric Properties of the Wisconsin Schizotypy Scales in an Undergraduate Sample: Classical Test Theory,Item Response Theory,and Differential Item Functioning

The Wisconsin Schizotypy Scales are widely used for assessing schizotypy in nonclinical and clinical samples. However, they were developed using classical test theory (CTT) and have not had their psychometric properties examined with more sophisticated measurement models. The present study employed item response theory (IRT) as well as traditional CTT to examine psychometric properties of four of the schizotypy scales on the item and scale level, using a large sample of undergraduate students (n = 6,137). In addition, we investigated differential item functioning (DIF) for sex and ethnicity. The analyses revealed many strengths of the four scales, but some items had low discrimination values and many items had high DIF. The results offer useful guidance for applied users and for future development of these scales.     

Between Remembering and Forgetting the Years of Political Violence: Psychosocial Impact of the Truth and Reconciliation Commission in Peru

This article analyzes the association between knowledge of the Truth and Reconciliation Commission (TRC), evaluation of TRC's achievements, experience of victimization, attitudes toward remembering and forgetting past political violence, perceptions of socioemotional climate (SEC), belief in forgiveness and attitudes toward violence in Peru based on a study conducted in three Peruvian cities with different rates of victimization due to political violence during 1980–2000 (n = 1200). Results showed that a positive attitude toward remembering the past of political violence was predominant and related to a positive evaluation of TRC's achievements. Attitude toward remembering also has an ambivalent collective effect increasing both positive and negative SECs, and it is less accepted by victims of political violence. On the other hand, attitude toward forgetting is less accepted by participants, and it also has an ambivalent effect by increasing positive and negative SECs. Attitude toward forgetting has more societal costs, since it is related to attitudes toward violence and decreased knowledge and a positive evaluation of TRC. In general, findings suggest that remembering traumatic events has an emotional cost, but also it is shown that remembering seems to be more beneficial for society in the long‐term than forgetting.     

Self-focused attention,performance expectancies,and the intensity of effort: Do people try harder for harder goals?

Many theories argue that goal striving is more intense when people have optimistic expectancies for achieving the goal and when attention is self-focused. Brehm’s motivational intensity theory, however, predicts that the intensity of motivation is only as high as necessary, so people will try harder for difficult tasks than for easy tasks, all else equal. The present experiment compared these two approaches by manipulating two levels of self-focused attention (low and high self-awareness, via a mirror) and two levels of task difficulty (easy and difficult). Effort was assessed as cardiovascular reactivity, particularly change in systolic blood pressure. Neither high self-focus nor an easy task per se caused increased effort; instead, high self-focus significantly increased systolic reactivity when the task was difficult. Effort was thus higher despite less optimistic goal expectancies, a finding that is predicted by Brehm’s motivational intensity theory but not by traditional self-regulation models.     

Vigilance and Avoidance of Threat in the Eye Movements of Children with Separation Anxiety Disorder

The vigilance-avoidance attention pattern is found in anxious adults, who initially gaze more at threatening pictures than nonanxious adults (vigilance), but subsequently gaze less at them than nonanxious adults (avoidance). The present research, using eye tracking methodology, tested whether anxious children show the same pattern. Children with separation anxiety disorder or no mental disorder viewed pairs of pictures, while the direction of their gaze was tracked. Each picture pair showed one picture of a woman separating from a child, the other picture of a woman reuniting with a child. The results supported the vigilance-avoidance model in children. Although the two groups’ gaze direction did not differ during the first second of viewing, anxious children gazed significantly more at separating (threatening) pictures than nonanxious children after a period of 1 s. But after 3 s the pattern reversed: anxious children gazed significantly less at the separating pictures than nonanxious children.     

Well-Being and Fairness

The article explores the interaction of two, potentially clashing, considerations, each reflecting a different conception of fairness concerning the resolution of interpersonal conflicts. According to the Equal Chance Principle, the harm for each person should be minimized in a significant and (roughly) equal degree; when this is impossible, each person should be accorded the highest possible equal chance to avoid the harm. According to the Importance Principle, the danger to the person who would otherwise suffer the more serious harm should be prevented. An erratum to this article is available at .     

Reactance and the dynamics of disagreement: multiple paths from threatened freedom to resistance to persuasion

Many experiments show that threats to attitudinal freedom create reactance, but the underlying dynamics of reactance‐based disagreement have not received much attention. The present experiments identified two paths from threats to disagreement. In one path, threats to attitudinal freedom directly motivate disagreement; in the other, negative cognitive responses mediate the threat's effect on disagreement. Two experiments demonstrated the causes and consequences of each path from threat to persuasion. When a communicator threatened freedom at the beginning of the message, unfavorable cognitive responses (counterarguing, negative perceptions of the source's credibility) fully mediated the effect of threat on disagreement. When the threat appeared at the end of the message however, threat had a direct, unmediated effect on disagreement (Experiment 1). The two paths had different consequences for sleeper effects: disagreement rooted in negative cognitive responses persisted, whereas disagreement directly motivated by the threat declined when the threat was removed (Experiment 2). Implications for reactance and for threat‐based sleeper effects are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

A Brain-Based Account of the Development of Rule Use in Childhood

ABSTRACT— The ability to follow explicit rules improves dramatically during the course of childhood, but relatively little is known about the changes in brain structure and function that underlie this behavioral improvement. Drawing from neuroscientific studies in human adults and other animals, as well as from an emerging literature in developmental cognitive neuroscience, we propose a brain-based account of the development of rule use in childhood. This account focuses on four types of rules represented in different parts of the prefrontal cortex: simple rules for reversing stimulus–reward associations, pairs of conditional stimulus–response rules (both univalent and bivalent), and higher-order stimulus–response rules for selecting among task sets. It is hypothesized that the pattern of developmental changes in rule use reflects the different rates of development of specific regions within the prefrontal cortex.