Martha Ann Bell

Individual differences in response to Stress and Cerebral Asymmetry

A number of studies suggest that the pattern of resting brain electrical activity, particularly in the frontal region, is a marker for individual differences in certain aspects of temperament or personality. We performed two studies with infants in which we observed their responses to brief maternal separation and recorded the electroencephalogram (EEG) either at the same session as separation or some weeks later. Study 1 examined the separation responses of 33 infants at 14 and 24 months of age. Study 2 investigated separation distress in 13 infants seen longitudinally, from 7 to 12 months of age. Across both studies, infants exhibiting right frontal activation were more likely to cry to maternal separation. The findings suggest that there is modest stability of frontal asymmetry during the second half of the first year of life. Differences between male and female infants in response to separation and frontal asymmetry were also found.

CRAWLING EXPERIENCE IS RELATED TO CHANGES IN CORTICAL ORGANIZATION DURING INFANCY : EVIDENCE FROM EEG COHERENCE

Greenoughs model of experience-expectant plasticity was used to examine EEG coherence among four groups of 8-month-old infants that varied in hands-and-knees crawling experience. Groups included prelocomotor infants, novice crawlers with 1-4 weeks experience, infants with 5-8 weeks, and long-term crawlers with 9+ weeks experience. Resting EEG was recorded from frontal, parietal, and occipital sites of both hemispheres. EEG coherence between intrahemispheric sites was computed. Novice crawlers (1-4 weeks) displayed greater coherence than either prelocomotor infants or experienced crawlers. These data suggest that the anticipation and onset of locomotion was related to an overproduction of cortico-cortical connections. Pruning of these overabundant connections may be a source of the decrease in coherence as crawling becomes more routine.

The Integration of Cognition and Emotion during Infancy and Early Childhood: Regulatory Processes Associated with the Development of Working Memory.

This study was an attempt to integrate cognitive development (i.e., cognitive control) and emotional development (i.e., emotion regulation) in the first years of life. The construct of temperament was used to unify cognition and emotion because of its focus on attentional and regulatory behaviors. Children were seen at 8 months and 412-years of age in a study designed to examine the correlates of working memory development. Frontal brain electrical activity and temperament predicted working memory performance at 8 months. Similarly, frontal brain electrical activity, temperament, and language predicted working memory at age 412-years. Temperament in early childhood mediated the relation between infant temperament and early childhood working memory performance. These associated temperament characteristics highlight the value of early-learned regulatory and attentional behaviors and the impact of these early skills on later development.

Stroop Color-Word Interference and Electroencephalogram Activation: Evidence for Age-Related Decline of the Anterior Attention System

Groups of healthy, community-dwelling younger and older adults performed a Stroop task in which color and word could be congruent or incongruent and spatially integrated or separated. During the task, continuous electroencephalogram (EEG) was recorded from frontal, parietal, and occipital regions. The magnitude of the Stroop interference effect and task-related EEG activation was greater for older than younger adults when stimuli were integrated. This effect was significant over medial and lateral frontal and parietal, but not occipital, regions. In comparison, interference and EEG activation did not differ for younger and older adults when stimuli were separated. These findings support the hypothesis that the anterior attention system is more sensitive to the effects of increasing age than the posterior attention system.

Biological Systems and the Development of Self-Regulation: Integrating Behavior, Genetics, and Psychophysiology

Self-regulation is the ability to control inner states or responses with respect to thoughts, emotions, attention, and performance. As such, it is a critical aspect of development and fundamental to personality and behavioral adjustment. In this review, we focus on attentional, cognitive, and emotional control as we discuss the genetic mechanisms and brain mechanisms that contribute to individual differences in self-regulation. We conclude with a discussion of the implications for deviations in the development of this complex construct and suggestions for future research.

Maternal Executive Function, Harsh Parenting, and Child Conduct Problems.

BACKGROUND Maternal executive function and household regulation both are critical aspects of optimal childrearing, but their interplay is not understood. We tested the hypotheses that (a) the link between challenging child conduct problems and harsh parenting would be strongest for mothers with poorer executive function and weakest among those with better executive function, and (b) this mechanism would be further moderated by the degree of household chaos. METHODS The socioeconomically diverse sample included 147 mothers of 3-to-7 year old children. Mothers completed questionnaires and a laboratory assessment of executive function. RESULTS Consistent with hypotheses, harsh parenting was linked with child conduct problems only among mothers with poorer executive function. This effect was particularly strong in calm, predictable environments, but was not evident in chaotic environments. CONCLUSION Maternal executive function is critical to minimizing harsh parenting in the context of challenging child behavior, but this self-regulation process may not operate well in chaotic environments.

Changes in Brain Functioning From Infancy to Early Childhood: Evidence From EEG Power and Coherence During Working Memory Tasks

Using measures of EEG power and coherence with a longitudinal sample, the goal of this study was to examine developmental changes in brain electrical activity during higher order cognitive processing at infancy and early childhood. Infants were recruited at 8 months of age and performed an infant working-memory task based on a looking version of the A-not-B task. At age 4.5 years, one half of the original sample returned for a follow-up visit and were assessed with age-appropriate working-memory tasks. At infancy, working memory was associated with changes in EEG power from baseline to task across the entire scalp, whereas in early childhood, working memory was associated with changes in EEG power from baseline to task at medial frontal only. Similar results were found for the EEG coherence data. At infancy, working memory was associated with changes in EEG coherence from baseline to task across all electrode pairs and by 4.5 years of age, EEG coherence changed from baseline to working-memory task at the medial frontal/posterior temporal pairs and the medial frontal/occipital pairs. These EEG power and coherence longitudinal data suggest that brain electrical activity is widespread during infant cognitive processing and that it becomes more localized during early childhood. These findings may yield insight into qualitative changes in cortical functioning from the infant to the early childhood time periods, adjustments that may be indicative of developmental changes in brain specialization for higher order processes.

Child development at the intersection of emotion and cognition

Developmental theorists have long speculated that emotion and cognition are inseparable components of the developmental process. Some even suggest that the two components are fully integrated by school age. Yet, despite considerable theoretical work describing this interaction, relatively little empirical work has been conducted on the subject. This volume addresses the codevelopment of emotional and cognitive processes by integrating theoretical and empirical work on these processes. The first part of the book demonstrates the codependence of emotional and cognitive processes, noting that both processes are clearly necessary for successful regulation of thought and behavior and that children with early adjustment difficulties often have deficits in both types of processing. The second part considers possible neurological and genetic mechanisms for the emotion-cognition link. Finally, the last part explores implications for clinical and educational research, highlighting atypical emotional and cognitive processing and its effect on adjustment in academic and social settings.

Brain Electrical Activity Associated With Cognitive Processing During a Looking Version of the A‐Not‐B Task

This work was designed to investigate individual differences in brain electrical activity during a looking version of the A-not-B task. It was proposed that this spatial task required the cognitive skills of working memory and inhibitory control, each associated with frontal lobe function. Electroencephalograms (EEGs) were recorded from 54 8-month-old infants during baseline and task. Only high performers on the looking task exhibited increases in 6- to 9-Hz EEG power from baseline to task. These task-related changes were evident at frontal and posterior scalp locations. High performers on the looking task exhibited lower EEG coherence values at right hemisphere frontal locations relative to the low performers. These lower coherence values were evident during baseline and task. All infants showed increased frontal-parietal coherence during the spatial working memory task relative to baseline values. These data confirm previous cognitive neuroscience work associating frontal lobe function with cognitive performance levels during infancy.

Comparable performance on looking and reaching versions of the A-not-B task at 8 months of age

Abstract The neuropsychological model of A-not-B performance focuses on the maturation of the frontal lobe and the development of skills associated with working memory, inhibition, and attention. These cognitive skills are essential for A-not-B performance regardless of the search modality required to exhibit object knowledge. This study used a within-subjects design to examine 8-month-old infants’ performance on looking and reaching versions of the A-not-B task. In both Experiment 1 (n = 62) and Experiment 2 (n = 47), there were no differences in A-not-B performance on looking and reaching versions of the task. These data suggest that the looking and reaching versions of the A-not-B task measure comparable cognitive abilities at 8 months of age.