Heath A. Demaree

Meta-analysis of intellectual and neuropsychological test performance in attention-deficit/hyperactivity disorder.

Cognitive measures are used frequently in the assessment and diagnosis of attention-deficit/hyperactivity disorder (ADHD). In this meta-analytic review, the authors sought to examine the magnitude of differences between ADHD and healthy participants on several commonly used intellectual and neuropsychological measures. Effect sizes for overall intellectual ability (Full Scale IQ; FSIQ) were significantly different between ADHD and healthy participants (weighted d =.61). Effect sizes for FSIQ were significantly smaller than those for spelling and arithmetic achievement tests and marginally significantly smaller than those for continuous performance tests but were comparable to effect sizes for all other measures. These findings indicate that overall cognitive ability is significantly lower among persons with ADHD and that FSIQ may show as large a difference between ADHD and control participants as most other measures.

Working Memory Capacity and the Self-Regulation of Emotional Expression and Experience

This research examined the relationship between individual differences in working memory capacity and the self-regulation of emotional expression and emotional experience. Four studies revealed that people higher in working memory capacity suppressed expressions of negative emotion (Study 1) and positive emotion (Study 2) better than did people lower in working memory capacity. Furthermore, compared to people lower in working memory capacity, people higher in capacity more capably appraised emotional stimuli in an unemotional manner and thereby experienced (Studies 3 and 4) and expressed (Study 4) less emotion in response to those stimuli. These findings indicate that cognitive ability contributes to the control of emotional responding.

Speed of information processing as a key deficit in multiple sclerosis: implications for rehabilitation

Speed of information processing was assessed in patients with multiple sclerosis and healthy controls using both an auditory and visual task designed to control for accuracy of performance across groups. After controlling for accuracy of performance, patients with multiple sclerosis were found to have significantly slower speed of information processing relative healthy controls, irrespective of the modality of stimulus presentation (auditory or visual). When given an adequate amount of time to process information, however, the patients performed similarly to controls. These results suggest that persons with multiple sclerosis experience deficits specifically in processing speed but not performance accuracy. Results are discussed in terms of rehabilitative guidelines for the cognitive improvement of persons with multiple sclerosis.

A meta-analysis of the neuropsychological sequelae of chemotherapy-only treatment for pediatric acute lymphoblastic leukemia

Mixed findings on the neuropsychological sequelae of chemotherapy‐only treatment for pediatric acute lymphoblastic leukemia (ALL), without radiation, indicate the need for a comprehensive meta‐analytic review. The purpose of the current study was to conduct a meta‐analysis assessing neuropsychological and academic functioning differences between children with ALL treated solely with chemotherapy and comparison groups.

The neuropsychology of depression: a literature review and preliminary model.

Neuropsychological research provides a useful framework to study emotional problems, such as depression, and their correlates. This paper reviews several prominent neuropsychological theories. Functional neuroanatomical systems of emotion and depression are reviewed, including those that describe cerebral asymmetries in emotional processing. Following the review, a model that is composed of three neuroanatomical divisions (left frontal, right frontal, and right posterior) and corresponding neuropsychological emotional sequelae within each quadrant is presented. It is proposed that dysfunction in any of these quadrants could lead to symptomatology consistent with a diagnosis of depression. The proposed model combines theories of arousal, lateralization, and functional cerebral space and lends itself to scientific methods of investigation. Accordingly, research, prevention, and treatment programs in accordance with the proposed model may promote an improved understanding of the neuropsychological mechanisms involved in depression.

Up- and down-regulating facial disgust: Affective, vagal, sympathetic, and respiratory consequences

Relative to watching in a natural manner, people asked to suppress or exaggerate their facial response to a negative emotional stimulus experience greater activation of the sympathetic nervous system but report a similar subjective emotional experience. The present research extends prior research on response modulation in two important ways. First, discrete indicators of cardiac vagal and sympathetic control (respiratory sinus arrhythmia (RSA) and pre-ejection period (PEP), respectively) were included as dependent measures along with interbeat interval (IBI) and skin conductance (EDR). Second, to help generalize results across response-focused modulation techniques, participants suppressed, exaggerated, or exerted no control over their responses while watching a disgust-eliciting film (for control purposes, a fourth group was asked to watch a neutral film naturally). Response modulation was associated with significantly decreased PEP (increased cardiac sympathetic control) relative to those in the natural-watch conditions. All participants evidenced increased EDR while watching the disgusting clip, but facial modulation did not produce EDR reactivity beyond that of watching the disgusting film naturally. Exaggerators experienced decreased IBI during modulation (perhaps due to increased muscle contraction) whereas all other groups showed increased IBI (i.e., the orienting response). Neither emotional experience nor facial modulation reliably impacted RSA, respiration rate, or inspiratory depth.

Working memory capacity and spontaneous emotion regulation: high capacity predicts self-enhancement in response to negative feedback.

Although previous evidence suggests that working memory capacity (WMC) is important for success at emotion regulation, that evidence may reveal simply that people with higher WMC follow instructions better than those with lower WMC. The present study tested the hypothesis that people with higher WMC more effectively engage in spontaneous emotion regulation following negative feedback, relative to those with lower WMC. Participants were randomly assigned to receive either no feedback or negative feedback about their emotional intelligence. They then completed a disguised measure of self-enhancement and a self-report measure of affect. Experimental condition and WMC interacted such that higher WMC predicted more self-enhancement and less negative affect following negative feedback. This research provides novel insight into the consequences of individual differences in WMC and illustrates that cognitive capacity may facilitate the spontaneous self-regulation of emotion.

Resting RSA is associated with natural and self-regulated responses to negative emotional stimuli.

Resting respiratory sinus arrhythmia (RSA) was assessed among 111 adult participants. These individuals were then asked to watch a positive or negative affective film in either a natural manner or while exaggerating their facial response. Facial reactions to the film were video-recorded and subsequently rated in terms of facial affect. Participants also self-reported the valence of their emotional experience. Results from regression analyses revealed that persons with low resting RSA behaviorally evidenced a more negative facial response to the negative film under natural-watch conditions. Low RSA individuals were also less able to modulate (i.e., amplify) their facial response to the negative film. In terms of self-report measures, persons in the exaggerate condition reported more positive affect to the positive film than did those in the natural-watch condition. Results suggest that cardiac vagal control is inversely associated with negative facial expression but positively associated with facial regulation ability to negative stimuli.

Differentiating simple versus complex processing speed: Influence on new learning and memory performance

The current study was designed to examine how the construct of human information processing speed is conceptualized and measured, while also examining the influence of information processing speed on higher cognitive processes (i.e., learning). A mixed medical sample of 92 subjects participated in this study. Subjects underwent a broad-based neuropsychological evaluation, including measures of verbal and visuospatial new learning, spatial and verbal working memory, simple reaction time, choice reaction time, and information processing speed. Principal components factor analysis with varimax rotation resulted in a three-factor solution, comprised of: (1) simple speed/reaction time, (2) complex information processing and new learning, and (3) working memory. Notably, this factor solution identified 2 distinct forms of processing speed – simple and complex information processing speeds. In contrast to the abundance of literature grouping these two constructs together under one term (i.e., processing speed), these results indicate simple and complex speed to be distinct constructs assessed with different neuropsychological instruments. While the expected relationship between complex information processing capacities and working memory abilities was evident in this study, information processing speed also showed a significant relationship with new learning ability. The implications of this intriguing relationship are discussed.

Cardiac vagal control predicts spontaneous regulation of negative emotional expression and subsequent cognitive performance

The present research investigated whether cardiac vagal control (as measured by respiratory sinus arrhythmia, RSA) predicts an individuals predisposition to suppress negative emotional expressions. One hundred thirty-six participants watched either a negative film or a neutral film. Facial expressions were recorded during the film and subjective emotional responses were assessed afterwards. Participants performed verbal and spatial working memory tasks both before and after the film clips. We found that resting RSA modulated the degree of coherence between facial expressions of emotion and subjective emotional experience in the negative film condition. Specifically, participants with higher resting RSA expressed less but reported feeling just as much negative emotion as those with lower resting RSA. Moreover, higher resting RSA predicted smaller pre-film to post-film improvements in spatial working memory performance in the negative film condition, suggesting that expressive suppression among high RSA participants temporarily undermined the operation of working memory. In the neutral film condition, resting RSA did not relate to expressive or subjective responses or subsequent working memory performance. These results support the notion that cardiac vagal control reflects an internal marker of self-regulatory tendencies and suggest that spontaneous self-regulation associated with individual differences in resting RSA may temporarily deplete self-regulatory resources.