Daniel N. McIntosh

Electrodermal responses to sensory stimuli in individuals with fragile X syndrome: a preliminary report.

The fragile X mutation and fragile X syndrome are associated with hyperarousal, hyperactivity, aggression, and anxiety. These may be related to strong reactions to auditory, tactile, visual, and olfactory stimuli [Hagerman, 1996b; Hagerman and Cronister, 1996]. However, almost no data exist describing hyperarousal and sensory sensitivity in individuals with the fragile X mutation. This study establishes a reliable laboratory paradigm for examining reactions to sensory stimuli. We found the pattern of electrodermal responses (EDRs) to stimulation in one sensory modality predicted the pattern of EDRs in four other sensory systems. In addition, the EDR pattern of individuals with the fragile X mutation was related to their FMR-protein expression. Finally, EDRs in individuals with fragile X syndrome were significantly different from those of normal controls, demonstrating greater magnitude, more responses per stimulation, responses on a greater proportion of trials, and lower rates of habituation. The findings support the theory that individuals with fragile X syndrome have a physiologically based enhancement of reactions to sensations. Because electrodermal activity indexes sympathetic nervous system activity, the data suggest that the over-arousal to sensation may involve the sympathetic system.

Sensory modulation dysfunction in children with attention‐deficit‐hyperactivity disorder

This study investigates the presence of sensory modulation dysfunction (SMD) among children with attention-deficit-hyperactivity disorder (ADHD). Twenty-six children with ADHD (mean age 8.3 years, 18 males, 8 females), and 30 typically developing children (mean age 8.2 years, 21 males, 9 females) were tested using a laboratory procedure that gauges responses to repeated sensory stimulation by measuring electrodermal reactivity (EDR). Parental report measures of limitations in sensory, emotional, and attentional dimensions were administered using the Short Sensory Profile, the Leiter International Performance Scale-Revised, Parent Rating subscales, and the Child Behavior Checklist (CBCL). Compared to the typical sample, the children with ADHD displayed greater abnormalities in sensory modulation on both physiological and parent-report measures. The children with ADHD also displayed more variability in responses. Within the group with ADHD, levels of SMD were highly correlated with measures of psychopathology on the CBCL. Implications of findings relate to the importance of considering sensory processing abilities in a subgroup of children with ADHD.

Sensory-modulation disruption, electrodermal responses, and functional behaviors.

It was hypothesized that children clinically identified with sensory‐modulation disruptions (SMD) would have atypical physiological responses to sensation, and that such responses would predict parent‐reported behavioral responses to sensation. Nineteen children with clinically identified disruptions, aged 3 to 9 years, mean 6.0 years, and 19 age‐and sex‐matched healthy (control) children, aged 3 to 9 years, mean 6.6 years, were examined. The subjects were presented with five stimuli. Ten trials were conducted for each stimulus and the electrodermal activity of the child was recorded. Four children with SMD did not show electrodermal responses (EDR) to stimulation; all control children responded. Excluding non‐responders, children with SMD showed more and larger EDR than control children. Participants with disruptions habituated more slowly to repeated stimulation, as measured by the number of responses to stimuli and proportion of stimuli that evoked responses. Children with atypical EDR had more parent‐reported abnormal behavioral responses to sensation. Children with clinically identified SMD respond physiologically differently to sensory stimuli than typically developing children; these differences have ramifications for functional behavior.

Facial feedback hypotheses: Evidence, implications, and directions.

This review evaluates four facial feedback hypotheses, each proposing a certain relation between the face and emotions. It addresses criticisms of the data, considers implications for emotional and social processes, and advises directions for future research. The current data support the following: Facial actions are sensitive to social context, yet correspond to the affective dimension of emotions; matches with specific emotions are unlikely. They modulate ongoing emotions, and initiate them. These two claims have received substantially improved support, in part due to studies controlling for effects of experimental demand and task difficulty. Facial action may influence the occurrence of specific emotions, not simply their valence and intensity. Facial action is not necessary for emotions. There are multiple and nonmutually exclusive plausible mechanisms for facial effects on emotions. Future work must focus on determining the relative contributions of these mechanisms, and the parameters of their effects on emotions.

More than mere mimicry? The influence of emotion on rapid facial reactions to faces.

Within a second of seeing an emotional facial expression, people typically match that expression. These rapid facial reactions (RFRs), often termed mimicry, are implicated in emotional contagion, social perception, and embodied affect, yet ambiguity remains regarding the mechanism(s) involved. Two studies evaluated whether RFRs to faces are solely nonaffective motor responses or whether emotional processes are involved. Brow (corrugator, related to anger) and forehead (frontalis, related to fear) activity were recorded using facial electromyography (EMG) while undergraduates in two conditions (fear induction vs. neutral) viewed fear, anger, and neutral facial expressions. As predicted, fear induction increased fear expressions to angry faces within 1000 ms of exposure, demonstrating an emotional component of RFRs. This did not merely reflect increased fear from the induction, because responses to neutral faces were unaffected. Considering RFRs to be merely nonaffective automatic reactions is inaccurate. RFRs are not purely motor mimicry; emotion influences early facial responses to faces. The relevance of these data to emotional contagion, autism, and the mirror system-based perspectives on imitation is discussed.

Terrorism, Acute Stress, and Cardiovascular Health: A 3-Year National Study Following the September 11th Attacks

CONTEXT The terrorist attacks of 9/11 (September 11, 2001) present an unusual opportunity to examine prospectively the physical health impact of extreme stress in a national sample. OBJECTIVE To examine the degree to which acute stress reactions to the 9/11 terrorist attacks predict cardiovascular outcomes in a national probability sample over the subsequent 3 years. DESIGN, SETTING, AND PARTICIPANTS A national probability sample of 2729 adults (78.1% participation rate), 95.0% of whom had completed a health survey before 9/11 (final health sample, 2592), completed a Web-based assessment of acute stress responses approximately 9 to 14 days after the terrorist attacks. Follow-up health surveys reassessed physician-diagnosed cardiovascular ailments 1 (n = 1923, 84.3% participation rate), 2 (n = 1576, 74.2% participation rate), and 3 (n = 1950, 78.9% participation rate) years following the attacks. MAIN OUTCOME MEASURES Reports of physician-diagnosed cardiovascular ailments over the 3 years following the attacks. RESULTS Acute stress responses to the 9/11 attacks were associated with a 53% increased incidence of cardiovascular ailments over the 3 subsequent years, even after adjusting for pre-9/11 cardiovascular and mental health status, degree of exposure to the attacks, cardiovascular risk factors (ie, smoking, body mass index, and number of endocrine ailments), total number of physical health ailments, somatization, and demographics. Individuals reporting high levels of acute stress immediately following the attacks reported an increased incidence of physician-diagnosed hypertension (rate ratios, 2.15 at 1 year and 1.75 at 2 years) and heart problems (rate ratios, 2.98 at 1 year and 3.12 at 2 years) over 2 years. Among individuals reporting ongoing worry about terrorism post-9/11, high 9/11-related acute stress symptoms predicted increased risk of physician-diagnosed heart problems 2 to 3 years following the attacks (rate ratios, 4.67 at 2 years and 3.22 at 3 years). CONCLUSION Using health data collected before 9/11 as a baseline, acute stress response to the terrorist attacks predicted increased reports of physician-diagnosed cardiovascular ailments over 3 years following the attacks.

Autism and the extraction of emotion from briefly presented facial expressions: stumbling at the first step of empathy.

Identification of other peoples emotion from quickly presented stimuli, including facial expressions, is fundamental to many social processes, including rapid mimicry and empathy. This study examined extraction of valence from brief emotional expressions in adults with autism spectrum disorder (ASD), a condition characterized by impairments in understanding and sharing of emotions. Control participants were individuals with reading disability and typical individuals. Participants were shown images for durations in the range of microexpressions (15 ms and 30 ms), thus reducing the reliance on higher level cognitive skills. Participants detected whether (a) emotional faces were happy or angry, (b) neutral faces were male or female, and (c) neutral images were animals or objects. Individuals with ASD performed selectively worse on emotion extraction, with no group differences for gender or animal?object tasks. The emotion extraction deficit remains even when controlling for gender, verbal ability, and age and is not accounted for by speed-accuracy tradeoffs. The deficit in rapid emotional processing may contribute to ASD difficulties in mimicry, empathy, and related processes. The results highlight the role of rapid early emotion processing in adaptive social?emotional functioning.

Rapid facial reactions to emotional facial expressions in typically developing children and children with autism spectrum disorder

Typical adults mimic facial expressions within 1000 ms, but adults with autism spectrum disorder (ASD) do not. These rapid facial reactions (RFRs) are associated with the development of social-emotional abilities. Such interpersonal matching may be caused by motor mirroring or emotional responses. Using facial electromyography (EMG), this study evaluated mechanisms underlying RFRs during childhood and examined possible impairment in children with ASD. Experiment 1 found RFRs to happy and angry faces (not fear faces) in 15 typically developing children from 7 to 12 years of age. RFRs of fear (not anger) in response to angry faces indicated an emotional mechanism. In 11 children (8-13 years of age) with ASD, Experiment 2 found undifferentiated RFRs to fear expressions and no consistent RFRs to happy or angry faces. However, as children with ASD aged, matching RFRs to happy faces increased significantly, suggesting the development of processes underlying matching RFRs during this period in ASD.

Nonverbal Channel Use in Communication of Emotion: How May Depend on Why

This study investigated the hypothesis that different emotions are most effectively conveyed through specific, nonverbal channels of communication: body, face, and touch. Experiment 1 assessed the production of emotion displays. Participants generated nonverbal displays of 11 emotions, with and without channel restrictions. For both actual production and stated preferences, participants favored the body for embarrassment, guilt, pride, and shame; the face for anger, disgust, fear, happiness, and sadness; and touch for love and sympathy. When restricted to a single channel, participants were most confident about their communication when production was limited to the emotions preferred channel. Experiment 2 examined the reception or identification of emotion displays. Participants viewed videos of emotions communicated in unrestricted and restricted conditions and identified the communicated emotions. Emotion identification in restricted conditions was most accurate when participants viewed emotions displayed via the emotions preferred channel. This study provides converging evidence that some emotions are communicated predominantly through different nonverbal channels. Further analysis of these channel-emotion correspondences suggests that the social function of an emotion predicts its primary channel: The body channel promotes social-status emotions, the face channel supports survival emotions, and touch supports intimate emotions.

Coping with Terrorism: Age and Gender Differences in Effortful and Involuntary Responses to September 11th

This study examined age and gender differences and similarities in stress responses to September 11th. Adolescents, young adults, and adults reported using a variety of strategies to cope with the terrorist attacks including acceptance, positive thinking, and emotional expression. In addition, involuntary stress responses such as physiological arousal, rumination, and emotional numbing were common. A number of age trends emerged, showing increases across the three groups in emotion-based coping strategies and decreases in some forms of disengagement coping. In addition, rumination decreased with age, whereas intrusive thoughts were more prevalent in the older groups. Females in both the adolescent and young adult samples reported using emotion-based strategies more than males, and these strategies were related to better functioning for females only. In addition, males reported higher levels of disengagement responses; and these responses were related to worse functioning, but only for females. The utility of using the Responses to Stress Questionnaire (Connor-Smith, Compas, Wadsworth, Thomsen, & Saltzman, 2000) to examine coping and involuntary stress responses in reference to terrorism and across a wide age range was examined. Implications for coping theory and empirical research are explored.