Methylphenidate and emotional-motivational processing in attention-deficit/hyperactivity disorder.

In line with the assumption that emotional-motivational deficits are one core dysfunction in ADHD, in one of our previous studies we observed a reduced reactivity towards pleasant pictures in adult ADHD patients as compared to controls. This was indicated by a lack of attenuation of the startle reflex specifically during pleasant pictures in ADHD patients. The first choice medical agents in ADHD, methylphenidate (MPH), is discussed to normalize these dysfunctions. However, experimental evidence in the sense of double-blind placebo-controlled study designs is lacking. Therefore, we investigated 61 adult ADHD patients twice, one time with placebo and one time with MPH with the same experimental design as in our study previously and assessed emotion processing during the presentation of pleasant, neutral and unpleasant pictures. We obtained startle reflex data as well as valence and arousal ratings in association with the pictures. As previously shown, ADHD patients showed a diminished startle attenuation during pleasant pictures while startle potentiation during unpleasant pictures was normal. Valence and arousal ratings unsuspiciously increased with increasing pleasantness and arousal of the pictures, respectively. There were no significant influences of MPH. The study replicates that ADHD patients show a reduced reactivity towards pleasant stimuli. MPH did not normalize this dysfunction. Possibly, MPH only influences emotions during more complex behavioural tasks that involve executive functions in adults with ADHD. Our results emphasize the importance for the use of double-blind placebo-controlled designs in psychopharmacological research.

Facial mimicry in its social setting.

In interpersonal encounters, individuals often exhibit changes in their own facial expressions in response to emotional expressions of another person. Such changes are often called facial mimicry. While this tendency first appeared to be an automatic tendency of the perceiver to show the same emotional expression as the sender, evidence is now accumulating that situation, person, and relationship jointly determine whether and for which emotions such congruent facial behavior is shown. We review the evidence regarding the moderating influence of such factors on facial mimicry with a focus on understanding the meaning of facial responses to emotional expressions in a particular constellation. From this, we derive recommendations for a research agenda with a stronger focus on the most common forms of encounters, actual interactions with known others, and on assessing potential mediators of facial mimicry. We conclude that facial mimicry is modulated by many factors: attention deployment and sensitivity, detection of valence, emotional feelings, and social motivations. We posit that these are the more proximal causes of changes in facial mimicry due to changes in its social setting.

Child impact on family functioning: a multivariate analysis in multiplex families with children and mothers both affected by attention-deficit/hyperactivity disorder (ADHD).

ADHD seriously impacts family functioning, even the more in families with simultaneous parental and child ADHD. The aim of the study was to examine associations between family impact of child ADHD and child, mother and family characteristics in multiplex families with children and mothers both affected by ADHD. One hundred and forty-four mother-child pairs were assessed (children: mean age 9.4 ± 1.7 years, 73.6 % male). Family impact of child ADHD was rated by mothers using the Family Impact Questionnaire (FIQ). Multiple linear regression analyses were performed with child and maternal psychopathology and basic family characteristics such as employment, partnership status and number of children as predictors and FIQ subscores as criteria. Rates of variance explained by family variables were 49 % for negative feelings towards the child, 37 % for impact on partnership, 31 % for impact on social life and 27 % for impact on finances (p < .001, respectively). Pearson correlations with family impact were especially strong for child externalizing symptoms, maternal ADHD and co-morbid symptoms of the mother. The strongest independent predictor was oppositional defiant child behaviour. In ADHD multiplex families, mothers' perception of the impact of an ADHD child on its family can be explained to a substantial degree by child psychopathology, maternal psychopathology and basic family characteristics. Although a cross-sectional design does not allow for causal interpretations, the findings of this study offer important targets for the treatment of ADHD in a family context pointing to the need for assessing and treating parental mental health and co-morbid symptoms besides ADHD core symptoms.

The face of schadenfreude: Differentiation of joy and schadenfreude by electromyography.

The present study investigated whether the facial expression of the social emotion schadenfreude, the pleasant emotion which arises in response to another's misfortune, can be differentiated from the facial expression of joy. Schadenfreude was induced by videos displaying unsuccessful penalty shots of Dutch soccer players and joy by successful penalty shots of German soccer players. Thirty-two participants watched videos while the activity of four facial muscles was recorded electromyographically. Furthermore, they judged each stimulus according to valence, arousal, joy, schadenfreude and sadness. Electromyography (EMG) results revealed that schadenfreude expressions did not differ from joy with regard to involved muscles (increase of Musculus zygomaticus major and M. orbicularis oculi activity, decrease of M. corrugator supercilii activity, no activity change of M. frontalis medialis). Furthermore, facial reactions developed fast in both conditions and EMG indicated stronger reactions in the schadenfreude condition, but according to ratings participants felt more pleasure in the joy condition.

Autonomic hypoactivity in boys with attention-deficit/hyperactivity disorder and the influence of methylphenidate.

OBJECTIVES: This study investigates an overall autonomic hypoactivity reflecting hypoarousal as important aetiological factor in ADHD at baseline during rest and in response towards stimuli. In addition, effects of methylphenidate (MPH) are examined. We further assessed whether this hypoarousal is a stable characteristic or ameliorated by arousing emotional stimuli. METHODS: Boys with ADHD were examined with (n = 35) or without MPH (n = 45) and compared with healthy boys (n = 22) regarding skin conductance level (SCL) during rest and skin conductance responses (SCRs) as well as valence and arousal ratings in response to positive, neutral, and negative pictures. RESULTS: ADHD children without MPH were characterized by reduced baseline SCL and overall reduced SCRs. ADHD children with MPH never differed from control children. All groups displayed normal valence and arousal ratings of the stimuli and enhanced SCRs to emotional in comparison to neutral pictures. CONCLUSIONS: This is the first study to unravel (1) a general autonomic hypoactivity in ADHD children at baseline and in response to low arousing neutral and highly arousing emotional stimuli, and (2) hints that MPH normalizes this hypoactivity. Results contribute to the understanding of ADHD aetiology and MPH functionality, and are consistent with the cognitive-energetic model of ADHD.

Altered processing of emotional stimuli in migraine: an event-related potential study.

BACKGROUND: Migraine patients report psychosocial stress to be among the major triggers for their migraine attacks. The mechanisms underlying the onset of migraine attacks are not yet fully understood. Neuroimaging studies have shown changes in the cortical excitability of migraine patients. Here, we investigated cortical activation related to processing of emotional stimuli in individuals with migraine. METHOD: Twenty-four participants suffering from migraine attacks and 25 healthy volunteers had to passively observe pictures of emotional facial expressions (angry, happy and neutral). Electro-cortical activity was continuously recorded by means of an electroencephalogram (EEG), and ratings of valence (unpleasant vs. pleasant) and arousal (calm vs. exciting) were collected. RESULTS: The migraine and control group did not differ in their ratings of valence and arousal of the visual stimuli. However, participants with migraine, in contrast to healthy controls, showed larger N170 amplitudes toward angry facial expressions compared to neutral ones. DISCUSSION: Individuals with migraine may have an altered cortical activity linked to the processing of emotional information. Thus, these individuals may process high arousing and threatening events preferentially, and this facilitated processing may be related to their already high cortical excitability.

Androstadienone in motor reactions of men and women toward angry faces.

The endogenous compound androstadienone modulating the evaluation of others and activating the human fear system was hypothesized in terms of processing socially relevant cues by regulating responses to angry faces. Androstadienone was investigated in association with arm movements of 62 participants (30 women) in response to happy and angry facial expressions. Volunteers pushed away or pulled toward them a joystick as fast as possible on seeing either an angry or a happy cartoon face on a computer screen. This task was repeated twice: once during exposure to androstadienone masked with clove oil and once to clove oil only. In the former condition participants' reaction speed was accelerated, especially when reacting to angry faces. This observation may indicate an androstadienone-related activation of the fear system leading to faster responses to threat signals, assuming an enhanced allocation of attentional resources toward threat-related social cues.

Facial mimicry and the mirror neuron system: simultaneous acquisition of facial electromyography and functional magnetic resonance imaging.

Numerous studies have shown that humans automatically react with congruent facial reactions, i.e., facial mimicry, when seeing a vis-á-vis' facial expressions. The current experiment is the first investigating the neuronal structures responsible for differences in the occurrence of such facial mimicry reactions by simultaneously measuring BOLD and facial EMG in an MRI scanner. Therefore, 20 female students viewed emotional facial expressions (happy, sad, and angry) of male and female avatar characters. During picture presentation, the BOLD signal as well as M. zygomaticus major and M. corrugator supercilii activity were recorded simultaneously. Results show prototypical patterns of facial mimicry after correction for MR-related artifacts: enhanced M. zygomaticus major activity in response to happy and enhanced M. corrugator supercilii activity in response to sad and angry expressions. Regression analyses show that these congruent facial reactions correlate significantly with activations in the IFG, SMA, and cerebellum. Stronger zygomaticus reactions to happy faces were further associated to increased activities in the caudate, MTG, and PCC. Corrugator reactions to angry expressions were further correlated with the hippocampus, insula, and STS. Results are discussed in relation to core and extended models of the mirror neuron system (MNS).

Electrocortical evidence for preferential processing of dynamic pain expressions compared to other emotional expressions.

Decoding pain in others is of high individual and social benefit in terms of harm avoidance and demands for accurate care and protection. The processing of facial expressions includes both specific neural activation and automatic congruent facial muscle reactions. While a considerable number of studies investigated the processing of emotional faces, few studies specifically focused on facial expressions of pain. Analyses of brain activity and facial responses elicited by the perception of facial pain expressions in contrast to other emotional expressions may unravel the processing specificities of pain-related information in healthy individuals and may contribute to explaining attentional biases in chronic pain patients. In the present study, 23 participants viewed short video clips of neutral, emotional (joy, fear), and painful facial expressions while affective ratings, event-related brain responses, and facial electromyography (Musculus corrugator supercilii, M. orbicularis oculi, M. zygomaticus major, M. levator labii) were recorded. An emotion recognition task indicated that participants accurately decoded all presented facial expressions. Electromyography analysis suggests a distinct pattern of facial response detected in response to happy faces only. However, emotion-modulated late positive potentials revealed a differential processing of pain expressions compared to the other facial expressions, including fear. Moreover, pain faces were rated as most negative and highly arousing. Results suggest a general processing bias in favor of pain expressions. Findings are discussed in light of attentional demands of pain-related information and communicative aspects of pain expressions.

Call-associated acute fatigue in surgical residents--subjective perception or objective fact? A cross-sectional observational study to examine the influence of fatigue on surgical performance.

BACKGROUND: The effect of acute partial sleep deprivation on surgical proficiency is still controversially discussed. The present study correlated physiological parameters of fatigue with objective technical and cognitive skills, as well as subjective sleepiness of surgical residents. The aim of the study was to assess the effect of acute partial sleep deprivation on surgical performance. METHODS: Thirty-eight surgeons were interviewed on three consecutive mornings: prior to a 24 h call, post-call, and after 24 h of rest. Reported hours of sleep were recorded. Subjective alertness was assessed with the standardized Stanford-Sleepiness-Scale (SSS). Saliva cortisol concentrations and pupillary activity were measured by standardized ELISA and pupillography. The virtual reality (VR)-simulator LapSim was used to assess technical skills through low-fidelity VR-tasks ("cutting," "clip applying") and cognitive skills through high-fidelity VR-tasks ("intracorporeal suturing," "VR-cholecystectomy"). Objective alertness was measured by the standardized d2-Paper-Pencil Test. RESULTS: Recorded hours of sleep (p = 0.001) and subjective alertness (SSS) decreased (p = 0.001) significantly post-call. None of the three factors studied-saliva cortisol concentration (p = 0.313), pupillary activity (p = 0.998), or VR-performance of low-fidelity VR-tasks-differed significantly between assessments. Surprisingly, VR-performance of high-fidelity VR-tasks (error-score p = 0.044, time to complete task p = 0.0001, economy of instrument motion p = 0.0001) and objective alertness (d2-Paper-Pencil Test p = 0.027) significantly improved in the post-call setting. CONCLUSIONS: Acute call-associated fatigue seems to be a predominantly subjective perception. Physiological factors seem to outbalance an anticipated fatigue-associated impairment of technical performances within low-fidelity VR-tasks. In surgical residents, acute partial sleep deprivation seems to have a positive short-term effect on cognitive skills, leading to enhanced technical performance and increased objective alertness within complex tasks.

A polymorphism in the gene of the endocannabinoid-degrading enzyme FAAH (FAAH C385A) is associated with emotional-motivational reactivity.

RATIONALE: The endocannabinoid (eCB) system is implicated in several psychiatric disorders. Investigating emotional-motivational dysfunctions as underlying mechanisms, a study in humans revealed that in the C385A polymorphism of the fatty acid amide hydrolase (FAAH), the degrading enzyme of the eCB anandamide (AEA), A carriers, who are characterized by increased signaling of AEA as compared to C/C carriers, exhibited reduced brain reactivity towards unpleasant faces and enhanced reactivity towards reward. However, the association of eCB system with emotional-motivational reactivity is complex and bidirectional due to upcoming compensatory processes. OBJECTIVES: Therefore, we further investigated the relationship of the FAAH polymorphism and emotional-motivational reactivity in humans. METHODS: We assessed the affect-modulated startle, and ratings of valence and arousal in response to higher arousing pleasant, neutral, and unpleasant pictures in 67 FAAH C385A C/C carriers and 45 A carriers. RESULTS: Contrarily to the previous functional MRI study, A carriers compared to C/C carriers exhibited an increased startle potentiation and therefore emotional responsiveness towards unpleasant picture stimuli and reduced startle inhibition indicating reduced emotional reactivity in response to pleasant pictures, while both groups did not differ in ratings of arousal and valence. CONCLUSIONS: Our findings emphasize the bidirectionality and thorough examination of the eCB system's impact on emotional reactivity as a central endophenotype underlying various psychiatric disorders.

Reduced early visual emotion discrimination as an index of diminished emotion processing in Parkinson's disease? - Evidence from event-related brain potentials.

Although Parkinson's disease (PD) is defined by its motor symptoms, it is now well recognized that cognitive and affective domains, such as recognition of emotion from facial expressions, may also be impaired. To examine brain mechanisms involved in processing of emotion recognition from facial expressions, we obtained affective ratings and visual event-related potentials (ERPs) in response to facial expressions from 18 PD patients under dopamine-replacement therapy, and 17 healthy age- and sex-matched controls. In control subjects, the early posterior negativity (EPN) of the ERP, which is thought to reflect early perceptual emotion discrimination, was larger in response to emotional compared to neutral facial expressions. In contrast, this emotional modulation of the EPN was absent in PD patients indicating impaired early emotion discrimination. Behaviorally, PD patients showed no impairments in emotion recognition as measured by affective ratings. These findings suggest that facial emotion processing may be disrupted at an early stage of visual neural processing in PD. Absence of behavioral impairment may point to compensatory strategies of emotion recognition in medicated PD patients. Further research should clarify these dissociations between behavioral and neurophysiological levels of emotion processing in PD.

Processes underlying congruent and incongruent facial reactions to emotional facial expressions.

The present electromyographic study is a first step toward shedding light on the involvement of affective processes in congruent and incongruent facial reactions to facial expressions. Further, empathy was investigated as a potential mediator underlying the modulation of facial reactions to emotional faces in a competitive, a cooperative, and a neutral setting. Results revealed less congruent reactions to happy expressions and even incongruent reactions to sad and angry expressions in the competition condition, whereas virtually no differences between the neutral and the cooperation condition occurred. Effects on congruent reactions were found to be mediated by cognitive empathy, indicating that the state of empathy plays an important role in the situational modulation of congruent reactions. Further, incongruent reactions to sad and angry faces in a competition setting were mediated by the emotional reaction of joy, supporting the assumption that incongruent facial reactions are mainly based on affective processes. Additionally, strategic processes (specifically, the goal to create and maintain a smooth, harmonious interaction) were found to influence facial reactions while being in a cooperative mindset. Now, further studies are needed to test for the generalizability of these effects.

Methylphenidate normalizes emotional processing in adult patients with attention-deficit/hyperactivity disorder: preliminary findings.

Emotional-motivational dysfunctions may significantly contribute to symptoms of attention-deficit/hyperactivity disorder (ADHD). Hyperactive-impulsive symptoms and sensation seeking could be the result of a search for reinforcers, and cognitive dysfunctions might be due to a low motivational drive. Emotional-motivational dysfunctions could also explain social dysfunctions in ADHD patients because they may lead to misinterpretations of emotional and social clues. Since methylphenidate (MPH) is the first choice as a pharmacological treatment in ADHD, we examined its influence on dysfunctional emotional processes. 13 adult ADHD patients were examined twice, without and after intake of MPH according to their personal medication regimen. The affect-modulated startle paradigm was used to assess physiological (affect-modulated startle response) and subjective (valence and arousal ratings) responses to pleasant, neutral and unpleasant visual stimuli. Healthy controls displayed affective startle modulation as expected, with startle attenuation and potentiation while watching pleasant and unpleasant pictures, respectively. In contrast, unmedicated ADHD patients displayed deficient responses to pleasant stimuli; no startle attenuation during the exposure to pleasant pictures was observed. However, MPH reinstated a normal affective startle modulation, as indicated by attenuation and potentiation associated with pleasant and unpleasant pictures, respectively. Valence and arousal ratings of patients were not affected by MPH. The data suggest that MPH as first choice treatment in ADHD has a positive impact on emotional processes in adult ADHD patients and points to the clinical relevance of emotional-dysfunctions in ADHD.

Cortisol reactivity in boys with attention-deficit/hyperactivity disorder and disruptive behavior problems: the impact of callous unemotional traits.

There is a body of literature demonstrating an association between altered hypothalamic pituitary adrenal (HPA) axis reactivity and aggressive behavior. Aggressive and disruptive behavior also is highly prevalent in children with attention deficit/hyperactivity disorder (ADHD). Findings on HPA-axis reactivity in ADHD, however, are rather inconsistent. Specific temperamental risk factors previously were associated with a specific subtype of severe disruptive behavior. These traits might also be characterized by a distinct neurobiological profile across ADHD and disruptive behavior disorders. In this study we focus on psychopathic traits, notably callous unemotional (CU) traits. The main objective of the present study was to investigate whether two groups of ADHD patients with high or low CU traits differed in cortisol reactivity. Subjects were 36 boys with ADHD and disruptive behavior symptoms aged 8 to 14 years. Salivary cortisol probes were taken before and repeatedly after an experimental standardized stress test. Patients scoring high on CU traits showed a blunted HPA axis reactivity to the experimentally induced stress. Results underscore the need to consider specific personality traits in investigating neurobiological correlates in ADHD with disruptive behavior problems.

Stop looking angry and smile, please: start and stop of the very same facial expression differentially activate threat- and reward-related brain networks.

Static pictures of emotional facial expressions have been found to activate brain structures involved in the processing of emotional stimuli. However, in everyday live, emotional expressions are changing rapidly, and the processing of the onset vs the offset of the very same emotional expression might rely on different brain networks, presumably leading to different behavioral and physiological reactions (e.g. approach or avoidance). Using functional magnetic resonance imaging, this was examined by presenting video clips depicting onsets and offsets of happy and angry facial expressions. Subjective valence and threat ratings clearly depended on the direction of change. Blood oxygen level dependent responses indicate both reward- and threat-related activations for the offset of angry expressions. Comparing onsets and offsets, angry offsets were associated with stronger ventral striatum activation than angry onsets. Additionally, the offset of happy and the onset of angry expressions showed strong common activity in the lateral orbitofrontal cortex bilaterally, the left amygdala and the left insula, whereas the onset of happy and the offset of angry expressions induced significant activation in the left dorsal striatum. In sum, the results confirm different activity in motivation-related brain areas in response to the onset and offset of the same emotional expression and highlight the importance of temporal characteristics of facial expressions for social communication.

Conditioned cues for smoking elicit preparatory responses in healthy smokers.

RATIONALE: Smoking cues are theorized to be conditioned stimuli (CSs) formed by repeated pairing with drug. Smoking paraphernalia can elicit subjective and physiological responses in smokers, indicative of positive affect and motivation to consume. Although these responses are probably the result of conditioning, direct evidence from human conditioning studies with physiological measures of motivational valence is rare. OBJECTIVE: The present study investigated the motivational properties of experimentally conditioned cues for smoking. METHODS: Thirty-nine smokers completed a differential conditioning protocol. Abstract pictures were used as CSs and single puffs on a cigarette as unconditioned stimulus (US). Skin conductance responses and facial electromyography of the zygomatic, corrugator, and orbicularis oris muscles were measured during conditioning. RESULTS: The conditioned cue for smoking (CS+) elicited stronger skin conductance responses and more activity of the zygomatic and orbicularis oris muscles than the CS-. CONCLUSIONS: These results support the notion that through pairing with smoking, neutral stimuli acquire the ability to elicit preparatory physiological responses, which are assumed to play an important role in the maintenance of addiction and relapse in the natural environment.

Gene-environment interaction influences anxiety-like behavior in ethologically based mouse models.

Ethologically based animal models are widely used; however, results from different laboratories vary significantly which may partly be due to the lack of standardization. Here, we examined the effects of circadian rhythm, lighting condition and mouse strain (BALB/c and C57BL/6, known to differ in measures of avoidance and risk assessment behavior) on two well established behavioral tests in mice: the Elevated Plus Maze (EPM) and the Open Field (OF). Parameters from both paradigms are commonly used as indices of anxiety-like behavior. BALB/c mice and C57BL/6 mice were independently tested in the morning and at night, in regular laboratory lighting and in the dark. We developed a novel method based on infrared lighting from below, coupled to respective video-tracking equipment, which facilitates standard testing of behavior interference-free in complete darkness. The two mouse strains differed in anxiety-related variables for the EPM in the dark, and for the OF in regular laboratory lighting. Moreover, BALB/c displayed greater anxiety-like behavior than C57BL/6 in the OF but less anxiety-like behavior than C57BL/6 in the EPM. Lighting condition has a major influence on both behavioral tests and this to a considerably larger extent than circadian rhythm. In addition, the lighting condition interacts strongly with the genetic background, producing discriminative differences in the anxiety-related variables depending on mouse strain and lighting condition. These results challenge the comparability of not sufficiently standardized tests of anxiety-like behavior and emphasize the need for controlling environmental variables in behavioral phenotyping.

Brain Activations to Emotional Pictures are Differentially Associated with Valence and Arousal Ratings.

Several studies have investigated the neural responses triggered by emotional pictures, but the specificity of the involved structures such as the amygdala or the ventral striatum is still under debate. Furthermore, only few studies examined the association of stimuli's valence and arousal and the underlying brain responses. Therefore, we investigated brain responses with functional magnetic resonance imaging of 17 healthy participants to pleasant and unpleasant affective pictures and afterwards assessed ratings of valence and arousal. As expected, unpleasant pictures strongly activated the right and left amygdala, the right hippocampus, and the medial occipital lobe, whereas pleasant pictures elicited significant activations in left occipital regions, and in parts of the medial temporal lobe. The direct comparison of unpleasant and pleasant pictures, which were comparable in arousal clearly indicated stronger amygdala activation in response to the unpleasant pictures. Most important, correlational analyses revealed on the one hand that the arousal of unpleasant pictures was significantly associated with activations in the right amygdala and the left caudate body. On the other hand, valence of pleasant pictures was significantly correlated with activations in the right caudate head, extending to the nucleus accumbens (NAcc) and the left dorsolateral prefrontal cortex. These findings support the notion that the amygdala is primarily involved in processing of unpleasant stimuli, particularly to more arousing unpleasant stimuli. Reward-related structures like the caudate and NAcc primarily respond to pleasant stimuli, the stronger the more positive the valence of these stimuli is.