Stefan Duschek

Pain modulation arising from the cardiovascular system has repeatedly been described. It is mediated by the baroreceptor system, where the activity of baroreceptor afferents inhibits nociception. Body posture changes cause blood volume redistribution that might modulate baroreceptor activity and antinociceptive effects. This study investigated posture‐related differences in pain perception and their causation by cardiovascular factors. Pressure pain threshold and tolerance and pain intensity ratings were obtained in 83 healthy individuals (61 women and 22 men) while they were sitting, lying down and standing. Electrocardiography, impedance cardiography and continuous blood pressure were recorded in each posture. Pain threshold was higher while lying down than standing, and pain tolerance was higher while lying down than standing and sitting. Pain intensity ratings for suprathreshold stimulation (4 kg/cm ² ) were higher while standing than sitting and lying down. Blood pressure, stroke volume, cardiac output, total peripheral resistance and baroreflex sensitivity decreased while standing and increased while lying down. Blood pressure was positively associated with pain threshold in men, but not in women. Total peripheral resistance was positively associated with pain threshold and tolerance and blood pressure was negatively related to pain intensity ratings in the total sample. Lying down is associated with increased venous return, central blood volume and higher baroreceptor load, which may result in stronger antinociceptive effects. The opposite changes along with baroreceptor unloading occur while standing. Assuming a supine position is a functional human response to alleviate acute pain. However, in terms of negative reinforcement, pain reduction while lying down may contribute to passive coping behaviors in chronic pain.

Multisensory integration (MSI) is crucial to interact adaptively with our environment and create a coherent representation of the body. Body illusion techniques, such as the rubber hand illusion, provide useful tools to study MSI since they produce a conflict between different sensory modalities and alter body perception. While previous research revealed that body illusions modulate neural activity in unisensory and multisensory cortical areas during multisensory stimulation, cortical activity during unisensory stimulation has barely been studied. The present EEG study investigated brain mechanisms involved in MSI using unisensory (visual, tactile) and multisensory (visuotactile) stimulation. Alpha‐ and beta‐band power, as well as functional connectivity, were assessed in 36 subjects during visual, tactile, and visuotactile stimulation in the rubber hand illusion paradigm and a control condition. The illusion was associated with widespread reductions in alpha and beta power, alongside increased beta‐band connectivity between unisensory and multisensory cortical regions. Notably, alpha‐band effects revealed cross‐modal influences: visual stimulation modulated activity in somatosensory regions, while tactile stimulation affected occipital areas. Unisensory stimulation also elicited beta connectivity changes across modalities, with visual input enhancing sensorimotor coupling and tactile input increasing connectivity involving visual regions. The subjective strength of the illusion was associated with beta power reductions during visual stimulation, linking neural modulation to individual perceptual experience. These findings demonstrate that the illusory state is characterized by a global reconfiguration of sensory processing, extending beyond multisensory contexts and shaping unisensory processing through cross‐modal interactions.

Proactive cognitive control enables individuals to anticipate and prepare for upcoming cognitive demands. Whereas prior research highlights the involvement of the dorsolateral prefrontal cortex (DLPFC) in proactive cognitive control, the lateralization of this function remains unclear. In this single‐blind, sham‐controlled, within‐subject, randomized preregistered study, 31 healthy participants (mean age = 22.26, SD = 4.01; 18 women) received, in three separate sessions, sham and active high‐frequency (20hz) repetitive transcranial magnetic stimulation (HF‐rTMS) over the left and right DLPFC before performing a blocked version of the antisaccade task in combination with pupillometry to assess proactive cognitive control. Although preregistered analyses with saccade latency (i.e., time to initiate the first saccadic movement) did not show a significant effect of HF‐rTMS, exploratory analyses with fixation latencies (i.e., time to fixate the gaze at the correct target location) in antisaccade trials were significantly shorter after both active left and right DLPFC stimulation compared to sham. Moreover, analyses accounting for tonic pupil size showed that the pupil size during the anticipatory phase (reflecting phasic resource allocation) was relatively larger after active left and right HF‐rTMS (vs sham) on prosaccade trials, and that a larger pupil size during the anticipatory phase was associated with shorter fixation latencies in antisaccade trials. Tonic pupil size, reflecting sustained resource allocation, was larger after left DLPFC stimulation and was associated with longer saccade and fixation latencies after sham, but not active stimulation. These findings provide important evidence that helps reconcile mixed results in the field by supporting the involvement of both left and right DLPFC in proactive cognitive control via the regulation of anticipatory allocation of cognitive resources.

Proactive control refers to the biasing of information processing toward a task goal during anticipation of a relevant event. This study investigated proactive control of emotional information in adult attention-deficit/hyperactivity disorder (ADHD) using a manual face-word Stroop task. Individuals with ADHD and healthy controls (n = 51 per group) were selected from a large participant pool (n = 1,020) using the Adult ADHD Self-Report-Scale. Images of happy or anxious faces were presented, with the word HAPPY or ANXIOUS written across the faces, congruent or incongruent with facial expressions. Participants had to identify facial expressions while ignoring word meaning. To investigate contextual cue utilization, the proportion of incongruent trials was manipulated (75% vs. 25%) to generate mostly congruent (MC) and mostly incongruent (MI) contexts. Individuals with ADHD showed larger error rate and longer reaction time (RT) than controls. Context effects were reflected by a greater difference in error rate and RT between congruent and incongruent trials within the MC than the MI context. These effects were independent of the presence of ADHD. The findings suggest that the ability to use contextual cues to facilitate proactive cognitive control is preserved in adult ADHD, despite marked impairments in attention and processing speed.

Adult attention‐deficit/hyperactivity disorder (ADHD) is associated with substantial impairments in well‐being and quality of life. In addition to cognitive and behavioral symptoms, emotional dysregulation characterizes the disorder. This study investigated habitual worry in the context of cognitive control and heart rate variability (HRV) in adult ADHD. Groups with high and low ADHD symptoms (n = 51 per group) were selected from a large participant pool (n = 1020) using the Adult ADHD Self‐Report Scale. HRV was recorded during a breathing focus task assessing cognitive control. The task included two phases during which participants' ability to concentrate on their breathing was recorded before and after an instructed worry phase. While groups did not differ in HRV, participants with high ADHD symptoms reported greater habitual worry, more negative affect, and less positive affect than those with low ADHD symptoms. They exhibited less ability to concentrate on breathing, more frequent positive, neutral, and negative thought intrusions, and greater distress during instructed worry. In the total sample, habitual worry correlated negatively with breathing focus ability and positively with intrusive thoughts. HRV correlated positively with breathing focus ability and negatively with thought intrusions. Moreover, HRV correlated negatively with distress during instructed worry. Impaired cognitive control may contribute to exaggerated worry and negative emotional states related to ADHD symptoms. The lack of association between HRV and ADHD symptoms accords with previous studies. The correlations seen for HRV implicate prefrontal cortex function and vagal cardiac control in emotional regulation and inhibition of intrusive thoughts.

This EEG and eye‐tracking study investigated affective influences on cognitive preparation using a precued pro−/antisaccade task with emotional faces as cues. Negative information interfered with preparatory processes with high but not low executive function load.

This ERP study investigated the neural correlates of proactive and reactive control using a novel precued antisaccade paradigm. Proactive control refers to preparatory processes during anticipation of a behaviorally relevant event; reactive control is activated after such an event to ensure goal attainment. A 64‐channel EEG was obtained in 35 healthy subjects; video‐based eye tracking was applied for ocular recording. In the task, a target (probe) appeared left or right of the fixation point 1800 ms after a central cue; subjects had to look toward the probe (prosaccade) or its mirror image position (antisaccade). Probes were positive, negative or neutral face expressions, with their frame colors instructing task requirements. The cue informed about antisaccade probability (70% vs. 30%) in each trial. High antisaccade probability was associated with larger CNV amplitude than low antisaccade probability. In trials with incongruence between expected and actual task requirements, probe N2 and P3a amplitudes were larger than in congruent trials. In incongruent trials, P3a was smaller for negative than positive and neutral probes. Task accuracy and speed were lower in incongruent trials and varied according to affective probe valence. EEG source imaging suggested the origin of the ERPs to be in orbitofrontal cortex and superior frontal gyrus. The effect on the CNV indicates greater cortical activity during higher proactive control demands. Larger N2 and P3a in incongruent trials reflect greater resource allocation to conflict monitoring and conflict resolution, i.e., reactive control. The influence of probe valence on P3a suggests reduced processing capacity due to negative information.

In addition to chronic widespread pain and depression and anxiety symptoms, patients with fibromyalgia frequently experience cognitive problems. This study investigated executive functions in fibromyalgia via a Go/No-Go task. To obtain comprehensive information about performance, traditional and ex-Gaussian parameters of reaction time (RT) variability were used, in addition to speed and accuracy indices. Ex-Gaussian parameters show an excellent fit to empirical RT distributions. Fifty-two female fibromyalgia patients and twenty-eight healthy controls participated. The task included 60 visual stimuli, which participants had to respond to (Go stimuli) or withhold the response to (No-Go stimuli). After 30 trials, the task rule changed, such that previous No-Go stimuli had to be responded to. Performance was indexed by the hit rate, false alarm rate, and mean ( M ) and intraindividual standard deviation (SD) of RT and the ex-Gaussian parameters mu, sigma, and tau. Mu and sigma indicate the M and SD of the Gaussian distribution; tau reflects the M and SD of the exponential function. Patients exhibited a lower hit rate, higher M RT, and higher tau than controls. Moreover, patients showed greater decrease of the hit rate after the change of task rule. In the entire sample, SD, sigma, and tau were inversely associated with the hit rate and positively associated with the false alarm rate. While the greater decline in hit rate after the change in task rule indicates deficient cognitive flexibility, the lack of any difference in false alarm rate suggests intact response inhibition. Higher M RT reflects reduced cognitive or motor speed. Increased tau in fibromyalgia indicates greater fluctuations in executive control and more frequent temporary lapses of attention. For the first time, this study demonstrated that indices of RT variability, in particular those derived from the ex-Gaussian function, may complement speed and accuracy parameters in the assessment of executive function impairments in fibromyalgia. Optimized assessment may facilitate the personalization of therapies aimed at improving the cognitive function of those with the disorder.

Anger has been associated with increased pain perception, but its specific connection with Fibromyalgia Syndrome (FMS) has not yet been established in an integrated approach. Therefore, the present systematic review focuses on exploring this connection, and based on this connection, delimiting possible gaps in the research, altogether aimed at improving FMS clinical intervention and guiding future research lines. Anger is considered a basic negative emotion that can be divided into two dimensions: anger-in (the tendency to repress anger when it is experienced) and anger-out (the leaning to express anger through verbal or physical means). The current systematic review was performed based on the guidelines of the PRISMA and Cochrane Collaborations. The Prospective Register of Systematic Reviews (PROSPERO) international database was forehand used to register the review protocol. The quality of chosen articles was assessed and the main limitations and research gaps resulting from each scientific article were discussed. The search included PubMed, Scopus, and Web of Science databases. The literature search identified 13 studies eligible for the systematic review. Levels of anger-in have been shown to be higher in FMS patients compared to healthy participants, as well as patients suffering from other pain conditions (e.g., rheumatoid arthritis). FMS patients had also showed higher levels of state and trait anxiety, worry and angry rumination than other chronic pain patients. Anger seems to amplify pain especially in women regardless FMS condition but with a particularly greater health-related quality of life´s impact in FMS patients. In spite of the relevance of emotions in the treatment of chronic pain, including FMS, only two studies have proposed intervention programs focus on anger treatment. These two studies have observed a positive reduction in anger levels through mindfulness and a strength training program. In conclusion, anger might be a meaningful therapeutic target in the attenuation of pain sensitivity, and the improvement of the general treatment effects and health-related quality of life in FMS patients. More intervention programs directed to reduce anger and contribute to improve well-being in FMS patients are needed.