Improving processing speed and episodic memory in older adults is important for supporting their daily functioning. Although rewards can increase sympathetic activity and improve cognitive performance in younger adults, and aging may be associated with changes in arousal-related neurotransmitter systems, it remains unclear whether reward effects are altered in older adults. This study investigated the age-related effects of monetary and social rewards on processing speed, episodic memory, and sympathetic arousal. Twenty-nine adults aged 18-35 and 30 adults aged 56-73 completed an incentive delay task and a visual recognition task in which they could receive no reward, a monetary reward, or a social reward on a trial. Skin conductance responses during target preparation and stimulus encoding were measured across reward conditions. We found that younger and older adults similarly showed increased arousal and improved speed when either monetary or social reward was available, with monetary rewards producing stronger effects. Notably, the skin conductance response elicited during anticipation of monetary reward mediated the improvement in speed in older adults. Regarding memory, both age groups showed improved visual recognition and a greater ability to mentally re-experience past events when monetary reward was available. However, reward did not modulate skin conductance responses during encoding. Overall, these findings suggest that reward enhances older adults' processing speed and episodic memory similarly to those of younger adults, despite potentially different contributions of sympathetic arousal. They deepen our understanding of the three-way relationship among reward, psychophysiological functioning, and aging.

Failures in inhibitory control over negative emotional memories can lead to intrusive recollections that interfere with cognitive functioning and well-being. The present study examined whether acute exercise modulates the electrophysiological dynamics underlying inhibitory control during the suppression of negative emotional memories. Seventy healthy participants were randomly assigned to an acute exercise group or a seated-rest control group. The exercise group completed 30 min of moderate-intensity exercise, whereas the control group remained seated at rest. Participants completed the emotional Think/No-Think paradigm both before and after the intervention, while electroencephalography (EEG) was recorded. Event-related potentials (ERPs), time-frequency analyses, and multivariate pattern analysis (MVPA) were used to characterize neural processes associated with inhibitory control. Results showed that acute exercise selectively modulated late-stage neural activity during negative memory suppression, particularly within the 2400-3000 ms time window. This modulation was most evident over central site and left parietal site, and was accompanied by changes in alpha- and beta-band power at the left parieto-occipital junction. Overall, these findings suggest that acute exercise modulates late-stage neural dynamics during the suppression of negative memories. The observed neural changes were accompanied by a reduction in intrusion frequency during suppression attempts, consistent with the possibility that acute exercise facilitates late-stage sustained inhibition.

Abnormal interoception may be a hallmark of medically-unexplained symptoms (MUS), although its underlying mechanisms remain unclear. We investigated whether MUS are associated with enhanced interoceptive learning, potentially facilitated by post-learning stress. From 177 volunteers providing self-reports on MUS, 22 individuals were recruited from the upper and 26 from the lower quartile (high/HSR and low symptom reporters/LSR) and randomly assigned to a stress or a control condition (LSR-stress/n = 12; LSR + stress/n = 14; HSR-stress/n = 11; HSR + stress/n = 11). Participants underwent a heartbeat perception training as interoceptive perceptual learning task, followed by a socially-evaluated cold pressor stress or a control intervention. Interoceptive accuracy was measured using the heartbeat counting and discrimination task at baseline (T1), 30 min. (T2) and 24 h (T3) after the stress/control intervention. Sympatho-adreno-medullary (SAM) and hypothalamic-pituitary-adrenal (HPA) axes were measured in terms of heart rate, blood pressure (SBP/DBP) and salivary cortisol reflected reactivity. The stress test induced a robust increase of SBP/DBP in both stress groups, and a cortisol increase in the LSR + stress group only. Post-learning stress induced an increase of interoceptive accuracy (heartbeat discrimination) the HSR + stress group only. Correlation/regression analyses showed a positive association between changes in interoceptive accuracy (heartbeat discrimination) from T1 to T2 with MUS, and changes from T2 to T3 with SAM and HPA axis responsiveness. Post-learning stress may enhance interoceptive learning in MUS, which may explain why benign body sensations are perceived as symptoms. While MUS-specific heightened attention to body sensations may be responsible for early effects, physiological stress axes may explain late effects of interoceptive learning, including overnight consolidation.

The increasing prevalence of Cannabis Use Disorder (CUD) necessitates measures that reliably predict outcomes. Based in the incentive sensitization model of addiction, the late positive potential (LPP) has been used to predict choice of drug versus affective cues and classify individuals into clinically-relevant neuroaffective reactivity profiles derived from viewing affective and drug-related pictures in individuals who use substances. However, this approach has not been conducted on a sample of individuals who use cannabis nor has its retest reliability been assessed. This study replicated and extended the neuroaffective reactivity profile findings in individuals with CUD and tested the one-week profile reliability. At two lab visits one week apart, 44 participants completed a probabilistic choice task and viewed cannabis and affective pictures with EEG recording. k-means cluster analyses were applied to the resulting LPPs to create neuroaffective reactivity profiles. Consistent with past literature, at both lab visits, participants were organized into two clusters characterized by differences in the cannabis and pleasant LPP amplitudes (one with greater cannabis than pleasant LPPs and one with greater pleasant than cannabis LPPs), but LPP clusters did not differ in choice behavior or other indicators of problematic use. Despite this reliable classification at the group level, individual level retest reliability for the profiles was low, outperformed by residualized LPP scores and raw LPPs. These findings add to literature suggesting a common pattern of neuroaffective reactivity profiles across addiction populations but caution their clinical utility considering the unresolved reliability and lack of convergent validity across units of analysis.

Fibromyalgia (FM) is a nociplastic pain syndrome associated with altered central nervous system processing consistent with central sensitization, leading to enhanced pain perception. Despite its prevalence, the underlying neurophysiological mechanisms remain unclear. In this study, we characterized resting-state EEG (RS-EEG) dynamics in FM using a high resolution microstate (MS) framework combined with multivariate pattern analysis (MVPA) and source localization. 5-min eyes-closed RS-EEG was recorded from 57 female participants (29 FM patients and 28 healthy controls), and an 11-MS template was determined using the KL-GEV criterion. To assess the discriminative value of MS spatiotemporal features, we applied linear discriminant analysis with leave-one-out cross-validation. MS features were correlated with clinical measures, and source-level group differences were estimated using exact low-resolution electromagnetic tomography (eLORETA). MVPA identified MS G as the most discriminative state (AUC = 0.63), although it remained below commonly used thresholds for clinical interpretability (AUC > 0.75). Source-level analyses revealed significant differences in the insula (MS B and G), and in the middle frontal and postcentral gyri (MS E). No clinical associations survived correction for multiple comparisons, although exploratory trends suggested relationships between pain- and fatigue-related symptoms and MS B and E features. Overall, MVPA and eLORETA findings indicated altered spatiotemporal MS dynamics within somatosensory, salience, and executive networks in FM, consistent with central sensitization and dysfunction across large-scale pain networks. These findings highlight the potential of RS-EEG MS as candidate markers of pain-related neurophysiological heterogeneity within established FM, while their diagnostic utility remains to be established.

The dorsolateral prefrontal cortex (DLPFC) is central to regulating intrusive thoughts and worry, yet the lateralization and neurophysiological mechanisms underlying these processes remain unclear. Parasympathetic cardiac control, indexed by heart rate variability (HRV), has been proposed to correlate with prefrontal control over brain regions involved in emotional, cognitive, and autonomic regulation, but empirical evidence linking these domains is mixed. In this preregistered, single-blind, sham-controlled, within-subject study, we examined the effects of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) over the left and right DLPFC on parasympathetic cardiac control, worry, and intrusive thoughts in 31 healthy participants. HRV was assessed at rest and during a breathing focus task, a validated paradigm that measures attentional focus, spontaneous intrusive thoughts, and worry. Contrary to predictions, active stimulation did not differ from sham in modulating HRV, intrusive thoughts, or worry. However, right compared with left DLPFC stimulation was associated with higher self-reported worry and lower RMSSD. Exploratory analyses suggested that the differences in RMSSD were not present at baseline and were observed following stimulation. Notably, changes in HRV were not associated with changes in worry, indicating that the effects of HF-rTMS on worry co-occur with, though are not directly explained by, changes in parasympathetic cardiac control, challenging straightforward interpretations of HRV as a correlate of prefrontal regulatory control. Together, these findings provide evidence for hemispheric asymmetries in prefrontal contributions to autonomic and worry-related processes and may inform understanding of the effects of inhibitory right- or excitatory left-DLPFC stimulation protocols on worry-related symptoms.

Transcranial direct current stimulation (tDCS) is widely used to probe cognitive-affective processes, yet evidence for reliable single-session effects in healthy adults remains inconsistent. We examined whether anodal tDCS was associated with behavioral and event-related potential (ERP) changes during emotional distraction, using a within-subject, double-blind crossover design to distinguish stimulation-order effects from changes across repeated task blocks. Fifty-three healthy adults performed a color-detection task with emotional face distractors during EEG recording. Each session included baseline (T0), post-first stimulation (T1), and post-second stimulation (T2) blocks. Participants received both 20-min anodal tDCS (1.5 mA; C3-right supraorbital montage) and sham stimulation in counterbalanced order. Reaction times and P1, N170, P2, and LPP amplitudes were analyzed across all three blocks, with stimulation order as a between-subject factor. Reaction times showed a modest overall time effect without significant pairwise differences. Posterior P1 amplitudes increased from T0 to T1 and remained elevated at T2. Posterior P2 amplitudes increased from T0 to T1 in the broad-region analysis, but this effect was attenuated in the component-specific occipital sensitivity analysis. N170 amplitudes varied with facial emotion and showed a modest overall time effect without significant pairwise differences, whereas the predefined 500-800 ms LPP showed no significant time effect. No primary behavioral or ERP outcome showed a significant TIME × ORDER interaction. Repeated task assessment was therefore associated most clearly with early posterior ERP changes, whereas reliable order-dependent effects of acute tDCS were not detected under the present protocol.

Misophonia is a disorder characterized by exaggerated emotional responses and heightened autonomic arousal triggered by specific sounds. Despite evidence that higher-level cognitive processes contribute to misophonia, it remains uncertain whether they can be used to modulate misophonic responses to trigger sounds. Based on the observation that individuals with misophonia often report listening to music as a coping mechanism, we investigated how directing attention to music could modulate physiological responses of individuals with misophonia in the presence of trigger sounds. Participants with and without misophonia completed a task in which they selectively attended to music in one ear while sounds (trigger, unpleasant, or neutral) played in the other. Measures that capture autonomic nervous system state (i.e., pupil size, skin conductance response, and heart rate) were continuously recorded. Physiological reactions (skin and pupil responses) in misophonics were consistent with a higher arousal than in controls specifically for trigger sounds in silence. This heightened arousal to triggers persisted in the dual-stream conditions regardless of attentional focus, suggesting that music-directed attention did not meaningfully attenuate trigger responses in either group. Subjective ratings were roughly consistent with physiological measures, revealing greater cognitive workload in misophonics, and for generally unpleasant sounds (with no obvious interaction with attention condition). Overall, these data demonstrate the expected physiological and subjective responses experienced by misophonics when exposed to triggers, but suggest that attentional redirection towards music is insufficient to modulate it once trigger recognition has occurred.

Poor sleep quality is a prevalent issue linked to higher procrastination, which not only impairs academic and work functioning but also adversely affects mental and physical health. However, the psychological and neural basis underlying this association remain unclear. In this study, 1163 participants were initially assessed with self-report measures of sleep quality, procrastination, anxiety, and self-control and resting-state fMRI to examine the behavioral and neural correlates of the association between sleep quality and procrastination. After questionnaire and MRI quality control, 1079 participants were included in the final analyses. Elastic net regression revealed distinct functional connectivity patterns centered on the default mode network and prefrontal control regions, including the dorsolateral prefrontal cortex, medial prefrontal cortex, and anterior cingulate cortex, which significantly predicted poorer sleep quality. Furthermore, parallel mediation analyses indicated that anxiety and self-control statistically mediated the association between sleep quality and procrastination, and that composite brain network strength also showed an indirect association with procrastination involving these same behavioral pathways. Integrating these behavioral and neuroimaging findings, our results indicate that poor sleep quality is associated with atypical patterns of connectivity within prefrontal and default mode systems, which may be consistent with the proposed role of diminished psychological resources in emotion regulation and executive control. Guided by the conservation of resources model, this multi-level framework provides an integrated perspective on the psychological and neural basis of the relationship between sleep quality and procrastination, thereby providing potentially relevant directions for future intervention research.

Childhood trauma is a risk factor for sleep problems. However, the longitudinal relationship between childhood trauma and sleep problems and the mechanism underlying this link remains unclear. The present study explored the longitudinal relation between childhood trauma and sleep problems, and the mediating role of perceived stress and the moderating role of RSA suppression in this link among adolescents. Altogether, 284 adolescents completed the Childhood Trauma Questionnaire at baseline, the Perceived Stress Scale 1.5 years later, the Pittsburgh Sleep Quality Index at baseline and 1.5 years later, and a speech task during which their data of vagal regulation indexed by respiratory sinus arrhythmia (RSA) suppression was obtained at baseline. Results revealed that, after controlling for baseline sleep problems, childhood trauma was positively related to sleep problems 1.5 years later, and perceived stress 1.5 years later mediated this association. RSA suppression moderated the relation between perceived stress and sleep problems among male but not female adolescents. Specifically, perceived stress was positively related to sleep problems among male adolescents with lower RSA suppression, but this association was weaker in those with higher RSA suppression. The findings suggest that perceived stress may represent an important pathway in the longitudinal association between childhood trauma and sleep problems, and male adolescents with lower RSA suppression are more vulnerable to perceived stress and exhibit more sleep problems.

Recent research has explored whether sense of agency (SoA) over to-be-remembered items enhances performance in recognition memory tasks, and what the underlying mechanisms might be. The present study systematically investigates the role of self-referential processing in this improvement. Building on the Comparator Model of SoA, we manipulated SoA from two perspectives: retrospective inference (action-outcome consistency) in Experiment 1 and 2, and prospective inference (action volition) in Experiment 3 and 4. In experiment 1 and 3, we replicated the effect of SoA on recognition memory with a simple recognition task. The results showed that stronger induced SoA significantly improved recognition memory performance. Experiment 3 and 4 used a Remember/Know (R/K) memory paradigm, measured recollection/familiarity performance, and recorded Event-related potentials (ERP). SoA influenced R/K performance in Experiment 4, as evidenced by both behavioral and ERP results, specifically the R performance, FN400 and LPC components were all higher with volition induced SoA. In contrast, Experiment 2 did not reveal a significant R/K improvement effect. These findings suggest that voluntary actions, which carry more self-referential information as compared to involuntary actions, facilitate the SoA and enhance recognition memory. However, the self-referential information associated with action-outcome consistency in Experiment 2 might not have been sufficiently detectable, and its effect may have disappeared when recognition memory was measured using the R/K paradigm, which likely requires more cognitive resources.

Emotion regulation difficulties are a transdiagnostic vulnerability linked to maladaptive emotional responding, yet their neural correlates during emotional processing and regulation remain incompletely understood. The present study examined whether individual differences in emotion regulation difficulties are associated with modulation of the late positive potential (LPP), an event-related potential sensitive to emotional salience and regulatory modulation. Seventy-nine adults (mean age = 26.25 years) completed an emotion regulation task involving five conditions: natural viewing of neutral, negative, and positive stimuli, and two active regulation strategies-cognitive reappraisal and expressive suppression of negative social-affective stimuli-while EEG was recorded. Trait emotion regulation difficulties were assessed using the Chilean adaptation of the Difficulties in Emotion Regulation Scale (DERS-E). Trial-level linear mixed-effects models showed that Natural-Negative stimuli elicited larger LPP amplitudes than Natural-Neutral, Reappraisal-Negative, Suppression-Negative, and Natural-Positive trials, whereas Reappraisal-Negative, Suppression-Negative, and Natural-Positive did not differ significantly from Natural-Neutral. In a joint model including all five DERS-E dimensions, greater Lack of Emotional Control was uniquely associated with larger LPP amplitudes averaged across conditions, whereas greater Lack of Emotional Awareness was uniquely associated with smaller LPP amplitudes. Lack of Emotional Awareness was the only dimension showing a significant condition-dependent association, with a more negative LPP association during suppression than in each of the other four conditions. These findings support the LPP as an electrophysiological correlate of dimension-specific differences in emotion dysregulation during social-affective processing and regulation.