Biological Psychology

Humans make emotional facial expressions and have a cardiac response when they catch themselves in a mistake or receive feedback about task performance. We tested whether rats exhibit similar visceral responses in the context of metacognition. We assessed heart rate variability (HRV) and machine learning-detected facial expressions as female and male rats detected and stopped in-progress mistakes and received post-choice rewards or error cues. HRV increased during internally detected mistakes, as well as in response to external error cues for both sexes. Errors were associated with an HRV response when parasympathetic tone was higher, while rewards were associated with an HRV response when sympathetic tone was higher. We observed sex-specific effects of cardiac interoception on cognitive control over real-time action correction, in that low parasympathetic tone was associated with reduced ability to stop in-progress mistakes exclusively in females. Rats made facial expressions during mistake detection and in response to task feedback. Outcome-related facial expressions were valence-specific, in that the facial expression after error feedback was delayed relative to the post-reward facial expression. Our results suggest that rats have a visceral experience during metacognitive monitoring.

Empathy enables individuals to attune to others' experiences through shared affective, sensorimotor, and neural representations, but its influence on higher-level decision-making and social alignment remains unknown. We examined whether empathy promotes social conformity and whether this effect depends on physiological arousal, visual attention, and socio-emotional traits. Seventy-three participants completed an empathy-for-pain task followed by a modified random-dot task in which they interacted with previously seen empathy targets, while physiological signals and eye movements were recorded. Drift-diffusion modeling showed that feedback from empathy targets increased conformity, reflected in stronger decision bias toward targets, faster evidence accumulation, and reduced decision conservatism. Visual attention to the eyes or mouth was linked to greater conformity depending on the context. Heart rate variability was unrelated to conformity, whereas phasic skin conductance was associated with smaller bias changes and greater conservatism. Alexithymia and autistic traits further shaped the empathy-conformity relationships. These findings suggest that empathic shared representation extends beyond affective resonance to influence social alignment in decision-making.

Cortisol, our stress hormone, exerts widespread influence on neural activity. However, its influence on the aperiodic component of the electroencephalography power spectrum remains to be investigated. Given individual differences in the capacity to cope with stress and adversity, it also remains unclear whether trait resilience moderates this relationship. Hence, the present study examined whether individual differences in trait resilience moderates the association between resting cortisol and aperiodic activity. Participants (N=145) completed various self-report questionnaires (e.g., trait resilience). Electroencephalography was recorded over a 20-minute baseline period, followed by salivary cortisol collection. The results revealed a significant moderating effect of trait resilience in the occipital scalp region. Specifically, higher cortisol concentration was associated with flatter 1/f slopes amongst individuals with low trait resilience, whereas this association was reversed amongst those with high trait resilience. Overall, our findings highlight the role of individual differences in trait resilience in shaping hypothalamic-pituitary-adrenal axis-related neural dynamics.

Learning is typically understood as a process driven by prediction errors, when outcomes differ from expectations. Yet it remains unclear whether outcomes that perfectly match expectations are psychologically and computationally meaningful. Here, we tested whether zero prediction errors shape affect, belief updating, and neural feedback processing in human reinforcement learning. Participants repeatedly predicted rewards in environments varying in uncertainty, with a subset of trial outcomes manipulated to exactly match their predictions. Zero prediction errors produced the highest momentary happiness, and computational modeling showed that behavior was best explained by a model in which zero prediction errors induce a distinct latent belief state that guides subsequent updating, particularly under higher uncertainty and in individuals with greater intolerance of uncertainty. Outcome-locked EEG analyses further showed that zero prediction errors elicited distinct P3-like responses, with residual neural activity predicting attenuated updating after zero prediction errors but enhanced updating after standard prediction errors. These findings suggest that perfect predictions are not neutral, but informative events that actively shape affect, behavior, and neural feedback processing.

Previous research suggests that women and men may differ in moral decision-making involving instrumental harm. However, prior findings have yielded inconsistent explanations for these differences, suggesting effects of gender expression, empathy, action tendencies, and biological causes, such as differences in gonadal hormone levels. Yet, no data exists on the effects of endogenous estradiol and progesterone on moral decision-making, while the effects of testosterone are inconsistent. Our study aimed to close this research gap. A sample of 137 cis individuals (73 women, 64 men) completed a moral dilemma task based on the Consequences, Norms, Inaction (CNI) model either in the morning or evening. Relevant personality traits, including agreement with instrumental harm, impartial beneficence, empathy, and gender expression, were assessed via self-report. Blood samples were analyzed for estradiol, progesterone, testosterone, and cortisol. Contrary to prior literature, no behavioral differences between women and men were observed in moral decision-making. However, self-reported agreement with instrumental harm positively predicted sensitivity to consequences and negatively predicted adherence to moral norms in the whole sample. Estradiol concentration positively predicted sensitivity to consequences in the morning women group, and general inaction tendency in the morning men group. Overall, these findings highlight the joint influence of biological and personality factors on moral choices and hint towards subtle sex/gender differences.

Attention abilities, that are critical for most real-life cognitive task, can vary greatly across individuals. A plethora of behavioral and neural metric are commonly utilized to quantify attention; however, these often yield inconsistent and non-replicable results, raising questions as to which measures reliably account for and capture individual differences. To address this tension, here we employed a within-subject cross-paradigm design and quantified both behavioral and EEG-based neural measures associated with attention functioning, to test which measures converged across a gradient of artificial and ecological tasks. We found Inter-Subject Correlation (ISC), which quantifies the similarity in the pattern of neural response across individuals, captured consistent individual differences across both an artificial (Auditory Oddball) and ecological (Attention to Speech) task, with some correlation with performance. Moreover, we found that P300 neural responses to surprising events were qualitatively similar across artificial and ecological tasks, supporting their generalization across contexts. Interestingly, traditional cognitive-behavioral measures of attention - both from speeded response-time tasks and self-report of ADHD symptoms (ASRS) were not correlated with each other nor did they explain variance in neural metrics, nor were they explained by variation in general cognitive abilities (working memory or fluid intelligence). While these results demonstrate the shortcomings of many established measures of attention to generalize across contexts, they also point to the potential of neural measures, and specifically ISC, to serve as reliable indicators of individual differences and to bridge the gap between artificial and ecological studies of attention functioning.

Disordered eating attitudes exist on a continuum that extends well below clinical diagnostic thresholds, yet the cognitive correlates of this non-clinical variation remain incompletely understood. Previous research linking executive functioning to disordered eating in non-clinical samples has relied almost exclusively on self-report questionnaire measures of executive function, which show weak correspondence with performance-based assessments. This methodological reliance leaves open the question of how objective executive performance relates to eating behavior across the spectrum. The present study addressed this gap by examining the association between performance-based measures of executive function and disordered eating attitudes in a non-clinical sample of 243 university students via an online experiment, using a dimensional approach consistent with the Research Domain Criteria framework. Participants completed established neurocognitive tasks covering three executive function domains: working memory was assessed with Digit Span and an N-back task, inhibitory control with a Go/No-Go task, and cognitive flexibility with the Card Sorting Task. Disordered eating attitudes were indexed using the EAT-26 total score and its subscales. A notable correlation was identified between cognitive flexibility and disordered eating attitudes, while working memory and inhibitory control exhibited no such association. Overall, our findings provide evidence for associations between executive functioning and disordered eating attitudes in a non-clinical sample.

Reported perceptual differences in autism may arise from reduced use of prior context to shape incoming sensory input. Speech perception provides a critical test of this account because stable perception requires listeners to integrate variable acoustic signals with contextual expectations. This study examined context-dependent modulation of speech encoding in autistic and non-autistic adults using the frequency-following response (FFR), a neurophysiological measure of phase-locked auditory encoding. Participants heard English intonational pitch contours presented in repetitive and variable contexts while EEG was recorded. Principal component analysis of FFR metrics yielded components indexing neural encoding fidelity and timing. Non-autistic participants showed enhanced encoding fidelity in more predictable contexts, whereas autistic participants showed reduced context-dependent modulation. Neural encoding timing also showed divergent context effects across groups, suggesting altered balance between feedback-based predictive mechanisms and locally driven adaptation processes. Within the autistic group, greater context-related modulation of encoding fidelity was associated with lower ADOS-2 Social Affect severity but poorer speech-in-noise perception, suggesting that the functional impact of contextual modulation depends on input reliability and task demands. These findings indicate that context-dependent modulation of speech encoding is altered in autism and may contribute to individual differences in auditory and social-communicative function.

Music enjoyment and familiarity are closely related but often confounded in studies of neural music processing. Here, we investigated their distinct contributions to cortical oscillatory activity and neural tracking of music using electroencephalography (EEG). Thirty-two participants listened to self-selected all-time favourite songs, recent favourite songs, and tempo-matched songs from disliked genres. This novel paradigm dissociated familiarity from enjoyment by including highly enjoyed songs that differed in familiarity. Spectral power and cortical tracking (using Mutual Information) were analysed using linear mixed-effects models with enjoyment and familiarity ratings. Familiarity was associated with increased left-frontal alpha power, whereas enjoyment predicted increased theta and beta power, demonstrating distinct oscillatory signatures for these dimensions. An interaction revealed that the positive relationship between enjoyment and theta power was strongest for highly familiar music. Cortical tracking analyses showed that greater enjoyment was associated with reduced delta-band tracking, with a significant interaction indicating that this negative relationship was present for highly familiar songs but not for less familiar songs. These findings indicate that enjoyment and familiarity differentially shape neural responses to music and highlight the importance of modelling both factors to disentangle their distinct effects on neural activity during music listening.

Error monitoring allows for detecting mistakes and adapting behavior. Error monitoring is associated with increased theta (4-7 Hz) EEG activity recorded at midfrontal electrode sites located over the medial frontal cortex. Increases in theta synchrony after errors between midfrontal and lateral electrode sites, located over lateral prefrontal, motor, and sensory/parietal brain regions, are associated with post-error behavioral adaptations. However, there is a lack of research into whether such error-related theta inter-regional synchrony dynamics exhibit age-related changes across adolescence and whether such changes differ as a function of social observation. Moreover, there are discrepancies across studies in terms of how error-related theta synchrony between different electrode sites relates to specific forms of post-error adjustments. In this study, we used behavioral and EEG data from 262 adolescents aged 10-14 years who performed a flanker task twice: alone and while observed by a peer. Regardless of social observation, we found age-related increases in error-related midfrontal-frontolateral and midfrontal-midlateral theta synchrony. Additionally, we found that error-related theta synchrony between midfrontal and posterolateral regions increased only in the alone condition. Leveraging the shrinking spotlight drift diffusion model (SSP-DDM), we identified a positive association between error-related midfrontal-posterolateral theta synchrony and post-error attentional control but found no effects of social observation. These results are the first to demonstrate that error-related theta synchrony increases from early to mid-adolescence. Additionally, this work specifically links error-related midfrontal-posterolateral theta synchrony to post-error attentional control using computational modeling.

The ability to seek reward and avoid punishment is a fundamental survival instinct. In natural environments, however, the statistics of rewards and punishments can change independently of one another. In addition, individuals experiencing anxiety and depression may be selectively biased to process rewards and punishments differently. Here, we examine how humans adapt their behavior in such dynamic environments, using a task where cues are associated with independently changing probabilities of rewards (wins) and punishments (losses). We demonstrate that participants dynamically adjust their learning rates based on the relative volatility of each valence. Neuroimaging reveals that this behavioral flexibility is supported by valence-specific segregation of volatility signals within distinct subregions of the anterior cingulate cortex (ACC: perigenual and dorsal). Furthermore, individuals with higher levels of anxiety and depression exhibit a relative reduction in loss-volatility learning adaptation, accompanied by less distinct neural encoding of win and loss volatility in both ACC subregions. Together, our findings indicate that flexible adaptation to separate reward and punishment contingencies relies on distinct, valence-specific tracking of volatility within the prefrontal cortex. These findings suggest a potential computational and neuroanatomical framework for understanding maladaptive learning in affective disorders.

Sleep deprivation amplifies emotional reactivity to brief, overt threats in the external environment. However, its effects on emotional responses to prolonged, ambiguous threat remain unclear. In this pre-registered study, we combined virtual reality, psychophysiology and multidimensional experience sampling to test the hypothesis that sleep deprivation disrupts emotional adaptation to sustained or resolving threat. Following a night of restful sleep or total sleep deprivation, healthy young adults navigated an immersive virtual world that alternated between ambiguously threatening and non-threatening contexts. Despite initial increases in emotional arousal, sleep-rested individuals quickly downregulated affective responses to ambiguous threat, reflecting efficient adaptation to the aversive virtual environment. Sleep-deprived individuals, by contrast, were unable to overturn elevated arousal responses, and exhibited a breakdown of goal-orientated, emotional control. Interestingly, resting heart rate variability, an index of affective regulatory capacity, mitigated arousal responses to ambiguous threat after sleep deprivation. These findings suggest that insufficient sleep prevents an adaptive renormalisation of emotional arousal during prolonged and ambiguous threat, giving rise to a maladaptive state of anxiety.

How children come to evaluate social-affective cues is shaped within the family, yet the neural expression of this process and its dependence on family relationships remain unclear. We tested whether parent-child similarity in the neural coding of affective judgment varies with family environment, and whether it relates to youth affective distress. Twenty-five parent-child dyads (youth, mean age 11.8; parents mean age 42 years) judged faces morphed along an angry-to-happy continuum as positive or negative during fMRI. For each participant, we defined an evaluative choice axis distinguishing faces judged positive from negative, independent of expression intensity. Using searchlight-based parent-child cross-decoding, we tested whether one dyad member's evaluative coding predicted the other member's judgments, indexing shared evaluative coding rather than shared sensitivity to expression intensity. Inference focused a priori on medial prefrontal cortex. There was no reliable average parent-child neural similarity across the sample. Instead, higher family conflict was associated with lower parent-child neural similarity in ventromedial prefrontal cortex (vmPFC). Demonstrating specificity to negative relational strain, this effect was not observed for complementary dimensions of family cohesion or identity. Moreover, the effect was specific to true dyads rather than random pairings and to vmPFC rather than a face-selective network or other medial prefrontal regions. Lower vmPFC similarity showed a preliminary association with higher youth affective distress. These findings indicate that affective valuation, rather than sensory encoding, may be a representational level at which perceived family conflict is reflected in parent-child neural similarity.

Across contemplative traditions, deeper states of meditation are described as states of heightened clarity, vividness, and stillness of mind, yet what this clarity corresponds to in the brain has remained difficult to specify. The functional signal-to-noise ratio (f-SNR) framework frames mental clarity as a measurable property of neural signals: the degree to which brain activity tracks the causes of sensory signals rather than endogenous, irrelevant fluctuations. It predicts that deepening meditation should raise f-SNR, expressing sensory events more faithfully in neural signals against ongoing background activity. We tested this prediction across different levels of meditative depth. Twenty-nine experienced Vipassana practitioners meditated while auditory tones were presented, periodically reporting their depth of meditation. f-SNR was quantified from event-related potentials (ERPs) in a fronto-central P3 window and from single-trial decodability of auditory tone-evoked activity against no-tone background EEG. High-depth states were associated with greater ERP signal-to-noise ratio, stronger single-trial signal consistency, and improved decodability of auditory tones. These results suggest that meditative depth is expressed in the reproducibility and stimulus-background separability of sensory responses, consistent with deep meditation enhancing the brain's functional signal-to-noise ratio by improving the clarity of sensory signals and reducing endogenous noise.

Audiovisual cues ("bells and whistles") are ubiquitous in commercial gambling products. Pairing wins with sound and light cues in laboratory-based gambling paradigms increases risky choice, but the neurocognitive basis of this effect is unclear. Here we compared patterns of neural activation using functional MRI in healthy volunteers (n = 31) while they performed a two-choice lottery task. Reward-paired cues were either present or absent in a mixed-block, event-related design. As predicted, participants made riskier choices on cued trials. Choice latencies were also longer when cues were present, particularly on trials following a win. Activity within the nucleus accumbens and orbitofrontal cortex was greater during the decision phase when participants made risky choices. Nucleus accumbens signal was also greater when participants were anticipating risky outcomes, and in response to risky wins. Contrary to our pre-registered hypotheses, cue condition did not alter patterns of activity across any task phase, in either of these a priori regions of interest. As such, cue-induced risky choice does not appear to be driven by altered representation of risk or value within this canonically reward-sensitive circuitry. Instead, exploratory analyses revealed that the anterior insula was selectively activated by cued, risky wins. Such activation may signal the saliency of these events, or their emotional impact, and may reflect one mechanism through which cue-induced craving develops in vulnerable individuals.

Background: Childhood trauma exposure (TE) may heighten negative emotional responses, overwhelm cognitive control, and increase risk for anxiety disorders. Cognitive control is facilitated by glutamatergic (Glu) excitatory neurotransmission within the dorsal anterior cingulate cortex (dACC). Dynamic changes in dACC Glu levels were investigated using 1H functional magnetic resonance spectroscopy (1H fMRS) to assess the impact of negative emotional processing on neural mechanisms supporting cognitive control in TE-youth. Methods: Fifty adolescents were categorized into two TE-Groups: Higher (Mtrauma=6{+/-}1events) and Lower (Mtrauma=3{+/-}1events). 1H fMRS from the dACC was acquired during an inhibitory motor control task requiring tapping responses to stimuli under two Response Modes, NonSelective (100% response) and Selective (80% response, 20% inhibition), executed with two Stimuli Conditions, Squares (no emotion) and Faces (emotion). Glu modulation (relative to basal levels) was tested across TE-Group, Stimuli Condition, and their interaction. Within each Stimuli Condition, Glu modulation was tested across Response Modes by TE-Group. Results: We observed a 2-way interaction of TE-Group x Stimuli Condition ({chi}2=4.66, p=0.031). Post-hoc tests revealed significantly lower Glu modulation in Higher TE vs Lower TE (p=.023) during Faces but not Squares. This Glu modulation did not differ across Response Modes. Within the Higher TE-Group, Glu was significantly reduced during Faces compared to Squares (p<.001). Basal dACC Glu levels did not differ between groups. Conclusions: TE-Group differences in adolescent dACC Glu modulation were observed during cognitive control performed with emotional, but not non-emotional, stimuli, highlighting the value of 1H fMRS for detecting trauma-related differences in task-related excitatory neurochemical dynamics.

Autism is a heterogeneous neurodevelopmental condition, often accompanied by challenges in language and cognitive development. Although atypical functional connectivity (FC) has been reported in autism, the timing of when it first emerges and its relevance for later behavior remain poorly understood. In this study, we examined developmental trajectories of alpha-band FC and network organization across the first three years of life. We computed global alpha-band measures, including peak alpha connectivity frequency (PACF), mean FC, clustering coefficient, and modularity, to characterize nonlinear developmental trajectories from longitudinal EEGs collected from 238 children (3-to-36-month-olds) with (Autism; n=58) and without (LL-noAutism; n=180) autism. Network-based statistics (NBS-Predict) identified subnetworks contributing to group differences at each age. Exploratory graph analyses (EGA) examined associations among FC, network measures, and language outcomes. We observed that PACF increased linearly with age in both groups. Global alpha-band connectivity measures showed a similar developmental pattern, with mean global FC, clustering coefficient, and modularity all increasing rapidly during the first year in both groups. Thereafter, these measures declined in the Autism group but continued to gradually increase in the LL-noAutism group. Compared to LL-noAutism, NBS-Predict identified both hyper- and hypo-connectivity subnetworks in Autism at 3 months, followed by a hypo-connectivity subnetwork at 24 and 36 months. EGA indicated that early hyperconnectivity predicted later hypoconnectivity and was associated with subsequent network organization and language outcomes. These findings indicate that altered alpha-band connectivity trajectories are detectable in infancy in children later diagnosed with autism and may contribute to later differences in developmental outcomes.

The cortisol awakening response (CAR) marks the transition from rest to wake phase by a sharp increase in cortisol levels upon awakening in the morning. This increase may assist in cognitive and behavioral awakening, but its function is not fully understood yet. In this pilot study we aimed to provide first data on the influence of immune system activity on the CAR. Thereby, a within-subject analysis approach was applied to avoid confounding by between-subject bias and improve inference of the results. Three healthy subjects collected their overnight urine for analysis of neopterin (Th1 immune activation marker) and sampled saliva at 0, 30, and 45 minutes after awakening in the morning for cortisol determination and CAR estimation. Additionally, subjects wore an EEG-headband overnight for objective determination of the awakening timepoint. Random-effects models were computed to estimate the effect of overnight neopterin on the CAR. There was a significant positive effect of overnight neopterin levels on the CAR, indicating that overnight Th1 immune activation may predict the dynamic increase of cortisol in the morning, with higher immune levels leading to a stronger CAR. These results provide first evidence for the immunological awakening hypothesis and a potential role of the CAR in the maintenance of circadian immune rhythms, but given the small number of participants, findings should be interpreted as exploratory.

Alcohol drinking motives vary among individuals and shape experiences and beliefs about alcohol, influencing the processing of alcohol-related cues. In real-life settings, these cues are contextually rich, amplifying the role of such individualized drinking motives on cue processing. However, previous literature has primarily relied on images of alcohol, which lack contexts and differ significantly from real-life. Here, aiming to investigate real-life craving, we examined the role of alcohol drinking motives in craving in response to naturalistic alcohol-drinking videos. We asked fifty-three problematic alcohol users to speak about their reasons for drinking alcohol to capture unique alcohol drinking motives of each individual. Participants also underwent functional MRI while watching fifteen alcohol-drinking videos, and reported their subjective level of craving and self-relatedness for each video. Behavioral data analysis revealed that individuals with greater alcohol use severity tended to report greater cue-induced craving, but only when they reported that a video was related to themselves. Inter-subject representational similarity analysis showed that participants with similar alcohol drinking motives, reflected in shared drinking reasons and similar self-relatedness to the videos, exhibited synchronized craving-related neural responses during video-watching. Notably, these shared neural processes mediated the link between similar drinking motives and similar self-reported craving levels across participants. Together, our findings highlight the crucial role of alcohol drinking motives in shaping cue-induced alcohol craving, and provide deeper insights into craving in real-world contexts.

Hedonic valence, the intrinsic pleasantness or unpleasantness of an experience, is fundamental to human psychological functioning. Yet, how valence is represented in the brain remains an open question. Functional MRI studies have demonstrated that the brain encodes both positive and negative valence, but this evidence largely stems from experiments using simplified, controlled stimuli, such as images, sounds, or words. As a result, it remains unclear how valence is processed during rich, naturalistic experiences that more closely reflect real life. In addition, most studies adopt a single statistical model, raising concerns about the robustness of their findings. This study used a formal voxel-wise Bayesian model selection approach to test alternative statistical models supporting Bipo-larity, Valence-General, and Bivalence hypotheses to identify the most optimal model of valence representation during narrative listening. Our results provide evidence for the Bipolar model. We identified distributed brain re-gions that selectively encode valence as a bipolar continuum (negative to positive) during narrative comprehen-sion, including classical emotion-related hubs such as ventromedial prefrontal cortex, as well as regions not tradi-tionally associated with emotion processing, such as inferior occipital cortex, supramarginal cortex, inferior frontal cortex, and middle cingulate. Regions selectively encoding arousal and those broadly responsive to both valence and arousal were also identified. These findings highlight the importance of using formal model comparison and naturalistic paradigms in affective neuroscience, advancing our understanding of how valence is represented in the brain during real-world experiences.