International Journal of Psychophysiology

Sound perception extends beyond the boundaries of auditory sensation, encompassing a profound engagement with the entire human body. This intricate interplay between sound and body sensation has long captivated the interest of researchers. In this study, we examined the relationship between our perception of sound pitch and our bodily position senses, while also exploring the role of emotions in shaping this intriguing cross-modal correspondence. We also compare the topography of pitch-triggered body sensations between depressive, alexithymia, and the control groups, and examine their associations with anxiety. Our findings reveal that individuals with depression and alexithymia experience diffuse and less localized body sensations in response to sound pitch, accompanied by heightened feelings of anxiety and negative emotions. These findings imply that diffuse bodily sensations in response to sound may trigger negative emotions such as anxiety and indicate that monitoring pitch-triggered body sensations could serve as a valuable biomarker for emotional disorders. Our study sheds light on the profound importance of body sense awareness in response to sounds, a phenomenon that may be mediated by interoception. This research enhances our understanding of the intricate relationship between sound, emotions, and the human body, offering insights for potential interventions in emotional disorders.

Understanding the somatovisceral responses to auditory affective imagery has important implications in disorders like misophonia. The current study compared physiological responses to aversive and nonaversive states across three modalities: audiovisual, auditory, and auditory imagery. Electromyographic activity over corrugator supercilii (EMGc) and zygomaticus major (EMGz), electrodermal activity (EDA), heart rate (HR), and finger skin temperature (SKT) were measured. There was significant differentiation in EMGc, EDA, and HR deceleration between aversive and nonaversive audiovisual stimuli. EMGc potentiation was the only physiological measure showing consistent differentiation across the three modalities. Cross-modal aversiveness classification results revealed a similar physiological response pattern between audiovisual and auditory modalities. The physiological response pattern during auditory affective imagery was useful for predicting the aversiveness in audiovisual modality but not the other way around. Vividness in auditory imagery correlated with subjective hedonic valence ratings, but not physiological responses. Taken together, the current data suggest that the aversiveness of auditory imagery is differentiable in subjective affective experience and facial muscle potentiation. These results of the physiological responses to imagined aversive sounds in nonclinical population would serve as a comparison baseline for the study of misophonia.

Skin Conductance Response (SCR) is a phasic change in electric conductivity of the skin, occurring either non-specifically, or in response to a stimulus (event-related, or ER-SCR). It has long been understood that ER-SCR amplitudes are greater when associated with unpleasant or high-arousal stimuli; however, the relationship between emotional valence and arousal to other ER-SCR measures such as ER-SCR latency (interval between stimulus onset and ER-SCR onset) and ER-SCR rise time (interval between ER-SCR onset and peak amplitude) is less well-established. Here, we presented 60 emotive pictures from IAPS and NAPS affective picture systems to a group of 100 young, healthy adults (50 male and 50 female) and recorded their electrodermal activity. We found that higher emotional arousal was associated with greater ER-SCR amplitudes and shorter ER-SCR rise times. Interestingly, while the increase in ER-SCR amplitudes was only observed for a subset of high-arousal stimuli (score 7-9 on a 9 point scale), the effect on ER-SCR rise times was more graded and particularly sensitive to the difference between low (score 1-3) and medium-arousal (score 4-6) categories. Next, we found that while ER-SCR amplitudes were greater in response to unpleasant stimuli (valence score 1-3 on a 9-point scale), none of the ER-SCR measures could distinguish between neutral (score 4-6) and positive stimuli (score 7-9). We suggest that the increase in ER-SCR amplitudes for unpleasant stimuli is primarily driven by the inherent association between unpleasantness and high arousal. In conclusion, we demonstrate that ER-SCR rise time conveys valuable information about emotional arousal and represents a useful complementary measure to ER-SCR amplitude in order to discern between multiple degrees of emotional arousal. Furthermore, this study confirms the cross-cultural validity of the IAPS and NAPS databases in a sample of young adult Czechs.

Anxiety and depression are among the leading global causes of disability, yet their underlying neural mechanisms remain poorly understood. Traditional event-related potential (ERP) studies have shown attentional biases in anxiety and blunted responses to positive stimuli in depression, but limitations in sensitivity and interpretability hinder their clinical application. Fast Periodic Visual Stimulation (FPVS) offers an objective, high signal-to-noise ratio (SNR) approach to measuring neural responses to emotional stimuli. In this study, we applied FPVS with affective images to assess differences in emotional processing between individuals with anxiety and healthy controls across two experimental phases, optimizing stimulus presentation parameters. The results revealed that individuals with anxiety exhibited increased neural responses to negative stimuli compared to positive stimuli, as well as reduced responses to high-arousal stimuli, particularly in occipito-temporal and central-parietal regions. Additionally, individuals with comorbid depression showed blunted responses to high-arousal stimuli across multiple brain regions, consistent with reduced emotional reactivity. These findings support the feasibility of FPVS as a rapid and reliable tool for assessing emotional processing differences in clinical populations, with potential applications in translational research and psychiatric screening

Aversive generalization learning is an adaptive trait that is necessary for survival in a dynamic environment. However, this process is exaggerated in persons with anxiety disorders, leading to overgeneralization of learned threat associations, hyperreactive fight-or-flight responses, and persistent avoidance. Patients with social anxiety disorder (SAD) exhibit impaired conditioned threat discrimination particularly with respect to social stimuli, such as faces. The present study examined the relationship between social anxiety and generalization of visuocortical and pupil dilation responses to a series of facial morphs, one of which was always paired with a noxious sound. Steady-state visual evoked potentials (ssVEPs; N = 65) increasingly fit a model of generalization, and pupil dilation responses (N = 62) also decreasingly discriminated the CS+ as a function of social anxiety. These results contribute to a growing body of work suggesting that SAD dysregulates the ability of autonomic responses to specifically target social threat. The finding of widened visuocortical tuning in SAD implicates a role of the visual system in driving attentional biases in anxiety disorders, including increased visual processing of safety signals similar to threat cues.

Behavioral evidence shows that anxious individuals tend to be distracted by irrelevant stimulation not only for threat-related stimuli but also for non-emotional neutral stimuli. These findings suggest that anxious individuals may have a general impairment of attentional control, especially inhibition function. However, the neural mechanism underlying the anxiety-related impairment in attentional control is unclear. Here, in a visual search task with geometric stimuli, we examined attentional processing of the non-emotional neutral distractor on participants with different levels of anxiety, using the event-related-potential (ERP) indices of attentional selection (N2 posterior contralateral [N2pc]) and top-down inhibition (distractor positivity [Pd]). We found that distractor-evoked Pd amplitudes were negatively correlated with trait-anxiety scores, i.e., the higher the level of anxiety, the worse the ability of attentional inhibition. In contrast, the amplitudes of distractor-evoked N2pc did not vary with anxiety levels, suggesting that trait-anxiety level does not affect stimulus-driven attentional capture. We also observed attentional processing of target stimuli and found that the peak latency of target-evoked N2pc was delayed as anxiety levels rise, suggesting that anxiety impairs the efficiency of top-down attentional selection of the target. The present study provides direct neurophysiological evidence for general anxiety-related impairment of attentional control.

Expectations have an important role in guiding behavior and the interpretation of novel information, but can contain negative biases such as is the case in anxiety disorders. Positive future thinking may provide an accessible way to attenuate these negatively biases. However, much is still unclear about the optimal form of such positive interventions, and it is unknown if the effects go beyond subjective experience. Here, we used a positive future thinking intervention to adapt the way a stressful event is experienced. Participants imagined either task-relevant (N = 21) or irrelevant (N = 21) positive future events before being subjected to the Trier Social Stress Task, or did not receive the intervention (N= 20). We recorded resting state EEG during the anticipation and recovery phases of the TSST to assess intervention and trait anxiety related differences in the level of frontal delta-beta coupling, which is considered a neurobiological substrate of emotion regulation. Results show that the intervention reduces event-related stress and anxiety, and increases social fixation behavior and task performance, but only if future thinking is task relevant. Paradoxically, task-irrelevant positive future thoughts enhance negative perceptual biases and stress reactivity. This increase in stress reactivity in the task-irrelevant group was corroborated by the elevated levels frontal delta-beta coupling during event anticipation, especially for those with high trait anxiety. This suggests an increased demand for emotion regulation following the task-irrelevant intervention, possibly due to the contextual incongruence between positive imagery and the stressor. Together, these results show that positive future thinking can mitigate the negative emotional, behavioral and neurobiological consequences of a stressful event, but that it should not be applied indiscriminately. Task-relevant positive future thinking can be an accessible way to boost efficacy of exposure therapy for pathological anxiety, and can help people deal with negative anticipation in daily life.

This study explores the relationship between emotions, physiological responses, interoception, and time perception. We also aimed to understand how body dissatisfaction influences this interplay. Participants (N = 40) watched videos designed to evoke positive, neutral, and negative emotions while their heart rate was monitored via electrocardiography. Our findings indicate that video duration perception varied depending on emotional content. Negative and neutral videos were perceived as shorter, while positive videos were estimated more accurately. Negative emotions were linked to a decrease in heart rate, suggesting a "freeze response," while positive and neutral content did not significantly affect heart rate. A significant correlation between heart rate and time perception was observed in participants with a normal body image, indicating that heart rate might serve as an internal clock. However, this correlation was absent in those with body image dissatisfaction, implying a weakened link between physiological states and time perception. Additionally, a strong negative correlation between heart rate and interoceptive accuracy was found in participants with body image dissatisfaction. The results suggest that body image dissatisfaction disrupts the integration of emotional and physiological signals, affecting how we perceive and understand our internal bodily sensations and emotions.

ObjectiveEmotional states are expressed in body and mind through subjective experience of physiological changes. In previous work, subliminal priming of anger prior to lexical decisions increased systolic blood pressure (SBP). This increase predicted the slowing of response times (RT), suggesting that baroreflex-related autonomic changes and their interoceptive (feedback) representations, influence cognition. Alexithymia is a subclinical affective dysfunction characterized by difficulty in identifying emotions. Atypical autonomic and interoceptive profiles are observed in alexithymia. Therefore, we sought to identify mechanisms through which SBP fluctuations during emotional processing might influence decision-making, including whether alexithymia contributes to this relationship. MethodsThirty-two male participants performed an affect priming paradigm and completed the Toronto Alexithymia Scale. Emotional faces were briefly presented (20ms) prior a short-term memory task. RT, accuracy and SBP were recorded on a trial-by-trial basis. Generalized mixed-effects linear models were used to evaluate the impact of emotion, physiological changes, alexithymia score, and their interactions, on performances. ResultsA main effect of emotion was observed on accuracy. Participants were more accurate on trials with anger primes, compared to neutral priming. Greater accuracy was related to increased SBP. An interaction between SBP and emotion was observed on RT: Increased SBP was associated with RT prolongation in the anger priming condition, yet this relationship was absent under the sadness priming. Alexithymia did not significantly moderate the above relationships. ConclusionsOur data suggest that peripheral autonomic responses during affective challenges guide cognitive processes. We discuss our findings in the theoretical framework proposed by Lacey and Lacey (1970).

1.Several scientific studies using Western classical music and some using Indian classical music have reported benefits of listening to musical pieces of specific genre or Raga, in terms of stress reduction and mental well-being. Within the realm of a Raga, presentation of musical pieces varies in terms of low-level musical components (like tempo, octave, timbre, etc.), and yet there is hardly any research on their effect. A commonly preferred musical pattern in Carnatic classical music is to have incremental modulations in tempo and octave ( Ragam-Tanam-Pallavi), and we wanted to examine whether this could have better anxiolytic effect than music without such modulations.\n\nAccordingly, in the current study, we exposed 21 male undergraduate medical students to a custom recorded South Indian classical music clip for 1 week (8 minutes clip; Raaga Kaapi; only two instruments - Violin and Mridangam; listened thrice daily for 6 days). One set of the participants (Varying Music; n=11) listened to a version that had the incremental variations, whereas the other set (Stable Music; n=10) listened to a version without such variations. On all 6 days, one of the music listening sessions was conducted in the lab while collecting electroencephalography (EEG; 32 channels) and electrocardiography (ECG; 1 channel) data. Psychological assessment for anxiety (State-Trait Anxiety Inventory - STAI and Beck Anxiety Inventory - BAI) was conducted before (day 1) and after (day 6) the intervention. Physiological parameters studied included power spectrum across the scalp in delta, alpha, beta, theta and gamma bands from EEG and heart rate variability (HRV) from ECG, during the baseline recordings of day 1 and day 6 of intervention.\n\nOur results show that participants when exposed to varying music showed significant reduction in anxiety, in contrast to stable music or silence intervention. A global examination of power spectral changes showed a stark contrast between stable and varying music intervention in comparison to silence - former showing greater increase in higher frequencies whereas latter showing prominent decrease especially in lower frequencies, both in bilateral temporo-parieto-occipital regions. A more detailed spectral analysis in frontal region revealed that both music intervention showed greater left-dominant alpha/beta asymmetry (i.e., greater right brain activation) and decrease in overall midline power (i.e., lower default mode network or DMN activity), when compared to silence intervention. Interestingly, stable music resulted in more left asymmetry, whereas, varying music showed more midline power reduction. Both music intervention also didnt show the reduction in HRV parameters that was associated with silence intervention.\n\nWe speculate that, the enhancement in mind calming effect of Kaapi raaga when presented with incremental variations, could be brought about by a balanced switching between a heightened mind wandering state with attention to self during the lower-slower portions and a reduced mind wandering state with attention to music during the higher-faster portions of the music. Such a dynamic mind wandering exercise would allow training ones creative thinking as well as sustained attention, during the respective high and low mind wandering states - both helping prevent ruminating thoughts. Therefore, musical properties such as tempo and octave have non-trivial influence on the various neurological and psychological mechanisms underlying stress management. Considering the impact of this finding in selection of music clips for music therapy, further studies with larger sample size is warranted.

Emotion is key to human communication, inferring emotion in a speakers voice is a cross-cultural and cross-linguistic capability. Electroencephalography (EEG) studies of neural mechanisms supporting emotion perception have reported that early components of the event-related potential (ERP) are modulated by emotion. However, the nature of emotions effect, especially on the P200 component, is disputed. We hypothesised that early acoustic features of emotional utterances might account for ERP modulations previously attributed to emotion. We recorded multi-channel EEG from healthy participants (n = 30) tasked with recognising the emotion of utterances. We used fifty vocalisations in five emotions - anger, happiness, neutral, sadness and pleasure - drawn from the Montreal Affective Voices dataset. We statistically quantified instantaneous associations between ERP amplitudes, emotion categories, and acoustic features, specifically, intensity, pitch, first formant, and second formant. We found that shortly after utterance onset (120-250 ms, i.e., P200, early P300) ERP amplitude for sad vocalisations was less than for other emotional categories. Moreover, ERP amplitude at around 180 ms for happy vocalisation was less than for anger, sadness, and pleasure. Our analysis showed that acoustic intensity explains most of these early-latency effects. We also found that, at longer latency (220-500 ms; late P200, P300) ERP amplitude for neutral vocalisations was less than for other emotional categories. Furthermore, there were also ERP differences between anger and happiness, anger and pleasure, anger and sadness, happiness and pleasure, as well as happiness and sadness in shorter windows during this late period. Acoustic pitch and, to a lesser degree, acoustic intensity explain most of these later effects. We conclude that acoustic features can account for early ERP modulations evoked by emotional utterances. Because previous studies used a variety of stimuli, our result likely resolves previous disputes on emotions effect on P200.

Decision-making is central to daily function for executives in any organisation. Strategic leadership coaching (SLC) is an effective way to support complex decision-making, yet empirical neuroscientific data to support is lacking. The purpose of this study was to investigate the effects of SLC on young executives cortical arousal and their neural circuitry activation during the completion of computerized tasks which require activation of decision-making circuitry. We hypothesised SLC would improve cortical arousal when engaged with decision-making tasks, specifically increased electroencephalography (EEG) relative alpha band activity and improved neural circuitry engagement, measured as increased amplitude of event-related potential wave components. This study included thirty-one young male executives, of which eighteen underwent 8 sessions of SLC over two months. EEG records were collected thrice from those who underwent SLC (prior, post, and two months post), and twice from the control group (two months apart). The EEG recording session included completion of two decision-making tasks, an Iowa gambling task and Stroop colour-word conflict task. Finding, SLC increased alpha band activity over left frontal and central electrodes, and increased right parietal N170 amplitude and left parietal P300 amplitude. These findings support our hypothesis, as SLC improved cognitive cortical resources (enhanced alpha) which in turn permitted greater efficiency within decision-making circuitry (increased wave component amplitudes). This study provides the first and necessary neurobiological evidence to support and develop this line of research in SLC, and other forms of coaching, as it adds significant value.

Stress, anxiety, and depressive symptoms can be reduced by listening to music, but the underlying mechanisms remain unclear. To address this gap, we measured brain connectivity while participants listened to songs of different genres: ambient, pop, and metal. Additionally, affective ratings were obtained while participants (n = 30) listened to the six different songs, and subjective ratings of state anxiety were solicited at the terminus of each song. Electroencephalography (EEG) connectivity combining weighted Phase Lag Index and graph theory was utilised to document brain activity during listening. Repeated-measures ANOVA indicated that listening to more pleasant and less arousing songs was associated with lower self-reported state anxiety levels than songs rated unpleasant and highly arousing. Of interest, EEG alpha connectivity differed across two ambient songs, particularly in the frontal lobes, despite being from the same genre and rated as highly pleasant and low in arousal. We also observed a sex effect on EEG results, where female participants (n = 18) displayed stronger connectivity than male participants (n = 12). Combined, these results suggest that ambient songs reduce state anxiety but have divergent brain responses, possibly reflecting the complex nature of music listening, including sensory processing, emotion and cognition.

BackgroundSmartphones and social media have become ubiquitous in our lives, and while debates about their negative impact on mental health, addictive potential, and disruptive effects on daily activities have surged, neurobiological evidence remains scarce. Here, we investigated whether the behavioral and neural effects of interference of continuous attention by incoming social media messages on WeChat varies according to its problematic use as assessed via an addiction framework. MethodsN = 60 healthy individuals were stratified based on their level of problematic WeChat usage as measured by the WeChat Addiction Scale (WAS): LOW (15 males and 15 females) and HIGH (15 males and 15 females) addictive tendencies. Participants underwent an AX-Continuous Performance Task (AX-CPT) with WeChat-associated (incoming message) and neutral auditory distractors as well as a no distractor condition. Concurrent functional Near-Infrared Spectroscopy (fNIRS) assessments of the orbitofrontal cortex (OFC) were implemented to determine the underlying neurofunctional mechanisms. ResultsOn the behavioral level the HIGH group demonstrated faster reaction times during the WeChat and no distractor condition compared to the LOW group. Exploratory analyses indicated that the WeChat distraction decreased left lateral OFC activity in the LOW but enhanced activity in this region in the HIGH group. ConclusionAgainst our hypotheses WeChat distraction enhanced behavioral performance specially in individual with a tendency for problematic WeChat use, with the neural data pointing to less suppression of the OFC in individuals with a tendency for problematic usage. Findings underscore the complexity of the potential effects of new technology on daily live and indicate that addiction models might not be simply extendable to problematic social media usage.

Motivated by the Neurovisceral Integration Model (NVI) of cardiac vagal control, we investigated the relationship between relative left frontal activity (rLFA) and vagally mediated heart rate variability or respiratory sinus arrhythmia (RSA) in 287 participants, half of whom had a history of depression. We hypothesized that there would be a within-person association of rLFA and RSA such that when RSA is lower rLFA would also be lower (Hypothesis I). Moreover, it was hypothesized that this within-subject association would be moderated by a history of depression (Hypothesis II). Metrics of rLFA and RSA were derived from concurrent electroencephalogram and electrocardiogram recordings. The logarithmic difference in EEG alpha power between the homologous right and left electrodes (Ln (Right/Left)) in the frontal region was used to index rLFA. A Hilbert transform was applied to the mean-centered and bandpass-filtered (0.12-.40 Hz) inter-beat interval (IBI) time series to get a fine-grained measure (in the time domain) of RSA. A linear mixed ANOVA model with rLFA as the dependent variable and RSA as the main fixed effect found that participants had less rLFA during epochs when they had lower RSA, which was consistent with the prediction from Hypothesis I. Contrary to the prediction from Hypothesis II, the within-person association of RSA and rLFA was not moderated by a history of depression. However, the association between RSA and rLFA varied across the four pairs of frontal electrodes that we examined. Thus, more research is needed to determine the spatial extent of this association, e.g., examining the relationship between source-localized rLFA and RSA.

The startle reflex is considered a sensitive defensive reaction to potential threats that manifests as a unique eye blink-like pattern in the EMG. Eye blink EMG has a bell-shaped potential when startle probes are elicited, that strongly corresponds to amygdala activity. Considering how amygdala activity fluctuates over time in response to emotional and self-threatening stimuli, observing startle eyeblink size fluctuation over time could provide a cost-effective, convenient, and less resource intensive means for examining amygdala activity over time. Yet based on current standards in the literature, often startle evoked eye blink EMG values do not exhibit activity 3SDs from the mean eyeblink response, thus these trials are typically excluded from startle analyses. It stands to reason, however, that these trials may still index amygdala activity in a meaningful way. Through investigating the association between startle eyeblink amplitude, corresponding ERP amplitude, and underlying neural activity, the current study provides evidence that startle amplitudes exhibit a linear relationship with proxies for amygdala activity, e.g., N100 amplitudes and regions heavily interconnected with the amygdala. Specifically, the startle reflex correlates to large amount of brain regions in N100 time window in addition to the N100 amplitude. Thus, both valid and otherwise traditionally non-valid startle reflex responses appear to index amygdala activity and should be included accordingly. This approach could help salvage large amounts of meaningful data traditionally excluded from studies interested in amygdala responses to various stimuli over time.

The error-related negativity (ERN)--an index of error monitoring--is associated with anxiety symptomatology. Although recent work suggests associations between the ERN and anxiety are relatively modest, little attention has been paid to how variation in task parameters may influence the strength of ERN-anxiety associations. To close this gap, the current meta-analysis assesses the possible influence of task parameter variation in the Flanker task--the most commonly used task to elicit the ERN--on observed ERN-anxiety associations. Here, we leveraged an existing open database of published/unpublished ERN-anxiety effect sizes, supplementing this database by further coding for variation in stimulus type (letter vs. arrow), response type (one-handed vs. two-handed), and block-level feedback (with vs. without). We then performed meta-regression analyses to assess whether variation in these Flanker task parameters moderated the effect size of ERN-anxiety associations. No evidence for an effect of stimulus type was identified. However, both response type and block-level feedback significantly moderated the magnitude of ERN-anxiety associations. Specifically, studies employing either a two-handed (vs. one-handed) task, or those with (vs. without) block-level feedback exhibited more than a two-fold increase in the estimated ERN-anxiety effect size. Thus, accounting for common variation in task parameters may at least partially explain apparent inconsistencies in the literature regarding the magnitude of ERN-anxiety associations. At a practical level, these data can inform the design of studies seeking to maximize ERN-anxiety associations. At a theoretical level, the results also inform testable hypotheses regarding the exact nature of the association between the ERN and anxiety.

Empathy, a crucial prosocial human trait, is mainly measured through questionnaires, but performance in tasks involving emotional stimuli, brain activity during these tasks, and genetic information also provide relevant clues. These approaches are developed separately or by combining only some of these factors. Integrating them into a single study and analysis may help to better characterize their relative load and to understand the complexity of empathy. The IRI empathy scale was administered to 65 participants, who later performed a lexical decision task on emotional words while their performance and event-related potentials (ERPs) were recorded. Three genetic polymorphisms, one in the OXTR gene (SNP rs2254298) and two in the AVPR1a gene (RS1 and RS3 regions), were also analyzed. Generalized linear models revealed that these biobehavioral factors jointly predicted emotional but not cognitive empathy. Reaction times and the amplitude of the LPP component of ERPs in response to emotional words, along with rs2254298 AA/AG genotype, were significantly associated with scores on the IRI personal distress subscale. Meanwhile, LPP amplitudes and AVPR1a-RS1 LL genotype significantly predicted scores on the empathy concern subscale. The balanced loading of all these factors in the models reinforces the desirability of a comprehensive, multifaceted approach to characterizing empathy.

Development of neurophysiological treatment targets has been an important way to validate and advance treatment implementations. Anxiety Sensitivity (AS), described as a fear of fear, is one of the most well-researched transdiagnostic risk factors for psychopathology and has been demonstrated to be associated with a number of different INT symptoms and disorders, making it an ideal intervention target for treatment of anxiety and mood pathology. Currently, there exists a gap in terms of understanding underlying neural mechanisms of AS and treatment-related change in AS. The current study sought to examine the impact of 2 brief computerized interventions on AS in order to assess the P300 and late positive potential (LPP) event-related potential (ERP) components as an index of both baseline and treatment change in the transdiagnostic anxiety sensitivity construct. Participants received one of the following, with a 1-month follow-up: an anxiety reduction intervention of cognitive anxiety sensitivity treatment (CAST) alone, a mood intervention of cognitive bias modification interpretation (CBM-I), a combined CAST and CBM-I intervention, or a repeated contact control group. Baseline AS was significantly related to baseline P3/LPP, such that higher P3/LPP amplitude (heightened emotional reactivity) is associated with higher AS at intake. Further, treatment-related reductions in AS were associated with higher baseline reactivity: greater AS reductions at month one were associated with higher P3/LPP activity. Heightened emotional response was predictive of better treatment outcomes. Analyses also showed evidence for different mechanisms associated with CAST and CBM-I groups. Specifically, the CAST group evidenced predictions of treatment outcome in parietal areas, where the CBM-I group evidenced predictions in frontal areas. The Combined group evidenced both frontal and parietal activations, consistent with combining the effects from the CAST and CBM-I groups. These findings suggest that the P3/LPP is an index of cognitive-affective processes underlying AS at baseline and has predictive ability in assessing AS treatment outcome in that our observed treatment types engage different neural mechanisms.

Aversive conditioning prompts reliable changes in the power of EEG alpha-band oscillations and pupil dilation. Both variables have been used to test hypotheses on the acquisition, generalization, and extinction of conditioned threat. Existing studies have largely relied on trial averages and group-level analyses. Thus, the variability of these physiological markers to aversive learning at the subject level is currently unknown. Comparisons of group-level analyses in prior studies suggest that pupil dilation and EEG-alpha activity capture complementary information. However, to date, no study has directly compared these two markers in terms of their effect sizes at the level of individual participants. The present study employed Bayesian multilevel modeling to quantify the variability of conditioning effect estimates for alpha-band power and pupillometry. Estimates were examined at the group level and at the participant level, across two conditioning paradigms, involving visual and auditory cues. Although the two metrics shared similar effect sizes at the group level, participant-level variability in these effect sizes was substantially higher for pupil-dilation compared to alpha-power, and this finding was replicated across both paradigms. These findings have important implications for clinical and inter-individual difference research which requires both the quantification of effects at the participant-level as well as meaningful variability between-participants that can be linked to relevant differences such as anxiety.