Visual search is guided by mental representations of target-defining features (attentional templates) that are activated in a preparatory fashion. It remains unknown how many templates can be maintained concurrently, and what kind of costs are associated with multiple-template versus single-template search. Here, we compared the operation of attentional templates during three-colour and single-colour search tasks. Preparatory template activation processes were tracked by measuring N2pc components to task-irrelevant singleton colour probes that appeared in rapid succession during the interval between search displays. These probes attract attention (as indexed by an N2pc) if the corresponding colour template is active at the time when the probe appears. In a three-colour search task where target identity was fully predictable (Experiment 1), only probes that matched the upcoming target colour triggered N2pcs, demonstrating that only a single target template was activated. When three possible colour targets appeared randomly and unpredictably (Experiment 2), probes that matched any of these colours triggered N2pcs, demonstrating that all three templates were activated concurrently. However, relative to a single-colour search task, clear costs emerged in this three-colour task for the attentional guidance towards search targets and for search performance. These costs appear to be linked to inhibitory interactions between simultaneously active search templates. These findings show that while at least three target templates can be maintained in parallel, multiple-template search is still subject to capacity limitations which affect both template-guided attentional guidance and the subsequent selective processing of search targets.

This study examined neural signatures associated conflict-monitoring, recognition and feedback processing in a novel feedback Concealed Information Test (fCIT), and also examined whether all the ERPs can be used to detect concealed autobiographical information. Participants were randomly assigned to one of two groups (guilty or innocent) and then tested in the fCIT while undergoing electroencephalograms (EEGs). Results show that the probe (participants’ name) elicited more negative N200, more positive recognition P300 than irrelevants among guilty participants, and feedback following the probe elicited a larger feedback P300 than feedback following irrelevants. Further, we found that all indicators, including conflict-monitoring N200, recognition P300, and feedback P300, could significantly discriminate between guilty and innocent participants. Combining them is highly effective in discriminating between guilty and innocent participants (AUC = 0.96). These findings not only shed light on the neural processing of fCIT, but also suggest the potential of using fCIT to detect concealed autobiographical information.

Motivation is considered a crucial factor in determining emotion regulation choice (ER choice). Our previous study revealed that increased motivation led to a preference for distraction over reappraisal due to the narrowed attention, yet neural underpinnings supporting this phenomenon remain unclear. In this study, we used event-related potentials (ERPs) to investigate whether motivation influences ER choice by early attention processing (P2) or late resource engagement (LPP). EEG activities were recorded for the pictorial contexts varying in motivational intensity and direction, while participants (N=68) were required to decide which strategy from the two options they would use to regulate their emotions. Consistent with previous studies, the results indicated that individuals chose more distraction over reappraisal in high-withdrawal motivated contexts while a reversed pattern was observed in low-withdrawal motivated contexts. Moreover, high-intensity motivated emotional contexts result in enhanced P2 and LPP. Further analysis indicates that only frontal P2 and the early LPP mediate the effect of motivational intensity on ER choice. These findings suggest that heightened motivation leads to a preference for distraction over reappraisal during emotion regulation due to the greater occupation of attentional resources.

There is considerable evidence documenting associations between tobacco smoking, including initiation, maintenance, and relapse of addiction, with diminished cardiovascular responses to acute psychological stress. However, less is known about how smokers respond to repeated stress across time. The current study examined patterns of cardiovascular reactivity and adaptation to recurrent stress among abstinent smokers, smokers who continued to smoke at their normal rate, and non-smokers. Smokers were randomly assigned to one of two conditions; ad libitum (n = 42), or 24h abstinence (n = 61); and non-smokers (n = 43) provided comparative referencing. Across the two laboratory sessions, participants (n = 149) were asked to complete a modified version of the trier social stress test (TSST), while monitoring systolic and diastolic blood pressure, and heart rate activity. Results showed that while non-smokers had elevated cardiovascular reactivity to begin with, they showed a greater capacity to habituate to recurrent stress across sessions. The data also suggest that smokers displayed attenuated cardiovascular reactivity to acute psychological stress and showed little habituation to repeated stress. In adjusted models, smokers exhibited less systolic blood pressure tolerance to stress. This poorer response profile in smokers may be a potential mechanism that leads to further cardiotoxic effects on health. Key words: Smoking, cardiovascular reactivity, habituation, stress

For distinguished contributions to psychophysiology: Christopher J. Patrick

The neurovisceral integration model proposes that information flows bidirectionally between the brain and the heart via the vagus nerves and vagally-mediated heart rate variability (vmHRV) can be used to index heart-brain interaction. Recent research has shown that voluntary reduction of breathing rate (slow-paced breathing, SPB) can enhance cardiac vagal control. Additionally, prefrontal transcranial direct current stimulation (tDCS) can modulate the excitability of the prefrontal region and influence the vagus nerve. However, fundamental research on the combination of SPB and prefrontal tDCS to increase vmHRV and other physiological indices of the autonomic nervous system is scarce. Therefore, 200 healthy participants were assigned to four experimental groups. Each group received either 20 min of active or sham tDCS combined with 5.5 breath per minute (BPM) or 15 BPM breathing. Regardless of the tDCS condition, the SPB group showed a significant increase in vmHRV over 20 minutes, suggesting an increase in parasympathetic activity. In addition, a significant decrease in HR at the first and second 5-minute epochs of the intervention. Regardless of breathing condition, the active tDCS group exhibited higher HR at the fourth 5-minute epoch of the intervention compared to the sham tDCS group, suggesting more sympathetic arousal. However, there was no combined effect on vmHRV, HR, skin conductance, or blood pressure. SPB is a robust technique for increasing vmHRV, whereas prefrontal tDCS may produce effects that counteract those of SPB. More research is necessary to test whether and how top-down and bottom-up approaches can be combined to improve vagal control.

According to the arousal model of vigilance, the locus coeruleus-norepinephrine (LC-NE) system modulates sustained attention over long periods by regulating physiological arousal. Recent research has proposed that transcutaneous auricular vagus nerve stimulation (taVNS) modulates indirect physiological markers of LC-NE activity, although its effects on vigilance have not yet been examined. Aiming to develop a safe and non-invasive procedure to prevent vigilance failures in prolonged tasks, the present study examined the possibility to mitigate vigilance loss by stimulating the LC-NE system via taVNS. Following a pre-registered protocol (https://osf.io/tu2xy/), 50 participants completed three repeated-sessions in a randomized order in which either active taVNS at individualized intensity set by participant, active taVNS set at 0.5 mA for all participants, or sham taVNS, was delivered while performing an attentional and vigilance task (i.e., ANTI-Vea). Changes in salivary alpha-amylase and cortisol concentrations were measured as markers of LC-NE activity. Self-reports of feelings associated with stimulation and guessing rate of active/sham conditions supported the efficacy of the single-blind procedure. Contrary to our predictions, the observed vigilance decrement was not modulated by active taVNS. Pairwise comparisons showed a mitigation by active taVNS on cortisol reduction across time. Interestingly, Spearman’s correlational analyses showed some inter-individual effects of taVNS on indirect markers of LC-NE, evidenced by positive associations between changes in salivary alpha-amylase and cortisol in active but not sham taVNS. We highlight the relevance of replicating and extending the present outcomes, investigating further parameters of stimulation and its effects on other indirect markers of LC-NE activity.

Skin conductance is a commonly used physiological measure during psychology experiments, such as during fear conditioning. Methods for scoring skin conductance responses are highly heterogeneous, though most researchers agree that manually inspected scores provide the highest quality data when compared to most available fully automated scoring methods. However, manual scoring is extremely time-consuming. We developed a semi-automated scoring program that significantly reduces the time required to process skin conductance response data at a level of quality akin to manual scoring. In contrast to all previous scoring programs, our program enables scoring of first, second, and third interval skin conductance responses. Using interclass correlation coefficients, Bland-Altman plots and Pareto analysis, we show here that our method is highly reliable and produces data that are almost identical to data that are manually scored. This software is very easy to use and is freely available to download and modify. We expect that this software will be helpful in reducing the time required to produce high quality first, second, and third interval skin conductance data for psychology researchers around the world.

High frequency heart rate variability (HRV) is a vagally-mediated physiological index reflecting parasympathetic activity that has been linked to emotion regulation capacity. However, very limited research has examined associations of physiological indices of regulation such as HRV with emotional functioning in daily life. The few studies that exist have small samples sizes and typically focus on only a narrow aspect of emotion regulation or emotional functioning. In this study, we examined associations between HRV assessed in the laboratory and emotional/mental health functioning in daily life using a 7-day ecological momentary assessment design in 303 adult community participants. We hypothesized that higher resting HRV would be associated with higher positive affect, lower negative affect, less affective variability, greater wellbeing, fewer depressive and idiographic [person-specific] symptoms, greater use of engagement emotion regulation strategies, and less use of avoidance emotion regulation strategies, as assessed in daily life. Results revealed that higher resting HRV in the laboratory was significantly associated with lower negative affect and less frequent use of avoidance emotion regulation strategies in daily life, although only avoidance strategies remained significant when both were included in the same model. We also observed a trend association, such that idiographic symptoms in daily life were associated with lower resting HRV. Theoretical and clinical implications are discussed, including the association of HRV with negatively-valenced, rather than positively-valenced, daily life experiences.

With the discovery of event-related potentials elicited by errors more than thirty years ago, a new avenue of research on performance monitoring, cognitive control, and decision making was opened. Since then, the field has developed and expanded fulminantly. After a brief overview on the EEG correlates of performance monitoring, this article reviews recent advancements in the field of performance monitoring based on single-trial analyses using independent component analysis, multiple regression, and multivariate pattern classification. Given the close interconnection between performance monitoring and reinforcement learning, computational modeling and model-based EEG analyses have made a particularly strong impact. The reviewed findings demonstrate that error- and feedback-related EEG dynamics represent variables reflecting how performance monitoring signals are weighted and transformed into an adaptation signal that guides future decisions and actions. The model-based single-trial analysis approach goes far beyond conventional peak-and-trough analyses of event-related potentials and enables testing mechanistic theories of performance monitoring, cognitive control and decision making.

Research suggests a potential of gamma oscillation entrainment for enhancing memory in Alzheimer’s disease and healthy subjects. Gamma entrainment can be accomplished with oscillatory electrical, but also sensory stimulation. However, comparative studies between sensory stimulation and transcranial alternating current stimulation (tACS) effects on memory processes are lacking. This study examined the effects of rhythmic gamma auditory stimulation (rAS) and temporal gamma-tACS on verbal long-term memory (LTM) and working memory (WM) in 74 healthy individuals. Participants were assigned to two groups according to the stimulation techniques (rAS or tACS). Memory was assessed in three experimental blocks, in which each participant was administered with control, 40 Hz, and 60 Hz stimulation in counterbalanced order. All interventions were well-tolerated, and participants reported mostly comparable side effects between real stimulation (40 Hz and 60 Hz) and the control condition. LTM immediate and delayed recall remained unaffected by stimulations, while immediate recall intrusions decreased during 60 Hz stimulation. Notably, 40 Hz interventions improved WM compared to control stimulations. These results highlight the potential of 60 Hz and 40 Hz temporal cortex stimulation for reducing immediate LTM recall intrusions and improving WM performance, respectively, probably due to the entrainment of specific gamma oscillations in the auditory cortex. The results also shed light on the comparative effects of these neuromodulation tools on memory functions, and their potential applications for cognitive enhancement and in clinical trials.

Touch is important for many aspects of our daily activities. One of the most important tactile characteristics is its perceived intensity. However, quantifying the intensity of perceived tactile stimulation beyond subjective self-reports remains challenging. Here, we show that pupil responses can objectively index the intensity of tactile stimulation in the absence of overt participant responses. In Experiment 1 (n=32), we stimulated three reportedly differentially sensitive body locations (finger, forearm, calf) with a single tap of a tactor while tracking pupil responses. Tactile stimulation resulted in greater pupil dilation than a baseline without stimulation. Furthermore, pupils dilated more for the more sensitive location (finger) than for the less sensitive locations (forearm, calf). In Experiment 2 (n=20) we extended these findings by manipulating the intensity of the stimulation with three different intensities, here a short vibration, always at the little finger. Again, pupils dilated more when being stimulated at higher intensities as compared to lower intensities. In summary, pupils dilated more for more sensitive parts of the body at constant stimulation intensity and for more intense stimulation at constant location. Taken together, the results show that the intensity of perceived tactile stimulation can be objectively measured with pupil responses – and that such responses are a versatile marker for touch research. Our findings may pave the way for previously impossible objective tests of tactile sensitivity, for example in minimally conscious state patients.

Interoception is mainly related to morpho-functional characteristics of the insula, which shows hypnotizability-related differences in grey matter volume. Interoceptive accuracy (IA, measured by the heartbeat counting task and by HEP, heartbeat evoked cortical potential) is lower in high (highs) than in low hypnotizables (lows). The aim of the present study was to investigate IA in highs, lows, and medium hypnotizables (mediums), who represent most of the population (according to the Stanford Hypnotic Susceptibility Scale (SHSS), Form A), during a session including a simple relaxation (Part 1) and three trials of consecutive open eyes, closed eyes, heartbeat counting and post-counting conditions (Part 2). ECG and EEG were recorded in 14 highs, 14 mediums and 18 lows. HEP were extracted throughout the entire session and IA index was obtained for the heartbeat counting task. In Part 1, significant hypnotizability-related differences were observed in the right central region in both early and late HEP components, with lows showing positive and highs/mediums negative HEP amplitudes. In Part 2, the same group differences were limited to the early HEP component. Moreover, in the left frontal regions, only mediums modified their HEP during the counting task with respect to the open/closed eyes conditions, whereas highs displayed HEP differences between counting and post-counting rest. In conclusion, highs and mediums seem to be more similar than mediums and lows regarding HEP, despite the absence of differences in the counting task. Nonetheless, a negative correlation between SHSS scores and HEP amplitudes was observed in the regions showing group differences.

The Approach-Avoidance Task (AAT) is designed to 1) measure the implicit motivated action biases that are instantiated by emotional stimuli, and 2) assess the changes in such biases that drive psychiatric disorder. To establish AAT sensitivity to emotional action bias at a neural level, some work has measured event-related potential (ERP) correlates — however, a lack of research with unpleasant, pleasant, and neutral stimuli together and also a common focus on psychiatric disorder-matched (rather than generally evocative) content limits foundational conclusions that can be drawn. In current research, then, 38 subjects completed an AAT where normative (rather than idiosyncratic) unpleasant, pleasant, and neutral images were shown with a color border indicating if a joystick should be rapidly pushed or pulled to decrease or increase image size. Using generally arousing stimuli, response times (RTs) were found to be faster on unpleasant push compared to unpleasant pull trials, t(37)=2.4, p=.02, and 32-sensor electroencephalography (EEG) also revealed that amplitude of a stimulus-response conflict-related ERP – the N200 – was reduced on unpleasant compared to neutral push trials and un-pleasant push compared to unpleasant pull trials, t(32)=5.5, p<.001. In addition, preliminary exploration of individual differences suggested that relevant variables of dimensional trait anxiety, depression, and anxiety disorder treatment seeking status did not impact RT- or N200-indicated emotional biases. Together, then, findings are consistent with a neurobehavioral avoidance bias for unpleasant stimuli while also suggesting a need to further test whether selecting images for idiosyncratic relevance is critical to revealing individual variations in emotional bias.

Brain functional modular organization changes with age. Considering the brain as a dynamic system, recent studies have suggested that time-varying connectivity provides more information on brain functions. However, the spontaneous reconfiguration of modular brain structures over time during ageing remains poorly understood. In this study, we investigated the age-related dynamic modular reconfiguration using resting-state functional MRI data (615 participants, aged 18-88 years) from Cam-CAN. We employed a graph-based modularity analysis to investigate modular variability and the transition of nodes from one module to another in modular brain networks across the adult lifespan. Results showed that modular structure exhibits both linear and nonlinear age-related trends. The modular variability is higher in early and late adulthood, with higher modular variability in the association networks and lower modular variability in the primary networks. In addition, the whole brain transition matrix showed that the times of transition from other networks to the dorsal attention network were the largest. Furthermore, the modular structure was closely related to the number of cognitive components and memory-related cognitive performance, suggesting a potential contribution to flexibility cognitive function. Our findings highlighted the notable dynamic characteristics in large-scale brain networks across the adult lifespan, which enhanced our understanding of the neural substrate in various cognition during ageing. These findings also provided further evidence that dedifferentiation and compensation are the outcomes of functional brain interactions.

Individuals diagnosed with schizophrenia (SZ) demonstrate difficulty distinguishing between internally- and externally-generated stimuli. These aberrations in “source monitoring” have been theorized as contributing to symptoms of the disorder, including hallucinations and delusions. Altered connectivity within the default mode network (DMN) of the brain has been proposed as a mechanism through which discrimination between self-generated and externally-generated events is disrupted. Source monitoring abnormalities in SZ have additionally been linked to impairments in selective attention and inhibitory processing, which are reliably observed via the N100 component of the event-related brain potential elicited during an auditory paired-stimulus paradigm. Given overlapping constructs associated with DMN connectivity and N100 in SZ, the present investigation evaluated relationships between these measures of disorder-related dysfunction and sought to clarify the nature of task-based DMN function in SZ. DMN connectivity and N100 measures were assessed using EEG recorded from SZ after their first episode of illness (N = 52) and demographically-matched healthy comparison participants (N= 25). SZ demonstrated less evoked theta-band connectivity within DMN following presentation of pairs of identical auditory stimuli than HC. Greater DMN connectivity among SZ was associated with better performance on measures of sustained attention (p = 0.03) and working memory (p = 0.09), as well as lower severity of negative symptoms, though it was not predictive of N100 measures. Together, present findings provide EEG evidence of lower task-based connectivity among first-episode SZ, reflecting disruptions of DMN functions that support cognitive processes. Attentional processes captured by N100 appear to be supported by different neural mechanisms.

Recent evidence indicate that event-related potentials (ERPs) as measured on the electroencephalogram (EEG) are more closely related to transdiagnostic, dimensional measures of psychopathology (TDP) than to diagnostic categories. Given this, a comprehensive examination of correlations between well-studied ERPs and measures of TDP is called for. In this study, we recruited 50 patients with emotional disorders undergoing 14 weeks of transdiagnostic group psychotherapy as well as 37 healthy comparison subjects (HC) matched in age and sex. HCs were assessed once and patients three times throughout treatment (N = 172 datasets) with a battery of well-studied ERPs and psychopathology measures consistent with the TDP framework The Hierarchical Taxonomy of Psychopathology (HiTOP). ERPs were quantified using robust single-trial analysis (RSTA) methods and TDP correlations with linear regression models as implemented in the EEGLAB toolbox LIMO EEG. We found correlations at several levels of the HiTOP hierarchy. Among these, a reduced P3b as well as a reduced error-related negativity correlated strongly with worse symptomatology across the Internalizing spectrum. Conversely, increases in the correct-related negativity correlated with symptoms loading unto the Distress subfactor in the HiTOP. Increases in mismatch negativity were primarily related to maladaptive personality traits at the lowest levels of the HiTOP hierarchy. Our study highlights the advantages of RSTA methods and of using validated TDP constructs within a consistent framework such as the HiTOP. Future studies could utilize machine learning methods to predict TDP from a set of ERP features at the subject level.

The auditory system has an amazing ability to rapidly encode auditory regularities. Evidence comes from the popular oddball paradigm, in which frequent (standard) sounds are occasionally exchanged for rare deviant sounds, which then elicit signs of prediction error based on their unexpectedness (e.g., MMN, P3a). Here, we examine the widely neglected characteristics of deviants being bearers of predictive information themselves: Naïve participants listened to sound sequence constructed according to a new, modified version of the oddball paradigm including two types of deviants that followed diametrically opposed rules: one deviant sound occurred mostly in pairs (repetition rule), the other deviant sound occurred mostly in isolation (non-repetition rule). Due to this manipulation, the sound following a first deviant (either the same deviant or a standard) was either predictable or unpredictable based on its conditional probability associated with the preceding deviant sound. Our behavioural results from an active deviant-detection task replicate previous findings that deviant repetition rules (based on conditional probability) can be extracted when behaviourally relevant. Our electrophysiological findings obtained in a passive-listening setting indicate that conditional probability also translates into differential processing at the P3a level. However, MMN was confined to global deviants and was not sensitive to conditional probability. This suggests that higher-level processing concerned with stimulus selection and/or evaluation (reflected in P3a) but not lower-level sensory processing (reflected in MMN) considers rarely encountered rules.