Event-related potential components as measures of aversive conditioning in humans

EEG Microstates in Social and Affective Neuroscience

Social interactions require both the rapid processing of multifaceted socio-affective signals (e.g., eye gaze, facial expressions, gestures) and their integration with evaluations, social knowledge, and expectations. Researchers interested in understanding complex social cognition and behavior face a "black box" problem: What are the underlying mental processes rapidly occurring between perception and action and why are there such vast individual differences? In this review, we promote electroencephalography (EEG) microstates as a powerful tool for both examining socio-affective states (e.g., processing whether someone is in need in a given situation) and identifying the sources of heterogeneity in socio-affective traits (e.g., general willingness to help others). EEG microstates are identified by analyzing scalp field maps (i.e., the distribution of the electrical field on the scalp) over time. This data-driven, reference-independent approach allows for identifying, timing, sequencing, and quantifying the activation of large-scale brain networks relevant to our socio-affective mind. In light of these benefits, EEG microstates should become an indispensable part of the methodological toolkit of laboratories working in the field of social and affective neuroscience.

Reduced generalization of reward among individuals with subthreshold depression: Behavioral and EEG evidence

Altered stimulus generalization has been well-documented in anxiety disorders; however, there is a paucity of research investigating this phenomenon in the context of depression. Depression is characterized by impaired reward processing and heightened attention to negative stimuli. It is hypothesized that individuals with depression exhibit reduced generalization of reward stimuli and enhanced generalization of loss stimuli. Nevertheless, no study has examined this process and its underlying neural mechanisms. In the present study, we recruited 25 participants with subthreshold depression (SD group) and 24 age-matched healthy controls (HC group). Participants completed an acquisition task, in which they learned to associate three distinct pure tones (conditioned stimuli, CSs) with a reward, a loss, or no outcome. Subsequently, a generalization session was conducted, during which similar tones (generalization stimuli, GSs) were presented, and participants were required to classify them as a reward tone, a loss tone, or neither. The results revealed that the SD group exhibited reduced generalization errors in the early phase of generalization, suggesting a diminished ability to generalize reward-related stimuli. The event-related potential (ERP) results indicated that the SD group exhibited decreased generalization of positive valence to reward-related GSs and heightened generalization of negative valence to loss-related GSs, as reflected by the N1 and P2 components. However, the late positive potential (LPP) was not modulated by depression in reward generalization or loss generalization. These findings suggested that individuals with subthreshold depression may have a blunted or reduced ability to generalize reward stimuli, shedding light on potential treatment strategies targeting this particular process.

Pain reflects the informational value of nociceptive inputs

ABSTRACT

Pain perception and its modulation are fundamental to human learning and adaptive behavior. This study investigated the hypothesis that pain perception is tied to pain's learning function. Thirty-one participants performed a threat conditioning task where certain cues were associated with a possibility of receiving a painful electric shock. The cues that signaled potential pain or safety were regularly changed, requiring participants to continually establish new associations. Using computational models, we quantified participants' pain expectations and prediction errors throughout the task and assessed their relationship with pain perception and electrophysiological responses. Our findings suggest that subjective pain perception increases with prediction error, that is, when pain was unexpected. Prediction errors were also related to physiological nociceptive responses, including the amplitude of nociceptive flexion reflex and electroencephalography markers of cortical nociceptive processing (N1-P2-evoked potential and gamma-band power). In addition, higher pain expectations were related to increased late event-related potential responses and alpha/beta decreases in amplitude during cue presentation. These results further strengthen the idea of a crucial link between pain and learning and suggest that understanding the influence of learning mechanisms in pain modulation could help us understand when and why pain perception is modulated in health and disease.

Phase-locked breathing does not affect episodic visual recognition memory but does shape its corresponding ERPs

Recent studies have indicated that breathing shapes the underlying oscillatory brain activity critical for episodic memory, potentially impacting memory performance. However, the literature has presented conflicting results, with some studies suggesting that nasal inhalation enhances visual memory performance, while others have failed to observe any significant effects. Furthermore, the specific influence of breathing route (nasal vs. mouth) and the precise phase of the respiratory cycle during which stimuli are presented have remained elusive. To address this, we employed a visual recognition memory (VRM) and electroencephalography paradigm in which stimuli presentation was phase-locked to either inhalation or exhalation onset, using a within-subject design where participants performed the memory task while engaging in separate sessions of nose and mouth breathing. We show that neither breathing route nor breathing phase has a significant impact on VRM performance as measured by d-prime, with the data supporting the null hypothesis. However, we did find an effect of breathing phase on response bias, with participants adopting a more conservative decision criterion during exhalation. Moreover, we found that breathing phase during memory encoding shaped the late parietal effect (LPE) amplitude, while the Frontal Negative Component (FN400) and LPE during recognition were less impacted. While our study demonstrates that breathing does not shape VRM performance, it shows that it influences brain activity, reinforcing the importance of further research to elucidate the extent of respiratory influence on perception, cognition, and behavior.

Good moments to stimulate the brain - A randomized controlled double-blinded study on anodal transcranial direct current stimulation of the ventromedial prefrontal cortex on two different time points in a two-day fear conditioning paradigm

It is assumed that extinction learning is a suitable model for understanding the mechanisms underlying exposure therapy. Furthermore, there is evidence that non-invasive brain stimulation (NIBS) can elevate extinction learning by enhancing frontal brain activity and therefore NIBS can augment symptom reduction during exposure therapy in phobias. But, the underlying processes are still not well established. Open questions arise from NIBS time points and electrode placement, among others. Therefore, we investigated in a 2-day fear conditioning experiment, whether anodal transcranial direct current stimulation (tDCS) of the ventromedial prefrontal cortex (vmPFC) modulates either fear memory consolidation or dampened fear reaction during fear extinction. Sixty-six healthy participants were randomly assigned either to a group that received tDCS after fear acquisition (and before fear memory consolidation), to a group that received tDCS directly before fear extinction, or to a control group that never received active stimulation (sham). Differential skin conductance response (SCR) to CS+ vs. CS- was significantly decreased in both tDCS-groups compared to sham group. Our region of interest, the vmPFC, was stimulated best focally with a lateral anode position and a cathode on the contralateral side. But this comes along with a slightly lateral stimulation of vmPFC depending on whether anode is placed left or right. To avoid unintended effects of stimulated sides the two electrode montages (anode left or right) were mirror-inverted which led to differential effects in SCR and electrocortical (mainly late positive potential [LPP]) data in our exploratory analyses. Results indicated that tDCS-timing is relevant for fear reactions via disturbed fear memory consolidation as well as fear expression, and this depends on whether vmPFC is stimulated with either left- or right-sided anode electrode montage. Electrocortical data can shed more light on the underlying neural correlates and exaggerated LPP seems to be associated with disturbed fear memory consolidation and dampened SCR to CS+ vs. CS-, but solely in the right anode electrode montage. Further open questions addressing where and when to stimulate the prefrontal brain in the course of augmenting fear extinction are raised.

Enhanced late positive potential to conditioned threat cue during delayed extinction in anxious youth

BACKGROUND

Deficits in threat learning relate to anxiety symptoms. Since several anxiety disorders arise in adolescence, impaired adolescent threat learning could contribute to adolescent changes in risk for anxiety. This study compared threat learning among anxious and non-anxious youth using self-reports, peripheral psychophysiology measures, and event-related potentials. Because exposure therapy, the first-line treatment for anxiety disorders, is largely based on principles of extinction learning, the study also examined the link between extinction learning and treatment outcomes among anxious youth.

METHODS

Clinically anxious (n = 28) and non-anxious (n = 33) youth completed differential threat acquisition and immediate extinction. They returned to the lab a week later to complete a threat generalization test and a delayed extinction task. Following these two experimental visits, anxious youth received exposure therapy for 12 weeks.

RESULTS

Anxious as compared to non-anxious youth demonstrated elevated cognitive and physiological responses across acquisition and immediate extinction learning, as well as greater threat generalization. In addition, anxious youth showed enhanced late positive potential response to the conditioned threat cue compared to the safety cue during delayed extinction. Finally, aberrant neural response during delayed extinction was associated with poorer treatment outcomes.

CONCLUSIONS

The study emphasizes differences between anxious and non-anxious youth in threat learning processes and provides preliminary support for a link between neural processing during delayed extinction and exposure-based treatment outcome in pediatric anxiety.

Amplitude modulation of the contingent negative variation in psychopathy: A systematic review and meta-analysis

The CNV is analyzed in tasks related to EEG studies, often with participants presenting psychopathic personality traits. A systematic search of the literature was conducted, to solve some inconsistencies regarding CNV amplitude modulation by psychopathy. Nine studies (N = 317) were retrieved for analysis. Three meta-analyses were run - CNV, iCNV, tCNV. A qualitative analysis - reporting CNV amplitudes modulated by psychopathy dimensional features - was also featured. Overall effects for CNV and iCNV were not significant. Larger tCNV amplitudes were found in participants reporting higher psychopathy traits, g = -0.58, 95% CI [- 0.94, - 0.22]. These findings were surprising when confronted with previous assumptions in the literature, especially considering that no significant heterogeneity between studies was found. Neither of the studies' characteristics was a significant moderator. Findings require the need to discuss key differences between adaptive/(mal)adjustment patterns in participants presenting psychopathic traits. Future studies dissociating iCNV and tCNV modulation by psychopathy, especially in community samples and through a dimensional lens, could help to better understand the construct of psychopathy.

Coherence and divergence in autonomic-subjective affective space

A central tenet of many theories of emotion is that emotional states are accompanied by distinct patterns of autonomic activity. However, experimental studies of coherence between subjective and autonomic responses during emotional states provide little evidence of coherence. Crucially, previous studies investigating coherence have either adopted univariate approaches or made limited use of multivariate analytic approaches by investigating subjective and autonomic responses separately. The current study addressed this question using a multivariate dimensional approach to build a common autonomic-subjective affective space incorporating subjective responses and three different autonomic signals (heart rate, skin conductance response, and pupil diameter), measured during an emotion-inducing task, in 51 participants. Results showed that autonomic and subjective responses could be adequately described in a two-dimensional affective space. The first dimension included contributions from subjective and autonomic responses, indicating coherence, while contributions to the second dimension were almost exclusively of autonomic covariance. Thus, while there was a degree of coherence between autonomic and subjective emotional responses, there was substantial structure in autonomic responses that did not covary with subjective emotional experience. This study, therefore, contributes new insights into the relationship between subjective and autonomic emotional responses, and provides a framework for future multimodal emotion research, enabling both hypothesis- and data-driven testing.

Fear memory in humans is consolidated over time independently of sleep

Fear memories can be altered after acquisition by processes, such as fear memory consolidation or fear extinction, even without further exposure to the fear-eliciting stimuli, but factors contributing to these processes are not well understood. Sleep is known to consolidate, strengthen, and change newly acquired declarative and procedural memories. However, evidence on the role of time and sleep in the consolidation of fear memories is inconclusive. We used highly sensitive electrophysiological measures to examine the development of fear-conditioned responses over time and sleep in humans. We assessed event-related brain potentials (ERP) in 18 healthy, young individuals during fear conditioning before and after a 2-hour afternoon nap or a corresponding wake interval in a counterbalanced within-subject design. The procedure involved pairing a neutral tone (CS+) with a highly unpleasant sound. As a control, another neutral tone (CS-) was paired with a neutral sound. Fear responses were examined before the interval during a habituation phase and an acquisition phase as well as after the interval during an extinction phase and a reacquisition phase. Differential fear conditioning during acquisition was evidenced by a more negative slow ERP component (stimulus-preceding negativity) developing before the unconditioned stimulus (loud noise). This differential fear response was even stronger after the interval during reacquisition compared with initial acquisition, but this effect was similarly pronounced after sleep and wakefulness. These findings suggest that fear memories are consolidated over time, with this effect being independent of intervening sleep.

Electrophysiological responses to emotional and cocaine cues reveal individual neuroaffective profiles in cocaine users

Smokers with stronger neuroaffective responses to drug-related cues compared to nondrug-related pleasant images (C > P) are more vulnerable to compulsive smoking than individuals with the opposite brain reactivity profile (P > C). However, it is unknown if these neurobehavioral profiles exist in individuals abusing other drugs. We tested whether individuals with cocaine use disorder (CUD) show similar neuroaffective profiles to smokers. We also monitored eye movements to assess attentional bias toward cues and we further performed exploratory analyses on demographics, personality, and drug use between profiles. Participants with CUD (n = 43) viewed pleasant, unpleasant, cocaine, and neutral images while we recorded electroencephalogram. For each picture category, we computed the amplitude of the late positive potential (LPP), an event-related potential component that reflects motivational relevance. k-means clustering classified participants based on their LPP responses. In line with what has been observed in smokers, clustering participants using LPP responses revealed the presence of two groups: one with larger LPPs to pleasant images compared to cocaine images (P > C) and one group with larger LPPs to cocaine images compared to pleasant images (C > P). Individuals with the C > P reactivity profile also had higher attentional bias toward drug cues. The two groups did not differ on demographic and drug use characteristics, however individuals with the C > P profile reported lower distress tolerance, higher anhedonia, and higher posttraumatic stress symptoms compared to the P > C group. This is the first study to report the presence of these neuroaffective profiles in individuals with CUD, indicating that this pattern may cut across addiction populations. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

No trait anxiety influences on early and late differential neuronal responses to aversively conditioned faces across three different tasks

The human brain's ability to quickly detect dangerous stimuli is crucial in selecting appropriate responses to possible threats. Trait anxiety has been suggested to moderate these processes on certain processing stages. To dissociate such different information-processing stages, research using classical conditioning has begun to examine event-related potentials (ERPs) in response to fear-conditioned (CS +) faces. However, the impact of trait anxiety on ERPs to fear-conditioned faces depending on specific task conditions is unknown. In this preregistered study, we measured ERPs to faces paired with aversive loud screams (CS +) or neutral sounds (CS −) in a large sample (N = 80) under three different task conditions. Participants had to discriminate face-irrelevant perceptual information, the gender of the faces, or the CS category. Results showed larger amplitudes in response to aversively conditioned faces for all examined ERPs, whereas interactions with the attended feature occurred for the P1 and the early posterior negativity (EPN). For the P1, larger CS + effects were observed during the perceptual distraction task, while the EPN was increased for CS + faces when deciding about the CS association. Remarkably, we found no significant correlations between ERPs and trait anxiety. Thus, fear-conditioning potentiates all ERP amplitudes, some processing stages being further modulated by the task. However, the finding that these ERP differences were not affected by individual differences in trait anxiety does not support theoretical accounts assuming increased threat processing or reduced threat discrimination depending on trait anxiety.

Effect of familiarity and recollection during constrained retrieval on incidental encoding for new “foil” information

Behavioral studies have demonstrated differences in the effect of constrained retrieval of semantic vs. non-semantic information on the encoding of foils. However, the impact of recognition on foils between semantic and non-semantic trials remains unclear. This study thus examines the roles of recognition—familiarity and recollection—in constrained retrieval for foils. We applied the event-related brain potentials (ERPs) data of new/old effects to elucidate the neural mechanisms underlying the “foil effect.” Participants encoded semantic and non-semantic tasks (Phase 1), were tested in a blocked memory task with new words presented as foils (Phase 2), and performed a surprise recognition task involving foils and completely new words (Phase 3). Behavioral results showed better recognition performance regarding reaction times and accuracy by hit and correct reject for semantic vs. non-semantic trials in Phase 2. Conversely, inferior recognition performance in reaction times and accuracy by hit and correct reject was noted for semantic vs. non-semantic foils in Phase 3. ERP results showed more positive Frontal N400 (FN400) for hit in non-semantic trials, more positive late positive component (LPC) for correct rejects in semantic trials in Phase 2, and more positive LPC for hits in both semantic and non-semantic trials only in Phase 3. Through dual-processing theory, we prove that different task types in constrained retrieval depend on different retrieval processes. Particularly, familiarity may be applied more often in non-semantic trials, and recollection in semantic trials. The difference in processes between semantic and non-semantic trials during constrained retrieval affects incidental encoding of foils.

Alpha-2 Adrenoreceptor Antagonist Yohimbine Potentiates Consolidation of Conditioned Fear

BACKGROUND

Hyperconsolidation of aversive associations and poor extinction learning have been hypothesized to be crucial in the acquisition of pathological fear. Previous animal and human research points to the potential role of the catecholaminergic system, particularly noradrenaline and dopamine, in acquiring emotional memories. Here, we investigated in a between-participants design with 3 groups whether the noradrenergic alpha-2 adrenoreceptor antagonist yohimbine and the dopaminergic D2-receptor antagonist sulpiride modulate long-term fear conditioning and extinction in humans.

METHODS

Fifty-five healthy male students were recruited. The final sample consisted of n = 51 participants who were explicitly aware of the contingencies between conditioned stimuli (CS) and unconditioned stimuli after fear acquisition. The participants were then randomly assigned to 1 of the 3 groups and received either yohimbine (10 mg, n = 17), sulpiride (200 mg, n = 16), or placebo (n = 18) between fear acquisition and extinction. Recall of conditioned (non-extinguished CS+ vs CS-) and extinguished fear (extinguished CS+ vs CS-) was assessed 1 day later, and a 64-channel electroencephalogram was recorded.

RESULTS

The yohimbine group showed increased salivary alpha-amylase activity, confirming a successful manipulation of central noradrenergic release. Elevated fear-conditioned bradycardia and larger differential amplitudes of the N170 and late positive potential components in the event-related brain potential indicated that yohimbine treatment (compared with a placebo and sulpiride) enhanced fear recall during day 2.

CONCLUSIONS

These results suggest that yohimbine potentiates cardiac and central electrophysiological signatures of fear memory consolidation. They thereby elucidate the key role of noradrenaline in strengthening the consolidation of conditioned fear associations, which may be a key mechanism in the etiology of fear-related disorders.

Early Safety Discrimination Under Uncertainty in Trait Anxiety: An Event-Related Potential Study

Detection of safety-threat signals during uncertainty is an important mechanism of developmental anxiety disorder (AD). Although extensive research has focused on the detection of uncertain threat signals in anxious individuals, relatively little attention has been given to the identification of safety signals during uncertainty, which is an important way to relieve anxiety in individuals with AD. To investigate this phenomenon, 16 subjects with high trait anxiety (HTA) and 16 with low trait anxiety (LTA) completed a modified cue-target task in certain and uncertain stimulus blocks. In the uncertain block, the cue was followed by a threat picture or safety picture in 20% of trials, respectively; in the certain block, the cue could be followed by a threat picture or a safety picture on 100% of trials. Behavioral responses and event-related potentials (ERPs) were recorded. The ERP results demonstrated that LTA participants exhibited larger P2 amplitudes in the detection of safety cues than of threat cues during the uncertain block, whereas HTA participants showed significant P2 amplitudes between the safety and threat cues during the certain block, impairing the detection of safety stimuli during uncertainty. However, all participants exhibited greater N2 amplitudes following threat cues in certainty or uncertainty conditions. These findings pertaining to the P2 amplitude suggested distinctive attentional biases between HTA and LTA individuals, whereas the N2 amplitude showed association learning in uncertain conditions, compensating for safety-threat detection in HTA individuals.

Alpha-band EEG suppression as a neural marker of sustained attentional engagement to conditioned threat stimuli

Attention helps us to be aware of the external world, and this may be especially important when a threat stimulus predicts an aversive outcome. Electroencephalogram (EEG) alpha-band suppression has long been considered as a neural signature of attentional engagement. The present study was designed to test whether attentional engagement, as indexed by alpha-band suppression, is increased in a sustained manner following a conditioned stimulus (CS) that is paired with an aversive (CS+) vs neutral (CS-) outcome. We tested 70 healthy young adults in aversive conditioning and extinction paradigms. One of three colored circles served as the CS+, which was paired in 50% of the trials with a noise burst (unconditioned stimulus, US). The other colored circles (CS-) were never paired with the US. For conditioning, we found greater alpha-band suppression for the CS+ compared to the CS-; this suppression was sustained through the time of the predicted US. This effect was significantly reduced for extinction. These results indicate that conditioned threat stimuli trigger an increase in attentional engagement as subjects monitor the environment for the predicted aversive stimulus. Moreover, this alpha-band suppression effect may be valuable for future studies examining normal or pathological increases in attentional monitoring following threat stimuli.

Return of fear following extinction in youth: An event-related potential study

The ability to learn to differentiate safety from danger matures gradually, particularly when such learning occurs over an extended time period. And yet, most research on fear learning examines the early phases of such learning and mainly in adults. The current study examined fear conditioning and extinction, as well as one form of extended learning, return of fear (ROF). Thirty-three typically developing children (age range: 7-14 years) completed fear conditioning and extinction; self-reports and psychophysiological indices were measured at this point. Two weeks later, children completed a ROF test (n = 23), and event-related potentials (ERPs) were recorded. Results indicated successful fear acquisition and extinction. Moreover, participants reported greater fear of the conditioned stimulus (CS+) than the safety stimulus (CS-) in the ROF test 2 weeks later. In electrophysiology data, ROF manifested as a larger late positive potential (LPP) response to the CS+ than the CS-. Finally, these differences in LPP responses were positively correlated with poorer extinction, as indicated by the GSR responses 2 weeks earlier. This is the first ERP study to demonstrate ROF in children. The LPP measure may index an interplay between inhibitory and excitatory brain-related processes underlying the long-term effects of fear learning.

Reliability of web-based affective auditory stimulus presentation

Web-based experimental testing has seen exponential growth in psychology and cognitive neuroscience. However, paradigms involving affective auditory stimuli have yet to adapt to the online approach due to concerns about the lack of experimental control and other technical challenges. In this study, we assessed whether sounds commonly used to evoke affective responses in-lab can be used online. Using recent developments to increase sound presentation quality, we selected 15 commonly used sound stimuli and assessed their impact on valence and arousal states in a web-based experiment. Our results reveal good inter-rater and test-retest reliabilities, with results comparable to in-lab studies. Additionally, we compared a variety of previously used unpleasant stimuli, allowing us to identify the most aversive among these sounds. Our findings demonstrate that affective sounds can be reliably delivered through web-based platforms, which help facilitate the development of new auditory paradigms for affective online experiments.

Transfer of incentive salience from a first-order alcohol cue to a novel second-order alcohol cue among individuals at risk for alcohol use disorder: electrophysiological evidence

BACKGROUND AND AIMS

In susceptible individuals, cues associated with drug use are theorized to take on incentive-motivational properties, including the ability to reinforce higher-order, drug-related associative learning. This study aimed to test this prediction among people varying in risk for alcohol use disorder.

DESIGN, SETTING AND PARTICIPANTS

Repeated-measures experiment with a measured individual difference variable at a University psychology laboratory in Missouri, USA. One hundred and six young adults (96 contributed complete data) were pre-selected to represent the upper and lower quartiles of self-reported sensitivity to alcohol's acute effects.

MEASUREMENTS

Participants completed a second-order Pavlovian conditioning paradigm in which an initially neutral visual cue (second-order conditional stimulus; CS2 ) predicted onset of an olfactory cue (first-order conditional stimulus; CS1 ). Olfactory cues were isolated from alcoholic beverages, sweets and non-comestible substances, each presumed to have a natural history of first-order conditioning. Event-related potential responses to the CS2 across its conditioning and extinction, and to the CS1 , provided neurophysiological indices of incentive salience (IS).

FINDINGS

The IS of the alcohol CS1 was higher among participants low in alcohol sensitivity (LS), relative to their higher-sensitivity (HS) peers. The IS of the CS2 paired with the alcohol CS1 increased across the CS2 conditioning phase among LS but not HS participants. Also, LS (but not HS) individuals also experienced increases in alcohol craving following alcohol CS1 exposure, and this change was correlated with increases in the IS of the CS2 paired with the alcohol CS1 .

CONCLUSIONS

Alcoholic beverage odor, a proximal cue for alcohol consumption, appears to reinforce conditioning of neurophysiological responses to a novel cue among low alcohol sensitivity (LS) individuals but not high alcohol sensitivity individuals, providing the first evidence that the LS phenotype may be associated with differences in the conditioned reinforcing properties of alcohol-related cues. These findings support the idea that the LS phenotype may increase alcohol use disorder risk via susceptibility to incentive salience sensitization.

Learning dynamics of electrophysiological brain signals during human fear conditioning

Electrophysiological studies in rodents allow recording neural activity during threats with high temporal and spatial precision. Although fMRI has helped translate insights about the anatomy of underlying brain circuits to humans, the temporal dynamics of neural fear processes remain opaque and require EEG. To date, studies on electrophysiological brain signals in humans have helped to elucidate underlying perceptual and attentional processes, but have widely ignored how fear memory traces evolve over time. The low signal-to-noise ratio of EEG demands aggregations across high numbers of trials, which will wash out transient neurobiological processes that are induced by learning and prone to habituation. Here, our goal was to unravel the plasticity and temporal emergence of EEG responses during fear conditioning. To this end, we developed a new sequential-set fear conditioning paradigm that comprises three successive acquisition and extinction phases, each with a novel CS+/CS- set. Each set consists of two different neutral faces on different background colors which serve as CS+ and CS-, respectively. Thereby, this design provides sufficient trials for EEG analyses while tripling the relative amount of trials that tap into more transient neurobiological processes. Consistent with prior studies on ERP components, data-driven topographic EEG analyses revealed that ERP amplitudes were potentiated during time periods from 33-60 ms, 108-200 ms, and 468-820 ms indicating that fear conditioning prioritizes early sensory processing in the brain, but also facilitates neural responding during later attentional and evaluative stages. Importantly, averaging across the three CS+/CS- sets allowed us to probe the temporal evolution of neural processes: Responses during each of the three time windows gradually increased from early to late fear conditioning, while long-latency (460-730 ms) electrocortical responses diminished throughout fear extinction. Our novel paradigm demonstrates how short-, mid-, and long-latency EEG responses change during fear conditioning and extinction, findings that enlighten the learning curve of neurophysiological responses to threat in humans.

Noradrenergic Responsiveness Supports Selective Attention across the Adult Lifespan

Selectively attending to relevant information while blocking out distractors is crucial for goal-directed behavior, yet with advancing age, deficits emerge in attentional selectivity. Decrements in attention have been associated with altered noradrenergic activity in animals. However, research linking noradrenergic functioning to attention in aging humans is scarce, likely reflecting long-standing methodological challenges in noninvasive assessments. We studied whether age-related differences in the noradrenergic system predict differences in attention. We measured pupil dilation, a noninvasive marker of arousal-related norepinephrine (NE) release, while concurrently recording the EEG of male younger (N = 39; 25.2 ± 3.2 years) and older adults (N = 38; 70.6 ± 2.7 years). Arousal was modulated on a trial-by-trial basis using fear-conditioned (CS⁺) stimuli. During conditioning, pupil and EEG markers related to heightened arousal were identified. Afterward, in a dichotic listening task, participants were cued to direct attention to either the left or right ear while highly similar syllable pairs were presented simultaneously to both ears. During the dichotic listening task, presentation of fear-conditioned stimuli reinstated the acquired arousal response, as reflected in pupil and EEG α-β band responses. Critically, pupil dilation to CS⁺ was correlated with stronger EEG α-β desynchronization, suggesting a common dependence on NE release. On a behavioral level, stronger arousal reactions were associated with better attention. In particular, structural equation modeling revealed that the responsiveness of the NE system is associated with attention on a latent construct level, measured by several indicator tasks. Overall, our results suggest that the responsiveness of the NE system supports attention across the lifespan.SIGNIFICANCE STATEMENT In old age, the ability to selectively process relevant aspects of the environment fades. Animal research suggests that the neuromodulator norepinephrine helps to maintain selective attention. We tested younger and older adults across a variety of attention tasks. In addition, we used arousing stimuli to experimentally activate participants' noradrenergic system while recording pupillometry and EEG to infer its functional capacity. Older adults showed compromised attention and reduced noradrenergic responsiveness as indicated by interrelated pupil and EEG markers. Crucially, in both age groups, a more responsive noradrenergic system was strongly associated with attention. Our findings link animal and human studies on the neural underpinning of attention in aging and underscore the importance of the noradrenergic system in late-life cognition.

Relationship of sensation seeking with the neural correlates of appetitive conditioning

Previous research has linked sensation seeking with a heightened risk for drug abuse and other risk-taking behavior. As appetitive conditioning presents a model for the etiology and maintenance of addictive behavior, investigating sensation seeking in a classical conditioning paradigm might elucidate possible pathways toward addiction within this model. Furthermore, the theoretical concept underlying sensation seeking proposes a negative relationship between reward processing and sensation seeking in only moderately arousing situations, which has been neglected by previous research.

This study aimed to investigate this inverse relationship in moderately stimulating situations entailing reward processing using functional magnetic resonance imaging. Subjects (N = 38) participated in a classical conditioning paradigm in which a neutral stimulus (CS+) was repeatedly paired with a monetary reward, while another neutral stimulus (CS−) was not.

Imaging results revealed a negative relationship between sensation seeking and neural responses in the insula, amygdala and nucleus accumbens during the early phase and in the dorsal anterior cingulate cortex during the late phase of conditioning. These findings suggest reduced reward learning and consequently diminished processing of outcome expectancy in appetitive conditioning in subjects with high sensation seeking scores. The results are discussed with respect to clinical implications.

Learning to see the threat: temporal dynamics of ERPs of motivated attention in fear conditioning

Social threat detection is important in everyday life. Studies of cortical activity have shown that event-related potentials (ERPs) of motivated attention are modulated during fear conditioning. The time course of motivated attention in learning and extinction of fear is, however, still largely unknown. We aimed to study temporal dynamics of learning processes in classical fear conditioning to social cues (neutral faces) by selecting an experimental setup that produces large effects on well-studied ERP components (early posterior negativity, EPN; late positive potential, LPP; stimulus preceding negativity, SPN) and then exploring small consecutive groups of trials. EPN, LPP, and SPN markedly and quickly increased during the acquisition phase in response to the CS+ but not the CS-. These changes were visible even at high temporal resolution and vanished completely during extinction. Moreover, some evidence was found for component differences in extinction learning, with differences between CS+ and CS- extinguishing faster for late as compared to early ERP components. Results demonstrate that fear learning to social cues is a very fast and highly plastic process and conceptually different ERPs of motivated attention are sensitive to these changes at high temporal resolution, pointing to specific neurocognitive and affective processes of social fear learning.

The time-course of component processes of selective attention

Attentional selection shapes human perception, enhancing relevant information, according to behavioral goals. While many studies have investigated individual neural signatures of attention, here we used multivariate decoding of electrophysiological brain responses (MEG/EEG) to track and compare multiple component processes of selective attention. Auditory cues instructed participants to select a particular visual target, embedded within a subsequent stream of displays. Combining single and multi-item displays with different types of distractors allowed multiple aspects of information content to be decoded, distinguishing distinct components of attention, as the selection process evolved. Although the task required comparison of items to an attentional "template" held in memory, signals consistent with such a template were largely undetectable throughout the preparatory period but re-emerged after presentation of a non-target choice display. Choice displays evoked strong neural representation of multiple target features, evolving over different timescales. We quantified five distinct processing operations with different time-courses. First, visual properties of the stimulus were strongly represented. Second, the candidate target was rapidly identified and localized in multi-item displays, providing the earliest evidence of modulation by behavioral relevance. Third, the identity of the target continued to be enhanced, relative to distractors. Fourth, only later was the behavioral significance of the target explicitly represented in single-item displays. Finally, if the target was not identified and search was to be resumed, then an attentional template was weakly reactivated. The observation that an item's behavioral relevance directs attention in multi-item displays prior to explicit representation of target/non-target status in single-item displays is consistent with two-stage models of attention.

Angry Drivers Take Risky Decisions: Evidence from Neurophysiological Assessment

The present study investigated the risk-taking behaviors of angry drivers, which were coincidentally measured via behavioral and electroencephalographic (EEG) recordings. We manipulated a driving scenario that concerned a Go/No-Go decision at an intersection when the controlling traffic light was in its yellow phase. This protocol was based upon the underlying format of the Iowa gambling task. Variation in the anger level was induced through task frustration. The data of twenty-four drivers were analyzed via behavioral and neural recordings, and P300 was specifically extracted from EEG traces. In addition, the behavioral performance was indexed by the percentage of high-risk choices minus the number of the low-risk choices taken, which identified the risk-taking propensity. Results confirmed a significant main effect of anger on the decisions taken. The risk-taking propensity decreased across the sequence of trial blocks in baseline assessments. However, with anger, the risk-taking propensity increased across the trial regimen. Drivers in anger state also showed a higher mean amplitude of P300 than that in baseline state. Additionally, high-risk choices evoked larger P300 amplitude than low-risk choices during the anger state. Moreover, the P300 amplitude of high-risk choices was significantly larger in the anger state than the baseline state. The negative feedback induced larger P300 amplitude than that recorded in positive feedback trials. The results corroborated that the drivers exhibited higher risk-taking propensity when angry although they were sensitive to the inherent risk-reward evaluations within the scenario. To reduce this type of risk-taking, we proposed some effective/affective intervention methods.

The reality of "food porn": Larger brain responses to food-related cues than to erotic images predict cue-induced eating

While some individuals can defy the lure of temptation, many others find appetizing food irresistible. The goal of this study was to investigate the neuropsychological mechanisms that increase individuals' vulnerability to cue-induced eating. Using ERPs, a direct measure of brain activity, we showed that individuals with larger late positive potentials in response to food-related cues than to erotic images are more susceptible to cue-induced eating and, in the presence of a palatable food option, eat more than twice as much as individuals with the opposite brain reactivity profile. By highlighting the presence of individual brain reactivity profiles associated with susceptibility to cue-induced eating, these findings contribute to the understanding of the neurobiological basis of vulnerability to obesity.

Measuring the conditioned response: A comparison of pupillometry, skin conductance, and startle electromyography

In human fear conditioning studies, different physiological readouts can be used to track conditioned responding during fear learning. Commonly employed readouts such as skin conductance responses (SCR) or startle responses have in recent years been complemented by pupillary readouts, but to date it is unknown how pupillary readouts relate to other measures of the conditioned response. To examine differences and communalities among pupil responses, SCR, and startle responses, we simultaneously recorded pupil diameter, skin conductance, and startle electromyography in 47 healthy subjects during fear acquisition, extinction, and a recall test on 2 consecutive days. The different measures correlated only weakly, displaying most prominent differences in their response patterns during fear acquisition. Whereas SCR and startle responses habituated, pupillary measures did not. Instead, they increased in response to fear conditioned stimuli and most closely followed ratings of unconditioned stimulus (US) expectancy. Moreover, we observed that startle-induced pupil responses showed stimulus discrimination during fear acquisition, suggesting a fear potentiation of the auditory pupil reflex. We conclude that different physiological outcome measures of the conditioned response inform about different cognitive-affective processes during fear learning, with pupil responses being least affected by physiological habituation and most closely following US expectancy.