Electrophysiological correlates of inhibitory control in children: Relations with prenatal maternal risk factors and child psychopathology

Inhibitory control plays an important role in children's cognitive and socioemotional development, including their psychopathology. It has been established that contextual factors such as socioeconomic status (SES) and parents' psychopathology are associated with children's inhibitory control. However, the relations between the neural correlates of inhibitory control and contextual factors have been rarely examined in longitudinal studies. In the present study, we used both event-related potential (ERP) components and time-frequency measures of inhibitory control to evaluate the neural pathways between contextual factors, including prenatal SES and maternal psychopathology, and children's behavioral and emotional problems in a large sample of children (N = 560; 51.75% females; Mage = 7.13 years; Rangeage = 4-11 years). Results showed that theta power, which was positively predicted by prenatal SES and was negatively related to children's externalizing problems, mediated the longitudinal and negative relation between them. ERP amplitudes and latencies did not mediate the longitudinal association between prenatal risk factors (i.e., prenatal SES and maternal psychopathology) and children's internalizing and externalizing problems. Our findings increase our understanding of the neural pathways linking early risk factors to children's psychopathology.

Foster Care Leads to Lower Irritability Among Adolescents with a History of Early Psychosocial Deprivation

Irritability reflects a propensity for frustration and anger, and is a transdiagnostic symptom of both externalizing and internalizing psychopathology. While early adverse experiences are associated with higher levels of irritability, experiences of early psychosocial deprivation and whether family-based placements can mitigate the impact on subsequent irritability, remain underexplored. The current study examined irritability in 107 16-year-olds with a history of institutional care from a randomized controlled trial of foster care as an alternative to institutional care and 49 community comparison children. At age 16 years, irritability was assessed using parent- and self-report forms of the Affective Reactivity Index. Compared to community adolescents, those with a history of institutional care exhibited significantly elevated irritability levels. Among those who experienced institutional care, those randomized to foster care had lower levels of irritability compared to participants randomized to the care-as-usual group, and this effect persists after controlling for baseline negative emotionality. These findings suggest a causal link between high-quality foster care and lower irritability following psychosocial deprivation. Additionally, longer duration in institutional care and non-family placement at age 16 years were associated with higher levels of irritability, highlighting the role of caregiving in explaining variation in irritability in adolescence. Policies that support long-term, high-quality family placements for children without regular caregivers should be prioritized.

Induced error-related theta activity, not error-related negativity, predicts task performance as well as anxiety and worry during real-life stress in a youth sample

OBJECTIVE

The study examined differences between induced error-related theta activity (4-7 Hz) and error-related negativity (ERN) in youth and their unique associations with task performance as well as anxiety and worry during real-life stress a year later. We hypothesized that induced theta, but not the ERN, would predict task performance. We also hypothesized that induced theta would predict less anxiety and worries during situational stress a year later, while ERN would predict more anxiety and worries.

METHOD

Participants included 76 children aged 8-13 years who completed a flanker task while electroencephalogram (EEG) and behavioral data (t0 ) were collected. Approximately 1 year later (t1 ), during the first COVID-19 lockdown, 40 families from the original sample completed a battery of online questionnaires to assess the children's stress-related symptoms (anxiety, negative emotions and worries). We employed an analytical method that allowed us to differentiate between induced error-related theta and the evoked ERN.

RESULTS

Induced error-related theta, but not ERN, was associated with behavioral changes during the task, such as post-error speeding. Furthermore, induced error-related theta, but not ERN, was prospectively associated with less anxiety, worries, and fewer negative emotions a year later during COVID-19 lockdown.

CONCLUSIONS

Findings suggest ERN and error-related theta are dissociable processes reflecting error monitoring in youth. Specifically, induced error-related theta is more robustly associated with changes in behavior in the laboratory and with less anxiety and worries in real-world settings.

Emotional context and predictability in naturalistic reading aloud

[Correction Notice: An Erratum for this article was reported in Vol 24(3) of Emotion (see record 2024-72515-001). In the article (https://doi.org/10.1037/emo0001298), Table 1 as originally reported contained an error with respect to participant demographics. Specifically, participants who had selected multiple categories for race/ethnicity were mistakenly assigned to only the first alphabetical category selected. Updates have been made in the Race/ethnicity section of Table 1, to change the heading "American Indian or Alaska Native" to "Multiple selected," and to the relevant statistics under that heading as well as under the "Hispanic, Latino/a/x, or Spanish origin" and "Asian" headings. No inferential statistics are impacted by this correction, nor does it affect the results or conclusions of the article. All versions of this article have been corrected.] A robust experimental literature has found that word frequency and lexical valence contribute to visual word processing at the level of the individual word. Extensions of this literature to simplified sentences have essentially corroborated single-word findings, albeit with important influences of the unfolding discourse context, which may strengthen or attenuate single-word effects. This study sought to extend current knowledge one step further, beyond stand-alone sentences or sentence pairs, by investigating how word frequency and lexical valence, along with their interactions, influence oral reading performance for multisentence stimuli in a naturalistic context. Lexical features were averaged over short passages of text, which were presented to participants on-screen simultaneously, and performance was assessed as reading speed, in words per second. Overall, we find that the same patterns emerge for multisentence oral reading as in the prior literature: strong frequency effects that benefit higher-frequency content, a positivity bias that increases reading speed for more positive content, and an important interaction that disfavors relatively more negative (less positive), high-frequency content. We discuss these findings in light of possible interpretations based on associative connectivity in the mental lexicon, as well as oculomotor dynamics during naturalistic reading. Our data suggest that reading speed of multisentence texts is a viable alternative, and one that offers enhanced ecological validity, for investigations of visual word processing dynamics. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Social versus non-social behavioral inhibition: Differential prediction from early childhood of long-term psychosocial outcomes

Behavioral inhibition (BI) is a temperamental style characterized by cautious and fearful behaviors in novel situations. The present multi-method, longitudinal study examined whether young children's observed and parent-reported BI in social versus non-social contexts predicts different long-term psychosocial outcomes. Participants (N = 279) were drawn from a longitudinal study of socioemotional development. BI in social contexts ("social BI") was measured via children's observed wariness toward unfamiliar adults and peers at 24 and 36 months and parents' reports of children's social fear/shyness at 24, 36, and 48 months. BI in non-social contexts ("non-social BI") was measured via children's observed fearful responses to masks and novel toys, and parents' reports of children's distress to non-social novelty at 9 months and non-social fear at 48 months. At 15 years, anxiety was assessed via adolescent- and parent-reports, and global internalizing and externalizing problems were assessed via parent-reports. Confirmatory factor analysis showed that a two-factor model fit the BI data significantly better than a single-factor model, providing evidence for the dissociation of BI in social versus non-social contexts. Social BI was uniquely associated with adolescent social anxiety, whereas non-social BI was specifically associated with adolescent separation anxiety. Neither social BI nor non-social BI predicted global internalizing and externalizing problems, providing evidence for the specific relations between BI and anxiety problems. Together, these results suggest that young children's inhibited responses in social versus non-social situations predict different subtypes of anxiety problems in adolescence, highlighting the multifaceted nature of BI and the divergent trajectories of different anxiety problems.

Multimodal study of the neural sources of error monitoring in adolescents and adults

The ability to monitor performance during a goal-directed behavior differs among children and adults in ways that can be measured with several tasks and techniques. As well, recent work has shown that individual differences in error monitoring moderate temperamental risk for anxiety and that this moderation changes with age. We investigated age differences in neural responses linked to performance monitoring using a multimodal approach. The approach combined functional MRI and source localization of event-related potentials (ERPs) in 12-year-old, 15-year-old, and adult participants. Neural generators of two components related to performance and error monitoring, the N2 and ERN, lay within specific areas of fMRI clusters. Whereas correlates of the N2 component appeared similar across age groups, age-related differences manifested in the location of the generators of the ERN component. The dorsal anterior cingulate cortex (dACC) was the predominant source location for the 12-year-old group; this area manifested posteriorly for the 15-year-old and adult groups. A fMRI-based ROI analysis confirmed this pattern of activity. These results suggest that changes in the underlying neural mechanisms are related to developmental changes in performance monitoring.

Towards a mechanistic understanding of the role of error monitoring and memory in social anxiety

Cognitive models state social anxiety (SA) involves biased cognitive processing that impacts what is learned and remembered within social situations, leading to the maintenance of SA. Neuroscience work links SA to enhanced error monitoring, reflected in error-related neural responses arising from mediofrontal cortex (MFC). Yet, the role of error monitoring in SA remains unclear, as it is unknown whether error monitoring can drive changes in memory, biasing what is learned or remembered about social situations. Thus, we developed a novel paradigm to investigate the role of error-related MFC theta oscillations (associated with error monitoring) and memory biases in SA. EEG was collected while participants completed a novel Face-Flanker task, involving presentation of task-unrelated, trial-unique faces behind target/flanker arrows on each trial. A subsequent incidental memory assessment evaluated memory biases for error events. Severity of SA symptoms were associated with greater error-related theta synchrony over MFC, as well as between MFC and sensory cortex. SA was positively associated with memory biases for error events. Consistent with a mechanistic role in biased cognitive processing, greater error-related MFC-sensory theta synchrony during the Face-Flanker predicted subsequent memory biases for error events. Our findings suggest high SA individuals exhibit memory biases for error events, and that this behavioral phenomenon may be driven by error-related MFC-sensory theta synchrony associated with error monitoring. Moreover, results demonstrate the potential of a novel paradigm to elucidate mechanisms underlying relations between error monitoring and SA.

Context and domain matter: the error-related negativity in peer presence predicts fear of negative evaluation, not global social anxiety, in adolescents

BACKGROUND

Social anxiety symptoms are most likely to emerge during adolescence, a developmental window marked by heightened concern over peer evaluation. However, the neurocognitive mechanism(s) underlying adolescent social anxiety remain unclear. Emerging work points to the error-related negativity (ERN) as a potential neural marker of exaggerated self/error-monitoring in social anxiety, particularly for errors committed in front of peers. However, social anxiety symptoms are marked by heterogeneity and it remains unclear exactly what domain(s) of social anxiety symptoms are associated with ERN variation in peer presence, particularly within the adolescent period.

METHODS

To advance and deepen the mechanistic understanding of the ERN's putative role as a neural marker for social anxiety in adolescence, we leveraged a social manipulation procedure and assessed a developmentally salient domain of social anxiety during adolescence - fear of negative evaluation (FNE). Adolescents residing in Hanzhong, a small city in the southwestern region of mainland China, had EEG recorded while performing a flanker task, twice (peer presence/absence); FNE, as well as global social anxiety symptoms, was assessed.

RESULTS

Overall ERN increases in peer presence. FNE specifically, but not global levels of social anxiety symptoms, predicted ERN in peer presence.

CONCLUSIONS

These data are the first demonstration that the ERN relates to a specific domain of social anxiety in adolescents, as well as the first evidence of such relations within a non-WEIRD (Western, Educated, Industrialized, Rich and Democratic) sample. Results have important implications for theory and research into adolescent social anxiety.

Annual Research Review: Developmental pathways linking early behavioral inhibition to later anxiety

Behavioral Inhibition is a temperament identified in the first years of life that enhances the risk for development of anxiety during late childhood and adolescence. Amongst children characterized with this temperament, only around 40 percent go on to develop anxiety disorders, meaning that more than half of these children do not. Over the past 20 years, research has documented within-child and socio-contextual factors that support differing developmental pathways. This review provides a historical perspective on the research documenting the origins of this temperament, its biological correlates, and the factors that enhance or mitigate risk for development of anxiety. We review as well, research findings from two longitudinal cohorts that have identified moderators of behavioral inhibition in understanding pathways to anxiety. Research on these moderators has led us to develop the Detection and Dual Control (DDC) framework to understand differing developmental trajectories among behaviorally inhibited children. In this review, we use this framework to explain why and how specific cognitive and socio-contextual factors influence differential pathways to anxiety versus resilience.

Development of auditory change-detection and attentional capture, and their relation to inhibitory control

EEG methods offer a promising approach to study the development of attention or attention-related processes such as change-detection and attentional capture. However, the development of these attention processes from early to middle childhood is not well understood. In the current study, we utilized a passive three-stimulus oddball paradigm to examine age-related changes in auditory change-detection and attentional capture in a large sample of children across childhood (N = 475; 249 female, 226 male; Mage  = 6.71; SDage  = 2.22; Rangeage  = 4.01-11.5 years). Conventional ERP analyses revealed no age-related changes in change detection (mismatch negativity) and attentional capture (P3a) components, but we observed age-related reductions in late automatic processing of auditory change (late discriminative negativity). However, when utilizing time-frequency analyses, we observed developmental increases in frontocentral signal strength (power) and consistency (inter-trial phase synchrony) in delta and theta bands in response to novel sounds. Such frontocentral delta/theta responses have been linked in prior work to cognitive control. To further examine this possibility, we examined relations with inhibitory control. Results revealed that increased consistency in theta in response to novel sounds was related to improved inhibitory control. Together, our results advance our understanding of the development of attention in childhood. Moreover, they demonstrate the contributions of time-frequency approaches to studying neurocognitive development. Finally, our results highlight the utility of neuroimaging paradigms that have low cognitive and motor demands to study the development of psychological processes.

Age-related trends in aperiodic EEG activity and alpha oscillations during early- to middle-childhood

Age-related structural and functional changes that occur during brain development are critical for cortical development and functioning. Previous electroencephalography (EEG) and magnetoencephalography (MEG) studies have highlighted the utility of power spectra analyses and have uncovered age-related trends that reflect perceptual, cognitive, and behavioural states as well as their underlying neurophysiology. The aim of the current study was to investigate age-related change in aperiodic and periodic alpha activity across a large sample of pre- and school-aged children (N = 502, age range 4 -11-years-of-age). Power spectra were extracted from baseline EEG recordings (eyes closed, eyes open) for each participant and parameterized into aperiodic activity to derive the offset and exponent parameters and periodic alpha oscillatory activity to derive the alpha peak frequency and the associated power estimates. Multilevel models were run to investigate age-related trends and condition-dependent changes for each of these measures. We found quadratic age-related effects for both the aperiodic offset and exponent. In addition, we observed increases in periodic alpha peak frequency as a function of age. Aperiodic measures and periodic alpha power were larger in magnitude during eyes closed compared to the eyes open baseline condition. Taken together, these results advance our understanding of the maturational patterns/trajectories of brain development during early- to middle-childhood.

Family-based care buffers the stress sensitizing effect of early deprivation on executive functioning difficulties in adolescence

We examined whether family care following early-life deprivation buffered the association between stressful life events (SLEs) and executive functioning (EF) in adolescence. In early childhood, 136 institutionally reared children were randomly assigned to foster care or care-as-usual; 72 never-institutionalized children served as a comparison group. At age 16 years, adolescents (n = 143; 54% female; 67.1% Romanian) self-reported recent SLEs, completed a battery of memory and EF tasks, and completed a go/nogo task in which mediofrontal theta power (MFTP) was measured using electroencephalogram. More independent SLEs predicted lower EF and more dependent SLEs predicted lower MFTP, but only among adolescents with prolonged early deprivation. Findings provide preliminary evidence that family care following early deprivation may facilitate resilience against stress during adolescence on EF.

Development of Proactive Control and Anxiety Among Behaviorally Inhibited Adolescents

OBJECTIVE

Behavioral inhibition (BI) is an infant temperament characterized by heightened reactivity and negative affect in response to novel people and situations. BI is among the earliest and strongest predictors of future anxiety problems. However, not all children with a history of BI will manifest anxiety problems. A growing body of evidence suggests that proactive control skills may help buffer youth with BI from future anxiety difficulties; yet, it remains unclear how temperament may interact with the development of cognitive control to influence anxiety risk. The present study tested whether enhancements in proactive control occurring during adolescence may reduce risk for anxiety among youth with a history of BI.

METHOD

Participants included 185 adolescents (56% female) whose temperament was assessed during toddlerhood. In adolescence, participants completed anxiety assessments and an AX Continuous Performance Test (AX-CPT) to assess cognitive control strategy. Both assessments were administered at age 13 years and again at 15 years.

RESULTS

Latent change score modeling revealed that, on average, participants increasingly used proactive control strategies and experienced worsening anxiety from age 13-15 years. Early BI was associated with a smaller anxiety increase from 13-15 years, but only among participants whose proactive control skills improved at mean or greater rates.

CONCLUSION

The present findings suggest that greater proactive control development during adolescence protects youth with high BI from age-related increases in anxiety. Results support a framework that highlights cognitive control as a key moderator of anxiety risk among children with a history of high BI.

A Practical Introduction to EEG Time-Frequency Principal Components Analysis (TF-PCA)

This EEG methods tutorial provides both a conceptual and practical introduction to a promising data reduction approach for time-frequency representations of EEG data: Time-Frequency Principal Components Analysis (TF-PCA). Briefly, the unique value of TF-PCA is that it provides a data-reduction approach that does not rely on strong a priori constraints regarding the specific timing or frequency boundaries for an effect of interest. Given that the time-frequency characteristics of various neurocognitive process are known to change across development, the TF-PCA approach is thus particularly well suited for the analysis of developmental TF data. This tutorial provides the background knowledge, theory, and practical information needed to allow individuals with basic EEG experience to begin applying the TF-PCA approach to their own data. Crucially, this tutorial article is accompanied by a companion GitHub repository that contains example code, data, and a step-by-step guide of how to perform TF-PCA: https://github.com/NDCLab/tfpca-tutorial. Although this tutorial is framed in terms of the utility of TF-PCA for developmental data, the theory, protocols and code covered in this tutorial article and companion GitHub repository can be applied more broadly across populations of interest.

Time-frequency dynamics of error monitoring in childhood: An EEG study

Error monitoring allows individuals to monitor and adapt their behavior by detecting errors. Error monitoring is thought to develop throughout childhood and adolescence. However, most of this evidence comes from studies in late childhood and adolescence utilizing event-related potentials (ERPs). The current study utilizes time-frequency (TF) and connectivity analyses to provide a comprehensive examination of age-related changes in error-monitoring processes across early childhood (N = 326; 50.9% females; 4-9 years). ERP analyses indicated the presence of the error-related negativity (ERN) and error positivity (Pe) across all ages. Results showed no error-specific age-related changes in the ERN and the Pe. However, TF analyses suggested error-related frontocentral responses in delta and theta signal strength (power), delta consistency (intertrial phase synchrony), and delta synchrony (interchannel phase synchrony) between frontrocentral and frontolateral clusters-all of which increased with age. Additionally, the current study examines the reliability and effect size estimates of the ERP and TF measures. For most measures, more trials were needed to achieve acceptable reliability than what is commonly used in the psychophysiological literature. Resources to facilitate the measurement and reporting of reliability are provided. Overall, findings highlight the utility of TF analyses and provide useful information for future studies examining the development of error monitoring.

Longitudinal age- and sex-related change in background aperiodic activity during early adolescence

Aperiodic activity contains important and meaningful physiological information that has been shown to dynamically change with age. However, no longitudinal studies have examined its development during early-to-mid adolescence. The current study closes this gap by investigating age- and sex-related longitudinal change in aperiodic activity across early-to-mid adolescence (N = 186; 54.3% female). Participants completed a resting state task and a Flanker task while EEG was record at age 13 years and again at age 15 years. Across different tasks and two time points, we observed significant age-related reductions in aperiodic offset and exponent. In addition, we observed significant sex-related differences in the aperiodic offset and exponent over time. We did not find any significant correlation between aperiodic activity and behavioral measures, nor did we find any significant condition-dependent change in aperiodic activity during the Flanker task. However, we did observe significant correlations between aperiodic activity across tasks and over time, suggesting that aperiodic activity may demonstrate stable trait-like characteristics. Collectively, these results may suggest a developmental parallelism between decreases in aperiodic components alongside adolescent brain development during this period; changes to cortical and subcortical brain structure and organization during early adolescence may have been responsible for the observed sex-related effects.

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Early adolescence is associated with changes in the aperiodic signal.

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We observed significant sex-related differences in the aperiodic signal over time.

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Aperiodic activity is significantly correlated within/between tasks and over time.

Behavioral inhibition and dual mechanisms of anxiety risk: Disentangling neural correlates of proactive and reactive control

Background:

Behavioral inhibition (BI) is a temperament style characterized by heightened reactivity and negative affect in response to novel people and situations, and it predicts anxiety problems later in life. However, not all BI children develop anxiety problems, and mounting evidence suggests that how one manages their cognitive resources (cognitive control) influences anxiety risk. The present study tests whether more (proactive control) or less (reactive control) planful cognitive strategies moderate relations between early BI and later anxiety.

Methods:

Participants included 112 adolescents (55% female; M_age = 15.4 years) whose temperament was assessed during toddlerhood. In adolescence, participants completed an AX Continuous Performance Test while electroencephalography was recorded to disentangle neural activity related to proactive (cue-locked P3b) and reactive (probe-locked N2) control.

Results:

Greater BI was associated with greater total anxiety scores only among adolescents with smaller ΔP3bs and larger ΔN2s—a pattern consistent with decreased reliance on proactive strategies and increased reliance on reactive strategies. Additionally, a larger ΔP3b was associated with greater total anxiety scores; however, this effect was largely explained by the fact that females tended to have larger ΔP3bs and greater anxiety than males.

Conclusions:

Early BI relates to risk for later anxiety specifically among adolescents who rely less on proactive strategies and more on reactive control strategies. Thus, cognitive control strategy moderates the association between developmental context (i.e., temperament) and later anxiety. The present study is the first to characterize how proactive and reactive control uniquely relate to pathways toward anxiety risk.

Neurocognitive Profiles in Adolescence Predict Subsequent Anxiety Trajectories During the COVID-19 Pandemic

Background

The COVID-19 pandemic has created increased stress and anxiety for many; however, some individuals are particularly prone to heightened anxiety. It is unclear if and how prestress neurocognitive factors moderate risk for anxiety during high-stress situations. Enhanced error monitoring and a cognitive control strategy of more instantaneous (reactive) control have both been independently related to anxiety. We examined if a specific neurocognitive profile characterized by heightened error monitoring and a more reactive cognitive control strategy in adolescence predicts young adults’ anxiety trajectories across 3 early months of the COVID-19 pandemic.

Methods

As part of a longitudinal study (N = 291), data were acquired in adolescence (13 years) on error monitoring (n = 124) and cognitive control strategy (n = 119). In young adulthood (18 years), anxiety was assessed three times during the COVID-19 pandemic (n = 162).

Results

On average, participants experienced greater anxiety in the first COVID-19 pandemic assessment, then anxiety decreased in the following months. Error monitoring and cognitive control strategy interacted to predict anxiety trajectories, such that among adolescents with an increased reliance on reactive control, error monitoring predicted greater anxiety in the first assessment but greater decreases the following months as stay-at-home orders were lifted and families adapted to the restrictions.

Conclusions

Results suggest that neurocognitive profiles in adolescence predict young adults’ anxiety responses during a highly stressful period, such as the initial months of the COVID-19 pandemic. Our findings have implications for the early identification of individuals at greater risk for anxiety.

Understanding the Emergence of Social Anxiety in Children With Behavioral Inhibition

Behavioral inhibition (BI) is a temperament characterized in early childhood by distress to novelty and avoidance of unfamiliar people, and it is one of the best-known risk factors for the development of social anxiety. However, nearly 60% of children with BI do not go on to meet criteria for social anxiety disorder. In this review we present an approach to understanding differential developmental trajectories among children with BI. We review research using laboratory-based tasks that isolate specific attention processes that enhance versus mitigate risk for social anxiety among behaviorally inhibited children and studies that suggest that BI is associated with heightened detection of novelty or threat. Moreover, stimulus-driven control processes, which we term "automatic control," increase the probability that behaviorally inhibited children display socially reticent behavior and develop social anxiety. In contrast, goal-driven control processes, which we term "planful control," decrease risk for anxiety. We suggest that these three categories of processes (detection, automatic control, and planful control) function together to determine whether behaviorally inhibited children are able to flexibly regulate their initial reactions to novelty, and in turn, decrease risk for social anxiety. Although laboratory-based tasks have identified these processes underlying risk and resilience, the challenge is linking them to the emotions, thoughts, and behaviors of behaviorally inhibited children in real-world contexts.

Subthreshold error corrections predict adaptive post-error compensations

Relatively little is known about the relation between subthreshold error corrections and post-error behavioral compensations. The present study utilized lateralized beta power, which has been shown to index response preparation, to examine subthreshold error corrections in a task known to produce response conflict, the Simon task. We found that even when an overt correction is not made, greater activation of the corrective response, indexed by beta suppression ipsilateral to the initial responding hand, predicted post-error speeding, and enhanced post-error accuracy at the single-trial level. This provides support for the notion that response conflict associated with errors can be adaptive, and suggests that subthreshold corrections should be taken into account to fully understand error-monitoring processes. Furthermore, we expand on previous findings that demonstrate that post-error slowing and post-error accuracy can be dissociated, as well as findings that suggest that frontal midline theta oscillations and the error-related negativity (ERN) are dissociable neurocognitive processes.

The influence of monetary reward on proactive and reactive control in adolescent males

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Reward reduced RT interference during reactive control, but increased RT interference during proactive control in male adolescents.

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Increased reward-related cue-locked theta power was associated with increased RT interference on proactive trials.

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Increased reward-related stimulus-locked theta inter-channel phase synchrony was related to facilitated performance on proactive trials.

Adolescence is marked by increased reward-seeking, which can alter cognitive control abilities. Previous research found that rewards actually improve cognitive control in children, adolescents, and adults, but these studies only investigated reactive control. The goal of the current study was to elucidate reward’s influence on both proactive and reactive control during adolescence. To this end, 68 (Mean age = 13.61, SD = 2.52) male adolescents completed a rewarded cued flanker paradigm while electroencephalogram (EEG) was collected. Theta power and inter-channel phase synchrony, both implicated in cognitive control, were quantified after cues and stimuli to understand their role during reward-cognitive control interactions. The data suggest that reward reduced interference during reactive control; however, reward increased interference during proactive control in this sample of adolescent males. Reward-related increases in cue-locked theta power predicted more reward-related RT interference on proactive trials. In contrast, increases in stimulus-locked theta ICPS were associated with better performance on rewarded proactive trials. The pattern of results show that reward differentially impacted proactive and reactive control in adolescence, which may have implications for the increased risk-taking behaviors observed during adolescence.

The influence of social motivation on neural correlates of cognitive control in girls

Motivation influences cognitive control, particularly in childhood and adolescence. Previous work finds that the error-related negativity (ERN), an event-related potential (ERP) linked to cognitive control following errors, is influenced by social motivation. However, it is unclear whether the influences of social motivation on the ERN extend to stimulus-locked neural correlates of cognitive control. This study reexamines how social motivation influences cognitive control in adolescence by exploring motivational influences on two stimulus-locked ERPs; the N2 and P3. Adolescent girls (8-17 years of age) completed a flanker task under two different conditions. In the social condition, girls were led to believe that they were evaluated by a peer during a flanker task. In the nonsocial condition, girls completed a flanker task while evaluated by a computer. Results revealed that all girls exhibited a larger P3 in social as compared to nonsocial contexts, whereas the N2 was not different between contexts. In addition, the largest P3 enhancements were observed among younger girls. These findings suggest that social motivation influences some ERP components related to cognitive control, and such influences change across development. Additionally, findings suggest the importance of including multiple ERPs when interpreting the functional significance of motivation on cognitive control.

Adjusting ADJUST: Optimizing the ADJUST algorithm for pediatric data using geodesic nets

A major challenge for electroencephalograph (EEG) studies on pediatric populations is that large amounts of data are lost due to artifacts (e.g., movement and blinks). Independent component analysis (ICA) can separate artifactual and neural activity, allowing researchers to remove such artifactual activity and retain a greater percentage of EEG data for analyses. However, manual identification of artifactual components is time-consuming and requires subjective judgment. Automated algorithms, like ADJUST and ICLabel, have been validated on adults, but to our knowledge, no such algorithms have been optimized for pediatric data. Therefore, in an attempt to automate artifact selection for pediatric data collected with geodesic nets, we modified ADJUST's algorithm. Our "adjusted-ADJUST" algorithm was compared to the "original-ADJUST" algorithm and ICLabel in adults, children, and infants on three different performance measures: respective classification agreement with expert coders, the number of trials retained following artifact removal, and the reliability of the EEG signal after preprocessing with each algorithm. Overall, the adjusted-ADJUST algorithm performed better than the original-ADJUST algorithm and no ICA correction with adult and pediatric data. Moreover, in some measures, it performed better than ICLabel for pediatric data. These results indicate that optimizing existing algorithms improves artifact classification and retains more trials, potentially facilitating EEG studies with pediatric populations. Adjusted-ADJUST is freely available under the terms of the GNU General Public License at: https://github.com/ChildDevLab/MADE-EEG-preprocessing-pipeline/tree/master/adjusted_adjust_scripts.

The Heterogeneity of Anxious Phenotypes: Neural Responses to Errors in Treatment-Seeking Anxious and Behaviorally Inhibited Youths

OBJECTIVE

Although behaviorally inhibited (BI) temperament predicts risk for anxiety, anxiety in BI may involve distinct neural responses to errors. The current study examines the relations between anxiety and neural correlates of error processing both in youths identified as BI in early childhood and in youths seeking treatment for an anxiety disorder.

METHOD

All participants underwent functional magnetic resonance imaging using a flanker task to assess responses to errors. A study in healthy subjects assessed test-retest reliability to inform analyses in two other samples. For one sample, a cohort of BI youths (Low BI, n = 28; High BI, n = 27) was followed into adolescence. For the other, participants were recruited based on the presence or absence of an anxiety disorder. Using identical methods in medication-free subjects, analyses compared relations between anxiety and error processing across the two samples.

RESULTS

Error-processing exhibited acceptable reliability. Within a ventromedial-prefrontal-cortex (vmPFC) cluster, anxiety related to error processing only in youths whose early-life BI status was known. In the high BI group, anxiety related to reduced neural response to errors. No such associations manifested in treatment-seeking youths. Other analyses mapped relations between error-processing and anxiety in each sample on its own. However, only the vmPFC cluster statistically differentiated the neural correlates of anxiety in BI.

CONCLUSION

BI temperament may define a unique pathway into anxiety involving perturbed neural responding to errors. Although BI is a risk factor for later anxiety, the neural and associated features of anxiety in BI youths may differ from those in treatment-seeking youths.

The Maryland analysis of developmental EEG (MADE) pipeline

Compared to adult EEG, EEG signals recorded from pediatric populations have shorter recording periods and contain more artifact contamination. Therefore, pediatric EEG data necessitate specific preprocessing approaches in order to remove environmental noise and physiological artifacts without losing large amounts of data. However, there is presently a scarcity of standard automated preprocessing pipelines suitable for pediatric EEG. In an effort to achieve greater standardization of EEG preprocessing, and in particular, for the analysis of pediatric data, we developed the Maryland analysis of developmental EEG (MADE) pipeline as an automated preprocessing pipeline compatible with EEG data recorded with different hardware systems, different populations, levels of artifact contamination, and length of recordings. MADE uses EEGLAB and functions from some EEGLAB plugins and includes additional customized features particularly useful for EEG data collected from pediatric populations. MADE processes event-related and resting state EEG from raw data files through a series of preprocessing steps and outputs processed clean data ready to be analyzed in time, frequency, or time-frequency domain. MADE provides a report file at the end of the preprocessing that describes a variety of features of the processed data to facilitate the assessment of the quality of processed data. In this article, we discuss some practical issues, which are specifically relevant to pediatric EEG preprocessing. We also provide custom-written scripts to address these practical issues. MADE is freely available under the terms of the GNU General Public License at https://github.com/ChildDevLab/MADE-EEG-preprocessing-pipeline.

Changes in working memory influence the transition from reactive to proactive cognitive control during childhood

Cognitive control develops rapidly over the first decade of life, with one of the dominant changes being a transition from reliance on 'as-needed' control (reactive control) to a more planful, sustained form of control (proactive control). Although the emergence of proactive control is important for mature behavior, we know little about how this transition takes place, the neural correlates of this transition, and whether development of executive functions influences the ability to adopt a proactive control strategy. This study addresses these questions, focusing on the transition from reactive to proactive control in a cross-sectional sample of 79 children-forty-one 5-year-olds and thirty-eight 9-year-olds. Children completed an adapted version of the AX-Continuous Performance Task while electroencephalography was recorded and a standardized executive function battery was administered. Results revealed 5-year-olds predominantly employed reactive strategies, whereas 9-year-olds used proactive strategies. Use of proactive control was predicted by working memory ability, above and beyond other executive functions. Moreover, when enacting proactive control, greater increases in neural activity underlying working memory updating were observed; links between working memory ability and proactive control strategy use were mediated by such neural activity. These results provide convergent evidence that the transition from reactive to proactive control may be dependent on age-related changes in neurocognitive indices of working memory and that working memory may influence adopting a proactive control strategy.

Consequences of Not Planning Ahead: Reduced Proactive Control Moderates Longitudinal Relations Between Behavioral Inhibition and Anxiety

OBJECTIVE

Children with the temperament of behavioral inhibition (BI) face increased risk for developing an anxiety disorder later in life. However, not all children with BI manifest anxiety symptoms, and use of a cognitive control strategy could moderate the pathway between BI and anxiety. Individuals vary widely in the strategy used to instantiate control. The present study examined whether a more planful style of cognitive control (ie, proactive control) or a more impulsive strategy of control (ie, reactive control) would moderate the association between early BI and later anxiety symptoms.

METHOD

Participants were part of a longitudinal study examining the relations between BI (measured at 2-3 years of age) and later anxiety symptoms (measured at 13 years). Use of a cognitive control strategy was assessed at 13 years using the AX variant of the continuous performance task.

RESULTS

BI in toddlerhood significantly predicted increased use of a more reactive cognitive control style in adolescence. In addition, cognitive control strategy moderated the relation between BI and anxious symptoms, such that reliance on a more reactive strategy predicted higher levels of anxiety for children high in BI.

CONCLUSION

The present study is the first to identify the specific control strategy that increases risk for anxiety. Thus, it is not cognitive control per se, but the specific control strategy children adopt that could increase risk for anxiety later in life. These findings have important implications for future evidence-based interventions because they suggest that an emphasis on decreasing reactive cognitive control and increasing proactive cognitive control might decrease anxious cognition.

Advancing clinical neuroscience through enhanced tools: Pediatric social anxiety as an example

BACKGROUND

Clinical researchers face challenges when trying to quantify diverse processes engaged during social interactions. We report results from two studies, each demonstrating the potential utility of tools for examining processes engaged during social interactions.

METHOD

In the first study, youth (n = 57) used a smartphone-based tool to rate mood and responses to social events. A subset (n = 20) completed the second, functional magnetic resonance imaging study. This second study related anxiety to error-evoked brain responses in two social conditions-while being observed and when alone. We also combined these tools to bridge clinical, social-contextual, and neural levels of measurement.

RESULTS

Results from the first study showed an association between negatively-perceived social experiences and a range of negative emotions. In the second study there was a positive correlation during error monitoring between social-anxiety severity and context-specific activation of the pregenual anterior cingulate cortex. Finally, during imaging, the perceived quality of peer interactions as assessed using the smartphone-based tool, interacted with social context to predict levels of activation in the hippocampus and superior frontal gyrus.

CONCLUSIONS

By improving measurement, enhanced tools may provide new means for studying relationships among anxiety, brain function, and social interactions.

Relations between catechol-O-methyltransferase Val158Met genotype and inhibitory control development in childhood

The Val158Met rs4680 single-nucleotide polymorphism (SNP) at the catechol-O-methyltransferase (COMT) gene, primarily involved in dopamine breakdown within prefrontal cortex, has shown relations with inhibitory control (IC) in both adults and children. However, little is known about how COMT genotype relates to developmental trajectories of IC throughout childhood. Here, our study explored the effects of the COMT genotype (Val/Val, Val/Met, and Met/Met) on IC trajectories between the ages of 5 and 10 years. Children (n = 222) completed a Go/Nogo task at ages 5, 7, and 10; IC was characterized using signal detection theory to examine IC performance (d') and response strategy (RS) (criterion). COMT genotype was not related to initial levels of IC performance and RS at age 5 or change in RS from ages 5 to 10. In contrast, COMT genotype was related to change in IC performance between 5 and 10 years. While Val/Val children did not differ from Val/Met children in development of IC performance, children with the Met/Met genotype exhibited more rapid development of IC performance when compared with Val/Met peers. These results suggest that COMT genotype modulates the development of IC performance in middle childhood.

Development of inhibitory control during childhood and its relations to early temperament and later social anxiety: unique insights provided by latent growth modeling and signal detection theory

BACKGROUND

Children with the temperament of behavioral inhibition (BI) face increased risk for social anxiety. However, not all children with BI develop anxiety symptoms. Inhibitory control (IC) has been suggested as a moderator of the pathway between BI and social anxiety. This study uses longitudinal data to characterize development of IC and tests the hypothesis that IC moderates associations between early BI and later social anxiety symptoms.

METHODS

Children completed a Go/Nogo task at ages 5, 7, and 10 years as part of a longitudinal study of BI (measured at 2-3 years) and social anxiety symptoms (measured at 12 years). To assess IC development, response strategy (criterion) and inhibitory performance (d') were characterized using signal detection theory. Latent growth models were used to characterize the development of IC and examine relations among BI, IC parameters, and social anxiety symptoms.

RESULTS

IC response strategy did not change between 5 and 10 years of age, whereas IC performance improved over time. BI scores in toddlerhood predicted neither initial levels (intercept) nor changes (slope) in IC response strategy or IC performance. However, between ages 5 and 10, rate of change in IC performance, but not response strategy, moderated relations between BI and later parent-reported social anxiety symptoms. Specifically, greater age-related improvements in IC performance predicted higher levels of social anxiety in high BI children.

CONCLUSIONS

IC development in childhood occurs independent of BI levels. However, rapid increases in IC performance moderate risk for social anxiety symptoms in children with BI. Implications for theory and practice are discussed.

Frontal alpha asymmetry moderates the relations between behavioral inhibition and social-effect ERN

Behavioral inhibition (BI) is an early temperamental precursor of anxiety disorders, characterized by withdrawal from novel situations. Some but not all young children with BI go on to display anxiety disorders. Neural correlates, such as frontal alpha asymmetry or event-related negativity (ERN), could moderate the relations between early BI and later anxiety. The goal of this longitudinal study was to test frontal alpha asymmetry as a potential moderator of the relation between BI and later anxiety, and of the relation between BI and the social-effect ERN. 100 children were assessed for BI at ages 2 and 3, and we collected EEG during resting state and the social Flanker task at age 12. Frontal alpha asymmetry did not correlate with BI or anxiety, nor did it moderate the relation between early BI and later anxiety. However, frontal alpha asymmetry did moderate the relation between BI and the social-effect ERN. This suggests that, in adolescents who previously manifested BI, a pattern of resting EEG associated with avoidance predicts hypersensitivity to errors in a social context.

Reward Processing in Depression: A Conceptual and Meta-Analytic Review Across fMRI and EEG Studies

OBJECTIVE

A role for aberrant reward processing in the pathogenesis of depression has long been proposed. However, no review has yet examined its role in depression by integrating conceptual and quantitative findings across functional MRI (fMRI) and EEG methodologies. The authors quantified these effects, with an emphasis on development.

METHOD

A total of 38 fMRI and 12 EEG studies were entered into fMRI and EEG meta-analyses. fMRI studies primarily examined reward anticipation and reward feedback. These were analyzed using the activation likelihood estimation method. EEG studies involved mainly the feedback-related negativity (FRN) event-related potential, and these studies were analyzed using random-effects meta-analysis of the association between FRN and depression.

RESULTS

Analysis of fMRI studies revealed significantly reduced striatal activation in depressed compared with healthy individuals during reward feedback. When region-of-interest analyses were included, reduced activation was also observed in reward anticipation, an effect that was stronger in individuals under age 18. FRN was also significantly reduced in depression, with pronounced effects in individuals under age 18. In longitudinal studies, reduced striatal activation in fMRI and blunted FRN in EEG were found to precede the onset of depression in adolescents.

CONCLUSIONS

Taken together, the findings show consistent neural aberrations during reward processing in depression, namely, reduced striatal signal during feedback and blunted FRN. These aberrations may underlie the pathogenesis of depression and have important implications for development of new treatments.

Mu rhythm desynchronization is specific to action execution and observation: Evidence from time-frequency and connectivity analysis

Mu desynchronization is the attenuation of EEG power in the alpha frequency range recorded over central scalp locations thought to reflect motor cortex activation. Mu desynchronization during observation of an action is believed to reflect mirroring system activation in humans. However, this notion has recently been questioned because, among other reasons, the potential contamination of mu rhythm and occipital alpha activity induced by attention processes following presentation of visual stimuli in observation conditions. This study examined the validity of mu desynchronization as a measure of mirroring system activation in infants and further investigated the pattern of functional connectivity between the central and occipital regions during execution and observation of movement. EEG was recorded while 46 9-month-old infants executed grasping actions and observed an experimenter grasping. Current source density (CSD) was applied to EEG data and, time-frequency and connectivity analyses were performed in CSD transformed data. Mu desynchronization was evident over central regions during both execution and observation of movements. Independent alpha desynchronization over occipital region was also present in both conditions. The connectivity analyses revealed that central-occipital areas were functionally more connected compared to other areas of the brain during observation of movements. Collectively, the results demonstrate the validity of mu desynchronization as an index of infant mirroring system activity and support the proposal of a functional connection between distinct mirroring and attention processes during observation of action.

Time-frequency approaches to investigating changes in feedback processing during childhood and adolescence

Processing feedback from the environment is an essential function during development to adapt behavior in advantageous ways. One measure of feedback processing, the feedback negativity (FN), is an ERP observed following the presentation of feedback. Findings detailing developmental changes in the FN have been mixed, possibly due to limitations in traditional ERP measurement methods. Recent work shows that both theta and delta frequency activity contribute to the FN; utilizing time-frequency methods to measure change in power and phase in these frequency bands may provide more accurate representation of feedback processing development in childhood and adolescence. We employ time-frequency power and intertrial phase synchrony measures, in addition to conventional time-domain ERP methods, to examine the development of feedback processing in the theta (4-7 Hz) and delta (.1-3 Hz) bands throughout adolescence. A sample of 54 female participants (8-17 years old) completed a gambling task while EEG was recorded. As expected, time-domain ERP amplitudes showed no association with age. In contrast, significant effects were observed for the time-frequency measures, with theta power decreasing with age and delta power increasing with age. For intertrial phase synchrony, delta synchrony increased with age, while age-related changes in theta synchrony differed for gains and losses. Collectively, these findings highlight the importance of considering time-frequency dynamics when exploring how the processing of feedback develops through late childhood and adolescence. In particular, the role of delta band activity and theta synchrony appear central to understanding age-related changes in the neural response to feedback.

Approach, avoidance, and the detection of conflict in the development of behavioral inhibition

Motivation has played an integral role in understanding personality development. Two motivational systems, one associated with seeking reward (approach motivation) and one associated with avoidance of threat (avoidance motivation), have been theorized to represent individual differences in behavioral responses to the environment. However, contextual factors, particularly those with a high degree of novelty, ambiguity, and unpredictability, may simultaneously activate both systems, thereby causing approach-avoidance conflict. The resulting behavior, commonly called inhibition, is characterized by an inability to engage in motivated, goal-directed behavior and is theorized to reflect a core component of anxiety. A form of inhibition observed in childhood, behavioral inhibition (BI), is a relatively stable temperamental profile characterized by negative affect in response to unfamiliar and unpredictable contexts and is a risk factor for anxiety. Our review draws from findings in clinical and cognitive neuroscience to argue that BI reflects an increased sensitivity of both approach and avoidance motivational systems, thereby increasing the likelihood of approach-avoidance conflict within the context of unfamiliar or unpredictable stimuli and environments. Such motivational conflict activates neural systems associated with conflict monitoring, which leads to increases in arousal (e.g., sympathetic nervous system activity) and onlooking behavior, two commonly observed characteristics of childhood BI.

A Neurobehavioral Mechanism Linking Behaviorally Inhibited Temperament and Later Adolescent Social Anxiety

OBJECTIVE

Behavioral inhibition (BI) is a temperament identified in early childhood that is a risk factor for later social anxiety. However, mechanisms underlying the development of social anxiety remain unclear. To better understand the emergence of social anxiety, longitudinal studies investigating changes at behavioral neural levels are needed.

METHOD

BI was assessed in the laboratory at 2 and 3 years of age (N = 268). Children returned at 12 years, and an electroencephalogram was recorded while children performed a flanker task under 2 conditions: once while believing they were being observed by peers and once while not being observed. This methodology isolated changes in error monitoring (error-related negativity) and behavior (post-error reaction time slowing) as a function of social context. At 12 years, current social anxiety symptoms and lifetime diagnoses of social anxiety were obtained.

RESULTS

Childhood BI prospectively predicted social-specific error-related negativity increases and social anxiety symptoms in adolescence; these symptoms directly related to clinical diagnoses. Serial mediation analysis showed that social error-related negativity changes explained relations between BI and social anxiety symptoms (n = 107) and diagnosis (n = 92), but only insofar as social context also led to increased post-error reaction time slowing (a measure of error preoccupation); this model was not significantly related to generalized anxiety.

CONCLUSION

Results extend prior work on socially induced changes in error monitoring and error preoccupation. These measures could index a neurobehavioral mechanism linking BI to adolescent social anxiety symptoms and diagnosis. This mechanism could relate more strongly to social than to generalized anxiety in the peri-adolescent period.

Development of the error-monitoring system from ages 9-35: Unique insight provided by MRI-constrained source localization of EEG

The ability to self-detect errors and dynamically adapt behavior is a cornerstone of higher-level cognition, requiring coordinated activity from a network of neural regions. However, disagreement exists over how the error-monitoring system develops throughout adolescence and early adulthood. The present report leveraged MRI-constrained EEG source localization to detail typical development of the error-monitoring system in a sample of 9-35 year-olds (n = 43). Participants performed a flanker task while high-density EEG was recorded; structural MRIs were also acquired for all participants. Analysis of the scalp-recorded EEG data revealed a frontocentral negativity (error-related negativity; ERN) immediately following errors for all participants, although the topography of the ERN varied with age. Source localization of the ERN time range revealed maximal activity within the posterior cingulate cortex (PCC) for all ages, consistent with recent evidence that the PCC provides a substantial contribution to the scalp-recorded ERN. Activity within a network of brain regions, including dorsal anterior cingulate, PCC, and parietal cortex, was predictive of improved performance following errors, regardless of age. However, additional activity within insula, orbitofrontal cortex and inferior frontal gyrus linearly increased with age. Together, these data suggest that the core error-monitoring system is online by early adolescence and remains relatively stable into adulthood. However, additional brain regions become embedded within this core network with age. These results serve as a model of typical development of the error-monitoring system from early adolescence into adulthood.

Averted body postures facilitate orienting of the eyes

It is well established that certain social cues, such as averted eye gaze, can automatically initiate the orienting of another's spatial attention. However, whether human posture can also reflexively cue spatial attention remains unclear. The present study directly investigated whether averted neutral postures reflexively cue the attention of observers in a normal population of college students. Similar to classic gaze-cuing paradigms, non-predictive averted posture stimuli were presented prior to the onset of a peripheral target stimulus at one of five SOAs (100ms-500ms). Participants were instructed to move their eyes to the target as fast as possible. Eye-tracking data revealed that participants were significantly faster in initiating saccades when the posture direction was congruent with the target stimulus. Since covert attention shifts precede overt shifts in an obligatory fashion, this suggests that directional postures reflexively orient the attention of others. In line with previous work on gaze-cueing, the congruency effect of posture cue was maximal at the 300ms SOA. These results support the notion that a variety of social cues are used by the human visual system in determining the "direction of attention" of others, and also suggest that human body postures are salient stimuli capable of automatically shifting an observer's attention.

Using Electrophysiological Measures to Assess the Consumer Acceptability of Smokeless Tobacco Products

INTRODUCTION

Adequate evaluation of novel tobacco products must include investigation of consumers' psychological response to such products. Traditionally, subjective scales of product liking have been used to assess consumer acceptability of tobacco products. However, subjective scales may miss cognitive changes that can only be captured by direct neurophysiological assessment. The present investigation explored the viability of using electroencephalography (EEG), in combination with traditional subjective measures, to assess consumer acceptability of five smokeless tobacco products. Given previous work linking product liking to arousal/attentional (executive function) enhancement, we focused on EEG measures of attention/arousal to objectively characterize cognitive changes associated with tobacco product use.

METHODS

During five separate laboratory visits, smokeless tobacco users used Verve discs, Ariva dissolvables, Skoal snuff, Camel snus, or Nicorette lozenges. The N2 and P3b event-related potential components elicited by an oddball task were used to index attentional changes before/after product usage. Additionally, resting state alpha band EEG activity was analyzed before/after product usage to index cortical arousal.

RESULTS

Although analyses of the subjective results provided limited inference, analyses of the electrophysiological measures, particularly the alpha suppression measure, revealed robust differences between products. Skoal elicited significantly enhanced alpha suppression compared to all four other products tested. Additionally, alpha suppression was found to correlate positively with subjective measures of satisfaction and psychological reward, but was unrelated to perceived aversion.

CONCLUSIONS

The present results provide evidence that electrophysiological measures can yield important insights into consumer acceptability of novel tobacco products and are a valuable complement to subjective measures.

IMPLICATIONS

This study is the first to employ a combination of electrophysiological measures and traditional subjective assays in order to assess the consumer acceptability of smokeless tobacco products. The results highlight the importance of adopting a multidimensional/multi-method approach to studying the consumer acceptability of tobacco products.

Prestimulus oscillations in the alpha band of the EEG are modulated by the difficulty of feature discrimination and predict activation of a sensory discrimination process

Recent work has demonstrated that the occipital-temporal N1 component of the ERP is sensitive to the difficulty of visual discrimination, in a manner that cannot be explained by simple differences in low-level visual features, arousal, or time on task. These observations provide evidence that the occipital-temporal N1 component is modulated by the application of top-down control. However, the timing of this control process remains unclear. Previous work has demonstrated proactive, top-down modulation of cortical excitability for cued spatial attention or feature selection tasks. Here, the possibility that a similar top-down process facilitates performance of a difficult stimulus discrimination task is explored. Participants performed an oddball task at two levels of discrimination difficulty, with difficulty manipulated by modulating the similarity between target and nontarget stimuli. Discrimination processes and cortical excitability were assessed via the amplitude of the occipital-temporal N1 component and prestimulus alpha oscillation of the EEG, respectively. For correct discriminations, prestimulus alpha power was reduced, and the occipital-temporal N1 was enhanced in the hard relative to the easy condition. Furthermore, within the hard condition, prestimulus alpha power was reduced, and the occipital-temporal N1 was enhanced for correct relative to incorrect discriminations. The generation of ERPs contingent on relative prestimulus alpha power additionally suggests that diminished alpha power preceding stimulus onset is related to enhancement of the occipital-temporal N1. As in spatial attention, proactive control appears to enhance cortical excitability and facilitate discrimination performance in tasks requiring nonspatial, feature-based attention, even in the absence of competing stimulus features.

An electrophysiological correlate of conflict processing in an auditory spatial Stroop task: the effect of individual differences in navigational style

Recent work has identified an event-related potential (ERP) component, the incongruency negativity (N(inc)), which is sensitive to auditory Stroop conflict processing. Here, we investigated how this index of conflict processing is influenced by individual differences in cognitive style. There is evidence that individuals differ in the strategy they use to navigate through the environment; some use a predominantly verbal-egocentric strategy while others rely more heavily on a spatial-allocentric strategy. In addition, navigational strategy, assessed by a way-finding questionnaire, is predictive of performance on an auditory spatial Stroop task, in which either the semantic or spatial dimension of stimuli must be ignored. To explore the influence of individual differences in navigational style on conflict processing, participants took part in an auditory spatial Stroop task while the electroencephalogram (EEG) was recorded. Whereas behavioral performance only showed a main effect of congruency, we observed the predicted three-way interaction between congruency, task type and navigational style with respect to our physiological measure of Stroop conflict. Specifically, congruency-dependent modulation of the N(inc) was observed only when participants performed their non-dominant task (e.g., verbal navigators attempting to ignore semantic information). These results confirm that the N(inc) reliably indexes auditory Stroop conflict and extend previous results by demonstrating that the N(inc) is predictably modulated by individual differences in cognitive style.