Interplay among Anxiety, Digital Environmental Exposure, and Cognitive Control: Implications of Natural Settings

Inhibitory control performance may differ greatly as a function of individual differences such as anxiety. Nonetheless, how cognitive control proficiency might be influenced by exposure to various environments and how anxiety traits might impact these effects remain unexplored. A cohort of thirty healthy volunteers participated in the study. Participants performed a Go/No-Go task before exposure to a 'forest' and 'urban' virtual environment, in a counterbalanced design, before repeating the GNG task. The State-Trait Anxiety Inventory (STAI) was finally filled-in. Our findings unveiled an initial negative correlation between anxiety trait levels and GNG task performance, consistent with the established literature attributing difficulties in inhibitory functionality to anxiety. Additionally, different environmental exposures reported opposite trends. Exposure to the 'forest' environment distinctly improved the GNG performance in relation to anxiety traits, while the 'urban' setting demonstrated adverse effects on task performance. These results underscore the intricate relationship among cognitive control, environmental exposure, and trait anxiety. In particular, our findings highlight the potential of natural settings, such as forests, to mitigate the impact of anxiety on inhibition. This might have implications for interventions aimed at improving cognitive control.

Component-specific developmental trajectories of ERP indices of cognitive control in early childhood

Early childhood is characterized by robust developmental changes in cognitive control. However, our understanding of intra-individual change in neural indices of cognitive control during this period remains limited. Here, we examined developmental changes in event-related potential (ERP) indices of cognitive control from preschool through first grade, in a large and diverse sample of children (N = 257). We recorded ERPs during a visual Go/No-Go task. N2 and P3b mean amplitudes were extracted from the observed waveforms (Go and No-Go) and the difference wave (No-Go minus Go, or ∆). Latent growth curve modeling revealed that while N2 Go and No-Go amplitudes showed no linear change, P3b Go and No-Go amplitudes displayed linear decreases in magnitude (became less positive) over time. ∆N2 amplitude demonstrated a linear increase in magnitude (became more negative) over time whereas ∆P3b amplitude was more positive in kindergarten compared to preschool. Younger age in preschool predicted greater rates of change in ∆N2 amplitude, and higher maternal education predicted larger initial P3b Go and No-Go amplitudes in preschool. Our findings suggest that observed waveforms and difference waves are not interchangeable for indexing neurodevelopment, and the developmental trajectories of different ERP indices of cognitive control are component-specific in early childhood.

Effects of sensory integration training on balance function and executive function in children with autism spectrum disorder: evidence from Footscan and fNIRS

Introduction

This study investigates the efficacy of sensory integration training (SIT) in enhancing balance and executive functions in children with autism spectrum disorder (ASD), with the aim of highlighting its potential for organizing and processing sensory information in the brain.

Methods

Utilizing Footscan for biomechanical evidence and functional near-infrared spectroscopy (fNIRS) for neural activation, we engaged two participant groups: a control group (n = 9) and an experimental group (n = 9). Assessments involved the Sharpened Romberg Test (SRT) for balance under varied visual conditions and the Go/No-Go task for executive function.

Results

The SIT intervention significantly improved balance function, particularly in Visual Deprivation (VD) scenarios. Neurophysiological data revealed heightened activation in the right Inferior Frontal Gyrus (R-IFG) and right Middle Frontal Gyrus (R-MFG), suggesting enhanced executive function. The potential of R-IFG/MFG activation as a reliable biomarker for assessing executive function in ASD was identified.

Discussion

The study provides empirical evidence supporting SIT's effectiveness in enhancing balance and executive functions in children with ASD. The therapy not only improves sensory processing and motor skills but also appears to compensate for sensory deficits, particularly in vision, vestibular perception, and proprioception. Enhanced neural activation in specific PFC regions underscores SIT's role in improving cognitive aspects, including inhibitory control and cognitive flexibility. The multidisciplinary approach adopted for this research highlights the intricate interplay between sensory-motor functions and cognitive control in ASD, paving the way for integrated therapeutic strategies. Despite these advancements, the mechanisms through which SIT exerts these multifaceted effects require further exploration.

Meta-analysis of acute alcohol effects on response inhibition

Alcohol intoxication impairs response inhibition; however, discrepant findings have been reported regarding the magnitude and moderators of this effect. This meta-analysis of human laboratory studies aimed to quantify acute effects of alcohol on response inhibition and evaluate moderators of this effect. Eligible studies examined alcohol's effects on response inhibition with the Go/No-Go (GNG) task (n = 1616 participants) or Stop Signal Task (SST) (n = 1310 participants). Results revealed a detrimental effect of acute alcohol on response inhibition overall (g = 0.411, 95 % CI [0.350, 0.471]), with similar effects in studies using GNG (g = 0.431, SE = 0.031) and SST (g = 0.366, SE = 0.063). Effect sizes were larger in studies involving higher breath alcohol concentration levels and under GNG conditions that established a prepotent response set. These findings establish the magnitude, precision, and potential moderators of alcohol's effects on inhibitory control, furthering understanding of a key neurobehavioral mechanism proposed to underlie alcohol-related impulsivity and impaired control over consumption.

Differential optogenetic activation of the auditory midbrain in freely moving behaving mice

Introduction

In patients with severe auditory impairment, partial hearing restoration can be achieved by sensory prostheses for the electrical stimulation of the central nervous system. However, these state-of-the-art approaches suffer from limited spectral resolution: electrical field spread depends on the impedance of the surrounding medium, impeding spatially focused electrical stimulation in neural tissue. To overcome these limitations, optogenetic activation could be applied in such prostheses to achieve enhanced resolution through precise and differential stimulation of nearby neuronal ensembles. Previous experiments have provided a first proof for behavioral detectability of optogenetic activation in the rodent auditory system, but little is known about the generation of complex and behaviorally relevant sensory patterns involving differential activation.

Methods

In this study, we developed and behaviorally tested an optogenetic implant to excite two spatially separated points along the tonotopy of the murine inferior colliculus (ICc).

Results

Using a reward based operant Go/No-Go paradigm, we show that differential optogenetic activation of a sub-cortical sensory pathway is possible and efficient. We demonstrate how animals which were previously trained in a frequency discrimination paradigm (a) rapidly respond to either sound or optogenetic stimulation, (b) generally detect optogenetic stimulation of two different neuronal ensembles, and (c) discriminate between them.

Discussion

Our results demonstrate that optogenetic excitatory stimulation at different points of the ICc tonotopy elicits a stable response behavior over time periods of several months. With this study, we provide the first proof of principle for sub-cortical differential stimulation of sensory systems using complex artificial cues in freely moving animals.

Effects of binge drinking and depression on cognitive-control processes during an emotional Go/No-Go task in emerging adults

INTRODUCTION

The goal of the current study was to examine differences in neurocognitive processes across groups marked by binge drinking and depression to identify patterns of cognitive and affective processing impairments.

METHODS

Undergraduate students (N = 104; 64% female) were recruited based on self-reported symptoms of depression and alcohol use. They completed an emotional Go/No-Go task while undergoing EEG. Mean amplitudes for N2 and P3 components were examined with 2 (Depressed/Non-depressed) X 2 (Binge/Non-binge drinkers) X 4 (Happy/Sad/Angry/Calm) X 3 (Left/Middle/Right) X 2 (Go/No-Go) repeated measures ANOVAs.

RESULTS

There were significant Trial Type X Valence X Depression X Binge Drinking interactions for N2 (F(3, 80) = 6.62, p < .01) and P3 (F(3, 80) = 4.65, p < .01) components. There was a significant Valence X Depression X Binge Drinking interaction for response bias (F(3, 65) = 3.11, p < .05).

LIMITATIONS

The source of our sample may be a limitation, as all participants were university students, potentially making the results less generalizable. Further, we cannot be certain that social desirability did not interfere with honest reporting of alcohol use in this population.

CONCLUSIONS

Differences in early inhibitory control were observed across emotions based on trial type among depressed non-binge drinkers, and these differences were attenuated in the presence of binge drinking. Further, the effects of depression on later inhibitory control were specific to non-binge drinkers. Results help to clarify the nature of underlying patterns of neurocognitive and affective risk processes that could be targeted by prevention and intervention programs.

Response inhibition and error-monitoring in cystinosis (CTNS gene mutations): Behavioral and electrophysiological evidence of a diverse set of difficulties

Cystinosis, a rare lysosomal storage disease, is characterized by cystine crystallization and accumulation within tissues and organs, including the kidneys and brain. Its impact on neural function appears mild relative to its effects on other organs, but therapeutic advances have led to substantially increased life expectancy, necessitating deeper understanding of its impact on neurocognitive function. Behaviorally, some deficits in executive function have been noted in this population, but the underlying neural processes are not understood. Using standardized cognitive assessments and a Go/No-Go response inhibition task in conjunction with high-density electrophysiological recordings (EEG), we sought to investigate the behavioral and neural dynamics of inhibition of a prepotent response and of error monitoring (critical components of executive function) in individuals with cystinosis, when compared to age-matched controls. Thirty-seven individuals diagnosed with cystinosis (7-36 years old, 24 women) and 45 age-matched controls (27 women) participated in this study. Analyses focused on N2 and P3 No-Go responses and error-related positivity (Pe). Atypical inhibitory processing was shown behaviorally. Electrophysiological differences were additionally found between the groups, with individuals with cystinosis showing larger No-Go P3s. Error-monitoring was likewise different between the groups, with those with cystinosis showing reduced Pe amplitudes.

Disgust sensitivity and behavioural inhibitory systems in binge eating disorder: associations with eating pathology

Disgust sensitivity refers to how unpleasant a disgusting experience is to an individual and is involved in the development of many psychiatric conditions. Given its link with food ingestion, there is an interest in understanding how an individual's susceptibility to disgust relates to dietary habits. One possible mechanism giving rise to this association is through the effects negative emotions have on high-order cognitive processes, but few studies take this model into account. The aim of this study was to characterize general disgust sensitivity in a clinical binge eating disorder (BED) population, and explore whether disgust sensitivity relates to inhibitory control and eating pathology. Following a case-controlled study design, our results show that: (1) disgust sensitivity and its subscales do not differ between BED and healthy controls, (2) higher disgust sensitivity in BED relates to greater behavioural inhibition, (3) inhibitory control reaction times relate to aspects of eating pathology, and (4) inhibitory control does not mediate relationships between disgust sensitivity and BMI among participants with BED. Understanding the role of disgust sensitivity in BED may allow us to understand how negative emotion systems maintain dysregulated eating behaviours with the potential to inform emotion-regulation treatment approaches. Level of evidence: Level III: Evidence obtained from well-designed cohort or case-control analytic studies.

Dysconnectivity between the anterior insula and the dorsal anterior cingulate cortex during an emotion go/nogo paradigm is associated with aggressive behaviors in male schizophrenia patients

This study aimed to investigate the association between past-reported violent/aggressive behaviors and brain functional connectivity in male patients suffering from schizophrenia using a task modeling the interaction between negative emotion processing and response inhibition. Forty-four male patients with schizophrenia and twenty-two healthy male controls performed an emotional go/no-go task using angry and neutral faces during a functional magnetic resonance imaging session. Generalized psycho-physiological interaction was conducted to explore task-based functional connectivity and a negative binomial regression was used to evaluate the relationship between neural alterations and violent/aggressive behaviors. Regions involved in response inhibition and emotion regulation, such as the anterior insula, dorsal anterior cingulate cortex (dACC) and dorsolateral prefrontal cortex (DLPFC), were used as seed regions. During emotion-related response inhibition, patients with schizophrenia displayed altered connectivity between the anterior insula and amygdala, the DLPFC and lateral orbitofrontal cortex (OFC), as well as the anterior insula and the dACC when compared to healthy individuals. The latter was negatively associated with aggressive behaviors in participants with schizophrenia (Wald χ² = 9.51; p < 0.05, p-FDR corrected). Our results highlight alterations in functional connectivity in brain regions involved in cognitive control and emotion processing which are associated with aggressive behaviors in schizophrenia.

Functional connectivity in ADHD children doing Go/No-Go tasks: An fMRI systematic review and meta-analysis

Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders diagnosed in childhood. Two common features of ADHD are impaired behavioural inhibition and sustained attention. The Go/No-Go experimental paradigm with concurrent functional magnetic resonance imaging (fMRI) scanning has previously revealed important neurobiological correlates of ADHD such as the supplementary motor area and the prefrontal cortex. The coordinate-based meta-analysis combined with quantitative techniques, such as activation likelihood estimate (ALE) generation, provides an unbiased and objective method of summarising these data to understand the brain network architecture and connectivity in ADHD children. Go/No-Go task-based fMRI studies involving children and adolescent subjects were selected. Coordinates indicating foci of activation were collected to generate ALEs using threshold values (voxel-level: p < 0.001; cluster-level: p < 0.05). ALEs were matched to one of seven canonical brain networks based on the cortical parcellation scheme derived from the Human Connectome Project. Fourteen studies involving 457 children met the eligibility criteria. No significant convergence of Go/No-Go related brain activation was found for ADHD groups. Three significant ALE clusters were detected for brain activation relating to controls or ADHD < controls. Significant clusters were related to specific areas of the default mode network (DMN). Network-based analysis revealed less extensive DMN, dorsal attention network, and limbic network activation in ADHD children compared to controls. The presence of significant ALE clusters may be due to reduced homogeneity in the selected sample demographic and experimental paradigm. Further investigations regarding hemispheric asymmetry in ADHD subjects would be beneficial.

Machine Learning Based on Event-Related EEG of Sustained Attention Differentiates Adults with Chronic High-Altitude Exposure from Healthy Controls

(1) Objective: The aim of this study was to examine the effect of high altitude on inhibitory control processes that underlie sustained attention in the neural correlates of EEG data, and explore whether the EEG data reflecting inhibitory control contain valuable information to classify high-altitude chronic hypoxia and plain controls. (2) Methods: 35 chronic high-altitude hypoxic adults and 32 matched controls were recruited. They were required to perform the go/no-go sustained attention task (GSAT) using event-related potentials. Three machine learning algorithms, namely a support vector machine (SVM), logistic regression (LR), and a decision tree (DT), were trained based on the related ERP components and neural oscillations to build a dichotomous classification model. (3) Results: Behaviorally, we found that the high altitude (HA) group had lower omission error rates during all observation periods than the low altitude (LA) group. Meanwhile, the ERP results showed that the HA participants had significantly shorter latency than the LAs for sustained potential (SP), indicating vigilance to response-related conflict. Meanwhile, event-related spectral perturbation (ERSP) analysis suggested that lowlander immigrants exposed to high altitudes may have compensatory activated prefrontal cortexes (PFC), as reflected by slow alpha, beta, and theta frequency-band neural oscillations. Finally, the machine learning results showed that the SVM achieved the optimal classification F1 score in the later stage of sustained attention, with an F1 score of 0.93, accuracy of 92.54%, sensitivity of 91.43%, specificity of 93.75%, and area under ROC curve (AUC) of 0.97. The results proved that SVM classification algorithms could be applied to identify chronic high-altitude hypoxia. (4) Conclusions: Compared with other methods, the SVM leads to a good overall performance that increases with the time spent on task, illustrating that the ERPs and neural oscillations may provide neuroelectrophysiological markers for identifying chronic plateau hypoxia.

Kinematic Studies of the Go/No-Go Task as a Dynamic Sensorimotor Inhibition Task for Assessment of Motor and Executive Function in Stroke Patients: An Exploratory Study in a Neurotypical Sample

Inhibition of reaching and grasping actions as an element of cognitive control and executive function is a vital component of sensorimotor behaviour that is often impaired in patients who have lost sensorimotor function following a stroke. To date, there are few kinematic studies detailing the fine spatial and temporal upper limb movements associated with the millisecond temporal trajectory of correct and incorrect responses to visually driven Go/No-Go reaching and grasping tasks. Therefore, we aimed to refine the behavioural measurement of correct and incorrect inhibitory motor responses in a Go/No-Go task for future quantification and personalized rehabilitation in older populations and those with acquired motor disorders, such as stroke. An exploratory study mapping the kinematic profiles of hand movements in neurotypical participants utilizing such a task was conducted using high-speed biological motion capture cameras, revealing both within and between subject differences in a sample of healthy participants. These kinematic profiles and differences are discussed in the context of better assessment of sensorimotor function impairment in stroke survivors.

Sustained attention alterations in major depressive disorder: A review of fMRI studies employing Go/No-Go and CPT tasks

BACKGROUND

Major depressive disorder (MDD) is a severe psychiatric condition characterized by selective cognitive dysfunctions. In this regard, functional Magnetic Resonance Imaging (fMRI) studies showed, both at resting state and during tasks, alterations in the brain functional networks involved in cognitive processes in MDD patients compared to controls. Among those, it seems that the attention network may have a role in the disease pathophysiology. Therefore, in this review we aim at summarizing the current fMRI evidence investigating sustained attention in MDD patients.

METHODS

We conducted a search on PubMed on case-control studies on MDD employing fMRI acquisitions during Go/No-Go and continuous performance tasks. A total of 12 studies have been included in the review.

RESULTS

Overall, the majority of fMRI studies reported quantitative alterations in the response to attentive tasks in selective brain regions, including the prefrontal cortex, the cingulate cortex, the temporal and parietal lobes, the insula and the precuneus, which are key nodes of the attention, the executive, and the default mode networks.

LIMITATIONS

The heterogeneity in the study designs, fMRI acquisition techniques and processing methods have limited the generalizability of the results.

CONCLUSIONS

The results from the included studies showed the presence of alterations in the activation patterns of regions involved in sustained attention in MDD, which are in line with current evidence and seemed to explain some of the key symptoms of depression. However, given the paucity and heterogeneity of studies available, it may be worthwhile to continue investigating the attentional domain in MDD with ad-hoc study designs to retrieve more robust evidence.

Cue-induced craving and negative emotion disrupt response inhibition in methamphetamine use disorder: Behavioral and fMRI results from a mixed Go/No-Go task

BACKGROUND

Drug-related cue-reactivity, dysfunctional negative emotion processing, and response-disinhibition constitute three core aspects of methamphetamine use disorder (MUD). These phenomena have been studied independently, but the neuroscientific literature on their interaction in addictive disorders remains scant.

METHODS

62 individuals with MUD were scanned when responding to the geometric Go or No-Go cues superimposed over blank, neutral, negative-emotional and drug-related background images. Neural correlates of drug and negative-emotional cue-reactivity, response-inhibition and their interactions were estimated, and methamphetamine cue-reactivity was compared between individuals with MUD and 23 healthy controls. Relationships between behavioral characteristics and observed activations were investigated.

RESULTS

Individuals with MUD had longer reaction times and more errors in drug and negative-emotional compared to blank blocks, and more omission errors in drug compared to neutral blocks. They showed higher drug cue-reactivity than controls across prefrontal, fusiform, and visual regions (Z > 3.1, p-corrected<0.05). Response-inhibition was associated with precuneal, inferior parietal, anterior cingulate, temporal, and inferior frontal activations (Z > 3.1, p-corrected<0.05). Response-inhibition in drug cue blocks coincided with higher activations in the visual cortex and lower activations in the paracentral lobule and superior and inferior frontal gyri, while inhibition during negative-emotional blocks led to higher superior parietal, fusiform, and lateral occipital activations (Z > 3.1, p-corrected<0.05).

CONCLUSION

Drug cue-reactivity may impair response inhibition partly through activating dis-inhibitory regions, while temporal and parietal activations associated with response-inhibition in negative blocks suggest compensatory activity. Results suggest that drug and negative-emotional cue-reactivity influence response-inhibition, and the study of these interactions may aid mechanistic understanding of methamphetamine use disorder.

Electrocorticography to Investigate Age-Related Brain Lateralization on Pediatric Motor Inhibition

Response inhibition refers to the ability to suppress inappropriate actions that interfere with goal-driven behavior. The inferior frontal gyrus (IFG) is known to be associated with inhibition of a motor response by assuming executive control over motor cortex outputs. This study aimed to evaluate the pediatric development of response inhibition through subdural electrocorticography (ECoG) recording. Subdural ECoG recorded neural activities simultaneously during a Go/No-Go task, which was optimized for children. Different frequency power [theta: 4–8 Hz; beta: 12–40 Hz; high-gamma (HG): 70–200 Hz] was estimated within the IFG and motor cortex. Age-related analysis was computed by each bandpass power ratio between Go and No-Go conditions, and phase-amplitude coupling (PAC) over IFG by using the modulating index metric in two conditions. For all the eight pediatric patients, HG power was more activated in No-Go trials than in Go trials, in either right- or left-side IFG when available. In the IFG region, the power over theta and HG in No-Go conditions was higher than those in Go conditions, with significance over the right side (p < 0.05). The age-related lateralization from both sides to the right side was observed from the ratio of HG power and PAC value between the No-Go and Go trials. In the pediatric population, the role of motor inhibition was observed in both IFG, with age-related lateralization to the right side, which was proved in the previous functional magnetic resonance imaging studies. In this study, the evidence correlation of age and response inhibition was observed directly by the evidence of cortical recordings.

Impulsivity, inhibition, and internet addiction in medical students of North of Iran

BACKGROUND

Internet addiction, a serious psychological disorder, has rapidly increased among students and caused substantial interpersonal impairments. On the other hand, some evidence has indicated that impulsivity is associated with addictive behaviors.

OBJECTIVES

There are a few studies concerning the relationship between internet addiction and impulsivity in Iranian students. Therefore, this study aimed to evaluate the relationship between impulsivity and internet addiction in the medical students of Golestan University of Medical Sciences, Golestan, Iran, within 2020-2021.

METHODS

In a cross-sectional study, 260 medical students at Golestan University of Medical Sciences in 2021 completed demographic, Barratt Impulsiveness Scale, and Young questionnaires and participated in a Go/No-Go computer test. Based on Young test scores, the students were divided into three groups of normal users, at-risk users, and users requiring treatment and compared regarding impulsivity and inhibition ability. Data was analyzed using SPSS v 23.

RESULTS

The mean age of the participants was 24.16 years. The results showed a significant correlation between impulsivity and internet addiction (p = 0.001), which was established in all contextual indicators. A significant correlation was also shown between impulsivity and internet addiction (r = 0.602 and p = 0.001), both in male and female student. However, restraint index was correlated with internet addiction only in females (r = 0.187 and p = 0.033).

CONCLUSION

Based on these findings, impulsivity increases alongside the rising of the internet addiction severity and does not influence by gender.

5-HT2C receptor perturbation has bidirectional influence over instrumental vigour and restraint

The serotonin (5-HT) system, particularly the 5-HT2C receptor, has consistently been implicated in behavioural control. However, while some studies have focused on the role 5-HT2C receptors play in regulating motivation to work for reward, others have highlighted its importance in response restraint. To date, it is unclear how 5-HT transmission at this receptor regulates the balance of response invigoration and restraint in anticipation of future reward. In addition, it remains to be established how 5-HT2C receptors gate the influence of internal versus cue-driven processes over reward-guided actions. To elucidate these issues, we investigated the effects of administering the 5-HT2C receptor antagonist SB242084, both systemically and directly into the nucleus accumbens core (NAcC), in rats performing a Go/No-Go task for small or large rewards. The results were compared to the administration of d-amphetamine into the NAcC, which has previously been shown to promote behavioural activation. Systemic perturbation of 5-HT2C receptors-but crucially not intra-NAcC infusions-consistently boosted rats' performance and instrumental vigour on Go trials when they were required to act. Concomitantly, systemic administration also reduced their ability to withhold responding for rewards on No-Go trials, particularly late in the holding period. Notably, these effects were often apparent only when the reward on offer was small. By contrast, inducing a hyperdopaminergic state in the NAcC with d-amphetamine strongly impaired response restraint on No-Go trials both early and late in the holding period, as well as speeding action initiation. Together, these findings suggest that 5-HT2C receptor transmission, outside the NAcC, shapes the vigour of ongoing goal-directed action as well as the likelihood of responding as a function of expected reward.

Impact of Perceived Stress and Immune Status on Decision-Making Abilities during COVID-19 Pandemic Lockdown

The ability to make risky decisions in stressful contexts has been largely investigated in experimental settings. We examined this ability during the first months of COVID-19 pandemic, when in Italy people were exposed to a prolonged stress condition, mainly caused by a rigid lockdown. Participants among the general population completed two cognitive tasks, an Iowa Gambling Task (IGT), which measures individual risk/reward decision-making tendencies, and a Go/No-Go task (GNG), to test impulsivity, together with two questionnaires, the Perceived Stress Scale and the Depression, Anxiety and Stress Scales. The Immune Status Questionnaire was additionally administered to explore the impact of the individual health status on decision making. The effect of the questionnaires scores on task performance was examined. The results showed that higher levels of perceived stress and a more self-reported vulnerable immune status were associated, separately, with less risky/more advantageous choices in the IGT in young male participants but with more risky/less advantageous choices in older male participants. These effects were not found in female participants. Impulsivity errors in the GNG were associated with more anxiety symptoms. These findings bring attention to the necessity of taking into account decision-making processes during stressful conditions, especially in the older and more physically vulnerable male population.

Prenatal PM2.5 exposure in the second and third trimesters predicts neurocognitive performance at age 9-10 years: A cohort study of Mexico City children

INTRODUCTION

Prenatal exposure to fine particulate matter air pollution (PM2.5) is an important, under-studied risk factor for neurodevelopmental dysfunction. We describe the relationships between prenatal PM2.5 exposure and vigilance and inhibitory control, executive functions related to multiple health outcomes in Mexico City children.

METHODS

We studied 320 children enrolled in Programming Research in Obesity, GRowth, Environment and Social Stressors, a longitudinal birth cohort study in Mexico City. We used a spatio-temporal model to estimate daily prenatal PM2.5 exposure at each participant's residential address. At age 9-10 years, children performed three Go/No-Go tasks, which measure vigilance and inhibitory control ability. We used Latent class analysis (LCA) to classify performance into subgroups that reflected neurocognitive performance and applied multivariate regression and distributed lag regression modeling (DLM) to test overall and time-dependent associations between prenatal PM2.5 exposure and Go/No-Go performance.

RESULTS

LCA detected two Go/No-Go phenotypes: high performers (Class 1) and low performers (Class 2). Predicting odds of Class 1 vs Class 2 membership based on prenatal PM2.5 exposure timing, logistic regression modeling showed that average prenatal PM2.5 exposure in the second and third trimesters correlated with increased odds of membership in low-performance Class 2 (OR = 1.59 (1.16, 2.17), p = 0.004). Additionally, DLM analysis identified a critical window consisting of gestational days 103-268 (second and third trimesters) in which prenatal PM2.5 exposure predicted poorer Go/No-Go performance.

DISCUSSION

Increased prenatal PM2.5 exposure predicted decreased vigilance and inhibitory control at age 9-10 years. These findings highlight the second and third trimesters of gestation as critical windows of PM2.5 exposure for the development of vigilance and inhibitory control in preadolescent children. Because childhood development of vigilance and inhibitory control informs behavior, academic performance, and self-regulation into adulthood, these results may help to describe the relationship of prenatal PM2.5 exposure to long-term health and psychosocial outcomes. The integrative methodology of this study also contributes to a shift towards more holistic analysis.

Exploring Hypersexuality Pathways From Eye Movements: The Role of (Sexual) Impulsivity

BACKGROUND

Impulsivity is regarded as a key factor underpinning hypersexuality like-conditions. However, impulsivity is a multifaceted construct, and existing research has not been capturing such complexity, which includes the effects of domain-general and domain-specific impulsivity in hypersexuality.

AIM

The aim of this study was to test the predictive role of specific impulsivity domains, ie, domain-general and domain-specific, in hypersexuality and its associated consequences.

METHODS

Fifty-five men and 58 women went through an emotional Go/-no-Go task (including sexual, high-valence positive, and neutral pictures), aimed at capturing domain-general and domain-specific impulsivity. Ocular metrics were further considered in order to increase the validity of the experimental task, and provide a metric of attention capturing. The study was carried out in a community sample.

OUTCOMES

Self-reported (general)impulsivity and commission errors toward high-valence positive and sexual pictures (signaling domain-general and domain-specific impulsivity, respectively) were settled as independent variables, along with Time to First Fixation to stimuli, capturing early/uncontrolled attention. Scores on hypersexuality and negative consequences emerging from hypersexual behavior were settled as outcome variables.

RESULTS

Self-reported (general)impulsivity was the only predictor of hypersexuality scores, while negative consequences were best accounted by higher fixation time to sexual pictures. In all, findings did not support the role of domain-specific impulsivity (ie, sexual impulsivity) in hypersexuality.

CLINICAL TRANSLATION

Findings tentatively suggest that hypersexuality, as captured at the community level, may be best positioned within the general spectrum of psychopathology, thus influencing educational and clinical intervention protocols aimed at addressing hypersexuality related complaints. Protocols would be expected to primarily target general psychopathology phenomena, rather than specific sexual aspects.

STRENGTHS & LIMITATIONS

This study implemented an innovative approach to capture different impulsivity domains, thus adding to previous literature in the field. However, the current study precludes the generalization of findings to clinical samples, where psychological comorbidities are expected to impact results. Further, findings must be read with caution given to limited effect sizes.

CONCLUSION

While hypersexuality was related to self-reported (general) impulsivity, findings on the negative consequences associated with hypersexual behavior mirrored response patterns found in depression. Such evidence aligns with the assumption that hypersexuality related phenomena might be better positioned in the psychopathology domain, rather than simply framed as a specific sexual problem. Carvalho J, Rosa PJ, Štulhofer A. Exploring Hypersexuality Pathways From Eye Movements: The Role of (Sexual) Impulsivity. J Sex Med 2021;18:1607-1614.

Brain Network Analysis of EEG Recordings Can Be Used to Assess Cognitive Function in Teenagers With 15q13.3 Microdeletion Syndrome

15q13.3 microdeletion syndrome causes a spectrum of cognitive disorders, including intellectual disability and autism. We assessed the ability of the EEG analysis algorithm Brain Network Analysis (BNA) to measure cognitive function in 15q13.3 deletion patients, and to differentiate between patient and control groups. EEG data was collected from 10 individuals with 15q13.3 microdeletion syndrome (14–18 years of age), as well as 30 age-matched healthy controls, as the subjects responded to Auditory Oddball (AOB) and Go/NoGo cognitive tasks. It was determined that BNA can be used to evaluate cognitive function in 15q13.3 microdeletion patients. This analysis also significantly differentiates between patient and control groups using 5 scores, all of which are produced from ERP peaks related to late cortical components that represent higher cognitive functions of attention allocation and response inhibition (P < 0.05).

The Effects of Subliminal Goal Priming on Emotional Response Inhibition in Cases of Major Depression

Previous studies have provided evidence that automatic emotion regulation (AER), which is primed by control goals, can change emotion trajectory unconsciously. However, the cognitive mechanism and associated changes in depression remain unclear. The current study aimed to examine whether subliminal goal priming could change the emotional response inhibition among patients with major depressive disorder (MDD) and their healthy controls. A group of patients with depression and a healthy control group were both primed subliminally by playing control goal related or neutral words for 20 ms each; afterward, they judged the gender of happy or angry faces in an emotional Go/No-Go task. A group of depressed patients and a healthy control group both were both primed subliminally with control goal-related words (20 ms) or neutral words (20 ms), and they judged the gender of happy or angry faces in an emotional Go/No-Go task. Among patients with depression, there were fewer false alarms of the No-Go response to emotional stimulus after priming with control goal rather than neutral words. Meanwhile, patients with MDD in the subliminal regulation goal priming condition reacted faster to happy rather than angry faces; no significant difference was found in the subliminal neutral priming condition. These findings suggest the malleability of inhibitory control in depression using subliminal priming goals.

Atypical response inhibition and error processing in 22q11.2 Deletion Syndrome and schizophrenia: Towards neuromarkers of disease progression and risk

22q11.2 deletion syndrome (also known as DiGeorge syndrome or velo-cardio-facial syndrome) is characterized by increased vulnerability to neuropsychiatric symptoms, with approximately 30% of individuals with the deletion going on to develop schizophrenia. Clinically, deficits in executive function have been noted in this population, but the underlying neural processes are not well understood. Using a Go/No-Go response inhibition task in conjunction with high-density electrophysiological recordings (EEG), we sought to investigate the behavioral and neural dynamics of inhibition of a prepotent response (a critical component of executive function) in individuals with 22q11.2DS with and without psychotic symptoms, when compared to individuals with idiopathic schizophrenia and age-matched neurotypical controls. Twenty-eight participants diagnosed with 22q11.2DS (14-35 years old; 14 with at least one psychotic symptom), 15 individuals diagnosed with schizophrenia (18-63 years old) and two neurotypical control groups (one age-matched to the 22q11.2DS sample, the other age-matched to the schizophrenia sample) participated in this study. Analyses focused on the N2 and P3 no-go responses and error-related negativity (Ne) and positivity (Pe). Atypical inhibitory processing was shown behaviorally and by significantly reduced P3, Ne, and Pe responses in 22q11.2DS and schizophrenia. Interestingly, whereas P3 was only reduced in the presence of psychotic symptoms, Ne and Pe were equally reduced in schizophrenia and 22q11.2DS, regardless of the presence of symptoms. We argue that while P3 may be a marker of disease severity, Ne and Pe might be candidate markers of risk.

Response inhibition in Veterans with a history of mild traumatic brain injury: The role of self-reported complaints in objective performance

INTRODUCTION

Although objective deficits in response inhibition (RI) have been detected in civilians with mild traumatic brain injury (mTBI), it remains unclear whether objective RI is worse in military Veterans with mTBI despite the prevalence of self-reported disinhibition. Assessing RI in Veterans is critical due to their unique characteristics, including combat and blast exposure, in addition to the prevalence of psychiatric comorbidity. Therefore, the aims of this study were to (1) examine RI performance in Veterans with mTBI compared to non-mTBI Veterans and (2) compare RI performance in well-defined subgroups of mTBI Veterans with and without self-reported complaints of disinhibition to non-mTBI Veterans.

METHOD

53 mTBI Veterans and 37 non-mTBI Veterans completed a Go/No-Go RI task and measures of self-reported disinhibition (Frontal Systems Behavior Scale) and psychiatric symptoms. ANCOVAs covarying for mood and demographics compared RI performances of the non-mTBI Veterans to (1) the total sample of mTBI Veterans (n= 53) and to (2) mTBI Veterans with elevated (t-score ≥ 60; mTBI-SubjDis; n= 23) and low (t-score < 60; mTBI-NoSubjDis; n= 30) levels of self-reported disinhibition.

RESULTS

There were no significant differences in RI between the mTBI group as a whole and the non-mTBI Veterans group. However, when Veterans with mTBI were divided into groups by clinically-significant concern about their disinhibition, the mTBI-SubjDis group demonstrated significantly worse RI than the mTBI-NoSubjDis and non-mTBI Veteran groups. No significant differences in RI performance were observed between the mTBI-NoSubjDis and non-mTBI Veteran groups.

CONCLUSIONS

Results indicate that mTBI Veterans with elevated levels of self-reported disinhibition show diminished performance on objective measures of RI, independent of mood. Findings highlight the unique contribution of subjective complaints on executive functioning in mTBI, and they underscore the importance of assessing cognitive complaints in order to identify those most at risk for poor-long term outcomes.

Open-source raspberry Pi-based operant box for translational behavioral testing in rodents

BACKGROUND

Rodents have been used for decades to probe neural circuits involved in behavior. Increasingly, attempts have been developed to standardize training paradigms across labs; and to use visual/auditory paradigms that can be also tested in humans. Commercially available systems are expensive and thus do not scale easily, and are not optimized for electrophysiology.

NEW METHOD

Using the rich open-source technology built around Raspberry Pi, we were able to develop an inexpensive (<$1000) visual-screen based operant chamber with electrophysiological and optogenetic compatibility. The chamber is operated within MATLAB/Simulink, a commonly used scientific programming language allowing for rapid customization.

RESULTS

Here, we describe and provide all relevant details needed to develop and produce these chambers, and show examples of behavior and electrophysiology data collected using these chambers. We also include all of the tools needed to allow readers to build and develop their own boxes (CAD models for 3D printing and laser-cutting; PCB-board design; all bill of materials for required parts and supplies, and some examples of Simulink models to operate the boxes).

COMPARISON WITH EXISTING METHODS

The new boxes are far more cost-effective than commercially available environments and allow for the combination of automated behavioral testing with electrophysiological read-outs with high temporal precision.

CONCLUSION

These open-source boxes can be used for labs interested in developing high-throughput visual/auditory behavioral assays for ∼ 10th the cost of commercial systems.

Recent life stress predicts blunted acute stress response and the role of executive control

The present study examined the associations between recent life stress and responses to acute psychological stress, and how these associations varied with executive control. Heart rate (HR), heart rate variability (HRV), salivary cortisol, and affective states were measured before, during and after the Trier Social Stress Test (TSST), an effective laboratory stressor, in 54 healthy participants, and executive control function was tested with a Go/No-Go task in a neutral context on a different day. The hierarchical multiple regression analysis showed that high frequency of life stress during the last twelve months predicted blunted cardiovascular acute stress response, i.e., smaller HR and HRV reactivity. Moreover, the low executive control group showed a significant association between higher recent life stress and blunted acute stress response, which was not apparent in the high executive control group. The results suggested that greater executive control may benefit us with adaptive acute stress response under recent life stress.HighlightsThe Trier Social Stress Test induces cardiovascular and cortisol responses.Higher life event frequency (LEF) predicts smaller cardiovascular stress response.Executive control plays a role in the link of LEF to stress response.

Activation of medial hypothalamic orexin neurons during a Go/No-Go task

Orexin neurons (Orx; also referred to as hypocretin) are found exclusively in the hypothalamus, and release the neuropeptides orexin A and orexin B (also referred to as hypocretin 1 and 2) throughout the CNS. With its widespread targets, the orexin system is involved in a number of functions including, but not limited to stress, reward, wakefulness, and food seeking. Our laboratory has previously proposed that the dorsomedial hypothalamus (DMH) and perifornical (PFA) orexin neurons function in stress and arousal whereas those in lateral hypothalamus (LH) participate in reward processes (Harris and Aston-Jones, 2006). In the current study, we compared Fos activation in orexin neurons located in medial hypothalamus (DMH and PFA) to those in LH during a Go/No-Go task for a highly palatable food reward, a task that would likely activate regions for arousal/attention as well as reward. The Go/No-Go paradigm is a useful behavioral tool to measure behavioral inhibition, impulsivity, learning, and reaction time. Our results revealed increased activation of medial hypothalamic orexin neurons correlated with greater accuracy on the Go/No-Go task. No correlation was found between Go/No-Go accuracy and activation of lateral hypothalamic orexin neurons. This study supports a functional dichotomy of medial vs lateral orexin neurons, and indicates a role for medial orexin neurons in behavioral performance that requires response inhibition.

Psychological Resilience, Mental Health, and Inhibitory Control Among Youth and Young Adults Under Stress

Psychological resilience allows one to cope successfully with adversities occurring during stressful periods, which may otherwise trigger mental illness. Recent models suggest that inhibitory control (IC), the executive control function which supports our goal-directed behavior and regulates our emotional response, may underlie resilience. However, the ways in which this is manifested during stressful situations in real life is still unclear. Here, we examined the relationship between IC, psychological resilience, psychological distress, and anxiety among 138 female and male participants in a stressful situation: during their initial combat training in the military. Using a mobile app, we assessed IC using emotional and non-emotional variations of the Go/No-Go task. Psychological resilience, psychological distress, and anxiety were assessed using mobile versions of self-report questionnaires. We found that psychological resilience is significantly correlated with non-emotional IC (r = 0.24, p < 0.005), but not with emotional IC; whereas, psychological distress and anxiety are correlated with emotional IC (r = -0.253, p < 0.005 and r = -0.224, p < 0.01, for psychological distress and anxiety, respectively), but not with non-emotional IC. A regression model predicting emotional IC confirmed non-emotional IC and distress as unique contributors to the variance, but not psychological distress. In addition, associations between psychological distress and emotional IC were found only for female participants. Collectively, the results clarify the link between IC, resilience, and mental health in real-life stressful situations, showing separate mechanisms of IC involved in resilience on the one hand, and mental health on the other hand. These results have implications for building mobile resilience interventions for youth and young adults facing stressful situations.

Longitudinal associations between conflict monitoring and emergent academic skills: An event-related potentials study

Identifying the links between specific cognitive functions and emergent academic skills can help determine pathways to support both early academic performance and later academic achievement. Here, we investigated the longitudinal associations between a key aspect of cognitive control, conflict monitoring, and emergent academic skills from preschool through first grade, in a large sample of socioeconomically diverse children (N = 261). We recorded event-related potentials (ERPs) during a Go/No-Go task. The neural index of conflict monitoring, ΔN2, was defined as larger N2 mean amplitudes for No-Go versus Go trials. ΔN2 was observed over the right hemisphere across time points and showed developmental stability. Cross-lagged panel models revealed prospective links from ΔN2 to later math performance, but not reading performance. Specifically, larger ΔN2 at preschool predicted higher kindergarten math performance, and larger ΔN2 at kindergarten predicted higher first-grade math performance, above and beyond the behavioral performance in the Go/No-Go task. Early academic skills did not predict later ΔN2. These findings provided electrophysiological evidence for the contribution of conflict monitoring abilities to emergent math skills. In addition, our findings suggested that neural indices of cognitive control can provide additional information in predicting emergent math skills, above and beyond behavioral task performance.

Effects of aerobic exercise on sad emotion regulation in young women: an electroencephalograph study

The effects of exercise on cognitive abilities have been studied. However, evidence regarding the neural substrates of sad emotion regulation is limited. Women have higher rates for affective disorders than men, but insufficient outcomes assess how aerobic exercises modulate central frontal activation in sad emotion inhibition and resilience among healthy women. This study investigated the effects of aerobic exercise-related brain activity on sad emotion inhibition processing in young women. Sad facial Go/No-Go and neutral Go/No-Go trials were conducted among 30 healthy young women to examine the changes in the N2 component, which reflects frontal inhibition responses, between pre-exercise and post-exercise periods. The first test was performed before aerobic exercise (baseline; 1st) and the second test was performed during an absolute rest period of 90 min after exercise. The sad No-Go stimuli that evoked N200 (N2) event-related potential were recorded and analyzed. The results showed that in the sad No-Go trials, N2 activation at the central-prefrontal cortex was significantly attenuated after exercise compared to the baseline N2 activation. Exercise-modulated N2 activation was not observed in the neutral No-Go trials. The behavioral error rates of sad No-Go trials did not differ between the two experiments. A reduced engagement of central-frontal activation to sad No-Go stimuli was shown after exercise. However, behavioral performance was consistent between the two measurements. The findings scope the benefits of the aerobic exercise on the neural efficiency in responding to sad emotion-eliciting cues as well as adaptive transitions reinstatement for regulatory capabilities in healthy young women.

Quantitative decision-making in randomized Phase II studies with a time-to-event endpoint

One of the most critical decision points in clinical development is Go/No-Go decision-making after a proof-of-concept study. Traditional decision-making relies on a formal hypothesis testing with control of type I and type II error rates, which is limited by assessing the strength of efficacy evidence in a small isolated trial. In this article, we propose a quantitative Bayesian/frequentist decision framework for Go/No-Go criteria and sample size evaluation in Phase II randomized studies with a time-to-event endpoint. By taking the uncertainty of treatment effect into consideration, we propose an integrated quantitative approach for a program when both the Phase II and Phase III trials share a common endpoint while allowing a discount of the observed Phase II data. Our results confirm the argument that an increase in the sample size of a Phase II trial will result in greater increase in the probability of success of a Phase III trial than increasing the Phase III trial sample size by equal amount. We illustrate the steps in quantitative decision-making with a real example of a randomized Phase II study in metastatic pancreatic cancer.

Impulsive responding in threat and reward contexts as a function of PTSD symptoms and trait disinhibition

We examined current posttraumatic stress disorder (PTSD) symptoms, trait disinhibition, and affective context as contributors to impulsive and self-destructive behavior in 94 trauma-exposed Veterans. Participants completed an affective Go/No-Go task (GNG) with different emotional contexts (threat, reward, and a multidimensional threat/reward condition) and current PTSD, trait disinhibition, and risky/self-destructive behavior measures. PTSD interacted with trait disinhibition to explain recent engagement in risky/self-destructive behavior, with Veterans scoring high on trait disinhibition and current PTSD symptoms reporting the highest levels of these behaviors. On the GNG task, commission errors were also associated with the interaction of PTSD symptoms and trait disinhibition. Specifically, PTSD symptoms were associated with greater commission errors in threat vs. reward contexts for individuals who were low on trait disinhibition. In contrast, veterans high on PTSD and trait disinhibition exhibited the greatest number of commission errors in the multidimensional affective context that involved both threat and reward processing. Results highlight the interactive effects of PTSD and disinhibited personality traits, as well as threat and reward systems, as risk factors for impulsive and self-destructive behavior in trauma-exposed groups. Findings have clinical implications for understanding heterogeneity in the expression of PTSD and its association with disinhibited behavior.

ArControl: An Arduino-Based Comprehensive Behavioral Platform with Real-Time Performance

Studying animal behavior in the lab requires reliable delivering stimulations and monitoring responses. We constructed a comprehensive behavioral platform (ArControl: Arduino Control Platform) that was an affordable, easy-to-use, high-performance solution combined software and hardware components. The hardware component was consisted of an Arduino UNO board and a simple drive circuit. As for software, the ArControl provided a stand-alone and intuitive GUI (graphical user interface) application that did not require users to master scripts. The experiment data were automatically recorded with the built in DAQ (data acquisition) function. The ArControl also allowed the behavioral schedule to be entirely stored in and operated on the Arduino chip. This made the ArControl a genuine, real-time system with high temporal resolution (<1 ms). We tested the ArControl, based on strict performance measurements and two mice behavioral experiments. The results showed that the ArControl was an adaptive and reliable system suitable for behavioral research.

Brief Report: The Go/No-Go Task Online: Inhibitory Control Deficits in Autism in a Large Sample

Autism Spectrum Conditions (ASC, also referred to as Autism Spectrum Disorders) entail difficulties with inhibition: inhibiting action, inhibiting one's own point of view, and inhibiting distractions that may interfere with a response set. However, the association between inhibitory control (IC) and ASC, especially in adulthood, is unclear. The current study measured IC, using the Go/No-Go task online, in a large adult sample of 201 people with ASC and 240 controls. Number of both False Alarm and False Positive responses were significantly associated with autistic traits and diagnostic status, separately, but not jointly. These findings suggest that deficits in inhibition are associated with ASC. Future studies need to investigate the role of inhibition in ASC in everyday difficulties.

A mathematical and biological plausible model of decision-execution regulation in "Go/No-Go" tasks: Focusing on the fronto-striatal-thalamic pathway

Discovering factors influencing the speed and accuracy of responses in tasks such as "Go/No-Go" is one of issues which have been raised in neurocognitive studies. Mathematical models are considered as tools to identify and to study decision making procedure from different aspects. In this paper, a mathematical model has been presented to show several factors can alter the output of decision making procedure before execution in a "Go/No-Go" task. The dynamic of this model has two stable fixed points, each of them corresponds to the "Press" and "Not-press" responses. This model that focuses on the fronto-striatal-thalamic direct and indirect pathways, receives planned decisions from frontal cortex and sends a regulated output to motor cortex for execution. The state-space analysis showed that several factors could affect the regulation procedure such as the input strength, noise value, initial condition, and the values of involved neurotransmitters. Some probable analytical reasons that may lead to changes in decision-execution regulation have been suggested as well. Bifurcation diagram analysis demonstrates that an optimal interaction between these factors can compensate the weaknesses of some others. It is predicted that abnormalities of response control in different brain disorders such as attention deficit hyperactivity disorder may be resolved by providing treatment techniques that target the regulation of the interaction. The model also suggests a possible justification to show why so many studies insist on the important role of dopamine in some brain disorders.

Neurodynamic correlates of response inhibition from emerging to mid adulthood

Response inhibition, a key executive function, continues to develop in early adulthood in parallel with maturational processes of the underlying prefrontal regions known to support it. The current study examined behavioral and neurophysiological correlates of response inhibition during a visual Go/No-Go task in a large sample (N = 120) comprised of participants in their Early 20s (ages 19-21), Mid 20s (ages 23-27), and Early 30s (ages 28-42). The two younger groups had lower accuracy, shorter reaction times, and made more premature responses compared to Early 30s. These impulsive behavioral tendencies were reflected in a delayed N2 latency and reduced P2 and P3 amplitudes for Early 20s compared to Early 30s and were associated with personality traits such as impulsivity in an age-dependent manner. The results suggest that response inhibition may not develop fully before the approximate age of 25, as the refinement of the primarily prefrontal cognitive control network follows a protracted developmental trajectory throughout young adulthood.

A split-brain case study on the hemispheric lateralization of inhibitory control

Understanding the neurobiological mechanisms underlying inhibitory control is crucial given its role in various disease states and substance abuse/misuse. Neuroimaging research examining inhibitory control has yielded conflicting results on the relative importance of the left and right hemisphere during successful inhibition of a motor response. In the current study, a split-brain patient was examined in order to assess the independent inhibitory capabilities of each hemisphere. The patient's right hemisphere exhibited superior inhibitory ability compared to his left hemisphere on three inhibitory control tasks. Although inferior to the right, the left hemisphere inhibited motor responses on inhibitory trials in all three tasks. The results from this study support the dominance of the right hemisphere in inhibitory control.

Olfactory Cued Learning Paradigm

Sensory stimulation leads to structural changes within the CNS (Central Nervous System), thus providing the fundamental mechanism for learning and memory. The olfactory circuit offers a unique model for studying experience-dependent plasticity, partly due to a continuous supply of integrating adult born neurons. Our lab has recently implemented an olfactory cued learning paradigm in which specific odor pairs are coupled to either a reward or punishment to study downstream circuit changes. The following protocol outlines the basic set up for our learning paradigm. Here, we describe the equipment setup, programming of software, and method of behavioral training.

Progesterone attenuates impulsive action in a Go/No-Go task for sucrose pellets in female and male rats

Impulsivity, or a tendency to act without anticipation of future consequences, is associated with drug abuse. Impulsivity is typically separated into two main measures, impulsive action and impulsive choice. Given the association of impulsivity and drug abuse, treatments that reduce impulsivity have been proposed as an effective method for countering drug addiction. Progesterone has emerged as a promising treatment, as it is associated with decreased addiction-related behaviors and impulsive action. The goal of the present study was to determine the effects of progesterone (PRO) on impulsive action for food: a Go/No-Go task. Female and male rats responded for sucrose pellets during a Go component when lever pressing was reinforced on a variable-interval 30-s schedule. During the alternate No-Go component, withholding a lever press was reinforced on a differential reinforcement of other (DRO) behavior 30-s schedule, where a lever press reset the DRO timer. Impulsive action was operationally defined as the inability to withhold a response during the No-Go component (i.e. the number of DRO resets). Once Go/No-Go behavior was stable, responding between rats treated with PRO (0.5mg/kg) or vehicle was examined. Progesterone significantly decreased the total number of DRO resets in both males and females, but it did not affect VI responding for sucrose pellets. This suggests that PRO decreases motor impulsivity for sucrose pellets without affecting motivation for food. Thus, PRO may reduce motor impulsivity, a behavior underlying drug addiction.

Self-regulation interventions to reduce consumption of sugar-sweetened beverages in adolescents

This study evaluated the efficacy of self-regulation interventions through the use of drink-specific implementation intentions and drink-specific Go/No-Go training tasks as compensatory strategies to modify inhibitory control to reduce intake of sugar-sweetened beverages (SSB). In a between-subjects randomized manipulation of implementation intentions and Go/No-Go training to learn to inhibit sugary drink consumption, 168 adolescents reporting inhibitory control problems over sugary drinks and foods were recruited from high schools in southern California to participate. Analysis of covariance overall test of effects revealed no significant differences between the groups regarding calories consumed, calories from SSBs, grams of sugar consumed from drinks, or the number of unhealthy drinks chosen. However, subsequent contrasts revealed SSB implementation intentions significantly reduced SSB consumption following intervention while controlling for inhibitory control failure and general SSB consumption during observation in a lab setting that provided SSBs and healthy drinks, as well as healthy and unhealthy snacks. Specifically, during post-intervention observation, participants in the sugar-sweetened beverage implementation intentions (SSB-II) conditions consumed significantly fewer calories overall, fewer calories from drinks, and fewer grams of sugar. No effects were found for the drink-specific Go/No-Go training on SSB or calorie consumption. However, participants in SSB-II with an added SSB Go/No-Go training made fewer unhealthy drink choices than those in the other conditions. Implementation intentions may aid individuals with inhibitory (executive control) difficulties by intervening on pre-potent behavioral tendencies, like SSB consumption.

Effects of serotonin depletion on punishment processing in the orbitofrontal and anterior cingulate cortices of healthy women

Diminished synthesis of the neurotransmitter serotonin (5-HT) has been linked to disrupted impulse control in aversive contexts. However, the neural correlates underlying a serotonergic modulation of female impulsivity remain unclear. The present study investigated punishment-induced inhibition in healthy young women. Eighteen healthy female subjects (aged 20-31) participated in a double-blinded, counterbalanced, placebo-controlled, within subjects, repeated measures study. They were assessed on two randomly assigned occasions that were controlled for menstrual cycle phase. In a randomized order, one day, acute tryptophan depletion (ATD) was used to reduce 5-HT synthesis in the brain. On the other day, participants received a tryptophan-balanced amino acid load (BAL) as a control condition. Three hours after administration of ATD/BAL, neural activity was recorded during a modified Go/No-Go task implementing reward or punishment processes using functional magnetic resonance imaging (fMRI). Neural activation during No-Go trials in punishment conditions after BAL versus ATD administration correlated positively with the magnitude of central 5-HT depletion in the ventral and subgenual anterior cingulate cortices (ACC). Furthermore, neural activation in the medial orbitofrontal cortex (mOFC) and the dorsal ACC correlated positively with trait impulsivity. The results indicate reduced neural sensitivity to punishment after short-term depletion of 5-HT in brain areas related to emotion regulation (subgenual ACC) increasing with depletion magnitude and in brain areas related to appraisal and expression of emotions (mOFC and dorsal ACC), increasing with trait impulsivity. This suggests a serotonergic modulation of neural circuits related to emotion regulation, impulsive behavior, and punishment processing in females.

A signal detection analysis of executive control performance among adolescent inhalant and cannabis users

BACKGROUND

Inhalant users have multiple comorbid issues (e.g., polydrug use) that complicate identifying inhalant-specific cognitive deficits.

OBJECTIVES

The aim of the present study was to use signal detection theory to identify inhalant-specific differences in executive control.

METHODS

We examined three well-matched groups: 19 inhalant users, 19 cannabis users, and 19 controls using Stroop and Go/No-Go tasks.

RESULTS

Inhalant users demonstrated significantly lower d-prime scores relative to controls, but not cannabis users, on both tasks, suggesting possible executive deficits relative to controls. CONCLUSIONS/IMPORTANCE: The results of this study raise questions regarding inhalant toxicity and the vulnerability of the adolescent brain to drugs of abuse.

Increased forebrain activations in youths with family histories of alcohol and other substance use disorders performing a Go/NoGo task

BACKGROUND

Youths with a family history of alcohol and other drug use disorders (FH+) are at a greater risk of developing substance use disorders than their peers with no such family histories (FH-), and this increased risk may be related to impaired maturation of forebrain circuitry. FH+ individuals have shown altered forebrain activity at rest and while performing cognitive tasks. However, it is not fully understood how forebrain activity is altered in FH+ individuals, and ultimately how these alterations may contribute to substance use disorder risk.

METHODS

In this study, we tested 72 FH+ and 32 FH- youths performing a go/no-go task and examined activations in blocks with only go trials (Go Only), blocks with 50% go and 50% no-go trials (Go/NoGo), and a contrast of those 2 blocks.

RESULTS

FH+ youths had significantly greater cerebral activations in both the Go and Go/NoGo blocks than FH- youths in regions including the posterior cingulate/precuneus, bilateral middle/superior temporal gyrus, and medial superior frontal gyrus with no significant group differences in the subtraction between Go Only and Go/NoGo blocks. Additionally, FH+ youths had moderately slower reaction times on go trials in the Go Only blocks.

CONCLUSIONS

Our findings suggest that global activation increase in FH+ youths are modulated by FH density and are not specific to the inhibitory components of the task. This pattern of increased activations in FH+ youths may be at least partially due to impaired forebrain white matter development leading to greater activations/less efficient neural communication during task performance.

Timing of response differentiation in human motor cortex during a speeded Go/No-Go task

We explored the brain's ability to quickly prevent a pre-potent but unwanted motor response. To address this, transcranial magnetic stimulation was delivered over the motor cortex (hand representation) to probe excitability changes immediately after somatosensory cues prompted subjects to either move as fast as possible or withhold movement. Our results showed a difference in motor cortical excitability 90ms post-stimulus contingent on cues to either promote or prevent movement. We suggest that our study design emphasizing response speed coupled with well-defined early probes allowed us to extend upon similar past investigations into the timing of response inhibition.

Behavioral disinhibition in mice bred for high drinking in the dark (HDID) and HS controls increases following ethanol

BACKGROUND

Alcohol consumption and behavioral inhibition share some common underlying genetic mechanisms. The current study examined whether lines of mice selected for high blood ethanol concentrations, attained by heavy drinking in the dark period (DID) of the light-dark cycle that models binge drinking, also exhibit higher levels of drug-naïve inhibition. It also examined whether the administration of ethanol would result in higher levels of disinhibition in these selected lines compared to the founder stock (HS).

METHODS

A Go/No-Go task was used to assess baseline inhibition and the effects of acute ethanol on disinhibition (response to a No-Go cue) in the HS line and in mice selected for high levels of DID (HDID-1 and HDID-2).

RESULTS

Lines did not differ in inhibition at baseline and all lines showed increased disinhibition following moderate doses of ethanol. Ethanol decreased responding to Go cues for HDID-2 and HS lines at high doses but not HDID-1 mice.

CONCLUSIONS

These data corroborate previous work showing ethanol-induced increases in behavioral disinhibition. The selection paradigm did not result in differential sensitivity to the disinhibiting effects of ethanol, but did result in differential sensitivity to the suppressant effects of ethanol on operant behavior between the two HDID lines.

Mice bred for severity of acute alcohol withdrawal respond differently in a go/no-go task

BACKGROUND

Mice selectively bred for high or low withdrawal to acute alcohol differ on a number of traits, including consumption of alcohol, conditioned place preference for alcohol, and sensitivity to alcohol-induced locomotor activity. One trait that has not been examined in these mice is behavioral inhibition.

METHODS

High and low alcohol withdrawal mice (second replicate: high and low acute alcohol withdrawal [HAW-2/LAW-2]) were trained and tested in a Go/No-go task. Mice were administered 0.0, 0.5, 1.0, and 1.5 g/kg ethanol (EtOH) on 3 occasions according to an incomplete Latin Square. A separate cohort of C57BL/6J (B6) and DBA/2J (D2) mice (the progenitor strains for HAW-2/LAW-2 mice) underwent the same protocol, using the same EtOH doses.

RESULTS

HAW-2 and LAW-2 mice did not differ in behavioral inhibition at baseline, although LAW-2 mice did have higher overall levels of responding in the task. EtOH did not alter behavioral inhibition in these mice. However, it did decrease responses to the Go cue, and this effect was greater in HAW-2 mice than in LAW-2 mice. D2 mice had lower behavioral inhibition than B6 mice at baseline, and EtOH slightly decreased behavioral inhibition in both strains.

CONCLUSIONS

The findings with D2 and B6 mice generally fit with the existing literature. However, the lack of a difference in behavioral inhibition between HAW-2 and LAW-2 mice was unexpected, as well as the absence of any effect of these doses of EtOH on behavioral inhibition in these mice. Nonetheless, the findings do suggest that selectively breeding for high or low withdrawal to acute alcohol can lead to differences in operant behavior in the Go/No-go task.