Inhibitory control and trait aggression: Neural and behavioral insights using the emotional stop signal task

Aberrant glutamatergic systems underlying impulsive behaviors: Insights from clinical and preclinical research

Impulsivity is a broad construct that often refers to one of several distinct behaviors and can be measured with self-report questionnaires and behavioral paradigms. Several psychiatric conditions are characterized by one or more forms of impulsive behavior, most notably the impulsive/hyperactive subtype of attention-deficit/hyperactivity disorder (ADHD), mood disorders, and substance use disorders. Monoaminergic neurotransmitters are known to mediate impulsive behaviors and are implicated in various psychiatric conditions. However, growing evidence suggests that glutamate, the major excitatory neurotransmitter of the mammalian brain, regulates important functions that become dysregulated in conditions like ADHD. The purpose of the current review is to discuss clinical and preclinical evidence linking glutamate to separate aspects of impulsivity, specifically motor impulsivity, impulsive choice, and affective impulsivity. Hyperactive glutamatergic activity in the corticostriatal and the cerebro-cerebellar pathways are major determinants of motor impulsivity. Conversely, hypoactive glutamatergic activity in frontal cortical areas and hippocampus and hyperactive glutamatergic activity in anterior cingulate cortex and nucleus accumbens mediate impulsive choice. Affective impulsivity is controlled by similar glutamatergic dysfunction observed for motor impulsivity, except a hyperactive limbic system is also involved. Loss of glutamate homeostasis in prefrontal and nucleus accumbens may contribute to motor impulsivity/affective impulsivity and impulsive choice, respectively. These results are important as they can lead to novel treatments for those with a condition characterized by increased impulsivity that are resistant to conventional treatments.

Trait Aggression is Reflected by a Lower Temporal Stability of EEG Resting Networks

Trait aggression can lead to catastrophic consequences for individuals and society. However, it remains unclear how aggressive people differ from others regarding basic, task-independent brain characteristics. We used EEG microstate analysis to investigate how the temporal organization of neural resting networks might help explain inter-individual differences in aggression. Microstates represent whole-brain networks, which are stable for short timeframes (40-120 ms) before quickly transitioning into other microstate types. Recent research demonstrates that the general temporal stability of microstates across types predicts higher levels of self-control and inhibitory control, and lower levels of risk-taking preferences. Given that these outcomes are inversely related to aggression, we investigated whether microstate stability at rest would predict lower levels of trait aggression. As males show higher levels of aggression than females, and males and females express aggression differently, we also tested for possible gender-differences. As hypothesized, people with higher levels of trait aggression showed lower microstate stability. This effect was moderated by gender, with men showing stronger associations compared to women. These findings support the notion that temporal dynamics of sub-second resting networks predict complex human traits. Furthermore, they provide initial indications of gender-differences in the functional significance of EEG microstates.

Individual differences in intracortical inhibition predict action control when facing emotional stimuli

Efficient inhibitory control in the context of prepotent actions is vital. However, such action inhibition may be profoundly influenced by affective states. Interestingly, research indicates that action control can be either impaired or improved by emotional stimuli. Thus, a great deal of confusion surrounds our knowledge of the complex dynamics subtending emotions and action control. Here, we aimed to investigate whether negative stimuli, even when non-consciously presented and task-irrelevant, can affect action control relative to neutral stimuli. Additionally, we tested whether individual differences in intracortical excitability may predict action control capabilities. To address these issues, we asked participants to complete a modified version of the Stop Signal Task (SST) in which fearful or neutral stimuli were subliminally presented before the go signals as primes. Moreover, we assessed participants' resting-state corticospinal excitability, short intracortical inhibition (SICI), and intracortical facilitation (ICF). Results demonstrated better action control capabilities when fearful stimuli were subliminally presented and interindividual SICI predicted stronger action inhibition capabilities. Taken together, these results shed new light on the intricate dynamics between action, consciousness, and motor control, suggesting that intracortical measures can be used as potential biomarkers of reduced motor inhibition in research and clinical settings.

The role of pre-supplementary motor cortex in action control with emotional stimuli: A repetitive transcranial magnetic stimulation study

Swiftly halting ongoing motor actions is essential to react to unforeseen and potentially perilous circumstances. However, the neural bases subtending the complex interplay between emotions and motor control have been scarcely investigated. Here, we used an emotional stop signal task (SST) to investigate whether specific neural circuits engaged by action suppression are differently modulated by emotional signals with respect to neutral ones. Participants performed an SST before and after the administration of one session of repetitive transcranial magnetic stimulation (rTMS) over the pre-supplementary motor cortex (pre-SMA), the right inferior frontal gyrus (rIFG), and the left primary motor cortex (lM1). Results show that rTMS over the pre-SMA improved the ability to inhibit prepotent action (i.e., better action control) when emotional stimuli were presented. In contrast, action control in a neutral context was fostered by rTMS over the rIFG. No changes were observed after lM1 stimulation. Intriguingly, individuals with higher impulsivity traits exhibited enhanced motor control when facing neutral stimuli following rIFG stimulation. These results further our understanding of the interplay between emotions and motor functions, shedding light on the selective modulation of neural pathways underpinning these processes.

Self-control problems in Intermittent Explosive Disorder: Presentation of an explanatory approach

BACKGROUND AND OBJECTIVES

Intermittent Explosive Disorder (IED) is an impulsive aggression disorder with self-control problems. However, the mechanisms underpinning the self-control problems in IED have not been clearly investigated. Therefore, this study examined the nature of self-control problems and their types, including cognitive inhibition, behavioral inhibition, and emotional interference in IED.

METHODS

Participants included three groups: IED (n = 54), psychiatric control (n = 59), and healthy control (n = 62). They were first screened with SCL-90-R, and then they were clinically interviewed. They all did computerized neurocognitive tasks, including Color-Word Stroop Task, Emotional Stroop Task, Go-NoGo Task, and Stop-Signal Task.

RESULTS

MANOVA analyses showed that the IED group had poorer performance in cognitive inhibition, response inhibition, and increased emotional interference than the two psychiatric and healthy control groups. They performed much worse than the other two groups, particularly in action cancellation (Stop-Signal Task), and showed increasingly emotional interference.

LIMITATIONS

The brain reaction of individuals while doing the tasks was not examined, and some variables were not measured. Also, it is unclear how the emotional eruption interferes with cognitive content and behavioral inhibition.

CONCLUSIONS

These findings indicate that self-control problems in IED can be due to deficient cognitive, emotional, and behavioral inhibitions, each appearing sequentially during a step-by-step process and facilitating the onset of IED signs and symptoms. Such a distinguished understanding of the role of neurocognitive mechanisms can lead to the development of accurate explanatory approaches and increase the effectiveness of treatment.

Effect of emotional stimulus on response inhibition in people with mild cognitive impairment: an event-related potential study

Background

A few studies are emerging to explore the issue of how aging promotes emotional response inhibition. However, there is a lack of empirical study concerning the impact of pathological cognitive impairment on emotional response inhibition. The present study investigated the effect of emotion on response inhibition in people with mild cognitive impairment, the stage of cognitive impairment before dementia.

Methods

We used two emotional stop-signal tasks to explore whether the dual competition framework considering limited cognitive resources could explain the relationship between emotion and response inhibition in mild cognitive impairment.

Results

The results showed that negative emotions prolonged N2 latency. The Go trial accuracy was reduced in the high-arousal negative conditions and the stop-signal reaction time was prolonged under high-arousal conditions. This study also verified impaired response inhibition in mild cognitive impairment and found that negative emotions prolonged P3 latency in mild cognitive impairment.

Conclusion

Emotional information interferes with response inhibition in mild cognitive impairment populations, possibly because emotional information captures more attentional resources, thus interfering with response inhibition that relies on common-pool resources.

What does metaphoric language say about aggression? The relationships between metaphoric language, impulsivity, and aggression

Aggressive behavior among adolescents has been identified as a serious worldwide problem, especially when combined with trait impulsivity. This study investigates the impact of an overlooked aspect of language, namely, metaphor comprehension, on impulsivity and aggression in adolescents. A total of 204 adolescents completed self-reported questionnaires assessing impulsivity and aggression and underwent tests assessing familiar and less familiar metaphor comprehension. The findings reveal inverse relationships between metaphor comprehension and both impulsivity and aggression. Regarding aggression, notable distinctions were observed in the correlations between familiar and less familiar metaphors with specific aggression types. Additionally, impulsivity was found to mediate the relationship between the comprehension of familiar metaphors and aggression. These results are elucidated in the context of cognitive and executive functions, emphasizing the significance of considering metaphor comprehension as a cognitive process capable of modulating aggressive behavior.

Mediating effects of impulsivity and alexithymia in the association between traumatic brain injury and aggression in incarcerated males

Studies suggest both alexithymia and impulsivity (partially) explain aggressive behavior in traumatic brain injury (TBI) patients, but none of these studies use both questionnaire and performance-based measures as recommended, nor simultaneously investigate both impulsivity and alexithymia. The available studies therefore likely miss part of the constructs of alexithymia and impulsivity, and do not comprehensively assess the mediating effects of both constructs in the relationship between TBI and aggression. A sample of N = 281 incarcerated individuals were recruited from Dutch penitentiary institutions, and completed the Buss Perry Aggression Questionnaire (aggression), BIS-11 (impulsivity) and Toronto Alexithymia Scale-20 (alexithymia) questionnaires, as well as a stop-signal task and an emotion recognition paradigm. Several multiple mediation analyses were conducted using structural equation modelling, to assess the viability of a causal theoretical model of aggression. The final planned models were the original models with a good fit with the data (comparative fit index > 0.95, root mean square error of approximation and Standardized root mean square residual < 0.05), and results indicate that only questionnaire-based impulsivity mediated the relationship between TBI and aggression. TBI was unrelated to alexithymia, stop-signal or emotion recognition performance. Aggression was predicted by both alexithymia and impulsivity, but not by the performance measures. Post hoc analyses shows that alexithymia moderates the relationship between impulsivity and aggression. These results imply that aggressive incarcerated individuals showing impulsive behavior should be screened for TBI, since TBI is often overlooked or misdiagnosed, and indicate that both impulsivity and alexithymia are potential focus points for aggression reduction treatment in TBI patients.

The impact of emotional stimuli on response inhibition in an inpatient and day-hospital patient psychosomatic cohort

Objectives

To correctly recognize and respond to your counterpart's emotion is essential for a successful get-together. To ensure this, emotional processes and inhibitory control are linked and interact with each other. However, this interaction can be altered in several mental disorders. In a group of psychosomatic patients, we investigated possible differences in the response inhibition between neutral and emotional stimuli and whether a psychosomatic inpatient and day-hospital patient treatment influences response inhibition profiles.

Methods

One hundred and one patients, diagnosed with different psychiatric diagnoses (77 women, 41.43 ± 13.13 years), completed an emotional stop-signal task (ESST) and an impulsive behavior scale upon admission in an inpatient and day-hospital patient treatment on a psychosomatic ward (T0) and at discharge (T1). Patients with depressive disorders completed the test again after 1 year (follow-up measurement T2, n = 22). Emotional stimuli were angry and neutral faces. Stop-signal reaction time (SSRT) and stop-signal delay (SSD) were calculated as the main behavioral parameters.

Results

We found a significantly higher SSRT for neutral than angry faces at both admission (8.538 ms, p < 0.001) and discharge (11.142 ms, p < 0.001), with a matching higher SSD for angry than neutral faces at both timepoints (T0: 8.360 ms, p < 0.001, T1: (6.950 ms, p < 0.001). The SSRT for angry faces significantly decreased after treatment (-8.485 ms, p = 0.0110). For neutral faces, the decrease failed to reach significance (-5.881 ms, p = 0.250). A significant decrease in SSRT for neutral faces in patients with depressive disorders was found 1 year after discharge compared with admission (-19.040 ms, p = 0.0380).

Conclusion

Our data demonstrate a decreased response inhibition for neutral compared with emotional stimuli and an improved response inhibition for angry faces after discharge in a psychosomatic inpatient and day-hospital patient cohort. Additionally, patients with depressive disorders displayed a significantly better response inhibition for neutral faces 1 year after discharge compared with the baseline measurement. With this study, we provide more evidence for altered emotional response inhibition in different mental disorders and a hint that psychosomatic inpatient and day-hospital patient treatment may help to normalize it, even if the effects remained small and it needs further research to prove causality.

Brain responses in aggression-prone individuals: A systematic review and meta-analysis of functional magnetic resonance imaging (fMRI) studies of anger- and aggression-eliciting tasks

Reactive aggression in response to perceived threat or provocation is part of humans' adaptive behavioral repertoire. However, high levels of aggression can lead to the violation of social and legal norms. Understanding brain function in individuals with high levels of aggression as they process anger- and aggression-eliciting stimuli is critical for refining explanatory models of aggression and thereby improving interventions. Three neurobiological models of reactive aggression - the limbic hyperactivity, prefrontal hypoactivity, and dysregulated limbic-prefrontal connectivity models - have been proposed. However, these models are based on neuroimaging studies involving mainly non-aggressive individuals, leaving it unclear which model best describes brain function in those with a history of aggression. We conducted a systematic literature search (PubMed and Psycinfo) and Multilevel Kernel Density meta-analysis (MKDA) of nine functional magnetic resonance imaging (fMRI) studies (eight included in the between-group analysis [i.e., aggression vs. control groups], five in the within-group analysis). Studies examined brain responses to tasks putatively eliciting anger and aggression in individuals with a history of aggression alone and relative to controls. Individuals with a history of aggression exhibited greater activity in the superior temporal gyrus and in regions comprising the cognitive control and default mode networks (right posterior cingulate cortex, precentral gyrus, precuneus, right inferior frontal gyrus) during reactive aggression relative to baseline conditions. Compared to controls, individuals with a history of aggression exhibited increased activity in limbic regions (left hippocampus, left amygdala, left parahippocampal gyrus) and temporal regions (superior, middle, inferior temporal gyrus), and reduced activity in occipital regions (left occipital cortex, left calcarine cortex). These findings lend support to the limbic hyperactivity model in individuals with a history of aggression, and further indicate altered temporal and occipital activity in anger- and aggression-eliciting conditions involving face and speech processing.

Emotion Recognition and Inhibitory Control in Adolescent Players of Violent Video Games

Developmental changes during adolescence may make youth susceptible to violent media effects. Two studies with male adolescents (N₁  = 241; N₂  = 161; aged 12-17) examined how habitual and short-term violent video gaming may affect emotion recognition and inhibitory control. We found that not habitual exposure to violent video games, but to antisocial media content predicted worse emotion recognition. Furthermore, higher habitual exposure to violent games predicted better inhibitory control over emotional stimuli in a stop signal task. However, short-term causal effects of violent gameplay on adolescents were not found. While these results do not indicate a negative impact of violent video games on young players, future research may further investigate possible effects of antisocial media content on adolescents.

Irrelevant positive emotional information facilitates response inhibition only under a high perceptual load

Response inhibition involves suppressing those responses that are no longer needed. Previous research has separately studied the role of attentional resources and emotional information in response inhibition. Here, we simultaneously manipulate attentional resources and emotional information to investigate the interactive role of emotional information and attentional resources. Attentional resources were manipulated by changing the levels of perceptual load (low and high) of go signals. Emotional information was manipulated by changing the emotional content (irrelevant positive and negative emotional information) of the stop signals. Participants made a go response based on searching for a target letter in conditions of either low perceptual load or high perceptual load. They withheld their response on the presentation of a stop signal. The stop-signal stimulus was selected from two classes: arousal matched positive and negative IAPS images (Experiment 1) and happy, angry, and neutral faces (Experiment 2). The result showed a consistent interaction pattern of perceptual load and emotional information across the two experiments, such that irrelevant positive emotional information consistently improved inhibitory control, albeit only under high load. These results have theoretical implications for understanding the nature of emotional information and their interaction with attentional resources in cognitive control functions.

The Influence of Vicarious Fear-Learning in “Infecting” Reactive Action Inhibition

Since the dawn of cognitive neuroscience, emotions have been recognized to impact on several executive processes, such as action inhibition. However, the complex interplay between emotional stimuli and action control is not yet fully understood. One way to measure inhibitory control is the stop-signal task (SST), which estimates the ability to cancel outright an action to the presentation of a stop signal by means of the stop-signal reaction times (SSRTs). Impaired as well as facilitated action control has been found when faced with intrinsic emotional stimuli as stop signals in SSTs. Here, we aimed at investigating more deeply the power of negative stimuli to influence our action control, testing the hypothesis that a previously neutral stimulus [i.e., the image of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)], which has been conditioned through vicarious fear learning, has the same impact on reactive action inhibition performance as an intrinsically negative stimulus (i.e., a fearful face or body). Action control capabilities were tested in 90 participants by means of a SST, in which the stop signals were represented by different negative stimuli. Results showed that the SARS-CoV-2 image enhanced the ability to suppress an ongoing action similarly to observing fearful facial expressions or fearful body postures. Interestingly, we found that this effect was predicted by impulsivity traits: for example, the less self-control the participants had, the less they showed emotional facilitation for inhibitory performance. These results demonstrated that vicarious fear learning has a critical impact on cognitive abilities, making a neutral image as threatening as phylogenetically innate negative stimuli and able to impact on our behavioral control.

Clarifying the synergistic effects of emotion dysregulation and inhibitory control on physical aggression

Rising rates of violence underscore the need to better understand how systems that regulate distress and impulse control jointly modulate aggression risk. The goals of the current study were to investigate the unique and interactive effects of emotional dysregulation and inhibitory control on the perpetration of physical aggression. We recruited a high-risk community sample of 206 adults (M/SD_age  = 33.55/10.89 years old; 47.1% female) who reported a range of physically aggressive behaviors. All participants completed a self-report measure (Difficulties in Emotion Regulation Scale), neuropsychological testing (Color Word Interference Test), and clinical interviewing (Lifetime History of Aggression Interview), and a subset of individuals (n = 134) underwent a neuroanatomical scan. As expected, the interplay of emotional and inhibitory control explained unique variance in physical aggression above and beyond their main effects. The positive association between emotion dysregulation and aggression strengthened as inhibitory control decreased. Cortical thickness in two right prefrontal clusters, one that peaked in the superior frontal gyrus and one that peaked in the caudal middle frontal gyrus, was also associated with the interactive effects of emotional dysregulation and inhibitory control. Notably, thickness in the superior frontal gyrus mediated the association between emotion dysregulation and physical aggression at low levels of inhibitory control. Using a multilevel and multimethod approach, the present study revealed neuroanatomical correlates of emotion-cognition interactions that have translational relevance to violence perpetration. These findings extend previous work primarily focused on functional-based neural assessments and point to the utility of examining neuroanatomical correlates of emotion-cognition interactions for understanding human aggression.

Gray matter microstructural alterations in manganese-exposed welders: a preliminary neuroimaging study

OBJECTIVES

Chronic occupational manganese (Mn) exposure is characterized by motor and cognitive dysfunction. This study aimed to investigate structural abnormalities in Mn-exposed welders compared to healthy controls (HCs).

METHODS

Thirty-five HCs and forty Mn-exposed welders underwent magnetic resonance imaging (MRI) scans in this study. Based on T1-weighted MRI, the voxel-based morphometry (VBM), structural covariance, and receiver operating characteristic (ROC) curve were applied to examine whole-brain structural changes in Mn-exposed welders.

RESULTS

Compared to HCs, Mn-exposed welders had altered gray matter volume (GMV) mainly in the medial prefrontal cortex, lentiform nucleus, hippocampus, and parahippocampus. ROC analysis indicated the potential highest classification power of the hippocampus/parahippocampus. Moreover, distinct structural covariance patterns in the two groups were associated with regions, mainly including the thalamus, insula, amygdala, sensorimotor area, and middle temporal gyrus. No significant relationships were found between the findings and clinical characteristics.

CONCLUSIONS

Our findings showed Mn-exposed welders had changed GMV and structural covariance patterns in some regions, which implicated in motivative response, cognitive control, and emotional regulation. These results might provide preliminary evidence for understanding the pathophysiology of Mn overexposure.

KEY POINTS

• Chronic Mn exposure might be related to abnormal brain structural neural mechanisms. • Mn-exposed welders had morphological changes in brain regions implicated in emotional modulation, cognitive control, and motor-related response. • Altered gray matter volume in the hippocampus/parahippocampus and putamen might serve as potential biomarkers for Mn overexposure.

Fronto—Parietal Regions Predict Transient Emotional States in Emotion Modulated Response Inhibition via Low Frequency and Beta Oscillations

The current study evaluated the impact of task-relevant emotion on inhibitory control while focusing on midline cortical regions rather than brain asymmetry. Single-trial time-frequency analysis of electroencephalography recordings linked with response execution and response inhibition was done while thirty-four participants performed the emotion modulated stop-signal task. To evaluate individual differences across decision-making processes involved in inhibitory control, a hierarchical drift-diffusion model was used to fit data from Go-trials for each of the 34 participants. Response threshold in the early processing stage for happy and disgust emotions could be distinguished from the later processing stage at the mid-parietal and mid-frontal regions, respectively, by the single-trial power increments in low frequency (delta and theta) bands. Beta desynchronization in the mid-frontal region was specific for differentiating disgust from neutral emotion in the early as well as later processing stages. The findings are interpreted based on the influence of emotional stimuli on early perceptual processing originating as a bottom-up process in the mid-parietal region and later proceeding to the mid-frontal region responsible for cognitive control processing, which resulted in enhanced inhibitory performance. The results show the importance of mid-frontal and mid-parietal regions in single-trial dynamics of inhibitory control processing.

The effect of obstructed action efficacy on reward-based decision-making in healthy adolescents: a novel functional MRI task to assay frustration

Frustration is common in adolescence and often interferes with executive functioning, particularly reward-based decision-making, and yet very little is known about how incidental frustrating events (independent of task-based feedback) disrupt the neural circuitry of reward processing in this important age group. While undergoing functional magnetic resonance imaging (fMRI), 45 healthy adolescents played a card game in which they had to guess between two options to earn points, in low- and high-stake conditions. Functioning of button presses through which they made decisions was intermittently blocked, thereby increasing frustration potential. Neural deactivation of the precuneus, a Default Mode Network region, was observed during obstructed action blocks across stake conditions, but less so on high- relative to low-stake trials. Moreover, less deactivation in goal-directed reward processing regions (i.e., caudate), frontoparietal "task control" regions, and interoceptive processing regions (i.e., somatosensory cortex, thalamus) were observed on high-stake relative to low-stake trials. These findings are consistent with less disruption of goal-directed reward seeking during blocked action efficacy in high-stake conditions among healthy adolescents. These results provide a roadmap of neural systems critical to the processing of frustrating events during reward-based decision-making in youths and could help to characterize how frustration regulation is altered in a range of pediatric psychopathologies.

Neuropsychological functions in a pediatric case of partial agenesis of the corpus callosum: Clinical implications

The corpus callosum (CC) is involved in several cognitive processes and the interhemispheric transfer of information. The current case study investigated neurocognitive and emotional processes in a 7-year-old female with partial agenesis of the corpus callosum, with an absent splenium and posterior body, with comorbid autism and ADHD. We measured cognitive functions, such as response inhibition, error monitoring, attentional disengagement, and attention capture by irrelevant emotional stimuli. We found that response inhibition was intact in the case. When happy faces were used as stop-signals, it interfered with response inhibition compared to angry-face-stop-signals. Similarly, happy faces (relative to angry faces) interfered with error monitoring; irrelevant angry faces captured attention more than happy faces. Attentional disengagement functions were impaired in the case compared to healthy controls. The findings give an insight into the interaction between cognition and emotion in pediatric partial agenesis of the CC, and have important clinical and theoretical implications.

Relationships between Personality Traits and Brain Gray Matter Are Different in Risky and Non-risky Drivers

Personality traits such as impulsivity or sensitivity to rewards and punishments have been associated with risky driving behavior, but it is still unclear how brain anatomy is related to these traits as a function of risky driving. In the present study, we explore the neuroanatomical basis of risky driving behavior and how the level of risk-taking influences the relationship between the traits of impulsivity and sensitivity to rewards and punishments and brain gray matter volume. One hundred forty-four participants with different risk-taking tendencies assessed by real-life driving situations underwent MRI. Personality traits were assessed with self-report measures. We observed that the total gray matter volume varied as a function of risky driving tendencies, with higher risk individuals showing lower gray matter volumes. Similar results were found for volumes of brain areas involved in the reward and cognitive control networks, such as the frontotemporal, parietal, limbic, and cerebellar cortices. We have also shown that sensitivity to reward and punishment and impulsivity are differentially related to gray matter volumes as a function of risky driving tendencies. Highly risky individuals show lower absolute correlations with gray matter volumes than less risk-prone individuals. Taken together, our results show that risky drivers differ in the brain structure of the areas involved in reward processing, cognitive control, and behavioral modulation, which may lead to dysfunctional decision-making and riskier driving behavior.

Regional Gray Matter Volume Changes in Brains of Patients With Ulcerative Colitis

BACKGROUND

Ulcerative colitis (UC) and Crohn's disease (CD) are 2 subtypes of inflammatory bowel disease (IBD). Several studies have reported brain abnormalities in IBD patients. This study aims to identify differences of gray matter volume (GMV) between patients with UC and healthy controls (HCs).

METHODS

Fifty-seven patients with UC and 40 HCs underwent structural magnetic resonance imaging. Voxel-based morphometry method was used to detect GMV differences. Receiver operating characteristic (ROC) curve was applied to investigate reliable biomarkers for identifying patients with UC from HCs. Regression analysis was used to examine relationships between the structure alternations and clinical symptoms.

RESULTS

Compared with HCs, patients with UC showed decreased GMV in the insula, thalamus, pregenual anterior cingulate cortex, hippocampus/parahippocampus, amygdala, and temporal pole; they showed increased GMV in the putamen, supplementary motor area, periaqueductal gray, hypothalamus, and precentral gyrus. Receiver operating characteristic analysis showed the highest classification power of thalamus. The inclusion of anxiety and depression as covariates eliminated the differences in the right insula, pregenual anterior cingulate cortex, supplementary motor area, and precentral gyrus. Most of the GMV changes were found in active patients with UC, with few changes in patients with UC in remission. We also found significantly negative correlation between UC duration and GMV in several regions.

CONCLUSION

The current neuroimaging findings were involved in visceral sensory pathways and were partially associated with the levels of anxiety and depression and clinical stage of patients with UC. This study might provide evidence for possible neuromechanisms of UC.

Altered Brain Structural Reorganization and Hierarchical Integrated Processing in Obesity

The brain receives sensory information about food, evaluates its desirability and value, and responds with approach or withdrawal. The evaluation process of food in the brain with obesity may involve a variety of neurocircuit abnormalities in the integration of internal and external information processing. There is a lack of consistency of the results extant reported for aberrant changes in the brain with obesity that prohibits key brain alterations to be identified. Moreover, most studies focus on the observation of neural plasticity of function or structure, and the evidence for functional and structural correlations in the neuronal plasticity process of obesity is still insufficient. The aims of this article are to explore the key neural structural regions and the hierarchical activity pattern of key structural nodes and evaluate the correlation between changes in functional modulation and eating behavior. Forty-two participants with obesity and 33 normal-weight volunteers were recruited. Gray matter volume (GMV) and Granger causality analysis (GCA) were performed using the DPARSF, CAT12, and DynamicBC toolbox. Compared with the normal weight group, the obesity group exhibited significantly increased GMV in the left parahippocampal gyrus (PG). The obesity group showed decreased causal inflow to the left PG from the left orbitofrontal cortex (OFC), right calcarine, and bilateral supplementary motor area (SMA). Decreased causal outflow to the left OFC, right precuneus, and right SMA from the left PG, as well as increased causal outflow to the left middle occipital gyrus (MOG) were observed in the obesity group. Negative correlations were found between DEBQ-External scores and causal outflow from the left PG to the left OFC, and DEBQ-Restraint scores and causal inflow from the left OFC to the left PG in the obesity group. Positive correlation was found between DEBQ-External scores and causal outflow from the left PG to the left MOG. These results show that the increased GMV in the PG may play an important role in obesity, which may be related to devalued reward system, altered behavioral inhibition, and the disengagement of attentional and visual function for external signals. These findings have important implications for understanding neural mechanisms in obesity and developing individual-tailored strategies for obesity prevention.

The Influence of 5-HTTLPR, BDNF Rs6265 and COMT Rs4680 Polymorphisms on Impulsivity in Bipolar Disorder: The Role of Gender

Impulsivity has been proposed as an endophenotype for bipolar disorder (BD); moreover, impulsivity levels have been shown to carry prognostic significance and to be quality-of-life predictors. To date, reports about the genetic determinants of impulsivity in mood disorders are limited, with no studies on BD individuals. Individuals with BD and healthy controls (HC) were recruited in the context of an observational, multisite study (GECOBIP). Subjects were genotyped for three candidate single-nucleotide polymorphisms (SNPs) (5-HTTLPR, COMT rs4680, BDNF rs6265); impulsivity was measured through the Italian version of the Barratt Impulsiveness Scale (BIS-11). A mixed-effects regression model was built, with BIS scores as dependent variables, genotypes of the three polymorphisms as fixed effects, and centers of enrollment as random effect. Compared to HC, scores for all BIS factors were higher among subjects with euthymic BD (adjusted β for Total BIS score: 5.35, p < 0.001). No significant interaction effect was evident between disease status (HC vs. BD) and SNP status for any polymorphism. Considering the whole sample, BDNF Met/Met homozygosis was associated with lower BIS scores across all three factors (adjusted β for Total BIS score: −10.2, p < 0.001). A significant 5-HTTLPR x gender interaction was found for the SS genotype, associated with higher BIS scores in females only (adjusted β for Total BIS score: 12.0, p = 0.001). Finally, COMT polymorphism status was not significantly associated with BIS scores. In conclusion, BD diagnosis did not influence the effect on impulsivity scores for any of the three SNPs considered. Only one SNP—the BDNF rs6265 Met/Met homozygosis—was independently associated with lower impulsivity scores. The 5-HTTLPR SS genotype was associated with higher impulsivity scores in females only. Further studies adopting genome-wide screening in larger samples are needed to define the genetic basis of impulsivity in BD.

People with tobacco use disorder exhibit more prefrontal activity during preparatory control but reduced anterior cingulate activity during reactive control

Reduced inhibitory control and a hypersensitivity to reward are key deficits in drug dependents; however, they tend to be studied in isolation. Here, we seek to understand the neural processes underlying control over reward and how this is different in people with a tobacco use disorder (pTUD). A novel variant of the monetary incentive delay task was performed by pTUD (n = 20) and non-smokers (n = 20), where we added a stop-signal component such that participants had to inhibit prepotent responses to earn a larger monetary reward. Brain activity was recorded using functional magnetic resonance imaging (fMRI). We estimated stop signal reaction times (SSRTs), an indicator of impulsivity, and correlated these with brain activity. Inhibitory accuracy scores did not differ between the control group and pTUD. However, pTUD had slower SSRTs, suggesting that they may find it harder to inhibit responses. Brain data revealed that pTUD had greater preparatory control activity in the middle frontal gyrus and inferior frontal gyrus prior to successful inhibitions over reward. In contrast, non-smokers had greater reactive control associated with more activity in the anterior cingulate cortex during these successful inhibitions. SSRT-brain activity correlations revealed that pTUD engaged more control-related prefrontal brain regions when SSRTs are slower. Overall, while the inhibition accuracy scores were similar between groups, differential neural processes and strategies were used to successfully inhibit a prepotent response. The findings suggest that increasing preparatory control in pTUD may be one possible treatment target in order to increase inhibitory control over reward.

Large-scale functional brain networks of maladaptive childhood aggression identified by connectome-based predictive modeling

Disruptions in frontoparietal networks supporting emotion regulation have been long implicated in maladaptive childhood aggression. However, the association of connectivity between large-scale functional networks with aggressive behavior has not been tested. The present study examined whether the functional organization of the connectome predicts severity of aggression in children. This cross-sectional study included a transdiagnostic sample of 100 children with aggressive behavior (27 females) and 29 healthy controls without aggression or psychiatric disorders (13 females). Severity of aggression was indexed by the total score on the parent-rated Reactive-Proactive Aggression Questionnaire. During fMRI, participants completed a face emotion perception task of fearful and calm faces. Connectome-based predictive modeling with internal cross-validation was conducted to identify brain networks that predicted aggression severity. The replication and generalizability of the aggression predictive model was then tested in an independent sample of children from the Adolescent Brain Cognitive Development (ABCD) study. Connectivity predictive of aggression was identified within and between networks implicated in cognitive control (medial-frontal, frontoparietal), social functioning (default mode, salience), and emotion processing (subcortical, sensorimotor) (r = 0.31, RMSE = 9.05, p = 0.005). Out-of-sample replication (p < 0.002) and generalization (p = 0.007) of findings predicting aggression from the functional connectome was demonstrated in an independent sample of children from the ABCD study (n = 1791; n = 1701). Individual differences in large-scale functional networks contribute to variability in maladaptive aggression in children with psychiatric disorders. Linking these individual differences in the connectome to variation in behavioral phenotypes will advance identification of neural biomarkers of maladaptive childhood aggression to inform targeted treatments.

Cognitive Control Processes and Defense Mechanisms That Influence Aggressive Reactions: Toward an Integration of Socio-Cognitive and Psychodynamic Models of Aggression

Research on cognitive processes has primarily focused on cognitive control and inhibitory processes to the detriment of other psychological processes, such as defense mechanisms (DMs), which can be used to modify aggressive impulses as well as self/other images during interpersonal conflicts. First, we conducted an in-depth theoretical analysis of three socio-cognitive models and three psychodynamic models and compared main propositions regarding the source of aggression and processes that influence its enactment. Second, 32 participants completed the Hostile Expectancy Violation Paradigm (HEVP) in which scenarios describe a hostile vs. non-hostile social context followed by a character's ambiguous aversive behavior. The N400 effect to critical words that violate expected hostile vs. non-hostile intent of the behavior was analyzed. Prepotent response inhibition was measured using a Stop Signal task (SST) and DMs were assessed with the Defense Style Questionnaire (DSQ-60). Results showed that reactive aggression and HIA were not significantly correlated with response inhibition but were significantly positively and negatively correlated with image distorting defense style and adaptive defense style, respectively. The present article has highlighted the importance of integrating socio-cognitive and psychodynamic models to account for the full complexity underlying psychological processes that influence reactive aggressive behavior.

Frozen in (e)motion: How reactive motor inhibition is influenced by the emotional content of stimuli in healthy and psychiatric populations

Efficient inhibitory control is vital. However, environmental cues can influence motor control especially in an emotional context. One common task to measure inhibitory control is the stop-signal task (SST), which asks participants to respond to go stimuli knowing that on some trials a stop signal will be presented, requiring them to inhibit their response. This paradigm estimates the ability to inhibit already-initiated responses by calculating participants' stop-signal reaction times (SSRT), an index of inhibitory control. Here, we aim to review the existing, often contradictory, evidence on the influence of emotional stimuli on the inhibitory process. We aim to discuss which factors may reveal an interference as well as an advantage of emotional stimuli on action inhibition performance. Finally, we review the existing evidence that has investigated the effect of such stimuli on action inhibition in the psychiatric population. Important factors are the relevance, the intensity and the valence of the emotional stimulus, as well as the affected component of the motor control. From all this evidence, it is clear that understand precisely how emotion is integrated into core executive functions, such as inhibitory control, is essential not only for cognitive neuroscience, but also for refining neurocognitive models of psychopathology.

Verbal Response Inhibition in Adults Who Stutter

Purpose Adults who stutter (AWS) often attempt, with varying degrees of success, to suppress their stuttered speech. The ability to effectively suppress motoric behavior after initiation relies on executive functions such as nonselective inhibition. Although previous studies found that AWS were slower to inhibit manual, button-press response than adults who do not stutter (AWNS), research has yet to confirm a consistent relationship between manual and verbal inhibition. No study has examined verbal inhibition ability in AWS. The purpose of this study, therefore, is to compare verbal response inhibition between AWS and AWNS, and compare verbal response inhibition to both the overt stuttering and the lived experience of stuttering. Method Thirty-four adults (17 AWNS, 17 AWS) completed one manual and three verbal stop-signal tasks. AWS were assessed for stuttering severity (Stuttering Severity Instrument-Fourth Edition: SSI-4) and experience with stuttering (Overall Assessment of the Speaker's Experience With Stuttering [OASES]). Results Results indicate no correlation between manual and verbal inhibition for either group. Generalized linear mixed-model analyses suggested no significant group differences in manual or verbal inhibition. Manual and verbal inhibition did not predict SSI-4 in AWS. However, verbal inhibition was uniquely associated with OASES scores. Conclusion Although underlying manual and verbal inhibition was comparable between AWS and AWNS, verbal inhibition may be linked to the adverse experience of stuttering rather than the overt symptoms of stuttering severity. Supplemental Material https://doi.org/10.23641/asha.15145185.

Socially Induced Negative Emotions Elicit Neural Activity in the Mentalizing Network in a Subsequent Inhibitory Task

Despite the growing emphasis on embedding interactive social paradigms in the field of cognitive and affective neuroscience, the impact of socially induced emotions on cognition remains widely unknown. The aim of the present study was to fill this gap by testing whether facial stimuli whose emotional valence was acquired through social learning in an economic trust game may influence cognitive performance in a subsequent stop-signal task. The study was designed as a conceptual replication of previous event-related potential experiments, extending them to more naturalistic settings. We hypothesized that response inhibition to briefly presented faces of negative and positive game partners would be enhanced on the behavioral and neural levels as compared to trials with a neutral player. The results revealed that the trust game was an effective paradigm for the induction of differently valenced emotions towards players; however, behavioral inhibitory performance was comparable in all stop-signal conditions. On the neural level, we found decreased P3 amplitude in negative trials due to significantly stronger activation in the right frontoparietal control network, which is involved in theory-of-mind operations and underlies social abilities in humans, especially memory-guided inference of others' mental states. Our findings make an important contribution to the cognition-emotion literature by showing that social interactions that take place during an economic game may influence brain activity within the mentalizing network in a subsequent cognitive task.

The effects of emotional stimuli and oxytocin on inhibition ability and response execution in macaque monkeys

Social and emotional content of environmental stimuli influence executive control of behavior. There has been a great variability in the behavioral effects of emotional stimuli in humans. These variabilities might arise from other contextual factors, such as specific task demands or natural hormones, which potentially interact with emotional stimuli in modulating executive functions. This study aimed at examining the effects of social-emotional visual stimuli and a natural hormone (oxytocin) on inhibition ability and response execution of macaque monkeys. In a crossover design, monkeys received inhaled oxytocin or its vehicle before performing a stop-signal task in which they must respond rapidly to a visual go-cue in Go trials but inhibit the initiated response following the onset of a stop-cue in Stop trials. The social-emotional content (negative, positive or neutral) of the go-cue was changed trial-by-trial. We found that monkeys' inhibition ability was significantly influenced by the social-emotional content of stimuli and appeared as an enhanced inhibition ability when monkeys were exposed to negative stimuli. However, response execution was not influenced by the emotional content of stimuli in the current or preceding trials. The same dose of oxytocin, which modulated working memory in monkeys, had no significant effect on the inhibition ability, but significantly decreased monkeys' response time regardless of the stimulus valence. Our findings indicate that emotional stimuli, valence dependently, influence monkeys' inhibition ability but not their response execution and suggest that oxytocin might attenuate reorientation of cognitive resources to the task irrelevant emotional information.

Olfactory influences on reach-to-press movements in a stop-signal task

Response inhibition is sensitive to unexpected changes in the environment triggered by emotional stimuli. Whereas the impact of visual material on inhibition has been widely documented, the attention on the influence of olfactory stimuli has been neglected. Here, we examined the effect of pleasant (orange), unpleasant (trimethyloxazole), and control (clean air) odour primes in a stop-signal task. Twenty-five participants had to elicit or inhibit reach-to-press actions which allowed to examine the olfactory influences on both the planning (release phase) and the on-line control (reaching phase) of responses. Additionally, we manipulated the distance between the initial hand position and the target to be pressed (10 vs. 20 vs. 30 cm). The pleasant (vs. control) odour impaired inhibition, as reflected in slower stop-signal reaction times and higher release errors, indicating greater mobilisation of inhibitory resources by pleasant stimuli. Further, faster release responses were triggered by pleasant and unpleasant primes, supporting the idea of perceptual prioritisation of emotional (vs. non-emotional) stimuli. The olfactory manipulation did not affect the reaching phase of the responses. Instead, the distance manipulation modulated the reaching but not the release phase. These results extend the sparse literature on the influences of odour stimuli on response inhibition.

Dimensions of Impulsivity in Healthy People, Patients with Borderline Personality Disorder, and Patients with Attention-Deficit/Hyperactivity Disorder

Objective: Impulsivity, observed in patients with various psychiatric disorders, is a heterogeneous construct with different behavioral manifestations. Through confirmatory factor analysis (CFA), this study tests hypotheses about relationships between dimensions of impulsivity measured using personality questionnaires and behavioral tests. Method: The study included 200 healthy people, 40 patients with borderline personality disorder, and 26 patients with attention-deficit/hyperactivity disorder (ADHD) who underwent a comprehensive impulsivity test battery including the Barratt Impulsiveness Scale (BIS), UPPS-P Impulsive Behavior Scale, a Go-NoGo task, a stop-signal task, and a delay discounting task. Results: A CFA model comprising three self-reported and three behavioral latent variables reached a good fit. Both patient groups scored higher in the self-reported dimensions and impulsive choice; only the ADHD patients displayed impaired waiting and stopping impulsivity. Conclusions: Using the developed CFA model, it is possible to describe relations between impulsivity dimensions and show different impulsivity patterns in patient populations.

Do anger perception and the experience of anger share common neural mechanisms? Coordinate-based meta-analytic evidence of similar and different mechanisms from functional neuroimaging studies

The neural bases of anger are still a matter of debate. In particular we do not know whether anger perception and anger experience rely on similar or different neural mechanisms. To study this topic, we performed activation-likelihood-estimation meta-analyses of human neuroimaging studies on 61 previous studies on anger perception and experience. Anger perception analysis resulted in significant activation in the amygdala, the right superior temporal gyrus, the right fusiform gyrus and the right IFG, thus revealing the role of perceptual temporal areas for perceiving angry stimuli. Anger experience analysis resulted in the bilateral activations of the insula and the ventrolateral prefrontal cortex, thus revealing a role for these areas in the subjective experience of anger and, possibly, in a subsequent evaluation of the situation. Conjunction analyses revealed a common area localized in the right inferior frontal gyrus, probably involved in the conceptualization of anger for both perception and experience. Altogether these results provide new insights on the functional architecture underlying the neural processing of anger that involves separate and joint mechanisms. According to our tentative model, angry stimuli are processed by temporal areas, such as the superior temporal gyrus, the fusiform gyrus and the amygdala; on the other hand, the subjective experience of anger mainly relies on the anterior insula; finally, this pattern of activations converges in the right IFG. This region seems to play a key role in the elaboration of a general meaning of this emotion, when anger is perceived or experienced.

Intraspecific variation in inhibitory motor control in guppies, Poecilia reticulata

Inhibitory control (IC) is the ability to overcome impulsive or prepotent but ineffective responses in favour of more appropriate behaviours. The ability to inhibit internal predispositions or external temptations is vital in coping with a complex and variable world. Traditionally viewed as cognitively demanding and a main component of executive functioning and self-control, IC was historically examined in only a few species of birds and mammals but recently a number of studies has shown that a much wider range of taxa rely on IC. Furthermore, there is growing evidence that inhibitory abilities may vary within species at the population and individual levels owing to genetic and environmental factors. Here we use a detour-reaching task, a standard paradigm to measure motor inhibition in nonhuman animals, to quantify patterns of interindividual variation in IC in wild-descendant female guppies, Poecilia reticulata. We found that female guppies displayed inhibitory performances that were, on average, half as successful as the performances reported previously for other strains of guppies tested in similar experimental conditions. Moreover, we showed consistent individual variation in the ability to inhibit inappropriate behaviours. Our results contribute to the understanding of the evolution of fish cognition and suggest that IC may show considerable variation among populations within a species. Such variation in IC abilities might contribute to individual differences in other cognitive functions such as spatial learning, quantity discrimination or reversal learning.

Only irrelevant angry, but not happy, expressions facilitate the response inhibition

It has been debated that arousal rather than valence modulates the response-inhibition process. The processing of irrelevant information of happy and angry faces interacts with attention differently. In the present study, arousal-matched irrelevant happy and angry faces were used as stop-signals in the stop-signal paradigm. Participants were required to respond to go-signals (discriminate between X or O). Occasionally, a stop-signal was presented where participants were required to withhold their motor response. Results indicate a significant effect of emotion on response inhibition, which suggests that valence of a stop-signal modulates inhibitory control. More specifically, we found that only irrelevant angry, but not happy, expressions facilitate the response inhibition process. These results have theoretical implications for understanding the nature of emotions and its interaction with cognitive control functions.

Impulsivity as a multifactorial construct and its relationship to PTSD severity and threat sensitivity

Changes to the DSM-5's conceptualization of posttraumatic stress disorder (PTSD) highlight the importance of impulsivity within the context of PTSD-related arousal dysregulation. While the relationship between PTSD and threat sensitivity is well defined, how they relate to impulsivity remains understudied. We examined the relationship between PTSD symptom severity, threat sensitivity, and impulsivity. 124 participants completed the PTSD Checklist (PCL-C) and the Barratt Impulsiveness Scale 11th ed (BIS-11). BIS-11 items were separated to define cognitive and behavioral impulsivity subdomains. A trauma-exposed subsample of 39 participants were also exposed to no, ambiguous, and high threat conditions in a threat-enhanced acoustic startle paradigm with psychophysiological response as the outcome variable. PTSD severity was significantly associated with greater overall impulsivity and behavioral impulsivity. Greater overall impulsivity and both cognitive and behavioral impulsivity subdomains were significantly associated with psychophysiological magnitudes across threat conditions in the traumatized subsample. Our results suggest PTSD severity may linked to behavioral impulsivity and both cognitive and behavioral impulsivity are associated with threat sensitivity and hyperarousal. Assessing impulsivity within the context of PTSD, particularly in terms of its cognitive and behavioral subdomains, may provide important, clinically relevant information.

Manual response inhibition and quality of life in adults who stutter

BACKGROUND

A considerable amount of research has identified inhibition differences, including slower inhibition of manual responses, in people who stutter. Recent investigations have failed to link slowed motor inhibition with overt stuttering severity. This study investigated the potential relationship between slowed manual response inhibition and the negative impact of stuttering upon individual lives of adults who stutter (AWS).

METHODS

Thirty-four adults (AWS, n = 17; AWNS, n = 17) matched by nonverbal IQ completed a manual stop-signal task and provided a conversational speech sample. Motor inhibition latency for AWS and AWNS were compared. For AWS, motor inhibition latency was compared to the four subsections of the Overall Assessment of the Speaker's Experience with Stuttering (OASES; Yaruss & Quesal, 2006; General Information, Reactions to Stuttering, Communication in Daily Situations, Quality of Life).

RESULTS

Similar to previous studies, AWS were significantly slower to inhibit inaccurate manual responses than AWNS. Quality of Life subtest of the OASES was found to significantly predict inhibition latency.

CONCLUSION

These data replicate findings that indicate that AWS exhibit slower manual inhibition latency, and suggest that these inhibition differences may be associated with an individual's negative experience with stuttering rather than stuttering severity.

Prediction of Human Inhibition Brain Function with Inter-Subject and Intra-Subject Variability

The stop signal task has been used to quantify the human inhibitory control. The inter-subject and intra-subject variability was investigated under the inhibition of human response with a realistic environmental scenario. In present study, we used a battleground scenario where a sniper-scope picture was the background, a target picture was a go signal, and a nontarget picture was a stop signal. The task instructions were to respond on the target image and inhibit the response if a nontarget image appeared. This scenario produced a threatening situation and endorsed the evaluation of how subject's response inhibition manifests in a real situation. In this study, 32 channels of electroencephalography (EEG) signals were collected from 20 participants during successful stop (response inhibition) and failed stop (response) trials. These EEG signals were used to predict two possible outcomes: successful stop or failed stop. The inter-subject variability (between-subjects) and intra-subject variability (within-subjects) affect the performance of participants in the classification system. The EEG signals of successful stop versus failed stop trials were classified using quadratic discriminant analysis (QDA) and linear discriminant analysis (LDA) (i.e., parametric) and K-nearest neighbor classifier (KNNC) and Parzen density-based (PARZEN) (i.e., nonparametric) under inter- and intra-subject variability. The EEG activities were found to increase during response inhibition in the frontal cortex (F3 and F4), presupplementary motor area (C3 and C4), parietal lobe (P3 and P4), and occipital (O1 and O2) lobe. Therefore, power spectral density (PSD) of EEG signals (1-50Hz) in F3, F4, C3, C4, P3, P4, O1, and O2 electrodes were measured in successful stop and failed stop trials. The PSD of the EEG signals was used as the feature input for the classifiers. Our proposed method shows an intra-subject classification accuracy of 97.61% for subject 15 with QDA classifier in C3 (left motor cortex) and an overall inter-subject classification accuracy of 71.66% ± 9.81% with the KNNC classifier in F3 (left frontal lobe). These results display how inter-subject and intra-subject variability affects the performance of the classification system. These findings can be used effectively to improve the psychopathology of attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), schizophrenia, and suicidality.

Meta-analytic evidence for a joint neural mechanism underlying response inhibition and state anger

Although anger may weaken response inhibition (RI) by allowing outbursts to bypass deliberate processing, it is equally likely that RI deficits precipitate a state of anger (SA). In adolescents, for instance, anger occurs more frequently and often leads to escalating aggressive behaviors. Even though RI is considered a key component in explaining individual differences in SA expression, the neural overlap between SA and RI remains elusive. Here, we aimed to meta-analytically revisit and update the neural correlates of motor RI, to determine a consistent neural architecture of SA, and to identify their joint neural network. Considering that inhibitory abilities follow a protracted maturation until early adulthood, we additionally computed RI meta-analyses in youths and adults. Using activation likelihood estimation, we calculated twelve meta-analyses across 157 RI and 39 SA experiments on healthy individuals. Consistent with previous findings, RI was associated with a broad frontoparietal network including the anterior insula/inferior frontal gyrus (aI/IFG), premotor and midcingulate cortices, extending into right temporoparietal areas. Youths showed convergent activity in right midcingulate and medial prefrontal areas, left aI/IFG, and the temporal poles. SA, on the other hand, reliably recruited the right aI/IFG and anterior cingulate cortex. Conjunction analyses between RI and SA yielded a single convergence cluster in the right aI/IFG. While frontoparietal networks and bilateral aI are ubiquitously recruited during RI, the right aI/IFG cluster likely represents a node in a dynamically-adjusting monitoring network that integrates salient information thereby facilitating the execution of goal-directed behaviors under highly unpredictable scenarios.

Negative Impact of Sadness on Response Inhibition in Females: An Explicit Emotional Stop Signal Task fMRI Study

Response inhibition is a critical cognitive ability underlying executive control over reactions to external cues, or inner requirements. Previous studies suggest that high arousal negative emotions (e.g., anger or fear) could impair response inhibition in implicit emotional stop signal tasks (eSSTs). However, studies exploring how low arousal negative emotions (e.g., sadness) influence response inhibition remain sparse. In the current study, 20 female college students performed an explicit eSST to explore the influence of sadness on response inhibition and its neural mechanism. Participants are instructed to press a button to sad or neutral facial stimuli while inhibiting their response during the presentation of a stop signal. Results showed that compared with neutral stimuli, sad stimuli were related to increased stop signal reaction time (SSRT) (i.e., worse response inhibition). Compared with neutral condition, higher activation during sad condition was found within the right superior frontal gyrus (SFG), right insula, right middle cingulate cortex (MCC), bilateral superior temporal gyrus (STG), left lingual gyrus, and right motor cortex. These findings indicated that sadness, like other negative emotions, may impair response inhibition in an explicit way and highlight the explicit eSST as a new paradigm to investigate the subtle interaction between negative emotion processing and cognitive control.

Positive information facilitates response inhibition in older adults only when emotion is task-relevant

Emotional information is integral to everyday life and impacts a variety of cognitive abilities including response inhibition, a critical skill for maintaining appropriate and flexible behaviour. However, reported effects of emotion on response inhibition are inconsistent in younger adults, and very limited in older adults. Effects of aging are especially relevant because emotion regulation improves with aging despite declining inhibitory control over neutral information. Across three studies, we assessed the impact of emotional facial expressions on response inhibition in younger and older adults while manipulating attention to task stimuli. Emotional faces (versus neutral faces) altered response inhibition only when task instructions required explicit attention to emotional attributes of the faces. When directly comparing fear faces to happy faces, both age groups had better response inhibition to happy faces. Age further influenced differences across conditions, in that happy faces enhanced response inhibition relative to neutral faces in older adults but not younger adults. Thus, emotional response inhibition for task-relevant (but not task-irrelevant) positive information is enhanced in late life compared to early adulthood. The present work extends the nascent literature on emotional response inhibition in aging, and proffers a framework to reconcile the mixed literature on this topic in younger adults.

Inhibitory Control in Sexually Coercive Men: Behavioral Insights Using a Stop-Signal Task With Neutral, Emotional, and Erotic Stimuli

Response inhibition is defined as one's ability to voluntarily override an automatic or already initiated action when that action is inappropriate. Although a core mechanism of self-control, its association with sexual coercion perpetration and the impact of erotic cues on its exertion remain unknown. According to a domain-specific perspective on impulsivity, response inhibition performances should be disproportionately hindered by sexual cues in sexual coercion perpetrators. In total, 94 male college students completed a stop-signal task that included neutral, emotional, and erotic distracters. Results showed that men who reported past use of sexual coercion obtained overall poorer stop-signal task (SST) performances. Highly arousing sexual stimuli equally hindered the performances of perpetrators and non-perpetrators, whereas moderately arousing sexual and nonsexual positive stimuli did not significantly affect performances. Results do not support a domain-specific perspective on the link between response inhibition and sexual coercion, but rather suggest generally poorer inhibitory control among sexual coercion perpetrators.

Emotionally valenced stimuli impact response inhibition in those with substance use disorder and co-occurring anxiety and depression symptoms

BACKGROUND

Substance use disorder (SUD) is associated with impaired response inhibition. Given the deficits in emotion regulation associated with SUD, it is unclear if this impairment is exacerbated by emotionally valenced stimuli. Co-occurring conditions may further exacerbate these impairments as many co-occurring conditions further impact emotion regulation. It was hypothesized that negative stimuli may further impact response inhibition for this population.

METHODS

The current study used the stop-signal task to examine response inhibition to negative, neutral and positive stimuli in a sample of those with a history of SUD and co-occurring depression and anxiety symptoms.

RESULTS

Response inhibition was poorer for negative stimuli relative to neutral stimuli. There was no difference between negative and positive stimuli. Depression severity moderated the difference between response inhibition for negative and neutral stimuli. At elevated depression, response inhibition was worse and there was no difference across emotional stimuli. At low depression, there was a significant difference between negative and neutral stimuli. This effect was not found for anxiety symptoms.

LIMITATIONS

Study participants presented with polysubstance use of varying duration and amount. It is unclear whether findings are attributed to specific substances, or substance use broadly. Additionally, happy, angry, and calm facial emotions were used to represent positive, negative, and neutral valences respectively. It is unclear whether these findings are generalizable to other emotional expressions.

CONCLUSION

Results suggested that emotionally valenced stimuli affected response inhibition among those with low symptom severity. At elevated symptom severity, response inhibition to all stimuli were impaired.

Emotional Stop Cues Facilitate Inhibitory Control in Schizophrenia

OBJECTIVE

Inhibitory control is a key deficit in patients with schizophrenia. This study aims to test whether emotions can facilitate inhibition in patients with schizophrenia when they increase attention to inhibitory process.

METHOD

A total of 36 patients with schizophrenia and 36 healthy controls completed an emotional stop-signal task. The task involved selective responses to "Go" stimuli and stopped response when emotional or neutral stop cues occurred.

RESULTS

In all conditions, patients with schizophrenia took longer time to inhibit response compared with healthy controls, indicating an overall impairment in response inhibition. Importantly, patients with schizophrenia and controls acquired similar size of benefit from the negative stop cues, showing as reduced reaction time to negative than neutral stop cues. However, the negative stop cues impaired subsequent Go performance only in patients with schizophrenia, indicating additional cost of the negative stop cues for patients with schizophrenia. In both groups, the positive stop cues did not have any significant influence on response inhibition.

CONCLUSIONS

These findings provide novel evidence for the benefit of emotional stop cues on inhibitory control in patients with schizophrenia and reveal different after-effects of emotional enhancement effect in patients and healthy populations. The findings may help develop effective interventions for improving inhibitory control in patients with schizophrenia and other clinical populations.

Neural activity during the viewing of emotional pictures in veterans with pathological anger and aggression

Anger and aggression are common mental health problems after military deployment. Anger and aggression have been associated with abnormalities in subcortical and cortical levels of the brain and their connectivity. Here, we tested brain activation during the processing of emotional stimuli in military veterans with and without anger and aggression problems. Thirty military veterans with anger and aggression problems and 29 veterans without a psychiatric diagnosis (all males) participated in this study. During an fMRI scan 32 negative, 32 positive and 32 neutral pictures from the International Affective Picture System were presented in intermixed order. The Aggression group showed heightened activity in brain areas including the supplementary motor area, the cingulum and the parietal cortex, in response to stimuli, regardless of category. Furthermore, the Aggression group showed stronger connectivity between the dorsal anterior cingulate cortex (dACC) and the amygdala during the viewing of negative stimuli, and weaker connectivity between dACC and medial prefrontal cortex during the viewing of positive stimuli. Veterans with anger and aggression problems showed enhanced brain response to all stimuli during the task, irrespective of valence and they rated the pictures more likely as negative. We take this to indicate enhanced preparation for action and attention to the presentation of stimuli that could prove to be threatening. Further, group differences in functional connectivity involving the dACC reveal abnormal processing of stimuli with negative and positive valence. In sum, the results point towards a bias towards an enhanced sensitivity to perceived or potential threat in aggression.

Efficient but less active monitoring system in individuals with high aggressive predispositions

Aggressive behaviors in pathological and healthy populations have been largely related to poor cognitive control functioning. However, few studies have investigated the influence of aggressive traits (i.e., aggressiveness) on cognitive control. In the current study, we investigated the effects of aggressiveness on cognitive control abilities and particularly, on performance monitoring. Thirty-two participants performed a Simon task while electroencephalography (EEG) and electromyography (EMG) were recorded. Participants were classified as having high and low levels of aggressiveness using the BPAQ questionnaire (Buss and Perry, 1992). EMG recordings were used to reveal three response types by uncovering small incorrect muscular activations in ~15% of correct trials (i.e., partial-errors) that must be distinguished from full-error and pure-correct responses. For these three response types, EEG recordings were used to extract fronto-central negativities indicative of performance monitoring, the error and correct (-related) negativities (ERN/Ne and CRN/Nc). Behavioral results indicated that the high aggressiveness group had a larger congruency effect compared to the low aggressiveness group, but there were no differences in accuracy. EEG results revealed a global reduction in performance-related negativity amplitudes in all the response types in the high aggressiveness group compared to the low aggressiveness group. Interestingly, the distinction between the ERN/Ne and the CRN/Nc components was preserved both in high and low aggressiveness groups. In sum, high aggressive traits do not affect the capacity to self-evaluate erroneous from correct actions but are associated with a decrease in the importance given to one's own performance. The implication of these findings are discussed in relation to pathological aggressiveness.

Neural Basis of Response Bias on the Stop Signal Task in Misophonia

Objective: Misophonia is a newly described condition in which specific ordinary sounds provoke disproportionately strong negative affect. Since evidence for psychobiological dysfunction underlying misophonia is scarce, we tested whether misophonia patients, like many patients with impulse control or obsessive-compulsive spectrum disorders, show impaired ability to inhibit an ongoing motor response. Methods: We collected functional magnetic resonance imaging data during a stop signal task in 22 misophonia patients and 21 matched healthy controls. Results: Compared to controls, patients tended to show longer stop signal delays, which is the time between stimuli signaling response initiation and inhibition. Additionally, patients tended to activate left dorsolateral prefrontal cortex more during responding rather than successful inhibition, as was seen in controls. Furthermore, patients lacked inhibition success-related activity in posterior cingulate cortices and activated the superior medial frontal gyri less during inhibition success compared to failure, a feature correlated with stop signal delays over the sample. Conclusions: Misophonia patients did not show impaired response inhibition. However, they tended to show a response bias on the stop signal task, favoring accuracy over speed. This implies perfectionism and compulsive, rather than impulsive, behavior. Moreover, brain activations were in line with patients, compared to controls, engaging more cognitive control for slowing responses, while employing more attentional resources for successful inhibition.