Behavioral activation system modulation on brain activation during appetitive and aversive stimulus processing

The Androgen Dehydroepiandrosterone Sulfate Shows a Greater Relationship with Impulsivity than Testosterone in a Healthy Male Sample

This study was designed to examine the relationships among the impulsivity construct as a personality trait, the dehydroepiandrosterone sulfate (DHEA-S), and testosterone in a sample of 120 healthy middle-aged males (Mage = 44.39; SD = 12.88). The sum of the three BIS-11 scales, the SR, and the five UPPS-P scales correlated with DHEA-S 0.23 (p < 0.006) and testosterone 0.19 (p < 0.04), controlling for age. Partial correlations showed that DHEA-S was significantly related to motor impulsivity (0.24; p < 0.008), Sensitivity to Reward (0.29; p < 0.002), Lack of Premeditation (0.26; p < 0.05), and, to a lesser extent, Sensation Seeking (0.19; p < 0.04) and Positive Urgency (0.19; p < 0.04). Testosterone correlated with attention impulsivity (0.18; p < 0.04), Sensation Seeking (0.18; p < 0.04), and Positive Urgency (0.22; p < 0.01). Sensitivity to Reward, Negative Urgency, and Positive Urgency were significant predictors of DHEA-S (R2 = 0.28), and Positive Urgency for testosterone (R2 = 0.09). Non-parametric LOESS graphical analyses for local regression allowed us to visualize the non-linear relationships between the impulsivity scales with the two androgens, including non-significant trends. We discuss the implications of these results for impulsive biological personality traits, the limitations of our analyses, and the possible development of future research.

Etiopathogenesis in the Development of Borderline Personality Characteristics in Children and Adolescents

The validity and clinical significance of the characteristics of borderline personality disorder (BPD) in adolescents are increasingly being recognized. The persistence of BPD characteristics in adolescence is high and is associated with negative interpersonal, academic, professional, and financial outcomes. In the literature, BPD characteristics observed in children and adolescents are explained with psychodynamic theories, developmental models, and evolutionary approaches. Emotional dysregulation, interpersonal dysfunction, impulsivity, and self-harming behavior, negative life events, temperament characteristics, neuropsychological dysfunctions, neuroanatomical, genetic, hormonal, and immunological factors may play a role in BPD etiopathogenesis. This review aims to address different approaches and relevant factors for the development of BPD. The articles published between 1968-2021 in the PubMed database were reviewed, and prominent studies were selected for evaluation. The importance of invalidating environment, epistemic freezing and hypermentalization, complex or attachment trauma is emphasized in psychodynamic and developmental literature. In the evolutionary approach, on the other hand, romantic relationships and the onset of reproduction are emphasized as the reason for the emergence of symptoms during adolescence, and it is argued that BPD is related to the rapid life history strategy. It is stated that a decrease in volume in the orbitofrontal cortex and anterior cingulate cortex, which are involved in top-down emotional processing, and an increase in the activity of thalamus and hippocampus regions, which are involved in bottom-up emotional processing are observed in adolescents with BPD characteristics when compared to healthy controls. It is thought that the increase in activation in the superior temporal gyrus and precuneus observed in adolescents with BPD features is a neural indicator of hypermentalization, and the increase in activation in the insula is a neural indicator of social pain. It has been reported that the decrease in resting heart rate and the increase in heart rate variability observed in adolescents with BPD symptoms are associated with the activation of the parasympathetic system. BPD in adolescents is a disorder that challenges clinicians in terms of diagnosis, differential diagnosis, and treatment. It is crucial to evaluate the factors related to etiopathogenesis in BPD in a multifaceted and detailed manner. Keywords: Borderline Personality Disorder, Difficulty in Emotion Regulation, Mentalization, Trauma, Self-harming Behavior, Temperamental Characteristics.

Sensitive caregiving and reward responsivity: A novel mechanism linking parenting and executive functions development in early childhood

Sensitive caregiving is an essential aspect of positive parenting that influences executive functions development, but the mechanisms underlying this association are less clear. Using data from the Family Life Project, a large prospective longitudinal sample of 1292 families residing in rural, predominately low-income communities, the current study examined whether sensitive caregiving impacts executive functions development by shaping behavioral reward processing systems in early postnatal life. Results indicated that higher levels of sensitive caregiving during infancy were associated with heightened reward responsivity at age 4, which in turn predicted superior executive functions ability at age 5. Notably, children's reward responsivity partially mediated the relationship between sensitive caregiving in infancy and executive functions ability at school entry. These findings add to prior work on early experience and children's executive functions and highlight caregiver scaffolding of developing reward processing systems as a potential foundational mechanism for supporting adaptive behavior and self-regulation across the lifespan.

Basal ganglia lateralization in different types of reward

Reward processing is a fundamental human activity. The basal ganglia are recognized for their role in reward processes; however, specific roles of the different nuclei (e.g., nucleus accumbens, caudate, putamen and globus pallidus) remain unclear. Using quantitative meta-analyses we assessed whole-brain and basal ganglia specific contributions to money, erotic, and food reward processing. We analyzed data from 190 fMRI studies which reported stereotaxic coordinates of whole-brain, within-group results from healthy adult participants. Results showed concordance in overlapping and distinct cortical and sub-cortical brain regions as a function of reward type. Common to all reward types was concordance in basal ganglia nuclei, with distinct differences in hemispheric dominance and spatial extent in response to the different reward types. Food reward processing favored the right hemisphere; erotic rewards favored the right lateral globus pallidus and left caudate body. Money rewards engaged the basal ganglia bilaterally including its most anterior part, nucleus accumbens. We conclude by proposing a model of common reward processing in the basal ganglia and separate models for money, erotic, and food rewards.

Reward network connectivity "at rest" is associated with reward sensitivity in healthy adults: A resting-state fMRI study

The behavioral approach system (BAS), based on reinforcement sensitivity theory (RST), is a neurobehavioral system responsible for detecting and promoting motivated behaviors towards appetitive stimuli. Anatomically, the frontostriatal system has been proposed as the core of the BAS, mainly the ventral tegmental area and the ventral striatum and their dopaminergic connections with medial prefrontal structures. The RST also proposes the personality trait of reward sensitivity as a measurable construct of stable individual differences in BAS activity. However, the relationship between this trait and brain connectivity "at rest" has been poorly studied, mainly because previous investigations have focused on studying brain activity under reward-related contingency paradigms. Here, we analyzed the influence of reward sensitivity on the resting-state functional connectivity (rs-FC) between BAS-related areas by correlating the BOLD time series with the scores on the Sensitivity to Reward (SR) scale in a sample of 89 healthy young adults. Rs-FC between regions of interest were all significant. Results also revealed a positive association between SR scores and the rs-FC between the VTA and the ventromedial prefrontal cortex, and between the latter structure and the anterior cingulate cortex. These results suggest that reward sensitivity could be associated with different resting-state activity in the mesocortical pathway.

Keeping in Touch with Mental Health: The Orienting Reflex and Behavioral Outcomes from Calatonia

Physical and psychological therapy based on touch has been gradually integrated into broader mental health settings in the past two decades, evolving from a variety of psychodynamic, neurobiological and trauma-based approaches, as well as Eastern and spiritual philosophies and other integrative and converging systems. Nevertheless, with the exception of a limited number of well-known massage therapy techniques, only a few structured protocols of touch therapy have been standardized and researched to date. This article describes a well-defined protocol of touch therapy in the context of psychotherapy-the Calatonia technique-which engages the orienting reflex. The orienting reflex hypothesis is explored here as one of the elements of this technique that helps to decrease states of hypervigilance and chronic startle reactivity (startle and defensive reflexes) and restore positive motivational and appetitive states.

Microstates-based resting frontal alpha asymmetry approach for understanding affect and approach/withdrawal behavior

The role of resting frontal alpha-asymmetry in explaining neural-mechanisms of affect and approach/withdrawal behavior is still debatable. The present study explores the ability of the quasi-stable resting EEG asymmetry information and the associated neurovascular synchronization/desynchronization in bringing more insight into the understanding of neural-mechanisms of affect and approach/withdrawal behavior. For this purpose, a novel frontal alpha-asymmetry based on microstates, that assess quasi-stable EEG scalp topography information, is proposed and compared against standard frontal-asymmetry. Both proposed and standard frontal alpha-asymmetries were estimated from thirty-nine healthy volunteers resting-EEG simultaneously acquired with resting-fMRI. Further, neurovascular mechanisms of these asymmetry measures were estimated through EEG-informed fMRI. Subsequently, the Hemodynamic Lateralization Index (HLI) of the neural-underpinnings of both asymmetry measures was assessed. Finally, the robust correlation of both asymmetry-measures and their HLI’s with PANAS, BIS/BAS was carried out. The standard resting frontal-asymmetry and its HLI yielded no significant correlation with any psychological-measures. However, the microstate resting frontal-asymmetry correlated significantly with negative affect and its neural underpinning’s HLI significantly correlated with Positive/Negative affect and BIS/BAS measures. Finally, alpha-BOLD desynchronization was observed in neural-underpinning whose HLI correlated significantly with negative affect and BIS. Hence, the proposed resting microstate-frontal asymmetry better assesses the neural-mechanisms of affect, approach/withdrawal behavior.

Behavioral approach and orbitofrontal cortical activity during decision-making in substance dependence

Behavioral approach, defined as behavior directed toward a reward or novel stimulus, when elevated, may increase one's vulnerability to substance use disorder. Behavioral approach has been associated with relatively greater left compared to right frontal activity; behavioral inhibition may be associated with relatively greater right compared to left frontal brain activity. We hypothesized that substance dependent individuals (SDI) would have higher behavioral approach than controls and greater prefrontal cortical activity during decision-making involving reward. We hypothesized that behavioral approach would correlate with left frontal activity during decision-making and that the correlation would be stronger in SDI than controls. 31 SDI and 21 controls completed the Behavioral Inhibition System/Behavioral Approach System (BIS/BAS) scales and performed a decision-making task during fMRI. Orbitofrontal (OFC) and dorsolateral prefrontal activity were correlated with BIS and BAS scores. Compared to controls, SDI had higher BAS Fun Seeking scores (p<0.001) and worse decision-making performance (p=0.004). BAS Fun Seeking correlated with left OFC activity during decision-making across group (r=0.444, p<0.003). The correlation did not differ by group. There was no correlation between BIS and right frontal activity. Left OFC may play a role in reward-related decision-making in substance use disorder especially in individuals with high behavioral approach.

Development of self-inflicted injury: Comorbidities and continuities with borderline and antisocial personality traits

Self-inflicted injury (SII) is a continuum of intentionally self-destructive behaviors, including nonsuicidal self-injuries, suicide attempts, and death by suicide. These behaviors are among the most pressing yet perplexing clinical problems, affecting males and females of every race, ethnicity, culture, socioeconomic status, and nearly every age. The complexity of these behaviors has spurred an immense literature documenting risk and vulnerability factors ranging from individual to societal levels of analysis. However, there have been relatively few attempts to articulate a life span developmental model that integrates ontogenenic processes across these diverse systems. The objective of this review is to outline such a model with a focus on how observed patterns of comorbidity and continuity can inform developmental theories, early prevention efforts, and intervention across traditional diagnostic boundaries. Specifically, when SII is viewed through the developmental psychopathology lens, it becomes apparent that early temperamental risk factors are associated with risk for SII and a range of highly comorbid conditions, such as borderline and antisocial personality disorders. Prevention efforts focused on early-emerging biological and temperamental contributors to psychopathology have great potential to reduce risk for many presumably distinct clinical problems. Such work requires identification of early biological vulnerabilities, behaviorally conditioned social mechanisms, as well as societal inequities that contribute to self-injury and underlie intergenerational transmission of risk.

Wistar audiogenic rats display abnormal behavioral traits associated with artificial selection for seizure susceptibility

Accumulating evidence from different animal models has contributed to the understanding of the bidirectional comorbidity associations between the epileptic condition and behavioral abnormalities. A strain of animals inbred to enhance seizure predisposition to high-intensity sound stimulation, the Wistar audiogenic rat (WAR), underwent several behavioral tests: forced swim test (FST), open-field test (OFT), sucrose preference test (SPT), elevated plus maze (EPM), social preference (SP), marble burying test (MBT), inhibitory avoidance (IAT), and two-way active avoidance (TWAA). The choice of tests aimed to investigate the correlation between underlying circuits believed to be participating in both WAR's innate susceptibility to sound-triggered seizures and the neurobiological substrates associated with test performance. Comparing WAR with its Wistar counterpart (i.e., resistant to audiogenic seizures) showed that WARs present behavioral despair traits (e.g., increased FST immobility) but no evidence of anhedonic behavior (e.g., increased sucrose consumption in SPT) or social impairment (e.g., no difference regarding juvenile exploration in SP). In addition, tests suggested that WARs are unable to properly evaluate degrees of aversiveness (e.g., performance on OFT, EPM, MBT, IAT, and TWAA). The particularities of the WAR model opens new venues to further untangle the neurobiology underlying the co-morbidity of behavioral disorders and epilepsy. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".

Exercising self-control increases relative left frontal cortical activation

Self-control refers to the capacity to override or alter a predominant response tendency. The current experiment tested the hypothesis that exercising self-control temporarily increases approach motivation, as revealed by patterns of electrical activity in the prefrontal cortex. Participants completed a writing task that did vs did not require them to exercise self-control. Then they viewed pictures known to evoke positive, negative or neutral affect. We assessed electroencephalographic (EEG) activity while participants viewed the pictures, and participants reported their trait levels of behavioral inhibition system (BIS) and behavioral activation system (BAS) sensitivity at the end of the study. We found that exercising (vs not exercising) self-control increased relative left frontal cortical activity during picture viewing, particularly among individuals with relatively higher BAS than BIS, and particularly during positive picture viewing. A similar but weaker pattern emerged during negative picture viewing. The results suggest that exercising self-control temporarily increases approach motivation, which may help to explain the aftereffects of self-control (i.e. ego depletion).

Moods as ups and downs of the motivation pendulum: revisiting reinforcement sensitivity theory (RST) in bipolar disorder

Motivation is a key neurobehavioral concept underlying adaptive responses to environmental incentives and threats. As such, dysregulation of motivational processes may be critical in the formation of abnormal behavioral patterns/tendencies. According to the long standing model of the Reinforcement Sensitivity Theory (RST), motivation behaviors are driven by three neurobehavioral systems mediating the sensitivity to punishment, reward or goal-conflict. Corresponding to current neurobehavioral theories in psychiatry, this theory links abnormal motivational drives to abnormal behavior; viewing depression and mania as two abnormal extremes of reward driven processes leading to either under or over approach tendencies, respectively. We revisit the RST framework in the context of bipolar disorder (BD) and challenge this concept by suggesting that dysregulated interactions of both punishment and reward related processes better account for the psychological and neural abnormalities observed in BD. We further present an integrative model positing that the three parallel motivation systems currently proposed by the RST model, can be viewed as subsystems in a large-scale neurobehavioral network of motivational decision making.

A new window to understanding individual differences in reward sensitivity from attentional networks

Existing evidence suggests that the presence of reward cues modifies the activity in attentional networks, however, the nature of these influences remains poorly understood. Here, we performed independent component analysis (ICA) in two fMRI datasets corresponding to two incentive delay tasks, which compared the response to reward (money and erotic pictures) and neutral cues, and yielded activations in the ventral striatum using a general linear model approach. Across both experiments, ICA revealed that both the right frontoparietal network and default mode network time courses were positively and negatively modulated by reward cues, respectively. Moreover, this dual neural response pattern was enhanced in individuals with strong reward sensitivity. Therefore, ICA may be a complementary tool to investigate the relevant role of attentional networks on reward processing, and to investigate reward sensitivity in normal and pathological populations.

Reward sensitivity is associated with brain activity during erotic stimulus processing

The behavioral approach system (BAS) from Gray’s reinforcement sensitivity theory is a neurobehavioral system involved in the processing of rewarding stimuli that has been related to dopaminergic brain areas. Gray’s theory hypothesizes that the functioning of reward brain areas is modulated by BAS-related traits. To test this hypothesis, we performed an fMRI study where participants viewed erotic and neutral pictures, and cues that predicted their appearance. Forty-five heterosexual men completed the Sensitivity to Reward scale (from the Sensitivity to Punishment and Sensitivity to Reward Questionnaire) to measure BAS-related traits. Results showed that Sensitivity to Reward scores correlated positively with brain activity during reactivity to erotic pictures in the left orbitofrontal cortex, left insula, and right ventral striatum. These results demonstrated a relationship between the BAS and reward sensitivity during the processing of erotic stimuli, filling the gap of previous reports that identified the dopaminergic system as a neural substrate for the BAS during the processing of other rewarding stimuli such as money and food.

Reward sensitivity modulates connectivity among reward brain areas during processing of anticipatory reward cues

Reward sensitivity, or the tendency to engage in motivated approach behavior in the presence of rewarding stimuli, may be a contributory factor for vulnerability to disinhibitory behaviors. Although evidence exists for a reward sensitivity-related increased response in reward brain areas (i.e. nucleus accumbens or midbrain) during the processing of reward cues, it is unknown how this trait modulates brain connectivity, specifically the crucial coupling between the nucleus accumbens, the midbrain, and other reward-related brain areas, including the medial orbitofrontal cortex and the amygdala. Here, we analysed the relationship between effective connectivity and personality in response to anticipatory reward cues. Forty-four males performed an adaptation of the Monetary Incentive Delay Task and completed the Sensitivity to Reward scale. The results showed the modulation of reward sensitivity on both activity and functional connectivity (psychophysiological interaction) during the processing of incentive cues. Sensitivity to reward scores related to stronger activation in the nucleus accumbens and midbrain during the processing of reward cues. Psychophysiological interaction analyses revealed that midbrain-medial orbitofrontal cortex connectivity was negatively correlated with sensitivity to reward scores for high as compared with low incentive cues. Also, nucleus accumbens-amygdala connectivity correlated negatively with sensitivity to reward scores during reward anticipation. Our results suggest that high reward sensitivity-related activation in reward brain areas may result from associated modulatory effects of other brain regions within the reward circuitry.

Resting-state activity in the left executive control network is associated with behavioral approach and is increased in substance dependence

BACKGROUND

Individuals with drug addictions report increased willingness to approach rewards. Approach behaviors are thought to involve executive control processes and are more strongly represented in the left compared to right prefrontal cortex. A direct link between approach tendencies and left hemisphere activity has not been shown in the resting brain. We hypothesized that compared to controls, substance dependent individuals (SDI) would have greater left hemisphere activity in the left executive control network (ECN) at rest.

METHODS

Twenty-five SDI and 25 controls completed a Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) questionnaire and underwent a resting-state fMRI scan. Group independent component analysis was performed. We used template matching to identify the left and right ECN separately and compared the corresponding components across groups. Across group, BAS scores were correlated with signal fluctuations in the left ECN and BIS scores with right ECN.

RESULTS

BAS scores were higher in SDI compared to controls (p<.003) and correlated with signal fluctuation in the left ECN. SDI showed significantly more activity than controls in the left prefrontal cortex of the left ECN. Conversely, SDI showed less activity than controls in the right prefrontal cortex of the right ECN.

CONCLUSIONS

Results from this study suggest that approach tendencies are related to the left ECN, even during rest. Higher resting-state signal in the left ECN may play a role in heightened approach tendencies that contribute to drug-seeking behavior.

Neural correlates of personality: an integrative review

This review examines the neural correlates of Gray's model (Gray and McNaughton, 2000; McNaughton and Corr, 2004), supplemented by a fourth dimension: constraint (Carver, 2005). The purpose of this review is to summarize findings from fMRI studies that tap on neural correlates of personality aspects in healthy subjects, in order to provide insight into the neural activity underlying human temperament. BAS-related personality traits were consistently reported to correlate positively to activity of the ventral and dorsal striatum and ventral PFC in response to positive stimuli. FFFS and BIS-related personality traits are positively correlated to activity in the amygdala in response to negative stimuli. There is limited evidence that constraint is associated with PFC and ACC activity. In conclusion, functional MRI research sheds some light on the specific neural networks underlying personality. It is clear that more sophisticated task paradigms are required, as well as personality questionnaires that effectively differentiate between BAS, FFFS, BIS, and constraint. Further research is proposed to potentially reveal new insight in the neural subsystems governing basic human behavior.

Frontostriatal response to set switching is moderated by reward sensitivity

The reinforcement sensitivity theory (RST) relates individual differences in reward sensitivity to the activation of the behavioral approach system (BAS). Dopamine-related brain structures have been repeatedly associated with reward processing, but also with cognitive processes such as task switching. In the present study, we examined the association between reward sensitivity and the event-related fMRI BOLD response with set switching in 31 males. As expected, the right inferior frontal cortex (rIFG) and the striatum (i.e. the left putamen) were involved in set-switching activity for the overall sample. Interindividual differences in Gray's reward sensitivity were related to stronger activity in the rIFG and the ventral striatum. Thus, trait reward sensitivity contributed to the modulation of brain responsiveness in set-switching tasks. Having considered previous research, we propose that higher BAS activity is associated with a stronger reward to process a better implementation of goal-directed tasks and the diminished processing of secondary cues.