Gray's Neuropsychology of anxiety : An enquiry into the functions of septohippocampal theories

ADHD and the avoidance of mental effort: the role of response inhibition and avoidance motivation

OBJECTIVE

The tendency of people with ADHD to avoid tasks that require mental effort impacts their academic achievement. Findings in the literature suggest that children with ADHD find cognitive tasks more effortful and uncomfortable than their typically developing peers. However, neuropsychological processes contributing to this remain unclear. The present study investigated whether the relationship between prepotent motor response inhibition and avoiding mental effort is mediated by the ability to resist avoidance motivation and whether this proposed mediation mechanism is contingent on ADHD diagnosis.

METHOD

40 children with ADHD and 40 gender and age-matched typically developing peers participated in the study. They completed the Cognitive Effort Avoidance Measure, the Go/No-go Task, and the Reinforcement Sensitivity Theory-Personality Questionnaire-Children. Mediation and moderated mediation analyses were employed to test the hypotheses.

RESULTS

Children with ADHD scored lower in response inhibition and resisting avoidance motivation. Poorer scores in these variables were associated with a higher avoidance rate. Moreover, the ability to resist avoidance motivation completely mediated the relationship between response inhibition and avoidance rate only among children with ADHD.

CONCLUSION

Findings imply that poorer response inhibition led to an increase in avoidance motivation among children with ADHD, which becomes challenging to regulate effectively due to an impairment in the ability to resist avoidance motivation. Theoretical and clinical implications are discussed.

Parallel ventral hippocampus-lateral septum pathways differentially regulate approach-avoidance conflict

The ability to resolve an approach-avoidance conflict is critical to adaptive behavior. The ventral CA3 (vCA3) and CA1 (vCA1) subfields of the ventral hippocampus (vHPC) have been shown to facilitate avoidance and approach behavior, respectively, in the face of motivational conflict, but the neural circuits by which this subfield-specific regulation is implemented is unknown. We demonstrate that two distinct pathways from these subfields to lateral septum (LS) contribute to this divergent control. In Long-Evans rats, chemogenetic inhibition of the vCA3- LS caudodorsal (cd) pathway potentiated approach towards a learned conflict-eliciting stimulus, while inhibition of the vCA1-LS rostroventral (rv) pathway potentiated approach non-specifically. Additionally, vCA3-LScd inhibited animals were less hesitant to explore food during environmental uncertainty, while the vCA1- LSrv inhibited animals took longer to initiate food exploration. These findings suggest that the vHPC influences multiple behavioral systems via differential projections to the LS, which in turn send inhibitory projections to motivational centres of the brain.

Placental endocrine insufficiency programs anxiety, deficits in cognition and atypical social behaviour in offspring

Abnormally elevated expression of the imprinted PHLDA2 gene has been reported in the placenta of human babies that are growth restricted in utero in several studies. We previously modelled this gene alteration in mice and found that just 2-fold increased expression of Phlda2 resulted in placental endocrine insufficiency. In addition, elevated Phlda2 was found to drive fetal growth restriction (FGR) of transgenic offspring and impaired maternal care by their wildtype mothers. Being born small and being exposed to suboptimal maternal care have both been associated with the increased risk of mental health disorders in human populations. In the current study we probed behavioural consequences of elevated Phlda2 for the offspring. We discovered increased anxiety-like behaviours, deficits in cognition and atypical social behaviours, with the greatest impact on male offspring. Subsequent analysis revealed alterations in the transcriptome of the adult offspring hippocampus, hypothalamus and amygdala, regions consistent with these behavioural observations. The inclusion of a group of fully wildtype controls raised in a normal maternal environment allowed us to attribute behavioural and molecular alterations to the adverse maternal environment induced by placental endocrine insufficiency rather than the specific gene change of elevated Phlda2. Our work demonstrates that a highly common alteration reported in human FGR is associated with negative behavioural outcomes later in life. Importantly, we also establish the experimental paradigm that placental endocrine insufficiency can program atypical behaviour in offspring highlighting the under-appreciated role of placental endocrine insufficiency in driving disorders of later life behaviour.

Between Conspiracy Beliefs, Ingroup Bias, and System Justification: How People Use Defense Strategies to Cope With the Threat of COVID-19

The current situation around coronavirus disease 2019 (COVID-19) portrays a threat to us in several ways: It imposes uncertainty and a lack of control and reminds us of our own mortality. People around the world have reacted to these threats in seemingly unrelated ways: From stockpiling yeast and toilet paper to favoring nationalist ideas or endorsing conspiratorial beliefs. According to the General Process Model of Threat and Defense, the confrontation with a threat - a discrepant experience - makes humans react with both proximal and distal threat responses. While the proximal response manifests in behavioral inhibition that leads to heightened anxious arousal and vigilance, distal responses seek to lower behavioral inhibition and the associated state of anxiety and vigilance through engaging in distal defenses. In the present research, we propose that the reactions to COVID-19 may represent distal defense strategies to the pandemic and, therefore, can be explained and forecasted by the model. Thus, we hypothesized increased perceived COVID-19 threat to lead to a proximal threat response in the form of heightened behavioral inhibition. This, in return, should enhance the use of distal defenses (i.e., several ingroup biases, system justification, and conspiratorial beliefs) overlapping with the reactions observed as a response to COVID-19. This hypothesized mediated effect of increased perceived COVID-19 threat on distal defenses was tested in two preregistered studies: In Study 1 (N = 358), results showed perceived COVID-19 threat to be related to behavioral inhibition and, in turn, to be associated with increased distal defenses (i.e., higher entitativity, control restoration motivation, passive party support). In Study 2 (N = 348), we manipulated COVID-19 threat salience and found results suggesting the distal defenses of ingroup entitativity, system justification, and conspiratorial beliefs to be mediated by the proximal threat response. The results of the present research hint toward a common mechanism through which the seemingly unrelated reactions to COVID-19 can be explained. The results might help to predict future behavior during the COVID-19 pandemic and to design measures to counteract the detrimental effects of the pandemic.

Differential Effects of Infant Vocalizations on Approach-Avoidance Postural Movements in Mothers

Infant vocalization plays a pivotal role in communicating infant mood to parents and thereby motivating parenting responses. Although many psychological and neural responses to infant vocalization have been reported, few studies have examined maternal approach-avoidance behavior in response to infant vocalization. Thus, this research sought to determine how infant emotional vocalization affects maternal behavior. Twenty mothers participated in this behavioral study, all of whom had infants of 24 months old or less. In the experiment, they stood on a Balance Board that collected real-time data regarding center of pressure (COP), while listening to a series of infant vocalizations including cry, laugh, and babbling. They then listened to the same vocalizations for a second time and rated their felt emotions in response to each vocalization. The participants demonstrated significant postural movements of approaching in response to cry stimuli or to stimuli regarded as highly urgent. In contrast, they demonstrated postural movement of avoidance in response to laugh vocalization. These findings suggest that parenting behavior in response to infant emotional vocalization is regulated not by the pleasant-unpleasant axis but by the urgency of the stimulus.

The two faces of avoidance: Time-frequency correlates of motivational disposition in blood phobia

Contrary to other phobias, individuals with blood phobia do not show a clear-cut withdrawal disposition from the feared stimulus. The study of response inhibition provides insights into reduced action disposition in blood phobia. Twenty individuals with and 20 without blood phobia completed an emotional go/no-go task including phobia-related pictures, as well as phobia-unrelated unpleasant, neutral, and pleasant stimuli. Behavioral results did not indicate a phobia-specific reduced action disposition in the phobic group. Time-frequency decomposition of event-related EEG data showed a reduction of right prefrontal activity, as indexed by an increase in alpha power (200 ms), for no-go mutilation trials in the phobic group but not in controls. Moreover, theta power (300 ms) increased specifically for phobia-related pictures in individuals with, but not without, blood phobia, irrespective of go or no-go trial types. Passive avoidance of phobia-related stimuli subtended by the increased alpha in the right prefrontal cortex, associated with increased emotional salience indexed by theta synchronization, represents a possible neurophysiological correlate of the conflicting motivational response in blood phobia. Through the novel use of time-frequency decomposition in an emotional go/no-go task, the present study contributed to clarifying the neurophysiological correlates of the overlapping motivational tendencies in blood phobia.

Assessing future expectations and the two-dimensional model of affect in an Italian population

Future-directed thinking has been described as part of two underlying systems that integrate dimensions of affect, motivational systems, orientation to the future, and future expectations, which are initiated at the cognitive, affective, biological, behavioral, and motivational levels. The main aim of the present study is to test the two underlying frameworks model and explore future expectations in a general Italian-speaking population (N=345). Therefore, the second aim of the present paper is to confirm the factorial structure of the Subjective Probability Task (SPT; MacLeod et al., 1996), a questionnaire designed to assess specific positive and negative orientations towards the future. Results showed that the SPT has good psychometric properties and it is a reliable instrument to assess future-directed thinking. Moreover, our findings confirmed the role of future expectancies as cognitive correlates of depression and anxiety. Differently from previous studies (Clark and Watson, 1991; MacLeod et al., 1996), our results did not confirm that depression was characterized by low positive affect. We believe this paper contributes to the understanding of future expectancies and their relation with anxiety and depression, and will help to expand the availability of an instrument to assess future directed thinking.

Development of a theoretically-derived human anxiety syndrome biomarker

“Anxiety disorders” are extremely common; and are a major source of health costs and lost work days. Their diagnosis is currently based on clinical symptom check lists and there are no biological markers to diagnose specific syndromal causes. This paper describes: 1) a detailed theory of the brain systems controlling anxiolytic-insensitive threat-avoidance and anxiolytic-sensitive threat-approach — where, in specific brain structures, activity generates specific normal behaviours, hyperactivity generates abnormal behaviours, and hyper-reactivity (hypersensitivity to input) generates specific clinical syndromes; 2) a rodent model of systemic anxiolytic action (rhythmical slow activity), linked to the theory, that over a period of 40 years has shown predictive validity with no false positives or false negatives — and which is likely to assay the sensitivity of endogenous systems that control anxiety; and, 3) derivation from this rodent-based theory of a specific non-invasive biomarker (goal-conflict-specific rhythmicity) for the threat-approach system in humans. This new biomarker should allow division of untreated “anxiety” patients, with superficially similar clusters of symptoms, into distinct high scoring (syndromal) and low scoring groups with different treatment-responses. This would be the first theoretically-derived biomarker for any mental disorder and should: 1) predict treatment efficacy better than current symptom-based diagnoses; 2) provide a human single dose test of novel anxiolytics; 3) provide a starting point for developing biomarkers for other “anxiety” syndromes; and so, 4) greatly improve treatment outcomes and cost-effectiveness.