The duration discrimination respiratory task: A new test to measure respiratory interoceptive accuracy.

Interoception, which refers to the perception of body's internal state, is implicated in emotional processes and psychopathological disorders. Over the last decades, different tools have been developed to measure interoceptive accuracy, or the ability to accurately perceive physiological signals. Most of these tools have focused on cardiac interoception, but respiratory interoception has been less investigated due to the more complex and less portable equipment required. In this study, we suggest a new duration discrimination respiratory (DDR) task that does not require complex equipment. Using an adaptive staircase procedure, this task aims to determine an individual's ability to detect exhalation longer than their resting reference duration. One hundred and twenty-three healthy subjects completed the DDR task, an interoceptive task of heart rate discrimination, and filled out questionnaires on interoceptive awareness (Multidimensional Assessment of Interoceptive Awareness), alexithymia (Toronto Alexithymia Scale [TAS]), affects (Positive and Negative Affect Scale [PANAS]), and anamnestic. Results demonstrated a good internal consistency (Cronbach's alpha = .93) of the DDR task. On average, subjects needed 99.22% (SD = 36.38) of their reference exhalation time in addition to reference exhalation to detect a prolonged exhalation. Higher self-reported fitness levels, not counting during the DDR task and lower difficulty in describing feelings (TAS subscale), predicted higher respiratory discrimination duration. In conclusion, this study demonstrates the utility of the DDR task as a valid measure of interoception.

How are irritability and anhedonia symptoms linked? A network approach.

BACKGROUND: Anhedonia and irritability are two prevalent symptoms of major depressive disorder (MDD) that predict greater depression severity and poor outcomes, including suicidality. Although both symptoms have been proposed to result from paradoxical reward processing dysfunctions, the interactions between these symptoms remain unclear. Anhedonia is a multifaceted symptom reflecting impairments in multiple dimensions of reward processing (e.g., pleasure, desire, motivation, and effort) across distinct reward types (e.g., food, sensory experiences, social activities, hobbies) that may differentially interact with irritability. This study investigated the complex associations between anhedonia and irritability using network analysis. METHOD: Participants (N = 448, Mage = 33.29, SD = 14.58) reported their symptoms of irritability on the Brief Irritability Test (Holtzman et al., 2015) and anhedonia (i.e., pleasure, desire, motivation, and effort dimensions across four reward types) on the Dimensional Anhedonia Rating Scale (Rizvi et al., 2015). A regularized Gaussian Graphical Model was built to estimate the network structure between items. RESULTS: Irritability was negatively related to willingness to expand effort to obtain food/drinks (estimate = -0.18), social activities (-0.13), and hobbies (-0.12) rewards. Irritability was positively associated with a desire for food/drinks (0.12). LIMITATIONS: Only a small proportion (5.8%) of our sample was clinical and the study design was cross-sectional. CONCLUSION: A specific link between irritability and the effort dimension of the hedonic response across three reward types was identified. Investigating effort expenditure deficits with experimental paradigms may help us understand the mechanisms underlying the comorbidity between irritability and anhedonia in the context of MDD.

Electrophysiological correlates of attentional bias towards threat in children with high levels of social anxiety.

Pediatric social anxiety is characterized by attentional biases (AB) towards social threats. This study used a new response-based calculation method to assess AB from response times (RT) in a visual dot-probe task and electroencephalography (EEG) to explore its electrophysiological correlates. Twenty, high socially anxious children (HSA) (mean [M ] = 10.1 years; standard deviation [SD] = 1.01) were compared with 22 healthy control children (HC) (M = 10.20 years; SD = 1.30) matched in age and gender. Participants had to identify targets preceded by disgust-neutral, happy-neutral, or neutral-neutral pairs of faces. RT and electroencephalograms were recorded throughout the task. While no significant group difference was found at the behavioral level, principal component analyses performed on EEG data revealed that event-related potentials for threat-related stimuli were impacted by social anxiety. Analyses indicated a larger N170 amplitude in response to all facial stimuli in HC when compared to the HSA. However, we found increased P2 amplitudes for disgust-neutral pairs compared with happy-neutral pairs in has only. Then, thasHSA group showed increased P2 amplitudes for targets following disgusted faces on the opposite side of the screen compared with targets appearing on the same side of the screen. These results suggest that HSA may display an increased anchorage of attention on threatening stimuli and need more effort to disengage their attentional focus from threats and to perform the task correctly. Taken together, our data confirmed the presence of AB in children with high levels of social anxiety, which are reflected by increased neural processing during the confrontation to faces depicting a potential threatening expression.

Decision-making of patients with major depressive disorder in the framework of action control.

Introduction: Patients with major depressive disorder (MDD) experience dysfunctional emotional states and cognitive impairments, leading to behavioural, social, and functional issues. Neurocognitive theory proposes that the initiation and maintenance of MDD is primarily the result of a deficit of action control which in turn would lead to decision-making impairments.Methods: We assessed 27 medicated outpatients with MDD who were demographically matched with 16 healthy participants on decision-making (DM) processes (Iowa Gambling Task (IGT) and Reversal Learning Task (RLT)), clinical variables (depressive symptoms and self-efficacy), and volition (Lille Apathy Rating Scale).Results: Patients with MDD displayed deficits on the IGT but not on the RLT. Correlational analysis of patients with MDD revealed no significant associations between IGT or RLT performance and volition, depressive symptom severity, and self-efficacy. However, differences on the IGT between patients with MDD and controls became non-significant when controlling for the variance of these scores.Conclusions: MDD appears to have an impact on dynamic DM processes, while basic processes are preserved. Limitations as well as directions for future research are discussed with regard to the neurocognitive model of depression.

Thinking About One's Feelings: Association Between Alexithymia and Cognitive Styles in a Nonclinical Population.

Alexithymia is described as a disturbance in the cognitive and affective processing of emotions. Little is known about the cognitive styles associated with this personality trait. In this article, we examine to what extent alexithymia is linked with poorer rational cognitive style. A total of 685 participants from a nonclinical sample completed the Toronto Alexithymia Scale-20 along with self-reported and behavioral measures of cognitive styles. Results suggest that people with a high level of self-reported alexithymia show lower rational abilities. The findings of this study extend previous work on cognitive processes underlying emotional self-regulation impairments in alexithymia, suggesting that these difficulties may be linked to a poorer use of rational process.

[Physiological reactivity and interoceptive awareness in pediatric anxiety disorders: A conceptual and empirical review]. / Réactivité physiologique et conscience intéroceptive dans les troubles anxieux pédiatriques : une revue conceptuelle et empirique.

Objectives This review aims to summarize the data relative to objective and subjective measures of body responses in children and adolescents with anxiety.Methods We reviewed 24 studies measuring (1) cardiac responses and (2) interoceptive processes in children and adolescents with anxiety.Results Anxious children and adolescents generally do not differ from their non-anxious peers on their cardiac parameters and objective physiological reactivity to stressful events but some results suggest a reduced autonomic flexibility in pediatric anxiety related to chronic anxiety. Moreover, anxiety does not alter the interoceptive accuracy, but youths with anxiety misinterpret the intensity and the visibility of their symptoms.Conclusion Interoception are biased in pediatric anxiety and further studies are needed to provide information about the role of perceptive, attentional, and interpretative processes in these biases, as well as determine the respective influence of anxiety type and symptoms intensity.

Is there an all-embracing construct of emotion reactivity? Adaptation and validation of the emotion reactivity scale among a French-speaking community sample.

BACKGROUND: Emotion reactivity is defined as the extent to which an individual experiences emotions in response to a wide array of stimuli, intensely, and for a prolonged period. This construct is a key psychological factor in the development and maintenance of psychopathological disorders. The aim of the current study was to develop and validate a French version of the Emotion Reactivity Scale (ERS), which gauges three aspects of emotion reactivity: (1) emotional sensitivity, (2) emotional intensity, and (3) emotional persistence. METHOD: The French ERS and both concurrent and divergent validated scales were administered to 258 participants from the community. RESULTS: Confirmatory factor analyses revealed good fit indices for: (1) a single-factor model, (2) a three-factor model, and (3) a hierarchical three-factor solution with a single-factor solution as a second-order latent variable for a generic construct of emotion reactivity. The French version of the Emotion Reactivity Scale also exhibits acceptable internal scale score reliability (total scale and subscales). Eventually, meaningful relationships were found between factors of emotion reactivity and depression, distinct aspects of impulsive behaviors, and maladaptive emotion regulation strategies. CONCLUSION: Findings of the confirmatory factor analyses are consistent with previous studies suggesting that the ERS is mainly captured by a single major construct of emotion reactivity.

Fear of negative evaluation and attentional bias for facial expressions: an event-related study.

Numerous studies have shown an exacerbation of attentional bias towards threat in anxiety states. However, the cognitive mechanisms responsible for these attentional biases remain largely unknown. Further, the authors outline the need to consider the nature of the attentional processes in operation (hypervigilance, avoidance, or disengagement). We adapted a dot-probe paradigm to record behavioral and electrophysiological responses in 26 participants reporting high or low fear of evaluation, a major component of social anxiety. Pairs of faces including a neutral and an emotional face (displaying anger, fear, disgust, or happiness) were presented during 200 ms and then replaced by a neutral target to discriminate. Results show that anxious participants were characterized by an increased P1 in response to pairs of faces, irrespective of the emotional expression included in the pair. They also showed an increased P2 in response to angry-neutral pairs selectively. Finally, in anxious participants, the P1 response to targets was enhanced when replacing emotional faces, whereas non-anxious subjects showed no difference between the two conditions. These results indicate an early hypervigilance to face stimuli in social anxiety, coupled with difficulty in disengaging from threat and sustained attention to emotional stimuli. They are discussed within the framework of current models of anxiety and psychopathology.

Physiological reactivity at rest and in response to social or emotional stimuli after a traumatic brain injury: A systematic review.

Numerous studies have shown that alterations in physiological reactivity (PR) after traumatic brain injury (TBI) are possibly associated with emotional deficits. We conducted a systematic review of these studies that evaluated PR in adults with moderate-to-severe TBI, either at rest or in response to emotional, stressful, or social stimuli. We focused on the most common measures of physiological response, including heart rate (HR), heart rate variability (HRV), respiratory sinus arrhythmia (RSA), electrodermal activity (EDA), salivary cortisol, facial electromyography (EMG), and blink reflex. Methods: A systematic literature search was conducted across six databases (PsycINFO, Psycarticles, SciencDirect, Cochrane Library, PubMed, and Scopus). The search returned 286 articles and 18 studies met the inclusion criteria. Results: Discrepancies were observed according to the type of physiological measure. Reduced physiological responses in patients with TBI have been reported in most EDA studies, which were also overrepresented in the review. In terms of facial EMG, patients with TBI appear to exhibit reduced activity of the corrugator muscle and diminished blink reflex, while in most studies, zygomaticus contraction did not show significant differences between TBI and controls. Interestingly, most studies measuring cardiac activity did not find significant differences between TBI and controls. Finally, one study measured salivary cortisol levels and reported no difference between patients with TBI and controls. Conclusion: Although disturbed EDA responses were frequently reported in patients with TBI, other measures did not consistently indicate an impairment in PR. These discrepancies could be due to the lesion pattern resulting from TBI, which could affect the PR to aversive stimuli. In addition, methodological differences concerning the measurements and their standardization as well as the characteristics of the patients may also be involved in these discrepancies. We propose methodological recommendations for the use of multiple and simultaneous PR measurements and standardization. Future research should converge toward a common methodology in terms of physiological data analysis to improve inter-study comparisons.

Stress response and experiential avoidance among firefighters: Preliminary insights from network analyses.

Firefighters are at increased risk of developing posttraumatic stress disorder (PTSD) due to exposure to potentially traumatic events during their careers. However, little is known about the prevalence of PTSD among this population, particularly when taking moderating variables into account. Using Gaussian Graphical Models and Directed Acyclic Graphs, we conducted network analyses to examine the interactions between clusters of PTSD symptoms, perceived stress, hardiness, and experiential avoidance among 187 firefighters. The data and code are published with the paper. Experiential avoidance, as part of psychological inflexibility, was found to be the only variable that interacted with PTSD symptomatology. Strong positive associations were observed between experiential avoidance and the "negative mood and cognitions" subscale of the PTSD Checklist for DSM-5 (PCL-5). Through this association, other PTSD symptoms were activated, particularly avoidance and arousal. Our findings suggest that experiential avoidance and negative mood and cognition symptoms are particularly important in the expression of PTSD symptomatology in firefighters. In addition, experiential avoidance may be used as a coping strategy to reduce perceived stress during potentially traumatic events. Therefore, experiential avoidance may be a prime target for future interventions and training focused on flexible self-regulation strategies in this population.

Sex differences on emotional processing are modulated by subclinical levels of alexithymia and depression: a preliminary assessment using event-related potentials.

Several studies have suggested that women are more sensitive than men to emotions in general. Event-related potential (ERP) studies have demonstrated N2 and P3b modulations, suggesting that women allocate more attentional resources to emotions than men do. However, the exact origin of this emotional modulation by sex is still a matter of debate. We wondered whether these sex differences might be due to some specific personality traits of women and men. Thirty participants (15 males and 15 females) were selected so that there were no sex differences on alexithymia, or depression and anxiety scales. The participants were asked to complete a "modified emotional" oddball task, in which they had to detect deviant stimuli among frequent neutral ones as quickly as possible. Behavioral performance, N2 and P3b ERP data were analyzed. When personality factors were controlled for, the sex differences on N2 and P3b components of the ERPs disappeared. Moreover, linear regression analyses showed that alexithymia was much better than sex at predicting the N2 latencies, while depression was the best factor for predicting the P3b latency. These results suggest that personality factors should be taken into account when sex differences on emotional processing are investigated.

Cognitive flexibility and attentional patterns among trauma survivors: preliminary evidence from an eye-tracking study.

Background: Executive functioning has been linked to both the development of post-traumatic symptoms and the efficiency of therapy. Specifically, flexibility processes seem to play a major role in the use of efficient coping strategies after a traumatic event. However, only a few studies have focused on the links between flexibility, resilience, and concrete behaviours displayed by individuals. Objective: The aim of this study was to investigate the influence of emotional content on the efficiency of cognitive flexibility among trauma-exposed individuals. Method: Twenty-eight trauma-exposed (TE) and 27 non-trauma-exposed (NTE) individuals performed an overlap task in which neutral, positive, and negative pictures appeared in the centre of the screen. Participants were required to disengage their attentional focus from this picture to identify a peripheral target. Analyses included eye movements during the presentation of the scenes and the response times associated with target localization. Results: TE individuals initially presented a rapid overt disengagement from both neutral and negative emotional information. In other words, TE participants moved their gaze away from the central picture towards the target more rapidly than NTE participants. However, TE participants then displayed longer reaction times to identify the target in comparison with NTE participants. Discussion: This study presents preliminary evidence that cognitive flexibility may be relevant when considering the impact of trauma. The developed task could provide a novel way to assess this flexibility within an emotional context. HIGHLIGHTS: • This study developed an original assessment of cognitive flexibility processes in an emotional context.• Cognitive flexibility was assessed using an overlap task and eye-tracking technology.• Cognitive flexibility may be relevant when considering the impact of a trauma.

Antecedentes: El funcionamiento ejecutivo se ha relacionado tanto con el desarrollo de síntomas postraumáticos como con la eficiencia de la terapia. Específicamente, los procesos de flexibilidad parecen jugar un papel importante en el uso de estrategias de afrontamiento después de un evento traumático. Sin embargo, solo unos pocos estudios se han centrado en los vínculos entre la flexibilidad, la resiliencia y los comportamientos concretos que muestran los individuos.Objetivo: El objetivo de este estudio fue investigar la influencia del contenido emocional en la eficiencia de la flexibilidad cognitiva entre individuos expuestos a traumas.Método: 28 personas expuestas a trauma (ET) y 27 no expuestas a trauma (NET) realizaron una tarea superpuesta en la que aparecían imágenes neutras, positivas y negativas en el centro de la pantalla. Se pidió a los participantes que desvincularan su foco de atención de esta imagen para identificar un objetivo periférico. Los análisis incluyeron movimientos oculares durante la presentación de las escenas y los tiempos de respuesta asociados con la localización del objetivo.Resultados: Los individuos con ET inicialmente presentaron una desconexión abierta y rápida de la información emocional tanto neutral como negativa. En otras palabras, los participantes con ET alejaron su mirada de la imagen central hacia el objetivo más rápido que los participantes NET. Sin embargo, los participantes con ET mostraron tiempos de reacción más largos para identificar el objetivo en comparación con los participantes NET.Discusión: Los individuos con ET inicialmente presentaron una desconexión abierta y rápida de la información emocional tanto neutral como negativa. En otras palabras, los participantes con ET alejaron su mirada de la imagen central hacia el objetivo más rápido que los participantes NET. Sin embargo, los participantes con ET mostraron tiempos de reacción más largos para identificar el objetivo en comparación con los participantes NET.

French Adaptation of the Brief Irritability Test: Factor Structure, Psychometric Properties, and Relationship with Depressive Symptoms.

The Brief Irritability Test (BITe, Holtzman et al., 2014) is a brief, reliable, and valid self-report measure of irritability. Despite the growing interest to understand the underlying causes and consequences of irritability, this questionnaire has not been developed and validated for a French-speaking population yet. In the present study, 413 participants completed our French adaptation of the BITe (i.e., TCI; Test Court d'Irritabilité) and measures of associated constructs (depression, anger, hostility, and aggression) and well-being (life satisfaction and social support). Descriptive, psychometric (i.e., Cronbach alpha and Spearman correlation coefficients), and factor analyses were conducted. An exploratory factor analysis in sample 1 (n = 209), yielded one single factor. The confirmatory factor analysis in sample 2 (n = 204) showed a reasonable fit of this single factor model explaining 55.5% of the variance and presenting a strong internal consistency (α = .80). Compared to the original English questionnaire, the TCI shares similar unidimensional factor organization and correlations with other constructs, although a gender bias was identified, with women scoring higher than men. Irritability was higher among respondents in the age range 17-25, compared to older adults. A hierarchical regression analysis showed that TCI scores significantly predict depressive symptoms when demographics were controlled for. In summary, the TCI presents good psychometric properties and could constitute a valuable tool to evaluate irritability in clinical and research contexts.

Neural responses associated with attentional engagement and disengagement from threat in high socially anxious children: Evidence from temporal-spatial PCA.

BACKGROUND: Cognitive models indicated that social anxiety disorder (SAD) would be caused and maintained by a biased attentional processing of threatening information. This study investigates whether socially anxious children may present impaired attentional engagement and disengagement from negative emotional faces, as well as their underlying event-related potential responses. METHODS AND FINDINGS: Fifteen children with high levels of social anxiety (HSA; 9 boys; mean age = 9.99y; SD = 1.14) and twenty low socially anxious children (LSA; 16 boys; mean age = 10.47y; SD = 1.17) participated in a spatial cueing task in which they had to detect targets following neutral/disgusted faces in a valid or invalid location. No group effect was reported on reaction times [p>.05]. However, electrophysiological data showed lower P3a amplitude in HSA children compared with the LSA group when processing facial stimuli. They also reported larger N2 amplitudes for valid-disgusted targets and a larger P3a amplitude for the invalid-disgusted ones. CONCLUSION: In terms of electrophysiological data, our results validated, the hypothesis of attentional disengagement difficulties in SAD children. We also confirm the idea that high levels of social anxiety are associated with cognitive control impairments and have a greater impact on the processing efficiency than on the performance effectiveness.

Influence of acute stress on attentional bias toward threat: How a previous trauma exposure disrupts threat apprehension.

While previous trauma exposure is known to be a risk factor for the development and maintenance of many psychological disorders, it remains unclear how it increases individual risk for prospective psychopathology in the aftermath of a new trauma exposure. The aim of this study was to investigate how a prior exposure to trauma affects attentional processing of threat before and after an acute stress task. Specifically, we assessed attentional biases to threat before and after a cold pressor task in 17 individuals who have been exposed to trauma (TE) compared to 18 individuals without trauma exposure (NTE). Behavioral results showed difficulties to disengage from threat in TE but not in the control group prior to stress induction, as well as a switch to an attentional bias toward threat after the cold pressor task in the TE group. For the ERPs, we highlighted (1) decreased N1 negativity in response to threatening stimuli after an acute stress in both groups, and (2) a parallel increase in P1 for such stimuli only in the TE group. Those results suggest a vulnerability presented by previously traumatized individuals when dealing with threats as well as an acute responsitity toward stress. Those results are interpreted in regards with the theorical models of stress and anxiety.

The Role of Iconic Gestures in Speech Comprehension: An Overview of Various Methodologies.

Iconic gesture-speech integration is a relatively recent field of investigation with numerous researchers studying its various aspects. The results obtained are just as diverse. The definition of iconic gestures is often overlooked in the interpretations of results. Furthermore, while most behavioral studies have demonstrated an advantage of bimodal presentation, brain activity studies show a diversity of results regarding the brain regions involved in the processing of this integration. Clinical studies also yield mixed results, some suggesting parallel processing channels, others a unique and integrated channel. This review aims to draw attention to the methodological variations in research on iconic gesture-speech integration and how they impact conclusions regarding the underlying phenomena. It will also attempt to draw together the findings from other relevant research and suggest potential areas for further investigation in order to better understand processes at play during speech integration process.

Affective Ratings of Pictures Related to Interpersonal Situations.

Many studies require standardized and replicable protocols composed of emotional stimuli. To this aim, several databases of emotional pictures are available. However, there are only few images directly depicting interpersonal violence, which is a specific emotion evocative stimulus for research on aggressive behavior or post-traumatic stress disorder. The objective of the current study is to provide a new set of standardized stimuli containing images depicting interpersonal situations (both positive and negative). This will allow a sensitive assessment of a wide range of cognitions linked to social interaction (empathy, perspective taking, traumatic experiences, etc.). To this aim, 240 participants rated the valence and arousal of 79 pictures collected from online sources in 2018. Results showed (1) a distinctive pattern of valence and arousal regarding the picture content and (2) specific associations between those two dimensions. Taken together, these results suggest a good reliability of the selected images. In conclusion, our study provides an open access set of recent pictures depicting interpersonal situations along with normative valence and arousal ratings, that are available for download from: https://osf.io/ak4m7/?view_only=None.

Eye-tracking exploration of inhibitory control in post-traumatic stress disorder: an emotional antisaccade paradigm.

Background: Cognitive-behavioural studies among individuals suffering from post-traumatic stress disorder (PTSD) have highlighted attentional biases towards threats as a key factor in the maintenance of the disorder. Anxiety-related studies have hypothesized that attentional biases were due to attentional control difficulties in inhibition and flexibility of threatening information. Objective: Because it remains unclear how this theory could be applied to PTSD, this study aims to evaluate the inhibitory control and flexibility abilities of negative and threatening information in this population, using eye-tracking technology. Method: Fifteen adults with a history of physical assault and a current diagnosis of PTSD, and 15 healthy control participants, completed an original mixed antisaccade task. Results: We found enhanced overt attentional allocation towards every item of emotional information among PTSD participants, such as indexed by the latencies of the first saccade in prosaccade trials, followed by disengagement difficulties, such as indexed by increased reaction time to identify the target. Conclusion: Our results could represent empirical evidence of the general enhancement of attentional vigilance in people with PTSD in comparison with healthy controls, as well as specific inhibitory deficits. The results are interpreted through a fear-generalization hypothesis.

Antecedentes: Los estudios cognitivo-conductuales entre personas que padecen Trastorno de Estrés Postraumático (TEPT) han destacado los sesgos atencionales (AB, por su sigla en inglés) por amenaza como factor clave para el mantenimiento del trastorno. La literatura relacionada con ansiedad ha planteado la hipótesis de que los AB se debían a la dificultad del control atencional en la inhibición y flexibilidad de la información amenazante (Eysenck, 2008).Objetivo: Debido a que no está claro cómo se podría aplicar esta teoría al TEPT, este estudio tiene como objetivo evaluar el control inhibitorio y las capacidades de flexibilidad de la información negativa y amenazante en esta población, utilizando tecnología de seguimiento-ocular.Método: 15 adultos agredidos físicamente con un diagnóstico actual de TEPT y 15 participantes de Controles Sanos (CS) completaron una tarea original de antisacada mixta.Resultados: Encontramos una asignación atencional directa-abierta aumentada hacia información emocional entre los participantes con TEPT, tales como las latencias indexadas de la primera sacada en los ensayos de prosacada, seguida por las dificultades de desenganche, indexada por un tiempo de reacción mayor para identificar el objetivo diana.Conclusión: Nuestros resultados podrían representar una evidencia empírica de un aumento general de la vigilancia atencional en el TEPT en comparación con los CS, así como de déficits inhibitorios específicos. Los resultados se interpretan a través de una hipótesis de generalización del miedo.

Towards interpretable machine learning models for diagnosis aid: A case study on attention deficit/hyperactivity disorder.

Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that has heavy consequences on a child's wellbeing, especially in the academic, psychological and relational planes. The current evaluation of the disorder is supported by clinical assessment and written tests. A definitive diagnosis is usually made based on the DSM-V criteria. There is a lot of ongoing research on ADHD, in order to determine the neurophysiological basis of the disorder and to reach a more objective diagnosis. The advent of Machine Learning (ML) opens up promising prospects for the development of systems able to predict a diagnosis from phenotypic and neuroimaging data. This was the reason why the ADHD-200 contest was launched a few years ago. Based on the publicly available ADHD-200 collection, participants were challenged to predict ADHD with the best possible predictive accuracy. In the present work, we propose instead a ML methodology which primarily places importance on the explanatory power of a model. Such an approach is intended to achieve a fair trade-off between the needs of performance and interpretability expected from medical diagnosis aid systems. We applied our methodology on a data sample extracted from the ADHD-200 collection, through the development of decision trees which are valued for their readability. Our analysis indicates the relevance of the limbic system for the diagnosis of the disorder. Moreover, while providing explanations that make sense, the resulting decision tree performs favorably given the recent results reported in the literature.

Examining the Hierarchical Influences of the Big-Five Dimensions and Anxiety Sensitivity on Anxiety Symptoms in Children.

Anxiety sensitivity (AS), namely the fear of anxiety symptoms, has been described as a precursor of sub-threshold anxiety levels. Sexton et al. (2003) posited that increased AS would arise from an elevated neuroticism and that both would act as vulnerability factors for panic disorder (PD), obsessive-compulsive disorder (OCD), and generalized anxiety disorder (GAD) symptoms. Accordingly, this study aimed to (1) evaluate the applicability of this model to a pediatric population and (2) examine the influences of the other Big-Five personality dimensions on the four lower-order dimensions of AS (cognitive, physical, control, and physical) and on social phobia (SP), separation anxiety disorder (SAD) and depression symptoms. 200 children (104 girls) aged between 8 and 12 years old (mean age = 132.52 months, SD = 14.5) completed the Childhood Anxiety Sensitivity Index (Silverman et al., 1991), the Big Five Questionnaire for Children (Barbaranelli et al., 2003), and the Revised's Children Anxiety and Depression Scale (Chorpita et al., 2000). Regression analyses confirmed that AS and neuroticism together significantly predicted the presence of PD, OCD, and GAD symptoms but also SP, SAD, and depression symptoms. Moreover, neuroticism interacted with extraversion, conscientiousness and agreeableness to significantly predict SP, GAD, and depression. Surprisingly, the global AS score was only predicted by agreeableness, while AS dimensions also specifically related to openness. Finally, AS dimensions did not predict the presence of specific anxiety symptoms. To conclude, the predicting model of anxiety symptoms in children sets neuroticism and AS on the same level, with an unexpected influence of agreeableness on AS, raising the importance of other trait-like factors in the definition of such models. Moreover, AS should be considered as a unitary construct when predicting the presence of anxiety symptoms in children. Future interventions must consider these associations to help children detect and recognize the symptoms of their anxiety and help them to interpret them correctly.