Unconscious task set priming with phonological and semantic tasks.

International audienceWhether unconscious stimuli can modulate the preparation of a cognitive task is still controversial. Using a backward masking paradigm, we investigated whether the modulation could be observed even if the prime was made unconscious in 100% of the trials. In two behavioral experiments, subjects were instructed to initiate a phonological or semantic task on an upcoming word, following an explicit instruction and an unconscious prime. When the SOA between prime and instruction was sufficiently long (84ms), primes congruent with the task set instruction led to speedier responses than incongruent primes. In the other condition (36ms), no task set priming was observed. Repetition priming had the opposite tendency, suggesting the observed task set facilitation cannot be ascribed solely to perceptual repetition priming. Our results therefore confirm that unconscious information can modulate cognitive control for currently active task sets, providing sufficient time is available before the conscious decision

Disentangling racing thoughts from mind wandering in adult attention deficit hyperactivity disorder

IntroductionMental restlessness reported by adult with Attention Deficit Hyperactivity Disorder (ADHD) has been mainly explained by excessive mind wandering. However, the description of a mind constantly on the go is also akin to racing thoughts, predominantly described in bipolar disorder. This paper aimed at disentangling mind wandering from racing thoughts in adult with ADHD. Associations between those mental phenomena and the ADHD symptomatology were also investigated.MethodsTo this aim, 84 adults with ADHD completed self-reported questionnaires, including the Mind Wandering-Deliberate and Mind Wandering-Spontaneous questionnaires, the Racing and Crowded Thoughts Questionnaire and the Daydreaming Frequency Scale. Factorial analysis and multiple linear regressions were performed.ResultsThe factor analysis yielded a two-factor solution. The first factor encompassed the three facets of racing thoughts and was predicted by emotional lability. The second comprised deliberated-MW, spontaneous-MW and daydreaming, but was neither related to the ADHD symptoms, nor functional impairment.DiscussionThese findings suggest that MW and racing thoughts are two distinguishable mental phenomena. Racing thoughts appear to be a relevant hypothesis to explain the mental restlessness in adult ADHD

Wallerian-Like Degeneration of Central Neurons After Synchronized and Geometrically Registered Mass Axotomy in a Three-Compartmental Microfluidic Chip

Degeneration of central axons may occur following injury or due to various diseases and it involves complex molecular mechanisms that need to be elucidated. Existing in vitro axotomy models are difficult to perform, and they provide limited information on the localization of events along the axon. We present here a novel experimental model system, based on microfluidic isolation, which consists of three distinct compartments, interconnected by parallel microchannels allowing axon outgrowth. Neurons cultured in one compartment successfully elongated their axons to cross a short central compartment and invade the outermost compartment. This design provides an interesting model system for studying axonal degeneration and death mechanisms, with a previously impossible spatial and temporal control on specific molecular pathways. We provide a proof-of-concept of the system by reporting its application to a well-characterized experimental paradigm, axotomy-induced Wallerian degeneration in primary central neurons. Using this model, we applied localized central axotomy by a brief, isolated flux of detergent. We report that mouse embryonic cortical neurons exhibit rapid Wallerian-like distal degeneration but no somatic death following central axotomy. Distal axons show progressive degeneration leading to axonal beading and cytoskeletal fragmentation within a few hours after axotomy. Degeneration is asynchronous, reminiscent of in vivo Wallerian degeneration. Axonal cytoskeletal fragmentation is significantly delayed with nicotinamide adenine dinucleotide pretreatment, but it does not change when distal calpain or caspase activity is inhibited. These findings, consistent with previous experiments in vivo, confirm the power and biological relevance of this microfluidic architecture

Influences non conscientes sur des processus mentaux complexes : initiation de stratégies et sentiment de contrôle

Do unconscious stimuli modify processes that are typically associated with consciousness? This question is of particular interest in schizophrenia in which there is both impairments of implicit processes and abnormalities of conscious processes. For instance patients have difficulties to initiate a strategy or to feel in control of their actions. For this purpose, we wanted to know to what extent the choice of a task set or the feeling of control over the action could be influenced by unconscious cues. We conducted two studies in healthy subjects showing that unconscious stimuli can influence the preparation of a task set. However, we have shown that there are limitations to these unconscious influences: the processing of unconscious stimuli must be uninterrupted for some time, and it is modulated by attentional mechanisms. Our third study analyzed the effect of subliminal distortions of the haptic feedback (tactile and kinesthetic) on motor adaptation and on the conscious sense of control over the action. We have shown that the feeling of control was modulated by subliminal distortions of the haptic feedback. Unconscious influences have an impact on conscious processes, but in limited and controlled circumstances.Est-ce que des stimuli non conscients peuvent modifier des processus classiquement considérés comme conscients ? Cette question est d’un intérêt particulier dans la schizophrénie où il existe à la fois des anomalies de processus implicites et des anomalies de processus conscients, comme par exemple, initier une stratégie ou se sentir en contrôle de son action. Pour réaliser des études chez les patients, nous devions savoir dans quelle mesure le choix d’une stratégie ou le sentiment de contrôler son action sont soumis à des influences non conscientes. Nous avons réalisé deux études chez le sujet sain montrant qu’un stimulus non conscient peut influencer la préparation d’une stratégie. Cependant, il existe des limites à ces influences non conscientes : le traitement du stimulus non conscient ne doit pas être interrompu trop tôt, et des filtres attentionnels le modulent. Notre troisième étude a analysé l’effet de distorsions subliminales du retour haptique (tactile et kinesthésique) sur l’adaptation motrice et sur le sentiment conscient de contrôler son action. Nous avons montré que le sentiment de contrôler l’action était modulé par des distorsions du retour haptique, même quand celui-ci est subliminaire. Les influences non conscientes ont un impact sur les processus habituellement conscients, dans des circonstances limitées et contrôlées

Unconscious influences on complex mental processes : task set initiation and feeling of control

Est-ce que des stimuli non conscients peuvent modifier des processus classiquement considérés comme conscients ? Cette question est d’un intérêt particulier dans la schizophrénie où il existe à la fois des anomalies de processus implicites et des anomalies de processus conscients, comme par exemple, initier une stratégie ou se sentir en contrôle de son action. Pour réaliser des études chez les patients, nous devions savoir dans quelle mesure le choix d’une stratégie ou le sentiment de contrôler son action sont soumis à des influences non conscientes. Nous avons réalisé deux études chez le sujet sain montrant qu’un stimulus non conscient peut influencer la préparation d’une stratégie. Cependant, il existe des limites à ces influences non conscientes : le traitement du stimulus non conscient ne doit pas être interrompu trop tôt, et des filtres attentionnels le modulent. Notre troisième étude a analysé l’effet de distorsions subliminales du retour haptique (tactile et kinesthésique) sur l’adaptation motrice et sur le sentiment conscient de contrôler son action. Nous avons montré que le sentiment de contrôler l’action était modulé par des distorsions du retour haptique, même quand celui-ci est subliminaire. Les influences non conscientes ont un impact sur les processus habituellement conscients, dans des circonstances limitées et contrôlées.Do unconscious stimuli modify processes that are typically associated with consciousness? This question is of particular interest in schizophrenia in which there is both impairments of implicit processes and abnormalities of conscious processes. For instance patients have difficulties to initiate a strategy or to feel in control of their actions. For this purpose, we wanted to know to what extent the choice of a task set or the feeling of control over the action could be influenced by unconscious cues. We conducted two studies in healthy subjects showing that unconscious stimuli can influence the preparation of a task set. However, we have shown that there are limitations to these unconscious influences: the processing of unconscious stimuli must be uninterrupted for some time, and it is modulated by attentional mechanisms. Our third study analyzed the effect of subliminal distortions of the haptic feedback (tactile and kinesthetic) on motor adaptation and on the conscious sense of control over the action. We have shown that the feeling of control was modulated by subliminal distortions of the haptic feedback. Unconscious influences have an impact on conscious processes, but in limited and controlled circumstances

Trouble du déficit de l'attention avec hyperactivité (TDAH) chez l'adulte : à la croisée du neuro-développement et des comorbidités psychiatriques

Neuroscience

Unconscious influences on complex mental processes : task set initiation and feeling of control

Est-ce que des stimuli non conscients peuvent modifier des processus classiquement considérés comme conscients ? Cette question est d’un intérêt particulier dans la schizophrénie où il existe à la fois des anomalies de processus implicites et des anomalies de processus conscients, comme par exemple, initier une stratégie ou se sentir en contrôle de son action. Pour réaliser des études chez les patients, nous devions savoir dans quelle mesure le choix d’une stratégie ou le sentiment de contrôler son action sont soumis à des influences non conscientes. Nous avons réalisé deux études chez le sujet sain montrant qu’un stimulus non conscient peut influencer la préparation d’une stratégie. Cependant, il existe des limites à ces influences non conscientes : le traitement du stimulus non conscient ne doit pas être interrompu trop tôt, et des filtres attentionnels le modulent. Notre troisième étude a analysé l’effet de distorsions subliminales du retour haptique (tactile et kinesthésique) sur l’adaptation motrice et sur le sentiment conscient de contrôler son action. Nous avons montré que le sentiment de contrôler l’action était modulé par des distorsions du retour haptique, même quand celui-ci est subliminaire. Les influences non conscientes ont un impact sur les processus habituellement conscients, dans des circonstances limitées et contrôlées.Do unconscious stimuli modify processes that are typically associated with consciousness? This question is of particular interest in schizophrenia in which there is both impairments of implicit processes and abnormalities of conscious processes. For instance patients have difficulties to initiate a strategy or to feel in control of their actions. For this purpose, we wanted to know to what extent the choice of a task set or the feeling of control over the action could be influenced by unconscious cues. We conducted two studies in healthy subjects showing that unconscious stimuli can influence the preparation of a task set. However, we have shown that there are limitations to these unconscious influences: the processing of unconscious stimuli must be uninterrupted for some time, and it is modulated by attentional mechanisms. Our third study analyzed the effect of subliminal distortions of the haptic feedback (tactile and kinesthetic) on motor adaptation and on the conscious sense of control over the action. We have shown that the feeling of control was modulated by subliminal distortions of the haptic feedback. Unconscious influences have an impact on conscious processes, but in limited and controlled circumstances

Identifying different patterns of emotion dysregulation in adult ADHD

Abstract Background Emotion dysregulation (ED) is a core intrinsic feature of adult presenting Attention Deficit Hyperactivity Disorder (ADHD). However, the clinical expressions of ED are diverse and several questionnaires have been used to measure ED in adults with ADHD. Thus, to date, the characteristics of ED in adult ADHD remain poorly defined. The objective of this study is to identify the different patterns of ED in adults with ADHD. Methods A large sample of 460 newly diagnosed adults with ADHD were recruited. Patients completed a total of 20 self-reported questionnaires. Measures consisted in the several facets of ED, but also other clinical features of adult ADHD such as racing thoughts. A factor analysis with the principal component extraction method was performed to define the symptomatic clusters. A mono-dimensional clustering was then conducted to assess whether participants presented or not with each symptomatic cluster. Results The factor analysis yielded a 5 factor-solution, including “emotional instability”, “impulsivity”, “overactivation”, “inattention/disorganization” and “sleep problems”. ED was part of two out of five clusters and concerned 67.52% of our sample. Among those patients, the combined ADHD presentation was the most prevalent. Emotional instability and impulsivity were significantly predicted by childhood maltreatment. The ED and the “sleep problems” factors contributed significantly to the patients’ functional impairment. Conclusions ED in ADHD is characterized along emotional instability and emotional impulsivity, and significantly contributes to functional impairment. However, beyond impairing symptoms, adult ADHD may also be characterized by functional strengths such as creativity

Attention Deficit Hyperactivity Disorder And Borderline Personality Disorder In Adults: A Review Of Their Links And Risks

Attention deficit hyperactivity disorder (ADHD) and borderline personality disorder (BPD) are particularly common disorders, that are highly comorbid in adult populations. The symptomatic overlap between adult ADHD and BPD includes impulsivity, emotional dysregulation and interpersonal impairment, which makes the differential diagnosis difficult. Our review aims at focusing on recent data on the comorbid ADHD+BPD form, as well as the risk factors involved in the emergence of the two disorders. While adult ADHD and BPD share some genetic and temperamental risk factors, adult ADHD is characterized by more severe trait-impulsivity compared to non-comorbid BPD; BPD patients display more severe trait-emotion regulation symptoms compared to non-comorbid ADHD. Patients with the comorbid ADHD+BPD form have severe symptoms in both dimensions. Early-life exposure to adverse events is a shared risk factor for the development of ADHD and BPD, but type and timing of adversity seem to play a differential role in the development of BPD and ADHD symptoms. Age of onset used to be a discriminative diagnostic criterion between ADHD, an early-onset neurodevelopmental disorder, and BPD, a late-onset psychological disorder. However, this distinction has been recently called into question, increasing the need for more research aiming at delineating the disorders from a developmental and clinical standpoint. Clinicians should carefully consider the comorbidity, and consider ADHD and BPD dimensionally, in order to provide more effective patient management. This might improve early preventive interventions, and treatment for comorbid conditions in adulthood