[Improvement of the impulsive control in adolescents with attention deficit hyperactivity disorder (ADHD) after a cognitive behavioral therapy]. / Amélioration du contrôle impulsif chez les adolescents avec un trouble de l'attention avec hyperactivité (TDAH) ayant suivi une thérapie cognitive comportementale.

AIM: MPH is the more often prescribed stimulant for Attention Deficit Hyperactivity Disorder (ADHD), but it has been estimated that 30% of patients do not adequately respond or cannot tolerate it. Therefore, some other therapies are needed, such as cognitive behavioral therapy. Cognitive behavioral therapy is an intervention proposed over several sessions and aimed at modifying behavior by teaching different techniques that participants can re-use to control their symptoms. In our Institute, we used a program centered on attentional and metacognitive functions. It consists of a series of workshops performed in group at the rate of one workshop of 90minutes per week for 12 weeks. Positive effects on the behavior of adolescents with ADHD have been reported by parents and educators, but the effects of the program on specific cognitive processes have never been precisely investigated. METHOD: In the present study, we evaluated the impact of the program on impulsive control in adolescents with ADHD who are known to present impaired impulsive control. Impulsive control is required each time there is a conflict between an inappropriate prepotent action and a goal-directed action. At an experimental level, impulsive control can be studied with conflict tasks, such as the Simon reaction time task. Interpreted within the theoretical framework of the so-called « Dual-process activation suppression ¼ (DPAS) model, this task is a powerful conceptual and experimental tool to separately investigate the activation and inhibition of impulsive actions, which is almost never done in studies about impulsive control. Twenty adolescents followed the program and were tested before and at the end of the program by using dynamic analyses of performance associated with DPAS model. RESULTS: The results have shown an improvement of the impulsive control after three months of cognitive behavioral therapy, and this improvement was due to both a decrease of the propensity to trigger impulsive actions and an improvement of inhibitory processes efficiency. CONCLUSION: This program could be a relevant alternative to the stimulant medication, more particularly when parents are reluctant with medication or when the adolescent suffers from important side effects.

Neuronal substrates of haptic shape encoding and matching: a functional magnetic resonance imaging study.

We used functional magnetic resonance imaging to differentiate cerebral areas involved in two different dimensions of haptic shape perception: encoding and matching. For this purpose, healthy right-handed subjects were asked to compare pairs of complex 2D geometrical tactile shapes presented in a sequential two-alternative forced-choice task. Shape encoding involved a large sensorimotor network including the primary (SI) and secondary (SII) somatosensory cortex, the anterior part of the intraparietal sulcus (IPA) and of the supramarginal gyrus (SMG), regions previously associated with somatosensory shape perception. Activations were also observed in posterior parietal regions (aSPL), motor and premotor regions (primary motor cortex (MI), ventral premotor cortex, dorsal premotor cortex, supplementary motor area), as well as prefrontal areas (aPFC, VLPFC), parietal-occipital cortex (POC) and cerebellum. We propose that this distributed network reflects construction and maintenance of sensorimotor traces of exploration hand movements during complex shape encoding, and subsequent transformation of these traces into a more abstract shape representation using kinesthetic imagery. Moreover, haptic shape encoding was found to activate the left lateral occipital complex (LOC), thus corroborating the implication of this extrastriate visual area in multisensory shape representation, besides its contribution to visual imagery. Furthermore, left hemisphere predominance was shown during encoding, whereas right hemisphere predominance was associated with the matching process. Activations of SI, MI, PMd and aSPL, which were predominant in the left hemisphere during the encoding, were shifted to the right hemisphere during the matching. In addition, new activations emerged (right dorsolateral pre-frontal cortex, bilateral inferior parietal lobe, right SII) suggesting their specific involvement during 2D geometrical shape matching.