Contingency-based flexibility mechanisms through a reinforcement learning model in adults with Attention-Deficit/Hyperactivity Disorder and Obsessive-Compulsive Disorder

The probabilistic reversal learning paradigm is one of the most used to assess cognitive flexibility during a contingency-based learning process. Lack of cognitive flexibility is related to the symptomatology that characterizes disorders such as Attention-Deficit/Hyperactivity Disorder (ADHD) and Obsessive-Compulsive Disorder (OCD). Resting-state functional connectivity (rsFC) could be a specific predictor of performance in contingency-based cognitive flexibility. However, the mechanisms underlying learning and flexibility in an environment of uncertainty with OCD or ADHD adults have not been widely explored. Computational modelling may be helpful to separate components of the behavioural processes and identify the source of the disorders. In the present study, we aimed to identify the mechanisms underlying contingency-based cognitive flexibility in a sample of the impulsive-compulsive spectrum and healthy controls, and explore the rsFC between the frontoparietal networks (FPN) regions as a possible neuromarker. 148 Spanish-speaking participants (43 patients with OCD, 53 with ADHD, and 52 healthy controls) completed a probabilistic reversal learning task (PRLT). Previously, we obtained a record of FNP rsFC using functional near-infrared spectroscopy (fNIRS). For this purpose, we applied the reinforcement learning model in combination with Bayesian GLM. We found that groups showed an optimal performance in the acquisition phase of the PRLT and higher performance of HC compared to the diagnostic groups in the reversal block, although performance is still optimal in all groups. Likewise, we found that the parameters studied (reinforcement learning rate, punishment learning rate and inverse temperature) predict task performance differently by phase and group. Regarding FNP rsFC, we found that rsFC between left posterior parietal cortex (lpPC) and right posterior parietal cortex (rpPC) seems to credibly predict performance in the acquisition block in the healthy controls. These findings suggest that reducing the uncertainty between action-outcome may help to improve the adaptation of ADHD and OCD patients to changing environments. Thus, understanding sensitivity to punishment or reinforcement and its influence on the decision-making may be important for designing case-specific interventions. According to our data, rsFC between lpPC and rpPC could be important for optimal learning of our task. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The present study is part of the R&D and Innovation project funded by the Spanish Ministry of Science and Innovation Proyectos I+D+i: Generacion de Conocimiento [PID2019-108423RB-I00] and R&D and Innovation project funded by Junta de Andalucia Proyectos I+D+i: Retos de la Sociedad Andaluza [PID2019-108423RB-I00]. R.R.H [FPU20/01770] was supported by the FPU Fellowship Program of the Spanish Ministry of Education. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee/IRB of Bioethics Committee of Human Research of the University of Almeria gave ethical approval for this work. Ethics committee/IRB of Bioethics Committee of Provincial Research Ethics Committee of the Torrecardenas University Hospital gave ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors