Role of Theta Frequency Oscillations in Proactive and Reactive Control Processes in Youth With Attention Deficit Hyperactivity Disorder (ADHD) and Obsessive Compulsive Disorder (OCD)

Study Description: This is a pilot feasibility/tolerability study to evaluate the role of theta frequency oscillations in proactive and reactive control processes in youth with Attention Deficit Hyperactivity Disorder (ADHD) and Obsessive Compulsive Disorder (OCD). We hypothesize that: 1) Procedures will be tolerable for healthy volunteer (HV) children without a primary DSM-5 diagnosis, youth with ADHD and youth with OCD; 2) Procedures will be feasible for healthy volunteer (HV) children without a primary DSM-5 diagnosis, youth with ADHD and youth with OCD; 3) EEG and fMRI data for the majority of participants will be of sufficient quality for analysis (e.g. without artifact or excessive motion); 4) We will be able to identify cortical sources associated with resting-state and task-evoked theta oscillatory activity. This study will inform a future study where EEG-synchronized repetitive transcranial magnetic stimulation (rTMS) will modulate theta oscillations to improve cognitive control in youth with ADHD and youth with OCD. Objectives: Primary Objectives: 1. Evaluate the feasibility of MRI and EEG procedures at rest and during cognitive tasks in youth with ADHD, youth with OCD and HV youth. 2. Evaluate the tolerability of study procedures in youth with ADHD, youth with OCD and HV youth. 3. Evaluate the data quality obtained from the EEG and fMRI in youth with ADHD, youth with OCD and HV youth. 4. Identify cortical sources of resting-state and task-evoked theta oscillations in youth with ADHD, youth with OCD and HV youth. Secondary Objectives: 1\. Evaluate the reliability of task performance on cognitive control tasks across sessions. Exploratory Objectives: 1\. Compare the power of resting and task-evoked theta oscillations in the EEG recording across ADHD, OCD, and HV groups. 2a. Evaluate the relation between power in resting-state theta oscillations and task-evoked theta power in the electroencephalogram (EEG). 2b. Evaluate the relationship between power in resting-state theta oscillations in the EEG and task performance. 3\. Evaluate the data quality and compare the power of resting and task-evoked theta oscillations in the MEG recording across ADHD, OCD, and HV groups. 4\. Compare the BOLD activity, and connectivity within and across "task-positive" function networks (TPNs) across ADHD, OCD, and HV groups. 5\. Compare the power of task-evoked EEG and MEG theta oscillations and cortical sources of task-evoked theta oscillations across standardized cognitive control and working memory tasks in youth with ADHD, youth with OCD and HV youth. 6\. Develop latent executive functioning factors based on cognitive control and working memory task outcomes and evaluate the relationship between this latent factor and power of resting and task-evoked theta oscillations. Endpoints: Primary Endpoints: 1. Participant Retention for all visits of the study and task performance (Primary Objective 1). 2. Adverse Events reported related to study procedures (Primary Objective 2). 3. Percentage of EEG and fMRI data deemed to be of sufficient quality for analysis (e.g. without artifact or excessive motion) (Primary Objective 3). 4. Structural cortical region source localized from a combination of the EEG (and MEG in a subset of patients) and fMRI data (Primary Objective 4). Secondary Endpoints: 1\. Accuracy and reaction time behavioral responses to cognitive control tasks. Exploratory Endpoints: 1. EEG Power in the theta frequency band (4-7Hz) (Exploratory Objective 1, 2a and 2b, and 5). 2. Power of MEG oscillations in the theta (4-7Hz) frequency band during rest and during cognitive control tasks (Exploratory Objective 3 and 5). 3. BOLD activation and connectivity in TPN networks (Exploratory Objective 4). 4. Structural cortical region source localized from a combination of the EEG (and MEG in a subset of patients) and fMRI data (Exploratory Objective 5). 5. Latent Inhibitory Control Factor and Latent Working Memory Factor derived by structural equation modeling using performance-based metrics across the three inhibitory control tasks and two working memory tasks (Exploratory Objective 6).