Attention Deficit Disorder with or without Hyperactivity (ADHD) is a common neurodevelopmental disorder that affects a wide range of cognitive processes. The presence of the disorder results in difficulty with school and social functioning. Medication do exist but show multiple side effects. Hopefully, non-invasive alternative such as Neurofeedback (NF) are being developed but need a large number of sessions before being proven effective. In our protocol, we aim at adding a Virtual Reality (VR) environment to the neurofeedback training for the number of sessions needed to decrease. A functional Magnetic Resonance Imaging (fMRI) coupled with Electroencephalography (EEG) is performed with cognitive tasks before and after the NF/VR training to assess any change in functional connectivity. This present study aims at validating the cognitive tasks –Continuous Performance Task (CPT), calculation and memory tasks- that will be used. This is an essential first step in the NF/VR protocol that will be tested later. Here, we performed the cognitive tasks on healthy adults during fMRI sessions. As expected, fMRI analysis showed an increased activity in the dorsal attentional network during cognitive tasks except for the CPT. This lack of attentional involvement during the CPT could be explained by an overly predictable design that will need to be adjusted in the final protocol.