The goal of this project is to investigate and improve executive control function in two distinct pain conditions, namely neuropathic pain and fibromyalgia (FM). It is hypothesized that there is a significant difference in the executive control function of patients with neuropathic pain and FM pain. It is also hypothesized that all participants with poor executive control functioning will report significant improvements in pain intensity, functioning and cognitive complaints following cognitive training. The study tests and influence the working memory concepts of inhibition, updating and flexibility through an experimental, cross-over treatment design.