35 NA-CONTROL STUDY PROTOCOL 2 their hand. 58 First-person motor imagery use can further be corroborated by the effect of orientation: participants are faster for medially oriented stimuli that are associated with biomechanically easy movements towards the body midsagittal plane, than for laterally orientated stimuli, that are associated with biomechanically difficult movements away from the body midsagittal plane. 58 Participants are to report whether the hand drawing on display presented a left or right hand by pressing the corresponding button with their left or right foot. ii. Behavioral performance on this task is evaluated by means of response times (i.e. time from stimulus onset to button press) and error rates (i.e. the number of incorrect trials divided by the total number of valid trials). iii. During the task, alertness is monitored with an eye monitor and bipolar surface electromyography (EMG) over both thumbs is performed, to monitor muscle activity indicative of hand movements and exclude the influence of overt movements. Other parameters Some measures will be collected to describe the study population and if applicable, to correct for possible confounding effects: A. Demographics: demographic data that will be collected includes age, sex and education level B. NA characteristics: data on several characteristics of patients with NA will be collected. These include disease onset and duration, history of prior attacks and use of medication. Other characteristics may include, presence of atrophy, pattern of motor paresis, mechanical sensitivity of the plexus to pain, maximal severity of paresis during the attack and duration of primary pain. C. Comorbidity: relevant information on comorbid conditions and medication use will be collected. D. Motor imagery ability: there are individual differences in motor imagery ability.61 As a subject’s ability to imagine movements might affect his/her performance on the motor imagery tasks in this study, motor imagery ability is assessed with the short version of the Kinesthetic and visual imagery questionnaire (KVIQ-10). The KVIQ-10 assesses the clarity of the image (visual), and the intensity of the sensations (kinesthetic), that the subject is able to imagine from the first-person perspective. 61 Exploratory outcomes In addition to its primary and secondary outcomes, the NA-CONTROL study includes some exploratory outcome measures that have not been used before to study NA or any similar patient populations. They were added to the study to gain additional insight in the underlying mechanisms of the residual complaints in this disorder. Cerebral (re)organization Cerebral (re)organization in NA will further be explored by means of additional MRI scans. For this purpose, functional and high-resolution anatomical images of the whole brain will be acquired on a 3 T Siemens whole body scanner at the Donders Centre for Cognitive