fMRI study of a VR-based motor imagery and observation task, a conventional motor imagery task, and a motor execution task

We used functional magnetic resonance imaging (fMRI) to map brain activation during: i) a VR-based motor imagery and observation task called NeuRow; ii) a conventional non-VR, motor imagery task based on the Graz paradigm; and iii) a motor execution task. Data were collected from two groups of healthy right-handed participants: 11 young adults (mean 58 age 27 ± 4 years) and 10 older adults (mean age 51 ± 6 years). The experimental protocol was designed in collaboration with the local healthcare system of Madeira, Portugal (SESARAM), in accordance with the 1964 Declaration of Helsinki, and approved by the scientific and ethic committees of the Central Hospital of Funchal with approval reference number: 21/2019. A written informed consent was obtained from each participant upon recruitment.

Imaging was carried out on a 3T GE Signa HDxt MRI scanner (General Electrics Healthcare, Little Chalfont, United Kingdom) using a 12-channel head coil. fMRI data were acquired using a multi-slice 2D gradient-echo EPI sequence (TR/TE = 2500/30 ms, voxel size = 3.75x3.75x3.00 mm3, flip angle = 90, and FoV = 240x240 mm2). For co-registration purposes, whole-brain structural images were also acquired using a T1-weighted 3D Fast Spoiled Gradient-Echo (FSPGR) sequence (TR/TE = 7.8/3.0 ms, voxel size = 1.00x1.00x0.60 mm3).

The following three tasks were performed for left and right arm movement separately, yielding a total of six fMRI runs (pseudo-randomized order): (a) NeuRow task: motor imagery and observation task through VR scenario (NeuRow); (b) Graz task: motor imagery only with abstract instructions (Graz), (c) and motor execution (ME): finger-tapping. Each fMRI run consisted of 8 trials, each with 20 s of baseline followed by 20 s of task (total run duration 5.33 min).