Motor Imagery dataset from Ofner et al 2017 (Upper limb Motor imagery dataset from the paper)

We recruited 15 healthy subjects aged between 22 and 40 years with a mean
age of 27 years (standard deviation 5 years). Nine subjects were female,
and all the subjects except s1 were right-handed.

We measured each subject in two sessions on two different days, which were
not separated by more than one week. In the first session the subjects
performed ME, and MI in the second session. The subjects performed six
movement types which were the same in both sessions and comprised of
elbow flexion/extension, forearm supination/pronation and hand open/close;
all with the right upper limb. All movements started at a
neutral position: the hand half open, the lower arm extended to 120
degree and in a neutral rotation, i.e. thumb on the inner side.
Additionally to the movement classes, a rest class was recorded in which
subjects were instructed to avoid any movement and to stay in the starting
position. In the ME session, we instructed subjects to execute sustained
movements. In the MI session, we asked subjects to perform kinesthetic MI
of the movements done in the ME session (subjects performed one ME run
immediately before the MI session to support kinesthetic MI).

The paradigm was trial-based and cues were displayed on a computer screen
in front of the subjects, Fig 2 shows the sequence of the paradigm.
At second 0, a beep sounded and a cross popped up on the computer screen
(subjects were instructed to fixate their gaze on the cross). Afterwards,
at second 2, a cue was presented on the computer screen, indicating the
required task (one out of six movements or rest) to the subjects. At the
end of the trial, subjects moved back to the starting position. In every
session, we recorded 10 runs with 42 trials per run. We presented 6
movement classes and a rest class and recorded 60 trials per class in a
session.