Experimental set-up. The NMR field probes were placed between the transmit and the receiver Rf coils. The optical camera (MPT, Kineticor) is fixed to the inside of the magnet bore. The positions of the probes are shown in (b).

The plots show examples of simultaneous measurements of head motion parameters (top row) and magnetic field (bottom row). The subject performed various head movements (rest, head shaking, head nodding, feet wiggling). Measurements were acquired with and without simultaneous EPI scanning.