A first apparatus applies magnetic field pulses to a subject, a second apparatus records electric signals of the subject, wherein the electric signals are received as analog signals from the subject while the magnetic field pulses are being applied to the subject. The first apparatus has a generating unit for generating the magnetic field pulses, a first clock generator for generating a first clock, and a first control unit for triggering generation of the magnetic field pulses by the generating unit with a fixed repetition rate based on the first clock. The second apparatus has an analog-to-digital conversion unit for converting the analog signals to corresponding digital signals by sampling each of the analog signals with a sampling rate, a second clock generator for generating a second clock, and a second control unit for causing the analog-to-digital conversion unit to set the sampling rate based on the second clock. A synchronizing unit synchronizes the second clock with the first clock.
