His early research with Hans Helmut Kornhuber in the mid-1960s led to the discovery of the Bereitschaftspotential (or readiness potential), which is a measure of neural activity in the brain that precedes voluntary movements.

In order to record brain activity prior to an unforeseeable event – which a voluntary movement undoubtedly is – it needs a special method: the reverse averaging, which was invented by Kornhuber and Deecke in the same year (1964).

[8] The second component of the Bereitschaftspotential (BP2 oder BPlate) is generated by the primary motor cortex M1, and BP2 is asymmetrical with unilateral movements, namely dominant over the contralateral hemisphere.

[9][10] In 1982 during Deecke's visiting professorship on invitation of Hal Weinberg in Vancouver, the Magnetoencephalographic-(MEG-) analogue of the Bereitschaftspotential, the Bereitschaftsmagnetfeld (Bereitschaftsfield, BF) was first recorded.

Deecke and his team were successful to prove the participation of the SMA not only with the early Bereitschaftspotential but also with the Bereitschaftsmagnetfeld (Bereitschaftsfield in the MEG, solving the cancellation problem of the two SMAs opposing each other.

[19] This means that the formation of the will has already taken place in the frontal lobe and the preparation and planning of the action has been transferred initially to the unconscious routine processes of the basal ganglia, which do the groundwork for the motor cortex, M1.

[20][21][23][24] The views of Kornhuber and Deecke upon the SMA and CMA[7][20][21][23][24] were confirmed in the meantime by Ross Cunnington and his team: The limbic system is always involved in the early planning for action – the matching with the inner needs, the emotional basic state, and our respective mood – has been postulated by Kornhuber and Deecke for quite some time [20][21][23][24] and has been confirmed recently by the Cunnington group.