  Self-initiated voluntary acts, such as pressing a button, are preceded by a
negative electrical brain potential, the Bereitschaftspotential (BP), that can
be recorded over the human scalp using electroencephalography (EEG). Up to now,
the BP required to initiate voluntary acts has only been recorded under
well-controlled laboratory conditions. It is thus not known if this form of
brain activity also underlies motor initiation in possible life-threatening
decision making, such as jumping into a 192-meter abyss, an act requiring
extraordinary willpower. Here, we report BP before self-initiated 192-meter
extreme bungee jumping across two semi-professional cliff divers (both male,
mean age 19.3 years). We found that the spatiotemporal dynamics of the BP is
comparable to that recorded under laboratory conditions. These results,
possible through recent advancements in wireless and portable EEG technology,
document for the first time pre-movement brain activity preceding possible
life-threatening decision making.
