There are situations, however, where our normal sense of agency is disrupted. Perhaps the most striking example is alien control delusions. Patients with these delusions report that particular body movements are controlled by some external entity (Spence, 2001). A reduced sense of agency is also a defining characteristic of hypnotic responding. Individuals who are highly hypnotisable will often report that actions they make in response to hypnotic suggestions occur without their conscious intention. Hypnosis provides a marvellous opportunity to study sense of agency alteration. Whereas patients with alien control delusions are relatively rare and often unwilling or impractical research participants, hypnosis can be used in experimental designs with members of the general public to create safe, fully reversible instances of agency change in the lab (Oakley& Halligan, 2013).