Depiction of the gradual and constant frequency-altered feedback (FAF) conditions. During baseline (trials 1-30), the pitch of auditory feedback was not manipulated. During perturbation (FAF) trials, presented in gray, auditory feedback was manipulated from trial 31 (solid vertical line) to trial 80 (all FAF trials represented by the dashed line). (A) Auditory feedback was gradually manipulated downwards, in -2 cent increments across trials until auditory feedback was shifted by -100 cents (1 semitone). (B) Auditory feedback was shifted by a constant value (-100 cents) for all FAF trials.