Temporal and sequential probability in evoked potential studies.

Abstract

The late components of the evoked potential to a detected target stimulus are related to probability. The literature is unclear whether the determining variable is sequential probability, the probability of a target within a number of stimuli or temporal probability, the probability of a target within a period of time. Altering the interval between the stimuli of a train while maintaining a constant sequential probability for the target caused significant changes in the late components of the target-evoked potential, demonstrating their dependence on temporal probability. Simultaneous manipulation of both temporal and sequential probability showed temporal probability to be the determining factor for the late components of the evoked potential.