P300 and the internal model in a multiple choice reaction-time task
- Other Title
It has been suggested that the P300 component of the event-related brain potential is a manifestation of the brain activity which updates one's internal model of the environment. Recently, Ullsperger and his colleagues have attempted to explain the change of P300 amplitudes within the framework of Helson's “adaptation-level theory.” In the present study, we examined their hypothesis by using a symbolic stimulus discrimination task. Equiprobable and randomized sequences of five successive alphabet letters (Q-U) were presented. Subjects (n=8) were required to respond to each letter with a corresponding finger of the right hand. Although the adaptation-level model couldn't apply to this task, like Ullsperger et al.'s experiments, an “U-shaped” trend of P300 amplitude changes was found. Their model was extended in order to explain the results of this experiment. In the revised model, it was assumed that “a reference point” was used in the stimulus-evaluation process which was related to the response dimension, and that the P300 amplitude reflected the distance between this reference point and the eliciting event.
- Japanese Journal of Physiological Psychology and Psychophysiology
Japanese Journal of Physiological Psychology and Psychophysiology 12 (1), 29-37, 1994
Japanese Society for Physiological Psychology and Psychophysiology