Slow cortical and heart rate correlates of discrimination performance

Abstract

Slow EEG potentials ( F z , C z , P z ) and heart rate were recorded during the foreperiod of a reaction task, which involved different levels of discrimination difficulty. A simple reaction task was compared with a selective reaction task where either an easy or a difficult discrimination was required. In general, the terminal amplitude of the CNV was not affected by task difficulty. However, a prolonged negative wave was found when the difficulty of the task was not known to the subject in advance but was indicated by S 1. Moreover, the heart-rate deceleration around S 2 was more pronounced the more difficult the discrimination required at S 2.