ABSTRACTAn experiment was designed to evaluate the effects of pleasantness and un‐pleasantness and instructions to verbalize on directional fractionation of autonomic response. Degrees of pleasant and unpleasant stimulation were presented toSs under two verbalization instruction conditions. Something like directional fractionation was found for the very unpleasant no‐verbalization condition only, but the pattern disappeared upon the addition of a later‐verbalization requirement. More generally, it was found without exception that conditions of no verbalization are accompanied by cardiac deceleration, regardless of degree or of quality of affect, while later verbalization conditions produce cardiac acceleration, again regardless of degree or quality of affect. The authors conclude that verbalization instructions are important for determining the degree and direction of cardiac activ