Instructions influence UR magnitude and conditioned alpha blocking

Abstract

This study tried to assess the effects of instructions on conditioned alpha blocking. To do this, an equal number of college students were first assigned to an informed group (IG) or an uninformed group (UIG) and administered the same number and sequence of pseudoconditioning, conditioning, and extinction trials, using one of three different light intensities. The reinforcing property of a light US was also assessed by measuring UR magnitude in pseudoconditioning for individual subjects; the college students were later grouped with respect to the presence of low or high URs. It was found that UR magnitude, not US intensity, was predictive of conditioned alpha blocking. Nonetheless, conditioned alpha blocking occurred only for the subjects in the UIG who had low URs. For this group, conditioned alpha blocking was manifested as an increased effectiveness of the CS in blocking the alpha rhythm following a series of paired CS-US trials, and longer latencies of the alpha CR in conditioning and extinction as compared with the OR-produced responses in pseudoconditioning. The use of UR magnitude as a measure of the effectiveness of the US in producing conditioned alpha blocking and the effects of instructions on the conditionability of the EEG response system are discussed.