Sensitization and association in alpha blocking “conditioning”

Abstract

1. 1. The main purpose of this investigation was to determine whether the typical alpha blocking “conditioned” response is a response which requires pairing of stimuli in a precise relationship or a form of sensitization. This was accomplished by combining a delayed “conditioning” with a simple discrimination design, and measuring changes in alpha activity at different periods during the presentation of the stimulus. Changes due to contiguity and sensitization were measured against a group receiving continuous habituation. 2. 2. Pairing of tone and light produced increments in the number of alpha blocking responses which were not present in non-paired conditions. These increments were manifested primarily in the tone interval closest to the light, after a small number of presentations, and decreased with the accumulation of trials. 3. 3. Alpha blocking responses attributed to pairing seem to be superimposed upon a background of responses due to sensitization (produced by introduction of light) and incomplete habituation. 4. 4. It was suggested that differences in the number of alpha blocking responses between O 1P 3, O 2P 4 and O 2C z were probably related to intrinsic cerebral factors (subjects') since no interactions between derivations and the other variables were obtained. 5. 5. Responses attributed to pairing were labelled “contingent responses” and those attributed to other circumstances; i.e., non-paired light, “sensitization responses” even though the contribution of associative and non-associative factors was not entirely clarified, particularly for the latter. 6. 6. It was argued that contingent and sensitization alpha blocking responses could not explained simply in terms of “a return of the adapted out orienting reflex” on the basis of the evidence presented.