Contingent Alpha Blocking and Sensitization

Abstract

THE term ‘conditioned’ was used by Pavlov to describe changes involving effector organs. This definition should not be loosely used to characterize alterations in brain mechanisms. Therefore, following the lead of W. Grey Walter¹ and Visser², the term ‘contingent’ or ‘contingent response’ (CR) will be used to replace ‘conditioned’ in this communication. Several investigators^3,4 have recently raised the question of whether contingent alpha blocking requires pairing of stimuli. This problem was initially posed by Knott and Henry⁵, who thought that this CR might also represent a sensitization phenomenon. Sensitization may be defined as the process by which serial repetitions of the unconditioned stimulus following neutral stimuli can produce responses to the neutral stimuli resembling those following pairing of the two^6,7. Martinson's unpublished work cited by Knott⁸ demonstrated that sensitization was obtained by presenting two intensities of tone stimuli randomly interspersed with two intensities of light stimuli. This work, while indicating that sensitization can occur, in no way negates the existence of a ‘true’ CR. In order to obtain this CR, Knott and Henry⁵ recommended a specific temporal separation of the paired stimuli to minimize the occurrence of sensitization.