Date of Award


Degree Type


Degree Name

Doctor of Philosophy in Psychology



First Advisor

Nelson F. Smith


This study assessed the efficacy of positive electrical stimulation of the brain in counterconditioning fear in 100 albino laboratory rats. A parametric investigation was undertaken in which fear was conditioned through presentation of electric foot shock and then reduced through response prevention, in combination with different types of electrical stimulation of the brain. The basic measure of fear was the Conditioned Emotional Response (CER), as seen in the suppression of licking behavior.

Electrical stimulation of the brain (ESB) has been used to effectively reduce active avoidance responding, another measure of conditioned fear, and its effects resemble closely those obtained when traditional reinforcers are used: as counterconditioners. The CER procedure had not been used, however, to measure the reduction of fear following counterconditioning with rewarding electrical stimulation of the brain.

The effects of rewarding brain stimulation followed standard conditioning parameters and effectively reduced the fear complex more than non-rewarding brain stimulation or response prevention alone. ESB was then used to reassess a classical conditioning explanation of the reduction of conditioned fear following response prevention.



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