Does pre-exposure inhibit fear context conditioning? A Virtual Reality Study.

Several studies in animals and humans have indicated that familiarity toward cues reduces cue-conditioning effects. The influence of familiarity of a context on context conditioning has been confirmed in animal studies only. Thus, this study examined contextual fear conditioning in humans depending on pre-exposure to the to-be-conditioned context. To accomplish this, a virtual reality paradigm presented via a head mounted display was realized. During conditioning, participants were exposed to one of two office rooms (contexts), of which one became associated with aversive electric stimuli (UCS). 1 day before conditioning, participants were randomly exposed to either the later to-be-conditioned context (n = 20) or to an unrelated virtual environment (n = 20). Startle reflex, skin conductance response, heart rate, and ratings of valence, arousal, and anxiety were measured to assess context conditioning. Successful context conditioning was demonstrated for both ratings and physiological indicators. Pre-exposure did not prevent successful context conditioning. We conclude that in humans, contextual fear conditioning is not easily modified by pre-exposure to the context.