Classical conditioning of autonomic and affective responses to fear-relevant and fear-irrelevant stimuli

Abstract

Classical conditioning of autonomic and affective (evaluative) responses was examined to slides of fear-relevant and fear-irrelevant conditioned stimuli (CSs). Sixty-four subjects (14 males) who had previously rated 60 slides (which included the CSs) on three dimensions of affect (valence, arousal, and dominance) underwent a two-phase classical conditioning session. Following habituation to three slides, during acquisition, the fear-relevant group (n = 32) saw a slide of a snake or spider (CS forward, CSf) immediately preceding shock (US), and a flower or mushroom (CS backward, CSb) immediately after the US. The fear-irrelevant group had these stimuli reversed. Both groups also observed a neutral slide (basket or fork) explicitly unpaired with the shock (CSu). Skin conductance responses (SCRs) and expectancy of the US were recorded. Both groups learnt the contingency and acquired a conditioned SCR to the CSf in comparison to the CSu. Forty-three subjects later rated the same 60 slides; however, no significant differences between change scores (from pre- to post-conditioning) for any type of CS were seen, suggesting that the association of the slides with the US did not influence their subsequent affective evaluation. Thus, the present data demonstrated classical conditioning of the autonomic, but not affective, response to the CSs.