Abstract
Prior research showed that mere instructions about the contingency between a conditioned stimulus (CS) and an unconditioned stimulus (US) can generate fear reactions to the CS. Little is known, however, about the extent to which actual CS–US contingency experience adds anything beyond the effect of contingency instructions. Our results extend previous studies on this topic in that it included fear potentiated startle as an additional dependent variable and examined return of fear (ROF) following reinstatement. We observed that CS–US pairings can enhance fear reactions beyond the effect of contingency instructions. Moreover, for all measures of fear, instructions elicited immediate fear reactions that could not be completely overridden by subsequent situational safety information. Finally, ROF following reinstatement for instructed CS+s was unaffected by actual experience. In summary, our results demonstrate the power of contingency instructions and reveal the additional impact of actual experience of CS–US pairings.
Acknowledgement
We would like to thank Dr Matthias Gamer for providing the software for the SCR and FPS scoring.
Disclosure statement
No potential conflict of interest was reported by the authors.
Supplementary material
Supplemental data for this article can be accessed here.
Notes
1 There was no specific reason why the credibility questionnaire was prepared in English. However, participants were recruited to be comfortable with an English speaking experimenter and none of the participants reported difficulties completing this questionnaire.
2 When the analyses of the test phase is restricted to the first block only, which was the most sensitive block for effects of CS–US pairing experience in the study of Raes et al. (Citation2014), fear reactions are significantly higher for CSI+E compared to CS-I on US expectancy, F(1, 35) 10.85, p = .002, = .24; Fear ratings F(1, 35) = 21.09, p < .001,
= .38; and FPS, F(1, 33) = 6.20, p = .018,
= .16; but not on SCR, F(1, 35) < 1.