The establishment of positive and negative evaluative conditioning reflex of neutral facial expression / 中华行为医学与脑科学杂志

ABSTRACT

Objective To examine the effect of positive and negative evaluative conditioning (EC) on neutral faces.Methods The experiment consisted of three phasesbaseline phase,conditioning phase,and re-evaluative phase,in which 41 college students participated,watching sequences of neutral faces (CS) pairing to either a positive stimulus (USpos) or a negative stimulus (USneg).Their emotional experiences (valence and arousal) and physiological reactivity (eyeblink startle reflex and skin conductance) were recor ded.Results (1) In the re-evaluative phase,CSpos was rated significantly more positive than CSneg and CSneut,while CSneg was rated significantly more negative than CSneut (CSpos (5.05± 1.24),CSneg (3.73± 1.48),CSneut (4.46± 1.04),P＜0.05).(2)In the re-evaluative phase,the mean startle eyeblink response magnitude(T score) to CSpos was significantly smaller than the responses elicited by CSneg and CSneut (CSpos (45.04±5.56),CSneg (51.44±9.30),CSneut (54.52± 10.60),P＜0.01).Conclusion The findings suggest that neutral faces can acquire valences and approach motivation through EC.