Previous studies on aversive learning have suggested a right
hemispheric advantage for eliciting autonomic reactions to a
masked conditioned facial stimulus (CS) depicting anger. The
present study investigated the effects of visual field (VF),
stimulus awareness, and emotional valence of the CSs on indicators
of conditioning (bilateral SCRs, HR) using a differential
conditioning paradigm (N = 41). In Group 1, four different
negatively valenced facial expressions (CS+) but not four
positively valenced CS− were associated with an unconditioned
stimulus (US, aversive vocalization, 97 dB, 3 s) during
acquisition. Group 2 received a treatment reversal with positive
CS+ associated with the US. In a repeated measures design, CSs
were presented with or without awareness during extinction (two
weeks interval, order counterbalanced). SOAs were adapted for
each subject and condition prior to the experiment so that
identification performance was approaching chance level. The
results revealed that both negative and positive facial expressions
could be aversively conditioned providing evidence for a
generalization of learning in the valence dimension. During
extinction, preattentive negative CS+ presented to the left
VF showed a trend towards greater electrodermal and cardiac
reactions. However, no such effect emerged under full awareness
of the CSs. These results confirm and further specify the nature
of hemispheric asymmetries in emotional associative learning.