Excitatory Strength of Expressive Faces: Effects of Happy and Fear Expressions and Context on the Extinction of a Conditioned Fear Response

In a recent study, Orr and Lanzetta (1984) showed that the excitatory properties of fear facial expressions previously described ( Lanzetta & Orr, 1981 ; Orr & Lanzetta, 1980 ) do not depend on associative mechanisms; even in the absence of reinforcement, fear faces intensify the emotional reaction to a previously conditioned stimulus and disrupt extinction of an acquired fear response. In conjunction with the findings on acquisition, the failure to obtain extinction suggests that fear faces have some of the functional properties of "prepared" (fear-relevant) stimuli. In the present study we compared the magnitude of conditioned fear responses to happy and fear faces when a potent danger signal, the shock electrodes, are attached or unattached. If fear faces are functionally analogous to prepared stimuli, then, even in the absence of veridical support for an expectation of shock, they should retain excitatory strength, whereas happy faces should not. The results are consistent with this view of fear expressions. In the absence of reinforcement, and with shock electrodes removed, conditioned fear responses and basal levels of arousal were of greater magnitude for the fear-face condition than for the happy-face condition.