Differential impact of threat type on defensive motivation and attention during the NPU-threat task

The (un)predictability of threat influences anticipatory emotional and motivational states. However, few investigations have examined the impact of threat type on defensive motivation. Two within-subject studies (total N = 134) examined defense motivation (startle reflex) and attentional engagement (probe N100, P300) in anticipation of shock and an aversive noise (scream) during a no, predictable, and unpredictable threat (NPU-threat) task. In Study 1, startle was potentiated for unpredictable shock and scream, but potentiation was greater for shock. Startle was potentiated for predictable shock but attenuated for predictable scream. In Study 2, the scream was paired with a scared female face. Startle was potentiated for both predictable and unpredictable shock and scream. The probe N100 was enhanced during unpredictable threat and the probe P300 was suppressed during both predictable and unpredictable threat. The present study suggests that threat type impacts unpredictable (but not predictable) defensive motivation but not attentional engagement. Moreover, predictable auditory aversive stimuli need a paired visual stimulus to enhance defensive motivation.