Additive effects of threat-of-shock and picture valence on startle reflex modulation.
The present study examined the effects of sustained anticipatory anxiety on the affective modulation of the eyeblink startle reflex. Towards this end, pleasant, neutral and unpleasant pictures were presented as a continuous stream during alternating threat-of-shock and safety periods, which were cued by colored picture frames. Orbicularis-EMG to auditory startle probes and electrodermal activity were recorded. Previous findings regarding affective picture valence and threat-of-shock modulation were replicated. Of main interest, anticipating aversive events and viewing affective pictures additively modulated defensive activation. Specifically, despite overall potentiated startle blink magnitude in threat-of-shock conditions, the startle reflex remained sensitive to hedonic picture valence. Finally, skin conductance level revealed sustained sympathetic activation throughout the entire experiment during threat- compared to safety-periods. Overall, defensive activation by physical threat appears to operate independently from reflex modulation by picture media. The present data confirms the importance of simultaneously manipulating phasic-fear and sustained-anxiety in studying both normal and abnormal anxiety.
Department of Psychology, School of Social Sciences, University of Mannheim, Mannheim, Germany. f.bublatzky@uni-mannheim.de
Florian
F
Bublatzky
Pedro M
PM
Guerra
M Carmen
MC
Pastor
Harald T
HT
Schupp
Jaime
J
Vila
D000293:Adolescent; D000328:Adult; D059031:Anticipation, Psychological / Q000502:physiology*; D001007:Anxiety / Q000503:physiopathology* / Q000523:psychology*; D005260:Female; D005712:Galvanic Skin Response; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D013216:Reflex, Startle / Q000502:physiology*; D012449:Safety; D057566:Self Report; D013997:Time Factors; D055815:Young Adult