Related Experiment Video
Updated: Aug 16, 2026

Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat
Published on: September 12, 2014
Cortisol and DHEA-S are associated with startle potentiation during aversive conditioning in humans
Christian Grillon1, Daniel S Pine, Johanna M P Baas
1NIMH/NIH/DHHS, Mood and Anxiety Disorder Program, 15K North Drive, MSC 2670, Bethesda, MD 20892-2670, USA. Christian.Grillon@nih.gov
Rationale:
Fear conditioning reliably increases the startle reflex and stress hormones, yet very little is known about the effect of stress hormones on fear-potentiated startle. Cortisol and the sulfate ester of dehydroepiandrosterone (DHEA-S) are involved in stress and anxiety. Evidence suggests that low cortisol/DHEA-S ratio has a buffering effect on stress and anxiety in preclinical and clinical studies, suggesting that there may be a relationship between fear-potentiated startle and cortisol and DHEA-S activity.
Objective:
The aim of the study was to examine whether there is a relationship between cortisol/DHEA-S ratio and fear-potentiated startle.
Methods:
Thirty healthy subjects participated in a differential aversive conditioning experiment during which one of two stimuli (CS+) was paired with a shock, and the other was not (CS-). Conditioned responses were assessed with the startle reflex, defined as startle potentiation during CS+ compared to CS-. DHEA-S and cortisol levels were assayed from blood samples collected in both a baseline and an aversive conditioning session. Subjective state anxiety, arousal, and valence were assessed at various times during testing.
Results:
Fear-potentiated startle was larger in individuals with high compared to low cortisol/DHEA-S ratio. Multiple regression analyses revealed that fear-potentiated startle was positively associated with cortisol and negatively associated with DHEA-S. There was no significant correlation between DHEA-S and cortisol levels.
Conclusion:
These data suggest that cortisol and DHEA-S are involved in fear conditioning.
Related Concept Videos
Physiological Foundation of Stress
Role of the Sympathetic Nervous System
Adrenaline triggers the...
Cushing Syndrome II: Pathophysiology
Classical Conditioning in Daily Life
John B. Watson and Rosalie Rayner famously demonstrated the development of fear through classical conditioning in their experiment with Little Albert. They paired the...
Desensitization and Tachyphylaxis
Several...
Cushing Syndrome I: Introduction
Sympathetic Activation

