Related Experiment Videos
Diazepam blocks fear-potentiated startle in humans
C J Patrick1, B D Berthot, J D Moore
1Department of Psychology, Florida State University, Tallahassee 32306-1051, USA.
Journal of Abnormal Psychology
|February 1, 1996
Summary
Diazepam, an anxiolytic drug, reduces fear responses to unpleasant stimuli by blocking startle reflex potentiation. This indicates a common defensive mechanism in humans and animals for assessing drug effects on fear.
Area of Science:
- Psychopharmacology
- Neuroscience
- Human Emotion Research
Background:
- The startle reflex is a physiological measure of defensive responses.
- Anxiolytic drugs like diazepam are known to affect emotional processing.
- Understanding drug effects on fear is crucial for mental health treatment.
Purpose of the Study:
- To investigate the effects of diazepam on emotional responses to aversive stimuli.
- To examine the role of the startle probe reflex in assessing these effects.
- To determine if diazepam alters fear-related physiological responses.
Main Methods:
- A double-blind study involving 54 university students.
- Participants were assigned to placebo, 10 mg, or 15 mg diazepam groups.
- Blink responses to noise probes were measured during neutral and unpleasant visual stimuli.
Main Results:
- Diazepam significantly blocked startle reflex potentiation during aversive stimulus viewing.
- The drug did not reduce the overall magnitude of startle responses.
- Findings align with animal studies on diazepam's effects on defensive states.
Conclusions:
- Startle reflex potentiation is a valid index of fear in humans, mediated by a common defensive state.
- Diazepam modulates fear responses by affecting this defensive state.
- The startle probe reflex can be utilized to evaluate the emotional impact of various pharmacological agents.