How many blinks are necessary for a reliable startle response? A test using the NPU-threat task

Area of Science:

• Affective science
• Psychophysiology
• Clinical psychology

Background:

• Emotion-modulated startle is a key psychophysiological measure in affective science.
• Assessing the reliability of startle responses is crucial for valid research outcomes.
• The optimal number of startle responses (NoS) for reliable measurement remains unclear.

Purpose of the Study:

• To determine the minimum number of startle responses (NoS) required for reliable emotion-modulated startle.
• To evaluate the impact of NoS on reliability within a threat-of-shock paradigm (NPU-threat task).
• To examine reliability across clinical (panic disorder, major depression) and non-clinical samples.

Main Methods:

• Assessed reliability of startle responding as a function of NoS.
• Utilized the NPU-threat task in clinical (N=205) and non-clinical (N=92) participants.
• Examined internal consistency and retest reliability across different diagnostic groups.

Main Results:

• Reliability generally increased with a higher NoS.
• Six startle responses per condition appeared sufficient for acceptable reliability in both samples.
• Some variation in reliability was noted based on diagnosis and retest assessment.

Conclusions:

• Six startle responses per condition are recommended for reliable emotion-modulated startle measurement using the NPU-threat task.
• This guideline supports robust data collection in both clinical and non-clinical populations.
• Further research may refine NoS recommendations based on specific diagnostic profiles and experimental designs.