Brain Electrical Activation Profile (BEAP / P300 Test)
Definition
A method that uses electroencephalography (EEG) to detect the P300 event-related potential, a positive-going brainwave that occurs approximately 300 milliseconds after a subject recognises a stimulus as meaningful or familiar. In forensic use, probes related to crime-specific details are embedded in a series of neutral stimuli, and a strong P300 to a probe is interpreted as indicating stored memory of the crime.
- Also known as
- P300 test
- Signal measured
- P300 event-related potential via EEG
- Latency
- Approximately 300 milliseconds after recognition
- Logic
- Strong P300 to crime-specific probe implies stored memory
Common questions
How does BEAP differ from a polygraph test?+
A polygraph measures autonomic arousal such as heart rate and skin conductance to infer deception, while BEAP measures a specific brainwave response to recognition of familiar stimuli, so it is framed as detecting stored memory rather than lying as such.
Why is BEAP evidence treated cautiously by courts?+
Its scientific validity and standardisation are contested, results can be affected by how probes are constructed and administered, and in India the Supreme Court's 2010 ruling on narcoanalysis and related tests requires informed consent, which limits how such evidence can be obtained and used.
Related terms
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- Selvi V State of Karnataka
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