- Introduction
- Polygraph
- Brain Electrical Oscillation Signature (BEOS)
- What is the difference between BEOS and Brain Fingerprinting?
- Suspect Detection System (SDS)
- Layered Voice Analysis (LVA)
- Conclusion
- References
Introduction
Forensic psychology is an intersection of law, psychology, and the criminal justice system. It is the application of psychological principles in the criminal justice system. This field is concerned with identifying whether the suspect has committed the crime they are accused of to reduce the miscarriage of justice. For this purpose, forensic psychologists in India use various tools whose principles were found in different psychological theories. These tools include polygraphs, which are the oldest and most used tool in the field of forensic psychology to detect deception. Polygraph is used for screening as well as for interrogation purposes. Other tools, such as the suspect detection system and Layered Voice Analysis, are mainly used for suspect screening. Brain Electrical Oscillation Signature Profiling is an indigenous tool developed by Professor C. R. Mukundan, which is used to detect whether or not the participant has a memory of crime-related events.
Interrogation Techniques and False Confessions
Let’s now know these tools in detail:
Polygraph
Polygraph is one of the oldest tools used in deception detection. It has been in use since the 1920s. Polygraph uses multiple sensors to detect psychophysiological changes in the individual in question. The sensors used in the polygraph include two pneumograph sensors, which measure abdominal and thoracic respiration; a sphygmomanometer, which measures the blood pressure volume; and an EDA sensor, which measures the electrodermal activity of the individual. These are the primary sensors that are used to measure changes. Other sensors are also used as countermeasures to ensure the individual is not trying to beat the system. These sensors include a pressure gauge kept on the seat and detects any movement in the seat. Polygraph has also included countermeasures for feet and hands now so that the suspect does not try to use different techniques to cheat the test and get away.
Brain Electrical Oscillation Signature (BEOS)
Brain Electrical Oscillation Signature Profiling is used in Forensic Psychology to aid investigations. This tool was developed in India and has been used since the early 2000s. BEOS has been used on more than 600 suspects and has helped investigators in many cases. BEOS looks at the neural signatures related to the memory of crime events. In this investigative tool, the individual in question is presented with short statements called Probes in a sequential and chronological manner. Each statement is presented only once and analyzed for activations in different brain areas to look for experiential knowledge. Here, the participant is not required to speak or respond in any manner. The individual only needs to listen to the probes being presented to him/her. The probes presented could be in any language, as the system gives the freedom to record the probes before being presented.
What is the difference between BEOS and Brain Fingerprinting?
BEOS and Brain Fingerprinting are two very different tools and techniques used in Forensics. Brain Fingerprinting looks at P300, an event-related evoked potential, whereas BEOS looks at the neural signatures of memory. These two tools also differ in how the stimulus is presented to the suspect. In Brain Fingerprinting, the suspect is presented with images or short phrases multiple times, whereas in BEOS, the suspect is presented with short sentences only once. Brain Fingerprinting is very similar to an oddball task, but BEOS uses a different set of principles.
Suspect Detection System (SDS)
Suspect Detection System is another tool used in Forensic Psychology to screen individuals. This system uses only one sensor to detect deception, which is EDA. This sensor measures any changes in the person’s electrodermal activity. The questioning technique in this tool is similar to that of the polygraph. The subject is asked questions in the Concealed Information Test or Guilt Knowledge Test. This tool takes less time and is very useful for screening multiple suspects.
Psychological Autopsy: Need of Forensic Psychology
Layered Voice Analysis (LVA)
Layered Voice Analysis is another tool used in the Forensic Science Labs for suspect screening. LVA was originally developed in 1997 by Amir Liberman. This tool detects subtle, hidden emotional cues in the suspect’s speech and understands their mental state and emotional reactions at any moment. It can identify various stress levels in a person’s voice. It reveals how the suspect is thinking by analyzing different cognitive processes. LVA identifies and detects various patterns and anomalies in the speech flow and then classifies these patterns in terms of stress, excitement, confusion, and other relevant emotional states. LVA technology claims to uncover sensitive or significant areas of the speaker. It can also help the examiner highlight the topic requiring more attention from the subject. It works on online and offline data, meaning you can use the LVA tool on pre-recorded audio or use it in real time.
Conclusion
These tools are being used in various Forensic Science Labs in the division of Forensic Psychology to aid investigations. These tools are accepted as corroborative pieces of evidence in the court. Understanding the basics of human physiology and psychology is important to become a good examiner. There are a lot of cases where physical evidence falls short. These cases turn cold due to the lack of any substantial evidence. These technologies can help investigators uncover new details about the case during that time. Information from these tools can lead the investigation in a new direction. All the tools mentioned above are language-independent, meaning they can be used in any language. This is an extremely important point since India has various dialects. These tools overcome that limitation and are unbiased in the context of language. To safeguard individual rights, these tools do require the court’s permission and the individual’s consent. To obtain the maximum benefit of these state-of-the-art tools, the examiners should administer them cautiously.
Common FAQ Related To Forensic Science
References
- https://www.nemesysco.com/lva-technology/
- https://medwinpublishers.com/IJFSC/understanding-the-differences-between-brain-finger-printing-and-brain-electrical-oscillations-signature-(beos)-profiling-systems-used-for-forensic-psychological-investigation.pdf
- Essentials of Polygraph and Polygraph Testing Nathan J. Gordon
- https%3a%2f%2fwww.biopac.com%2fwp-content%2fuploads%2fEDA-Guide.pdf/RK=2/RS=YCQX8W.a3_D.yUrggzXdBY5KQao-
Authored By
Prashansa Tripathi
Prashansa Tripathi is a Researcher and Forensic Psychologist with a master’s degree in Forensic Psychology and two years of experience. She is dedicated to making forensic psychology accessible to all and is particularly interested in deception and the neuropsychology of truth-telling. Outside of work, she enjoys reading, writing, and exploring nature.
