Forensics: exact science or dramatised fiction? #7
‘Brain fingerprinting’ is another farcical technique that hopes to determine whether specific information is stored in a subject’s brain. They claim to do so by measuring electrical brainwave responses to words, phrases, or pictures that are presented on a computer screen. In essence, the irrationality inherent in it is the same as in the polygraph or lie detector that we have discussed earlier. Brain fingerprinting takes the pseudo-scientific fraud to another level. The so-called lie detectors claimed that they could detect lies. Brain fingerprinting claims that it can find out about all sorts of information.
The obsessive desire behind brain fingerprinting is one that has fascinated mankind for ages—the desire to ‘read someone’s mind’. This has been a tremendously popular motivation for the simple reason that it would yield terrific power in the hands of one who may accomplish it.
Electrical activity in the brain
Most of the readers would be familiar with EEG (Electroencephalogram). In very simplified terms, you can think of the EEG as the brain equivalent of the ECG (electrocardiogram). An electrocardiogram records the electrical signals in your heart. Once again, in simplified terms, you can think of the heart as an electrical machine that requires electric signals to function properly. Our heart’s electrical system controls the timing of the heartbeat by sending an electrical signal through these cells. Now you can understand why a failing heart is sought to be revived by sending an electrical shock to the heart using a machine called the defibrillator.
Similarly, the EEG detects electrical activity in our brain using small but very sensitive electrodes attached to the scalp and other sophisticated instruments. Now how does electrical activity come in the brain? What happens is that our brain cells communicate via very small electrical impulses and are active all the time, even when we are asleep. This activity shows up as wavy lines on an EEG recording. An EEG is one of the main diagnostic tests for epilepsy, besides other brain disorders. In fact, an epileptic seizure is caused by an abnormal electrical discharge in the brain.
Still, the EEG has nothing to do with your thoughts—the EEG or no other equipment can read your thoughts! While your EEG is being taken, you can be angry or amorous; the EEG would remain the same.
Enter a scientist-turned-businessman and his fanciful theory
Brain fingerprinting was sort of ‘invented’ by a scientist-turned-businessman Lawrence Farwell and he still remains its sole main proponent. Nobody else in the world’s scientific community supports him. To understand the fanciful theory he wove, we will have to learn a little about brain waves.
Brain wave patterns seen in an EEG scan are actually a very complex mix and may reflect a variety of unrelated brain activity functions. It was only with the development of computers and mathematical analytical tools that it became possible to sort out specific wave components on an EEG and identify the correlation between the waves and specific stimuli.
Amongst different brain wave components, there is a component called the P300. The P300 wave component was discovered by Dr Samuel Sutton in 1965. It is supposed to be a specific event-related brain potential (ERP) that is triggered when information relating to a specific event is recognised by the brain as being significant or surprising. Farwell took off from there.
The ‘presumed’ hypothesis of brain fingerprinting is that the brain processes known and relevant information differently than unknown or irrelevant information. The test subject is exposed to auditory or visual stimuli (words, sounds, pictures, videos) that are relevant to the facts being investigated along with other irrelevant words and pictures. Such stimuli are broadly classified as material `probes’ and neutral `probes’.
The hypothesis underlying its use in forensics is that in the case of guilty suspects, the exposure to the material probes will lead to the emission of P300 wave components which will be duly recorded by the instruments. By examining the records of these wave components the examiner is supposed to make inferences about the individual’s familiarity with the information related to the crime.
Once again, there is no scientific basis for such a hypothesis. The human brain is an extremely complex machine that does not function in a simple manner as a computer. The computer is much faster in calculations and computing than a human brain but, in terms of its architecture in comparison, it is a very simple machine. It should be easy to see that it too, like narco-analysis, presumes a computer hard disk-like model of the brain in which information is neatly stored in different sectors and that the information is processed quite like a computer. Unfortunately, the brain does not function that simply and its functioning is infinitely more complex.
His theory has not received support amongst his peers—a necessity for scientific validation. On the contrary, there are numerous research publications in peer-reviewed journals in which the technique has been criticised. Some of them include the papers by Fox, Abdollah, and Rosenfeld. In the most polite scientific language also, their conclusion is categorical—the claims of brain fingerprinting are exaggerated and misleading.
However, the stupid idea has made a tremendous impact on the nincompoops in the media, the police and intelligence agencies who regard it as the ultimate discovery—particularly in India.
Other similarly farcical techniques
Without getting too technical, just for information of the readers, it may be kept in mind that there is a similar thing called brain mapping also. Brain mapping can be thought of as a higher form of neuro-imaging, producing brain images supplemented by the result of additional (imaging or non-imaging) data processing or analysis, such as maps projecting (measures of) behaviour onto brain regions.
There is yet another fraud called Functional Magnetic Resonance Imaging (FMRI) that involves the use of MRI scans for measuring blood flow between different parts of the brain which is, without any basis, claimed to bear a correlation to the subject’s truthfulness or deception.
Practical difficulties from a legal perspective
Scientific objections apart, there are some simple logical problems in the very concept of brain fingerprinting, which limit its scope severely. For example, if the suspect knows everything that the investigators know about the crime for whatever reason, the test cannot be applied. There are several circumstances in which this may be the case. If a suspect acknowledges being at the scene of the crime but claims to be a witness and not a perpetrator, then the resulting “information present” response would simply show that the suspect knew the details about the crime—knowledge which he already admits and which he gained at the crime scene whether he was a witness or a perpetrator. Thus the technique cannot distinguish between witness and perpetrator.
Another case where brain fingerprinting is not applicable would be one wherein a suspect and an alleged victim—say, of an alleged sexual assault—agree on the details of what was said and done, but disagree on the intent of the parties. Brain fingerprinting can detect only information, and not the intent. The fact that the suspect knows the uncontested facts of the circumstance does not tell us which party’s version of the intent is correct.
Another situation where brain fingerprinting is not applicable is one where the investigators have no information about what crime may have taken place. For example, an individual may disappear under circumstances where a specific suspect had a strong motive to murder the individual. Without any evidence, authorities do not know whether a murder took place, or the individual decided to take a trip and tell no one, or some other criminal or non-criminal event happened. If there is no known information on which a suspect could be tested, a brain fingerprinting test cannot be structured.
Scientific rebuttal of the pseudo-science by the Supreme Court
Citing the research of John G. New in its support, a Three-Judge Bench of the Supreme Court in the case of Selvi & Ors vs State of Karnataka & Anr (2010). observed, “In the aftermath of crimes that receive considerable media attention the subject can be exposed to the test stimuli in many ways. Such exposure could occur by way of reading about the crime in newspapers or magazines, watching television, listening to the radio or by word of mouth…There is always a chance that a subject may have had prior exposure to the material probes. In case of such prior exposure, even if the subject is found to be familiar with the probes, the same will be meaningless in the overall context of the investigation.”
“Another significant limitation is that even if the tests demonstrate familiarity with the material probes, there is no conclusive guidance about the actual nature of the subject’s involvement in the crime being investigated. For instance, a bystander who witnessed a murder or robbery could potentially be implicated as an accused if the test reveals that the said person was familiar with the information related to the same. Furthermore, in cases of amnesia or ‘memory hardening on part of the subject, the tests could be blatantly misleading.”
The Court cautioned, “It is plausible that investigators could obtain statements from individuals by threatening them with the possibility of administering either of these tests. The person being interrogated could possibly make self-incriminating statements on account of apprehensions that these techniques will extract the truth. Such behaviour on part of investigators is more likely to occur when the person being interrogated is unaware of his/her legal rights or is intimidated for any other reason.”
In one sweeping stroke, the Supreme Court held polygraphs, narco-tests and brain fingerprinting all to be illegal.
Unethical promotion in India
While the scientific community of the world has discredited and discarded this fraud, in India, this pseudo-science is being promoted by certain so-called ‘forensic scientists’, mainly from Bangalore, Gandhinagar and Bombay with the ulterior motive of garnering their few seconds of publicity on the TV. This is an example and proof of the collective lack of critical faculty in this country.
The use of these techniques is a sign of despotic state
Jinee Lokaneeta in her book ‘The Truth Machines: Policing, Violence, and Scientific Interrogations in India’ says that the use of the so-called ‘truth machines’ using discredited technologies of lie detection, brain scan and narco-analysis for the purposes of police interrogation, is not humane devices to end police torture and third-degree interrogation. They actually perpetrate violence with their regimen of attempting to capture evidence from the possibly betraying conscious will.
Lokaneeta gives a comprehensive history of these technologies as they emerged in the United States, where they now stand repudiated. She also points out that these so-called forensic psychologists have replaced the police as interrogators and they ‘reinforce the structure of Indian policing, which has long emphasized violence and confession’. Forensic psychologists, Lokaneeta argues, are both semi-state actors and cyborgs.
(To be continued…)