Riding the Waves

The electroencephalograph, or EEG, has been the boon and the bane of neuroscientists and bioengineers for decades. Scientists have scoured strip chart recordings for any clue of neurophysiological function. Engineers have studied the “inverse problem” of localizing within the skull the source of electrical potentials measured at the scalp. Clinicians have compared patients’ EEG data with healthy subjects in an effort to uncover what’s wrong with an individual. All three groups have had some taste of success and more than their fair share of frustration.

The advent of digital processing tools and signal analyzers has helped make enormous progress in key tasks such as artifact removal, data reduction and compression, and event detection and classification. Sophisticated mathematical modeling is helping to decipher EEG rhythm generators not discernible by visible inspection.

An intriguing form of symbiosis is at play here: As engineers and mathematicians further enhance the processing of EEG signals, they offer scientists a clearer picture of brain function. Conversely, as neuroscientists learn more about the function of different brain regions, they offer engineers more data useful for signal ­analysis.

As both these trends converge, the potential for developing truly useful neurodiagnostic tools for detecting neurological and psychological disorders such as autism, Alzheimer’s disease, and sleep apnea is tantalizingly close. But more than technology development is required here.

As David Griffith reports in his article on quantitative EEG firms, vendors of neurodiagnostic systems should be careful about making overreaching claims about their system until a sufficient amount of peer-reviewed and replicated scientific testing exists. (That said, we find it hard to imagine that venture capital firms who blithely swallowed the ludicrous claims of the dot-com industry a few years back should be so concerned about the mere pittance squandered on neurometrics ventures).

If these were normal times, we might be inclined to include Larry Farwell and his Brain Fingerprinting Laboratories in this group. But these are not normal times and it does not seem unreasonable for counter-terrorist agencies to wonder if this technology—however immature and unproven—might yield some clues as to the identity or intent of terrorists in our midst.
In time of declared war on a declared enemy, different standards of incarceration apply and however distasteful the notion of brain monitoring, it is far preferable to the means of interrogation used by some other countries.

But even if it were a mature and proven technology, we believe that brain fingerprinting should never be contemplated as a criminal justice tool unless the suspect requests its use. We feel the same way about involuntary, or semi-voluntary polygraph testing, or drug testing, for that matter. There are many other tools and techniques for ensuring safety that do not penetrate the veil of cognition that may not have been apparent to the gentlemen who authored the fourth amendment, but who most certainly would have found such intimate search patently unreasonable.

For all its shortcomings, the EEG—and its cousin, the magnetoencephalograph—offer science and industry a unique and powerful tool that will only become more useful, if we use it wisely.

James Cavuoto
Editor and Publisher



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