Colors pulsate within the image projected to the television screen. First pink, next amber, and then a small spot of red pops to the surface. The sound of the pens scratching thin, black lines out on paper first hints at trouble -- 32 pens, each one attached to an electrode on the patient's head, flip into ominous synchrony.
Then powerful shades of bright blue appear to the left on the monitor and break across the image with the force of a summer thunderstorm. Brillant greens follow. The fury swirls into a vortex -- blue, green, purple -- and disappears as fast as it came.
The colors depict the electrical energy of a 27-year-old man's brain as he undergoes one phase of a petit mal seizure -- a mild form of epileptic convulsion. Observers would have noticed little change in the man, perhaps just a distant stare or a slight loss of muscle tone.
But neuroscientists watching the television monitor view a far different picture, a kind of moving weather map of brain activity known as EEG imaging. The technique allows brain researchers to film color motion pictures of the brain's electrical activity with greater detail and more definition than ever before seen.
The technique is the newest, and one of the most sophisticated, additions to a growing number of brain probing instruments. Its biggest advantage: the ability to link behavior with brain activity as it occurs every split second.
"Only EEG imaging has the capacity to look at behavior and brain changes within milliseconds," says biophysicist Richard Coppola, who developed an EEG imaging machine for the National Institute of Mental Health (NIMH). "This allows EEG images to be related to behavior in an on-going manner."
The technique has wide-ranging applications for a host of psychiatric, neurologic and behavioral uses, be it investigating the violent storms of epilepsy or the eerie calm of Alzheimer's disease, which gradually shuts down the brain.
EEG imaging can map the injury of a boxer's knockout punch, track the long-term effects of lead poisoning or watch for the regrowth of a deadly brain tumor. It can assess stroke damage, read differences in brain activity of learning disabilities like dyslexia and spot the effects of certain drugs on the brain. It is even beginning to probe thinking and memory processes.
EEG stands for electroencephalography, a technique that dates to the 1920s, when electrodes were first placed on people's heads to record the electrical pulses generated by the firing of some 10 billion brain cells.
By relying on a minimum of 20 electrodes attached to the head like a mythological Gorgon's wig, EEGs collect vast amounts of information sent out by firing brain cells. EEG imaging uses a computer to synthesize the information from those electrodes and display it in topographic maps of brain activity on a special television screen.
According to some, that's a long needed change. Many researchers believe that a lot of standard EEG information falls by the wayside because of the tedious and difficult way it is analyzed. Even today, clinicians analyze standard EEG information by hand, poring over reams of paper printouts to measure the squiggly data lines with a ruler.
Computer-generated imaging "can make information that's available in a paper record more readily visible to the eye," says Coppola. "The best computer that we have is our own brain. Imaging allows us to get the data into our own heads."
The computers used in EEG imaging can sort and store vast amounts of information picked up by the electrodes, allowing better measurement of some basic brain functions that are usually masked by normal brain activity. The computers can also compare results from groups of people, a method that often shows differences not otherwise apparent.
For example, this process enabled Dr. Frank H. Duffy, a neurologist and mathematical engineer who is one of the major innovators of EEG imaging, to detect brain wave abnormalities in dyslexic children.
Duffy ran EEG imaging tests on 24 youngsters at Children's Hospital in Boston in 1980. He found the dyslexic group had brain wave abnormalities in regions of the brain corresponding to motor areas. In addition, the dyslexic group's left side of the brain, long thought to control speech, showed abnormalities. Both findings were undetected by other methods.
Similarly, EEG imaging is finding epilepsy in patients thought to suffer from schizophrenia or other mental disorders. An estimated 10 percent of epileptics are misdiagnosed and often get mired in the mental health system. Standard EEG tests on these people don't look abnormal, so they may be given the wrong medications or treatment.
One young patient complained of "hearing voices" after suffering a head injury in a car accident. Tested by standard EEG, his brain waves looked normal. He was diagnosed as having atypical schizophrenia and the patient's psychiatrist asked Duffy to run an EEG imaging test. The results showed an unseen epilepsy, which was controlled by medications. The man's "voices" disappeared.
Though EEG mapping is the only system that correlates brain electrical activity with behavior in real time, it is not expected to replace other tests -- including the standard EEG exam.
"Each of these imaging techniques is a different window on brain function from a different angle," says Dr. John M. Morihisa, chief of the Clinical Neurophysiology Unit at NIMH. "So, if you look through each of the different windows and see each of the different patterns, maybe together, we can begin to understand the puzzle of mental illness and of other brain disorders."
Morihisa, a 34-year-old Harvard-trained psychiatrist, is trying to do just that at the NIMH where he oversees several EEG imaging studies.
Among the patients being studied are those suspected of having Alzheimer's disease, schizophrenia and autism, an attention disorder that can afflict children.
For the future, EEG imaging is becoming a tool to investigate eating disorders such as bulimia and other psychological illnesses such as depression and alcoholism. The technique also is now being used in the operating room to aid in removing brain tumors. EEG mappers monitor newborns in the nursery and are beginning to test children for dyslexia.
"Can we recognize that pattern in preschool youngsters and help them avoid failure?" asks Duffy. "It's too early to tell, but we're encouraged by the results."
Other work by Duffy includes a study of a particularly fast growing brain tumor that is ultimately fatal called glioblastoma multiforme. Duffy and Dr. Fred Hochberg have increased survival time for some patients by using EEG imaging to catch early recurrences detected through subtle brain activity changes.
There is also the question of using EEG mapping for even more startling diagnoses: mind reading. Can neuroscientists read minds with this expanded EEG information?
"We can tell whether what someone is thinking is arousing or disturbing to them," says Coppola, noting that certain waves in the EEG change patterns.
"We can't read the contents of your mind, but we can tell if you're asleep or awake," adds Dr. Emmanuel Donchin, chairman psychology department at the University of Illinois in Champagne-Urbana.
Donchin's research uses a multiple electrode technique closely related to EEG imaging, but without the pictures. His studies are funded by the Advanced Research Projects Agency (ARPA) of the Department of Defense.
"We can also tell if you're attending or not attending to your task and we can tell if something surprised you or not, but we can't tell the reason why," he says. "So I guess in a way you can say, yes, we're reading minds."