Last month I wrote an article about Patient H.M. and the new findings recently published by UCSD researcher Jacopo Annese. H.M. or Henry Molaison, as you may recall, suffered from a rare form of amnesia caused when a neurosurgeon removed his hippocampus in a procedure designed to alleviate severe epileptic seizures.
After the operation, H.M. was unable to form new memories, and became one of the most studied subjects in the history of neuroscience.
When Henry Molaison died in 2009, his brain was left to the Brain Observatory at UCSD. Its founder, Dr. Annese, performed a marathon dissection of H.M.’s brain, cutting it into 2,401 tiny slices over a period of 56 hours. The slices were later used to create a 3-D model in minute detail, down to the neuronal level.
I later found out that two weeks before I wrote that article, the world had lost one of the pioneers in the field of live brain imaging and the development of fMRI, or functional magnetic resonance imaging – Dr. Jack Belliveau.
Dr. Belliveau, who passed away on February 14th at the much-too-young age of 55, was a 30-year-old researcher at the Athinoula A. Martinos Center for Biomedical Imaging at Massachusetts General Hospital when he came up with a plan to make images of the brain in action.
According to his obituary in the New York Times, up to that point, doctors had been taking x-rays of the brain to look for injuries and had also used positron emission tomography scans, which required dangerous radioactive materials.
Dr. Belliveau had recently developed a technique to track blood flow in the brain, which he called dynamic susceptibility contrast, using an MRI machine. His technique had been used to evaluate blood flow in stroke patients, and now he wanted to try it on a healthy brain in the act of thought or perception.
At first, Dr. Belliveau used a strobe light for his tests. He would ask subjects to watch the strobe as they sat in an MRI machine, which took split second images of their brain. He then compared the results to images taken while the strobe was turned off.
When this method failed to yield results, Belliveau switched to a set of goggles imprinted with a checkerboard pattern. This time he found success and the visual areas of the brain showed up clearly on the images. The results of these tests were published in a paper in the journal Science on November first, 1991, accompanied by a famous cover illustration depicting a human head, seen from the back, with a circle removed to reveal an illuminated visual cortex.
Other researchers such as Dr. Seiji Ogawa and Ken Kwong, were also instrumental in the development of fMRI and its use in cognitive science. After the initial results were published, technological aspects of the procedure were improved and fMRI became an important research tool.
Dr. Belliveau went on to become the first president of the Organization for Human Brain Mapping and was working on combining different technological processes in order to produce clearer images at the time of his death.
fMRI and Cognitive Science
Since 1991, fMRI has played an important role in the development of cognitive science. To mark its 20th anniversary in 2011, Dr. Bruce Rosen, who was Jack Belliveau’s adviser at the Martinos Center, gave a talk at the International Society for Magnetic Resonance in Medicine meeting where he reviewed the impact of fMRI.
According to Dr. Rosen, as of 2011 fMRI had been a key tool in research that led to the publication of around 21,000 articles listed on PubMed, and that nine of the top ten university psychology departments in the U.S. counted on an fMRI system. fMRI has been key to our understanding of memory, helping lead to a new conceptualization of memory from a retrospective function to one in which memory gives us the necessary information to make future predictions.
fMRI has also been instrumental to our understanding of the plasticity and development of the brain, and, perhaps most importantly, has helped change public perception of mental illness, showing, through before and after images, that mental illness has a biological basis and can indeed be treated. In fact, governmental pressure, using fMRI images as evidence, led to the eventual coverage of mental illness by the health insurance industry, a major breakthrough for public health.
Although we have made huge strides in our understanding of the human brain over the last few decades, we have yet to uncover the majority of its mysteries. We salute all the researchers, including Dr. Jack Belliveau, Jacopo Annese and their many colleagues, as they strive to find the answers to innumerable questions through the painstaking application of science.