Banner by Sarah Lindley

A Peek Inside our Minds

By Pravanvel Balamurugan

Imagine yourself in your early forties. You have yourself a loving family, a job you enjoy, and a beautiful house. You are able to treat yourself to vacation every once in a while and you have managed to maintain most of your friendships from college and work. Despite the fact that everything you desired to accomplish has seemingly been fulfilled, the pit in your stomach never disappears. Why? Well, when you decide to visit and thank the people who got you this far in life—your parents, a relative, or another mentor—they stare blankly, unsure why tears run down your face. Unable to recognize who you are.

Alzheimer’s is one hell of a beast—a disease that destroys its host’s memory and emotionally destroys their loved ones. Although there exists medication that slows the progression of the disease, a cure is yet to be discovered. A significant portion of modern-day scientific research is dedicated to Alzheimer’s alone.

A key technique used in the study of Alzheimer’s and other neurological disorders is neuroimaging, or medical imaging of the brain. It is used primarily to study brain structure and function in vivo—in living organisms. William Oldendorf is considered the father of modern-day neuroimaging. Disgusted by the hazards posed by scanning methods in the 1950s, which included permanent brain damage and paralysis, he came up with the concept of axial tomography, a radiological imaging technique that would prove to be monumental in diagnosing neurological disorders in children. Today, brain imaging tools such as functional magnetic resonance imaging (fMRI), electroencephalogram (EEG), and positron emission tomography (PET) are at the forefront of neurological research, allowing scientists to map changes in blood flow, measure electrical activity, and produce three-dimensional images of the brain. 

Imaging used clinically is very different from imaging used in research. “If you go to the doctor, the goal…is to ideally use imaging to give you a diagnosis,” says Dr. Alberto Vazquez, an Associate Professor of Radiology and Bioengineering and a part of the Neuroimaging Laboratory at Pitt. However, most neuroimaging is not used in this way. In order to improve human brain imaging at the single-subject level, Vazquez began doing work with animals. His work focuses on “trying to see what could be possible in terms of imaging brain function with translatable tools like MRI and PET” and hopefully apply this in a way where neurologists can make determinations on individual patients at their clinic. 

Currently, the most widely-used neuroimaging technique is fMRI. By taking advantage of the magnetic properties of the human brain, it allows one to noninvasively assess patterns in brain activity and blood flow. There are various forms of fMRI, including contrast fMRI and perfusion MRI, all of which can be used to track changes in metabolic activity within the brain. For example, BOLD fMRI is sensitive to the magnetic properties of iron in hemoglobin. EEG, another popular neuroimaging technology, measures electrical activity by utilizing electrodes. Spontaneous EEG measures responses that do not come from stimuli, whereas other types of EEG are associated with specific stimuli or thoughts. However, despite these advancements in technology, there still exist shortcomings in the world of neuroimaging. The hemodynamic response in BOLD fMRI is quite slow and weak, averaging fourteen seconds in response to a single stimulus. EEG is not as sensitive to deeper parts of the brain as it is to superficial layers. One major issue shared by all forms of neuroimaging is the inability to measure individual neurons, perhaps the most important component of the brain. Even if the “path to development is unclear,” Vazquez believes that more direct neuroimaging methods will be discovered.

For those interested in the world of neuroimaging, articles in Nature Reviews are a great starting point. From there, a large collection of field-specialized journals can be explored, such as NeuroImage and Human Brain Mapping. Neuroimaging is becoming increasingly important in current research, proving to have important uses in the study of Down syndrome, neurodevelopment, and more. Recent research has used neuroimaging to map processes like the creative thinking process of the brain. As a rapidly developing field with undeniable impacts on the study of Alzheimer’s, schizophrenia, and other neurological diseases, neuroimaging may be the key to saving us from the mental turmoil of seeing loved ones alive but gone at the same time.