Cerebral Hemispheres 2


The Neuroimaging Revolution

One of the most exciting scientific advances of the past fifty years has been the development of complex neuroimaging techniques. Since computerized axial tomography (CAT or CT) was introduced in the 1970s we have seen the development of positron emission tomography (PET), magnetic resonance imaging (MRI), and functional MRIs (fMRI), each more effective than the one before, and each allowing for a drastically improved understanding of the brain and behavior. The dominant method of imaging through the past twenty years of brain research has been the fMRI. MRIs create an image of the brain out of radio waves emitted by hydrogen atoms in the body when they are manipulated by a magnetic field. fMRIs go a step further, allowing for a measurement of actual brain activity. When brain areas are active, they have an increased need for oxygen, and thus there is an increased amount of oxygenated blood moved to that area. fMRIs take advantage of the fact that oxygenated and deoxygenated blood have different magnetic resonance signals, and create an image of brain activity based on blood oxygenation levels. Here are pictures of an MRI (left) and fMRI (right):

MRI scan showing the structure of the human brain.

MRI scan showing the structure of the human brain.

fMRI scan showing human brain activity.

fMRI scan showing human brain activity.

fMRIs are effective and now integral in brain science, but don't think for a second that the desire to create precise brain imaging techniques ends there. There are a number of other techniques still being perfected that you may not hear about until they become more prevalent. One that is already starting to now give us a more complete picture of the brain is diffusion tensor imaging (DTI). While MRI shows the major structures of the brain, it has not been able to recreate the connections between those structures, such as the white matter tracts that connect the two hemispheres of our brain. DTI uses measurement of water diffusion along nerve fibers to image this subarchitecture. Compare the colorful DTI picture below to the MRI and fMRI pictures above.

Diffusion tensor image showing white matter tracts of the human brain.

Diffusion tensor image showing white matter tracts of the human brain.

DTI has already begun to be utilized in research. Randy Buckner and colleagues used DTI to measure white matter integrity in older patients. They studied it along with fMRI, and found that, in older individuals who had experienced a loss of cognitive ability, the integrity of white matter connections was decreased along with that of functional connections. It is hoped that the use of DTI will provide insight into the cognitive loss associated with aging, as well as into dementias like Alzheimer's disease.


Sleep. Memory. Pleasure. Fear. Language. We experience these things every day, but how do our brains create them? Your Brain, Explained is a personal tour around your gray matter. Building on neuroscientist Marc Dingman’s popular YouTube series, 2-Minute Neuroscience, this is a friendly, engaging introduction to the human brain and its quirks using real-life examples and Dingman’s own, hand-drawn illustrations.

  • ...a highly readable and accessible introduction to the operation of the brain and current issues in neuroscience... a wonderful introduction to the field. - Frank Amthor, PhD, Professor of Psychology, The University of Alabama at Birmingham, author, Neuroscience for Dummies

  • Reading like a collection of detective stories, Your Brain, Explained combines classic cases in the history of neurology with findings stemming from the latest techniques used to probe the brain’s secrets. - Stanley Finger, PhD, Professor Emeritus of Psychological & Brain Sciences, Washington University (St. Louis), author, Origins of Neuroscience

  • Dingman weaves classic studies with modern research into easily digestible sections, to provide an excellent primer on the rapidly advancing field of neuroscience. - Moheb Costandi, author, Neuroplasticity and 50 Human Brain Ideas You Really Need to Know

  • An informative, accessible and engaging book for anyone who has even the slightest interest in how the brain works, but doesn’t know where to begin. - Dean Burnett, PhD, author, Happy Brain and Idiot Brain


This book shows a whole other side of how brains work by examining the most unusual behavior to emerge from the human brain. In it, you'll meet a woman who is afraid to take a shower because she fears her body will slip down the drain, a man who is convinced he is a cat, a woman who compulsively snacks on cigarette ashes, and many other unusual cases. As uncommon as they are, each of these cases has something important to teach us about everyday brain function.

  • Dingman brings the history of neuroscience back to life and weaves in contemporary ideas seamlessly. Readers will come along for the ride of a really interesting read and accidentally learn some neuroscience along the way. - Erin Kirschmann, PhD, Associate Professor of Psychology & Counseling, Immaculata University

  • Through case studies of both exceptional people as well as those with disorders, Bizarre takes us on a fascinating journey in which we learn more about what is going on in our skull. - William J. Ray, PhD, Emeritus Professor of Psychology, The Pennsylvania State University, author, Abnormal Psychology

  • A unique combination of storytelling and scientific explanation that appeals to the brain novice, the trained neuroscientist, and everyone in between. Dingman explores some of the most fascinating and mysterious expressions of human behavior in a style that is case study, dramatic novel, and introductory textbook all rolled into one. - Alison Kreisler, PhD, Neuroscience Instructor, California State University, San Marcos

  • Bizarre is a collection of stories of how the brain can create zombies, cult members, extra limbs, instant musicians, and overnight accents, to name a few of the mind-scratching cases. After reading this book, you will walk away with a greater appreciation for this bizarre organ. If you are a fan of Oliver Sacks' books, you're certain to be a fan of Dingman's Bizarre. - Allison M. Wilck, PhD, Researcher and Assistant Professor of Psychology, Eastern Mennonite University