The brain is a many splendored thing, and since the post-cold war stagnation of the space program has proudly taken up the ephemeral standard of the final frontier.  A frontier whose secrets are opening up like the Louisiansa Purchase, disclosed in the journals of Meriwether Lewis.   The insights of this new frontier are arriving on the backs of a visualization technique known as functional Magnetic Resonance Imaging (fMRI).  The brain has long been a black box of speculation and wonder and while still reluctant to reveal its more subtle secrets, fMRI permits a glimpse at some of the more coarse functions of the brain. This technology allows researchers to 'see' the brain, and more importantly, to track activation regions in the brain in response to different sets of carefully designed tasks, motivating the notion of mapping the entire organ based on function.  This allows neuroscientists to document which areas of the brain are responsible for which cognitive tasks, i.e., motor, visual, memory etc. and uncover many new insights into the causes of certain mental disorders and cognitive dysfunction.

While the careful design of cognitive tasks and controls is a crucial element to accurately stimulating desired regions of the brain, the work-horse in brain mapping is the fMRI technology and its ability to 'show' which regions of the brain are active.  How does this technology work?  The answer lies in examining what happens when you think.  The brain is an extremely active metabolizer,  it consumes more than 20% of the bodies oxygen and more than 15% percent of the bodies cardiac output.  The most significant portion of this oxygen intake goes into maintaining ionic gradients responsible for electrical activity in the brain, i.e., thinking.  The brain has efficient mechanisms to quickly transport extra blood to areas of the brain involved in nascent thought.  The metabolic processes of maintaining proper ionic gradients changes the "magnetic signature" of the blood in areas of neural activity.  fMRI takes advantage of this altered signature to identify regions of the brain that are, in short, thinking.  This is the technology behind the burgoening field of Brain Mapping.  Preliminary efforts in a rather new field have already uncovered startling information about the workings and dysfunction of the brain.
 
 

Dyslexia, as a disorder, has evolved from the status of an affliction of low intelligence, to a residue of poor education, to a legitimate dysfunction in language centers of the brain, to the current and striking evidence suggesting that a manifestation of the disorder is inactivity in specific areas of the brain's visual system typically stimulated by motion.  While the information doesn't reveal the connection between this inactivity and the difficulties in reading, writing, and spelling experienced by those suffering from dyslexia, it does offer a clear method by which the disorder can be accurately diagnosed at a much earlier stage, enabling treatment at an age where it is the most effective.  This evidence also may gives clues to the subtle properties and connections of the cognitive processes with which sufferers of dyslexia routinely struggle.   The findings indicating this inactivity would have been impossible without the aid of fMRI technology, finally enabling blind researchers to see what is actually transpiring in the brain.
 

The above image depicts the characteristic inactivity in the brain of a dyslexic when exposed to a series of moving dots.  The normal reponse is reflected by the high level of activity in the control subjects when confronting tasks of tracking and processing motion.
 
 

Memory functions in the brain has long been a disputed topic.  Notions of short-term and long-term memory as separate regions of the brain are breaking down, and the processes of visual memory and recall are merging.  Because of the relatively simply tasks required to stimulate the memory regions of the brain, much effort has been put into exploring memory by utilizing fMRI technology.  For the first time the regions of the brain responsible for different recall tasks are being catalogued and examined.  The idea of a Working Memory responsible for tasks such as remembering a short list of digits, such as a phone number, planning, organizing and rationalizing has been extended and refined.  Those suffering from Schizophrenia show distinct inactivity in the regions of working memory, perhaps owning to their sense of confusion and even fantasy.  Another area of memory under examination is that of visual recall, both via the cortex (viewing a familiar photo, or landscape) and eidetic recall (envisioning the face of a friend or scene).  Researchers claim to be able to identify, within very broad categories, what type of item one is thinking about by analyzing  the 'hot spots' in the regions of the brain devoted to memory.
 

The use of fMRI to map the various functions of the brain is very new and rather immature, yet already the efforts have revealed some staggering truths about how the brain works, and the implications of when it doesn't.  As the technology and the techniques improve, look for a greater understanding of how the brain manages its tasks and handles computation, and perhaps an insight into its more subtle ideas and abstractions, such as consciousness and self.
 

Primary Resource: National Institute of Primary Health