Brain Facts:
Diagnostic

Describes a variety of brain imaging modalities: CAT Scans, PET Scans, MRI, fMRI, EEG, SPECT, MEG, NIRS.

Brain imaging can reveal:

• Blood flow to areas of the brain
• Movement of neurotransmitters as they congregate to elicit mood changes and lay down long-term memories
• Energy the brain uses
• How the brain burns glucose to perform its tasks
• The voice of demons lurking in the brains of schizophrenics

Neuroesthetics

A new discipline called Neuroesthetics uses art as a pathway into understanding the organizational workings of our brains—in particular how our senses relay their messages into the brain, and what happens with the sensory information as it gets combined, restructured, and assimilated.

Zack Lynch
The Neuro Revolution
p. 115

Neuroimaging Techniques

Neuroimaging techniques can be divided into several categories, the most fundamental being the distinction between “structural” and “functional” scanning techniques.

Neuroimaging
—Functional

Functional neuroimaging refers to techniques that provide views of some particular aspect of brain activity, for example, cerebral blood flow, glucose metabolism, or oxygen consumption; these techniques are best knows by their acronyms—PET, SPECT, and MRI. Functional neuroimaging may be further subdivided into the methods that measure brain metabolism and those that measure brain electrical activity (“brain waves”) and magnetic activity.

Neuroimaging
—PET

Positron Emission Tomography utilizes the properties of the special radiation generated by positron-emitting substances, which generate pairs of photons traveling in exactly opposite direction. The technique takes advantage of positron emissions by what is called coincidence counting—simultaneous detection of each pair of photons by opposing detectors set at positions 180° from each other, allowing great precision in mapping the distribution in the brain of the substance in question.

Positron emission tomography has been used quite extensively to study higher mental function.

Neuroimaging
—SPECT

In SPECT, biochemicals of interest are labeled with radioactive compounds that emit gamma rays in all directions. These substances, called radiopharmaceuticals, are injected into the bloodstream of subjects. As the radiopharmaceuticals reach the brain, detectors surrounding or rotated about the head pick up their emissions, and computer programs are used to “reconstruct” what the distribution of the labeled substance must have been to generate the pattern of emissions sensed by the detectors. So far, SPECAT procedures have been used to measure cerebral blood flow and blood volume in three-dimensional cross sections of the brain.

Neuroimaging
—Structural

Structural neuroimaging refers to scanning techniques that show brain structure or anatomy, such as computerized tomography (CT) and standard magnetic resonance imaging (MRI). Structural scan typically show cross sections of the brain and may literally look as if one sliced through the brain and took a picture