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In-Depth Information
abnormalities due to a disease or brain damage.
Also, computers produce three-dimensional pic-
tures of the brain structures.
Functional neuroimaging techniques show
what's inside the brain. They provide pictures of
sites where the working memory is in action. For
example, it is possible to record how the short-term
and the long-term memory are involved in recog-
nizing an image of a familiar face. Brain imaging
techniques, including physiological recordings
(e.g., cerebral blood flow, electroencephalogra-
phy) and clinical neuropsychology (e.g., split-brain
patients), serve also for researching cognitive
imagery. Several techniques make possible map-
ping mental activity of the brain. Neuroimaging
techniques allow structural imaging for diagnosing
diseases and injuries of the brain, and functional
imaging used to diagnose metabolic diseases and
lesions, visualize fine structure of brain tissue,
conduct research on neurological, cognitive, and
psychological processes, and also develop inter-
faces between a brain and a computer. As listed
in textbooks (e.g., Sternberg, 2011, Sternberg &
Kaufman, 2011) and Wikipedia, types of func-
tional neuroimaging include several techniques.
•
Magnetic Resonance Imaging (MRI):
Uses magnetic fields and radio waves to
quickly construct a two- or three-dimen-
sional image of the brain structure on a
computer, and its changes over time, with-
out use of x-rays or radioactive tracers.
•
Functional Magnetic Resonance Imaging
(fMRI) Technique:
(Logothetis, Pauls,
Augath, Trinath, & Oeltermann, 2001)
Show images of changing blood flow in the
brain. Cognitive activity evoked by various
stimuli results in changes in the amount of
blood flow in different regions of the brain.
Changes in blood flow are associated with
perception, thought, and action related to
different tasks: it reflects reasoning, the
processing of emotions, conflict resolu-
tion, making moral judgments, or feeling
reward and pleasure after making a proper
conclusion.
•
Positron Emission Tomography (PET):
Is the functional brain imaging method
that tracks radioactively labeled chemicals
(such as glucose with radioactive atoms)
in the blood flow. Glucose is metabolized
in proportion to the brain activity, so ra-
dioactivity is concentrated in the most ac-
tive areas and provides multicolored 3D
images of brain areas in action. It serves
for detection of brain tumors and diseases
that cause damage to neurons and follow-
ing dementia.
•
Computed Tomography (CT) and
Computed Axial Tomography (CAT)
Scans or Computed Axial Tomography
(CAT) Scanning:
Use x-ray beams ac-
cording to a computer program; CT scan
technique provides three-dimensional rep-
resentations telling how tissues absorb ra-
dioisotope energy.
•
Diffuse Optical Imaging (DOI) or Diffuse
Optical Tomography (DOT) and High-
Density Diffuse Optical Tomography
(HD-DOT):
Are tomography based tech-
niques that use near infrared light and rely
on the absorption spectrum of hemoglo-
bin depending on its oxygenation status
(Eggebrecht, White, Chen, Zhan, Snyder,
Dehlgani, & Culver, 2012).
•
Single Photon Emission Computed
Tomography (SPECT):
Uses gamma ray
radioisotopes and a gamma camera to con-
struct two- or three-dimensional images
of active brain regions. The brain rapidly
takes up injected radioactive tracer, re-
flecting cerebral blood flow at the time of
injection. SPECT is used for epilepsy im-
aging and to differentiate diseases causing
dementia.
