Tools of Discovery and Older Brain Structures
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Early observation into brain function could only work with
head injuries that caused lesions.
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The three main tools for investigation are:
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Electro-Encephalogram or EEG
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Positron Emission Tomograph or PET
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Functional Magnetic Resonance Imagery or fMRI
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Of these three, the fMRI is king.
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See Fig. 5.3 (mp62, c2.14p63) an fMRI scan of a healthy
individual compared with that of a schizophrenic.
Older Brain Structures
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Fig. 5.4 (mp63,c2.15p64) The brainstem and thalamus
The brainstem, including the pons and medulla oblongata,
is an extension of the spinal cord.
The thalamus is attached to the top of the brainstem. The
thalamus receives information from all the senses except
smell. It also relays higher brain replies to the body.
Smell, being separate from the other senses, is a good
way to understand the evolution of the brain. It is a patch
job: new structures are patched into old ones by mutation.
For example, you cannot smell in your dreams.
The reticular formation passes through both brain
structures. It acts as a filter to incoming stimuli.
The reticular formation enables arousal.
Older Brain Structures
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Fig. 5.7 (mp65, c2.18p66) The limbic (or ring) system sits
between the evolutionary older parts and the cerebral
hemisphere. Here is located the hypothalamus, which
controls the pituitary gland.
The hippocampus is the seat of short-term memory
formation. It is the newest of the structures in the limbic
system.
The amygdala controls aggression and fear.
http://vimeo.com/29751394
Older Brain Structures
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Olds and Milner (1975) located the reward centers in the
hypothalamus.
The most important of these is the nucleus accumbens,
which is both a general dopamine-related reward system
and will specific areas devoted to eating, drinking and
sex.
What do you think will happen if the reward center
mutates, creating cross-connections between these
areas, or making these areas much closer together?
Deutsch (1972) and Hooper & Teresi (1986) discovered
that humans can be calmed by electrical stimulation of
specific areas of the hypothalamus, but not driven to a
frenzy.
Older Brain Structures
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Memorize Figure 5.11 mp67, c2.22p68):
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It is a review of brain structures and their functions.
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Especially: The Amygdala, the Hippocampus, and the
Hypothalamus.
Most psychotherapy--whether medication, counseling or
physiotherapy--is aimed at solving problems in these
limbic areas.