Purves et al., Chapter 29 (and part of Chapter 21) (and Chap 25 figure,
Chap 17 figure)
General - historical
Darwin - Expression of emotion in man and animals - 1872
James-Lange theory: physiological changes -> emotional experience "we
are afraid because we tremble" counterintuitive
Cannon-Bard theory: emotional experience is primary (Cannon coined "fight
or flight") (and, of course, it is the sympathetic nervous system that
prepares the body for both)
Fig. 29.1, p. 650
Bard did experiment implying that cortex inhibits hypothalamic (sham - directed
at everything) rage unless the caudal hypothalamus is also disrupted.
Hypothalamus -> reticular formation for rage
Walter Hess (1949 Nobel
prize) - rage or fear if hypothalamus stimulated.
(shared with Moniz who developed frontal lobotomy)
not in book: Electrical self-stimulation (Olds and Milner) - of hypothalamus
is positive reinforcement in operant conditioning paradigm in a Skinner
Fig Box 21A, p. 456
surprisingly not in book: Lesions to ventromedial nucleus makes a fat rat,
so older literature called this a satiety center, lesions to lateral hypothalamus
makes a thin rat, so LH was once called a hunger center. There are problems
with calling a small lesioned area a such-and-such-center based on the defect.
Also, LH is where medial forebrain (reward) system goes (dopamine, covered
Facial expression of emotion
Fig Chap 29 Box A, p. 648
Duchenne demonstration, electrical stimulation of face ("faradization")
mimics emotional expressions
Photos to demonstrate
Duchenne (1862) cannot will certain spontaneous smiles
Inability is over-riden (symmetrical) in involuntary movement ["Duchenne
smile"] as hypothalamus and amygdala feed to reticular formation and
hence to motor neurons.
Interesting story - voluntary facial paresis inability to volontarily move
lower facial muscles on one side due to lesion [pyramidal smile]
Fig. (no longer in text) like Box29A p. 649
Fig Box29A p. 649
Fig, box A, Chapter 17, p. 379
(related to moter coverage)
Started with Broca (1879)- limbic = "border"
Fig. 29.3, p. 652
Fig. 29.4, p. 653
Papez (1937) circuit
Note that in sheep brain tract dissection, the fornix and mammillo-thalamic
tract were shown in slide
rabies affects hippocampus - exxagerated fear etc.
tumors in cingulate cortex - fear & other emotions
Figs A & B, etc., Box 29B, p. 654
Amygdala connects to hypothalamus so it is related to the Papez (limbic)
lesions - fearlessness, difficulty recognizing emotions
stimulation - fear and violence
Box C (no figure) p. 656
Kluver-Bucy syndrome with amygdala lesion.
A terribly hostile monkey becomes docile with temporal lobe lesion (loss
of fear) - hypersexuality, mouthing objects, etc.
Box D, pp. 657-658
Patient SM has degeneration of amygdala - cannot recognize or draw fear
Urbach-Wiethe disease (autosomal recessive)
Fig (no longer in text)
Lesions can be big- Phineas Gage - spike through brain then acted oddly
(is it any wonder?)
Aprosody - inability to express emotion (like with monotone) with suprasylvian
parietal cortex (on right side)
Box E, pp. 659-660 - Affective disorders
Lincoln "I am now the most miserable man living...I must die or be
better, it appears to me,"
Depression (counting several categories) will affect 10 % of people.
Relieved by lots of drugs, fluoxetine (brand name Prozac) [serotonin uptake
inhibitor] widely prescribed likened to "soma" in Aldous Huxley's
"Brave New World" Late 1980's, now one of the most prescribed
drugs. Also sertraline (Zoloft) and paroxetine (Paxil)
Depression more common in females
Other coverage of depression in transmitters
and in "alumnus e-interview."
Exam questions from 2005 - 2012 relating to this outline
Say something about where the brain was severed in the classic Bard experiments
addressed to the presence or absence of "sham" rage.
if a hypothalamus that is deprived of cortical connection is still able
to feed down to the reticular formation, there is sham rage
56. "The 'pyramidal smile' (voluntary facial paresis) results from
an inability to voluntarily move the lower facial muscles on one side due
to a unilateral lesion. Answer either how you could over-ride this distorted
smile or what the symmetrical smile is called.
in the involuntary response, say, to humor, one gets the Duchenne smile
How do you prepare an animal to demonstrate that electrical self stimulation
can serve as a positive reinforcement?
anesthetize, install electrodes with head mount, allow recovery, plug in
Duchenne noted that people with certain kinds of brain damage could not
"will" a symmetrical smile. How could you elicit a symmetrical
smile from such people (without resorting to "faradizations")?
elicit a spontaneous smile (emotional, tell a joke)
"The limbic system has been implicated in olfaction, emotion and memory
- whew!" Which part was involved in classic studies of long term potentiation
directed toward understanding memory?
A graduate of a neuroscience course is required to be able to say who Phineas
a guy who had a spike blown through his brain and acted strangely after
Patient SM has Urbach-Wiethe syndrome that caused bilateral destruction
of the amygdala. In terms of recognition and drawing of facial expressions,
what was her specific and unusual deficit?
could not draw or recognize fear
What is the main motor nerve to control facial expression?
Why would paralysis be a more likely consequence of stroke in the lower
portion of the face than in the upper portion?
upper is bilaterally innervated, lower is not
Lesions to the lateral hypothalamus resulted in a thin rat, and so the lateral
hypothalamus was referred to as a hunger center. An alternative interpretion
involved the disruption of
what system involved in affect and motivation?
interrupt dopaminergic motivational tract
What part of the cerebral cortex is in the limbic system?
Dopamine comes to the caudate from what brain structure?
With brain cuts in and around the hypothalamus and with stimulations of
the hypothalamus, Bard and (the Nobel prize-winning) Hess (respectively)
studied what process?
Under what circumstances would a rat give itself electrical stimulation
of the brain?
electrode in hypothalamus, stimulation is reinforcement (reward), will press
bar in Skinner box
In voluntary facial paresis, a person with unilateral damage to fibers from
the motor cortes, the smile will be crooked. Under what circumstances will
the same person give a symmetrical smile?
a spontaneous smile resulting from humor
What happens to a monkey with a lesion in the amygdala?
get less aggressive, hypersexual
Why is it an oversimplification to call the lateral hypothalamus a hunger
center on the basis of lesion experiments?
there are logical problems, also the medial forebrain bundle traverses the
LH, and it has many controls on motivation
In the many functions attributed to the limbic system, what function did
Kluver & Bucy attribute to the amygdala?
mood on a scale from cuddly to ferocious
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