Flashcards in G02--> Emotions Deck (29):
Two basic theories of emotion linked brain and body. What was the first theory of emotion?
James-Lange Theory -->suggests that our emotional experience is induced by our emotional expressions.
Example --> we feel happy (emotional experience) because we smile (emotional expression)
what is the second theory of emotion?
Cannon-Bard Theory ---> Emotional Experiences (What we remember) triggers the emotional response of our body
example ---> our happiness (emotion experience) makes us smile
What was the first historical milestone toward the concept of the limbic system?
Broca described a ring of cortical area bordering the brainstem- the great limbic lobe, Broca, however did link this system to olfaction.
What structures does Broca's Limbic Lobe consist of?
Cingulate gyrus, subcallosal gyrus, isthmus, parahippocampal gyrus and uncus.
What did James Papez first notice about patients?
marked emotional outbursts from patients with damage to their hippocampus and/or cingulate gyrus.
What did papez develop based on his neurological findings?
Hippcampp-thalamo-cingulate-hippocampal circuit now known as the Papez Circuit
Describe the basic circulation of this model
1.Hippocampal formation is linked to mammillary body via the fibers from the fornix
2. Mammillo-thalamic tractfibers link the mamillary body with the anterior thalamic nuclei of the thalamus
3. The thalamus in turn is connected to the cingulate gyrus ,which links back to the hippocampal formation thus closing the loop.
What is the cingulate gyrus linked to in terms of emotion?
What is the hypothalamus linked to in terms of emotion/
Emotional Expression (ANS, somatic)
Paul MacLean added to the concept of the limbic system by adding what?
Incorporated the cortex and amygdala and together with the papez circuit named it the limbic system
What is the widely accepted theory bout the limbic system
the cortex shares input to the hypothalamus and therefore directly influences somatic (behavioral), autonomic and endocrine responses
What neurological case in history was responsible for the identification of the role of the Cerebral Cortex in Emotions
Case of Phineas Gage
Describe the case of phineas gage
iron rod impailed through his head which destroyed his frontal lobe
He went from being respectable and responsible foreman to not reliable and crazy
What is a frontal lobotomy?
surgical destruction of the frontal lobe to treat schizophrenic patients who displayed uncontrolled behavior
(was also performed on depression, panic disorder, mania, catatonia and manic depression)
What was the result in patients with frontal lobotomy?
their change is personality was generally unacceptable and thus this was no longer practiced.
long term effects: Emotional Flatness, Inappropriate behaviors, and difficulties concentrating
What is Kluver-Bucy Syndrome?
Removal/damage to temporal lobe including the anterior amygdala results in
hyperorality, visual/tactile and auditory agnosia, placidity, hyperphasia, intense desire to explore (hypermetamorphosis) and hypersexuality
On what animal were these experiments and surgical removal done?
patients developed similar symptoms as the monkeys that had their amygdala removed.
Describe what the fear conditioning experiments were?
in an experiment where rats were trained to fear a stimulus by associating it with electric shock lost their fear response following a bilateral removal of the amygdala
How did fMRI confirm amygdala in the emotional system of fear?
Humans were conditioned to fear a picture by associating it with a shock.
They were shown the picture while taking an fMRI which showed significant increase in the activity of the Amygdala
In another experiment, took fMRIs while subjects looked at pictures of ppl with different expressions, what were the results?
the highest level of amygdala activity was when looking at fearful faces
the lowest levels of amygdala activity was when looking at happy faces
Describe the neural circuit for learned fear
an emotionally competent stimulus produces the input signal to the basolateral nucleus of the amygdala
the amygdala will then send output to illicit behavioral, autonomic and endocrine responses
what is the "shortcut" in the circuit for learned fear?
Amygdala can directly receive nerve signals (via thalamus unless its auditory which is direct)
this cortical bypass saves time which allows faster signaling of defense behaviors, autonomic responses (HR/BP), endocrine responses (Stress hormone responses) and emotional responses (Fear)
What are some anxiety disorders discussed?
panic disorders, OCD, PTSD, phobia and generalized anxiety disorder
what are anxiety disorders attributable too?
Attributable to an imbalance of amygdala and hippocampus input to the hypothalamic stress response circuitry. Both hyperactivity of the amygdala pathway, or hypo-activity of the hippocampus, are causes.
What is another mechanism of attribution to panic disorders?
decrease benzodiazepine receptors in the frontal lobe
The findings about anxiety disorders not only manifest the key role of the amygdala in our emotional system, but also suggest what?
involvement of other brain structures such as hippocampus, hypothalamus and also the frontal lobe.
What behaviors are seen in patients with temporal lobe tumors?
temporal lobe tumors compromising the amygdala or its connections may lead to extreme aggression and hostility
tumors of the hypothalamus often display what kind of behavior in patients?
spontaneous fits of anger or deep sadness