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The Amygdala• part of the limbic system (with the
hippocampus and hypothalamus)• amygdala = “almond”• processes emotional significance of stimuli
and generates immediate reactions• damage to amygdala
– inability to recognize facial emotions– absence of fear– absence of conditioned fear response
• abnormal activation of amygdala – sudden violent rage
• in fMRI studies, the amygdala is activated by scary stimuli (even if you’re not aware of them)
1. Emotions communicate– consistent across cultures and even species
2. Emotions aid in decision-making– gut feelings often right– people with damage to the emotional system (orbitofrontal
cortex) are poor at using past outcomes to regulate future behavior in a gambling task
3. Emotions capture attention and aid memory4. Emotions strengthen interpersonal relations
– guilt, embarrassment , jealousy
Surprise SadnessDisgust
Eyes
• Female brain is hard wired for empathy
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Autism Quotient
• Spectrum disorder• Males are hardwired
for understanding and building systems
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Psych General
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Phineous Gage
• Railroad foreman
• Well-respected, hard-working
• 1848: tamping iron accident
• He never lost consciousness, and had no obvious neurological symptoms
• But he was “no longer Gage”
Phineas Gage“the powder exploded, carrying an iron instrument through his head an inch and a fourth in circumference, and three feet and eight inches in length, which he was using at the time. The iron entered on the side of his face, shattering the upper jaw, and passing back of the left eye, and out at the top of the head.
The most singular circumstances connected with this melancholy affair is, that he was alive at two o’clock this afternoon, and in full possession of his reason, and free from pain.”
– from Free Soil Union, September 1948
“The equilibrium or balance between his intellectual faculties and animal propensities, seems to have been
destroyed.”(Former R.R. Employer)
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Brain Anatomy - Phineas Gage
•Personality changed – Gage became crude, uncaring, impulsive, irrational, anti-social
• Damasio H., Grabowski T,. Frank R., Galaburda AM., Damasio AR. (1994). The return of Phineas Gage: clues about the brain from the skull of a famous patient. Science. 264(5162):1102-5,.
•Ventromedial region of the frontal lobes on both sides - causing a defect in rational decision making and the processing of emotion
Phineous Gage
Gage’s Doctor described Gage’s post accident personality as Fitful, irreverent, indulging at times in the greatest profanity which was not previously his custom, manifesting but little deference for his fellows, impatient of restraint and advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operation, which are no sooner arranged than they are abandoned … a child in his intellectual capacity and manifestations, he has the animal passions of a strong man.
“He was no longer Gage…”
• Several different angles of where the rod passed through his skull
Phineous gage
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Some symptoms associated with frontal lobe damage
•Working memory deficits•Temporal memory / Source memory•Perseveration•Loss of spontaneous behavior•Apathy•Planning deficits/impaired goal-directed behavior•Disinhibition/impulsive behavior•Impaired attention•Depression•Elevated mood
Mood/Affect/Emotion Symptoms
• Depression
• Mood elevation
• Apathy
Frontal Lobotomies• 1935: chimps who were neurotic before surgery became more relaxed after it
• 1930s: Egaz Moniz begins frontal lobotomies in humans (and eventually wins Nobel Prize)
• 1950s: psychosurgery in vogue; 40,000 frontal lobotomies in North America
• The story of Agnes (Kolb & Whishaw)– no outward signs of emotion– no facial expression– no feelings toward other people (but still liked her dog)– felt empty, zombie-like– Other patients lose prosody = emotional component of
speech
• orbitofrontal cortex – Patients with damage can remember info but don’t have
emotions associated with it
Frontal LobeLobotomy: Early Critisicms
Hoffman (1949)– "these patients are not only no longer distressed by
their mental conflicts but also seem to have little capacity for any emotional experiences - pleasurable or otherwise. They are described by the nurses and the doctors, over and over, as dull, apathetic, listless, without drive or initiative, flat, lethargic, placid and unconcerned, childlike, docile, needing pushing, passive, lacking in spontaneity, without aim or purpose, preoccupied and dependent."
Frontal LobeFrontal Lobe Damage• May have normal IQ on standard tests • Poor control: reasoning, planning & emotions
– Disinhibition: poor control of emotions
• Poor mental flexibility– Perseveration: e.g. trouble stopping action once
initiated, e.g. dialing 999.
• Frontal lobe modulates functions of other regions