Lecture 10 – Emotion,Aggression, & Stress
➢ Difficult to study (just like sleep)
➢ We behave differently, and different people show different emotions in response to the same situation
➢ Our expressed emotions may not reflect what we feel inside
➢ Different degrees of happiness, sadness, etc.
➢ Facial expressions and body language help us communicate
➢ We're good at facial expressions but maybe not that good at body language.
➢ Body postures can be beneficial to animals and humans (provides social info for danger, etc)
➢ Controlling Facial Expression
2 nerves: facial nerve and trigeminal nerve
Upper 1/3 of face controlled differently: ipsilaterally & contralaterally ==> bilaterally?
Bottom 2/3: controlled contralaterally
Different pathways as well: Spontaneuous (subcortrical system) vs. Voluntary smiles (motor cortex) are
controlled by different pathways.
Some pple with damage cannot voluntarily smile, but can do spontaneuous smiles. So these smiles are
managed by different areas of the brain.
No training needed to identify emotions
Happiness, disgust, anger, embarassment, fear, contempt. All other emotions are expressions of these
Animal Facial expressions
Hard to interpret
Dogs: they all look the same
Primates: Barred teeth = submissive to a dominant animal, not smiling. Open mouth is a play face,
sort of happy
Environmental influences on Emotions
The presence of others intensifies our emotional expression
More intent facial expressions to odours when other people are around you
Can We Spot Liars?
Liars slip up in body language: less upper body movement, nervous smiles, laugh a little bit more
Polygraphs are unreliable
• 40% of innocent pple were found guilty
• 25% of guilty people were found innocent
Functional MRI can be used to look at brain activity: good be more useful
Theories of Emotion
James-Lange Theory (1920s)
• perceived stimulus
• physical sensation
• then, feel the emotion
• Physical & Subjective feeling at the same time
• Perceived Stimulus
• General Arrousal • Associate it it with the context (Assessment of Surroundings)
• Then feel an emotion (subjective feeling)
Biological Correlates of Emotion
Autonomic Nervous System
• flight or fight response
• ANS produces different patterns of arrousal during different emotional states.
• Whether you're happy or sad.
• Easy to see when we have a positive or negative emotion
• Hard to tell the diff btwn 2 negative emotions or 2 positives (autonomic measures)
Amygdala (in the temporal lobe)
• 3 sets of nuclei
• central nuclei
• corticomedial nuclei
• basolateral nuclei
• Associated with fear (Research with rhesus monkeys)
• Kluver-Bucy Syndrome
• removed both temporal lobes(including both amygdalas) from rhesus monkeys
• They are usually agressive (& intense fear of snakes) but afterwards, they were calm
• Oral exploration, hypersexual, no fear of snakes.
• Change in emotional responses
• There's a fear circuit in the brain involving the amygdala
• What about humans?
• Damage to amygdala also produces difficulty in processing fear
• Can't identify what fear is or what it looks like.
• Fear Conditioning in Rodents