Lecture 16 Flashcards
Emotions 2 ways
You can cognitively think about an emotion and make your face express it
This is processed in the neocortex
You can feel a raw, reflexive response to a stimuli
This is processed in the limbic system, notably the amygdala
Volitional facial paresis
When you cannot fake an emotion but you can naturally do it
Primary motor cortex issue or subcortical connections
Emotional facial paresis
Cant make a response induce to a real emotion
Can to fake one
Damage to the insular cortex or parts of the thalamus
Raw feeling of emotion coincides with other types of responses
Behavioral - muscular movements (facial expressions, body language, choreographed movements)
Autonomic responses - fight or flight, quick mobilization of energy for movement
Hormonal responses - reinforce autonomic response
Emotions in this case is a feeling and THREE CONCRETE THINGS
Moneys tested for fear
Glass box with food on it
If the box has a ball in it, eat the food fast
If it has a spider or a snake, hesitate for ages, then eat the food
Theory of emotion (common sense)
Perception of the emotion eliciting event (see a bear)
Subjective feelings of emotion
Behavioral response (eg trembling, running away)
common sense view is that subjective feelings CAUSE physiological response
If you lesion to stop the behaviour, have you stopped the emotion or just the behavior? We cannot ask them
James-Lange Theory
Perception of emotion-eliciting event
Appropriate set of behavioral and physiological responses
Brain gets this feedback and interprets is and creates subjective feeling of emotions
James-Lange Theory (evidence)
Spinal injuries’.
The higher up the lesion, the less sensation you get back in and the greater the paralysis
This correlates with the reported loss of emotions
Some people look and acted angry while not experiencing it
Cos they and no feedback from the body for the brain to interpret
James-Lange Theory (evidence) - interfering with muscular movement & Rebuttal
interfering with muscular movement associated with an emotion lessons the ability to experience that emotion. Botox does this
Beta blockers blocks the behavior such as sweaty armpits caused by fight or flight. This modulates emotions as you do not have to deal with these but people on B blockers still subjectively feel the emotions, just does not look like it
BUT internal organs are relatively insensitive and do not respond quick enough to account for our feelings
Cutting the nerves between internal organs and the CNS does not abolish emotional behavior in animals
Injecting hormones or activating the ANS does not reliably or consistently elicit emotions
Limbic System
Amygdala crucial for recognizing emotion, especially fear
Central Nucleus of the Amygdala
Regulates emotional responses, especially fear
Lesions here reduce or eliminate fear responses. Monkeys like this do not back down and usually die when dominant monkeys kill them.
Stimulation causes fear, anxiety and agitation
Viewing threatening stimuli activates the central amygdala which receives input from the thalamus, association cortex and superior colliculi
Cortically blind people still mimic facial expressions of fear and happy due to amygdala
Humans with bilateral amygdala loss have no fear except to drowning stimulated by CO2 increase
They cannot even understand or conceptualize fear
Identifying emotions in others
SP had a bilateral amygdalectomy to treat a seizure
Cant experience fear but can generate artificial expressions of emotion (and fear) no issues
Cant identify expressions of fear in others. Can recognize their faces but not the expression.
Cant even ID emotion of fear in photos of her mimicking fear!
Ability to detect anger and surprise were unimpaired
Turns out people with this do not look at the eyes but the center of the face
Can be trained to and then gets emotions. But does not do it spontaneously and has to be reminded every time.
Maybe areas of the brain all control eye movement and without amygdala the part that pushes for looking at the eye does not work
Recognition of emotions - beyond the amygdala
Lots activated when we view emotional spaces like the somatosensory cortex, insular cortex, premotor cortex, anterior cingulate cortex
All of these especially in the right hemisphere are involved
Come people with damage here cannot ID expressions in others
Especially the primary motor cortex of the face, planning for face expressions and insular cortex
Mirror Neurons
Activate similarly when an animal does a behavior or when it sees another animal doing it
Mimicry and empathy
When we see an expression , we imagine ourselves doing it and try to make the expression
Found all over the brain
Might encode what emotions feel like (proprioceptively, and kino ly) Knowing what it feels like to make the expression may help us recognize the expression we are viewing
Most human fears are probably acquired socially, not through firsthand experience with them. Mirror neurons may help promote learning
Tone of voice and meaning of words
Word comprehension is on the left hemisphere
But tone involves the right primarily
If the words are neutral and you can only get the emotion from the tone = right
Classical conditioning
Unconditioned stimulus - inherent value eg food or shocks. No learning needed
Unconditioned response like freezing
Conditioned stimuli - pair with IS and neutral stimuli becomes associated
Conditioned response - the behavioral response that is associated with the CS
Works best and lasts longest if tightly paired together during conditioning
Classical conditioning In brain
Both the US and the CS have synapses on the lateral nucleus of the amygdala. The US has a strong synapse, the CS does not. When paired, there is overlap and the CS synapses strengthen when activated at the same time. This is how the animal learns
These weak inputs are now strong and able to cause a fear response on their own
Extinction learning
NOT forgetting
If the CS keeps occurring without a US, they stop being afraid
Synaptic strength between the vmPCF strengthen with amygdala. Inhibits the CR
Drops % of the CR but does not go to zero
Spontaneous recovery - CR back for no reason
Renewal - change in context brings CR back
Reinstatement - Random delivery of US brings back CS
Savings - refers to the reduction in the amount of time needed to retrain the animal on the same task or a related task. It is much faster
Ventromedial prefrontal cortex (vmPFC)
PFC region at base of the frontal lobes adjacent to the midline. Plays a role in inhibition of expression of emotions
Impulsive violence is seen as part of a failure of regulation of emotion
Frustrations elicit the urge to respond emotionally but ppl usually calm themselves and suppress the urge
PFC has connections with the amgdala. Destroyed in Phineas Gage
Anger, aggression and impulse control:
Research in in humans
Serotonergic neurons play a big role in inhibiting aggression
Low serotonin )indicated by low metabolite 5-HIAA in the CSF) are associated with aggression
Drugs that increase this like Prozac, drop aggression
Jail ppl have low serotonin
Maybe serotonin directs the vmPFC?
Test correlates with competition, not aggression
Damage to vmPFC in humans causes impairments in behavioral control and decision making
Not cognitive deficit so likely about emotional dysregulation
Train morality experiment:
If someone witched a level in a runaway train, 1 person will die instead of 5. In the impersonal condition; they are told “someone should do that” and agree. In the personal condition less say “I would” when it is personal.
vmPCF dudes say “I would” no issues
When they think about their behaviour they do not even think of the emotional aspects
Anger, aggression and impulse control:
Research in in monkeys
5-HIAA measured in the CSF of male monkeys over 4 years
The monkeys with the lowest levels are risk takers
Mad jumps and attack older, dominant monkeys
Typically died earlier
Metabolite for serotonin
5-HIAA
