lecture 23: emotion Flashcards
affect
Feeling or emotion, especially as manifested by facial expression or body language
- At least 6 categories: of emotion
sad
happy
disgust
surprise
anger
fear
Phylogeny and Ontogeny of Emotion
Probably all vertebrates get mad (think fish fights, nasty birds)
anterior cingulate cortex
social and physical pain
amygdala
fear
Two main components of the Expression and Perception of
Emotion
each has its own neuronal
pathways
Conscious perception
Physical expression
part of brain for disgust
insular cortex
Conscious perception
(afraid, embarrassed, happy, etc).
This is the conscious sensation or feeling associated with
an emotional state
Cerebral cortex
cingulate and frontal lobes and amygdala all part of arousal and appraisal
Physical expression
(tears, blushing, crying face,
tachycardia (fast heart beat), goose bumps, etc). This is
the physical manifestation of the emotional state
– Peripheral autonomic, endocrine, and motor systems by way of
subcortical structures: amygdala, hypothalamus, and brainstem.
And maybe cingulate for more complicated expressions like
laughing
- Hess (1949 Nobel) Physical Expression of Emotion
could instantly elicit rage and attack behavior by stimulation of the hypothalamus in awake normal cats (bottom). At other sites (in amygdala maybe?), he could get fear behavior at the sight of a rat (top)
Human Facial Expression
Emotional expression in humans is more about face than body language- Darwin
made the point that these expressions are
found throughout all of humankind- suggesting intrinsic not cultural mechanisms
duchenne vs posed smiles
We have a large number of face muscles that although most can be moved in a voluntary way, they are also involuntarily
activated by emotions
* A “pyramidal” smile (M1 motor cortex to lateral tracts– a.k.a. pyramidal tracts) that is
volitional looks different from a
spontaneous emotional smile (accessory motor areas in prefrontal cortex and ventral
basal ganglia- extrapyramidal pathway through the reticular formation in the brain
stem)
de Boulogne studied
the role of facial
muscle activation to
express emotions.
Facial stimulation of
muscles of smiling
looks different from
a happy smile
Lateralization
Emotional expression in
right hemisphere (thus starts in left face then spreads)
limbic system
This is phylogenetically
primitive cortex around the
brainstem
Kluver-Bucy syndrome in
humans (or bilateral removal of
the medial temporal lobes in
monkeys)
causes profound
tameness and fearlessness
John Downer Amygdala
removed one
amygdala in monkeys and
transected the optic chiasm and the
commissures (corpus callosum) that
link the two hemispheres: in so
doing he had an animal with a single
amygdala that had access to visual
information only from the eye on
the same side of the head
* Found that animals behavior
depended on which eye was used to
view the world.
* When the monkey used the eye on
the side with an amygdala it was
afraid of humans and aggressive.
When it used the eye on the side
without the amygdala he was tame.
S.M. an artist with Urbach-Wiethe disease
which caused
bilateral destruction of the
amygdalas: could not recognize
frightened faces, was herself rather fearless. She was not afraid of spiders, snakes, haunted houses, Central Park late at night, alone (!), etc
The James-Lange Theory
We experience
emotion in response to physiological changes in our body. We feel sad because we cry not the other way round. The physical changes
are the emotion
The James-Lange theory states that stimulating events trigger a physical reaction. The physical reaction is then labeled with a corresponding emotion. For example, if you run into a snake, your heart rate increases. James-Lange theory suggests that the increase in heart rate is what makes us realize we’re afraid.
Cannon-Bard Theory
Cannon and Bard introduced some important criticisms of the James-Lange theory. Firstly, physical sensations and emotions aren’t always connected. We can experience physical sensations without feeling a particular emotion, and vice versa.
Another criticism of the James-Lange theory is that physical reactions don’t have a single corresponding emotion. For instance, heart palpitations could suggest fear, excitement, or even anger. The emotions are different, but the physical response is the same.
conditioned stimulus
a stimulus when paired with an unconditioned stimulus that can eventually trigger a conditioned response
unconditioned stimulus
a stimulus that leads to an automatic response (dog drools when it sees food)
Depression
Most common of the major psychiatric disorders
* Lifetime incidence of 10-25% in women and 5- 12% in men
* 3-fold higher prevalence in 18-29 year olds than those over 60
* reduced concentration and attention
* reduced self-esteem and self-confidence
* ideas of guilt and unworthiness
* bleak and pessimistic views of the future
* ideas or acts of self-harm or suicide
* disturbed sleep
* diminished appetite
Increased blood flow in some brain regions associated with depression
left amygdala, orbital and medial prefrontal cortex
Deep Brain Stimulation for
intractable depression
The first specificnetwork
treatment for a
psychiatric disease
* If it is effective
could become like
Parkinson’s DBS
treatment (30,000
cases in the US)
Reward systems (such as nucleus accumbens, area 34)
seem dis-regulated in some cases of obsessive
compulsive disorder. Deep Brain Stimulation is effective
Emotion
- a subjective, personal state that is relatively intense and occurs in response to
something we experience. Emotion consists of two components: The expression, or physical
response which often involves the autonomic motor and endocrine systems and the
perception, that is the conscious registration of the emotion which involves the cerebral cortex
and amygdala. Emotions are largely spontaneous
Mood (Affect)
a prolonged, less intense, affective state that does not occur in response to
something we experience. Mood states may not be consciously recognized and do not carry
the intentionality that is associated with emotion
Autonomic nervous system
components of the nervous system concerned with the
regulations smooth muscle, cardiac muscle and glands (endocrine). Consists of the
sympathetic nervous system which prepares the body for a “fight or flight” response and the
parasympathetic nervous system which prepares the body for a “rest and digest” response
Limbic system
a complex group of structures that lies around the thalamus and the medial portion of the cortex (limbic lobe). Parts of the limbic system (prefrontal cortex, amygdala, thalamus, hypothalamus and basal ganglia) are especially important in the experience and expression of emotion (green in the diagram), but the limbic system as a group contains other brain regions as well (blue)
Amygdala
- a group of cells in the
anterior/medial portion of the
temporal lobe, comprised of several
distinct subnuclei. The amygdala
links cortical regions and thalamic
nuclei that process sensory
information with hypothalamic and
brainstem effector systems and thus plays an important role in the
expression of emotional behavior by
influencing activity of the motor
system
Hypothalamus
a collection of
nuclei located in the medial area
below the thalamus. It has diverse
function including the coordination
and expression of motor activities &
neuroendocrine activities that
promote homeostasis. The
hypothalamus plays a role in the
activation of the sympathetic
nervous system that is a part of any given emotional reaction
Classical conditioning
training paradigm that associates an involuntary response (e.g.
salivating) with a stimulus (e.g. bell ringing). Typically an involuntary, emotional, or reflexive
response
Operant conditioning
- training paradigm that associates a voluntary behavior (e.g. pressing a
lever) with a consequence (e.g. receiving a treat). Typically a voluntary response
Fear conditioning
a simple form of classical conditioning in which an animal learns to
associate a neutral stimulus such as a light or a tone with the presence of an innately aversive
stimulus such as a mild foot shock. After several pairings the animal will demonstrate fear
(freezing behavior in rodents) in
response to the neutral
stimulus alone. The amygdala
is a central structure in fear
conditioning
Unconditioned stimulus
a stimulus that naturally triggers
a response. (e.g. feeling
hungry when you smell food)
Conditioned stimulus
- a previously neutral stimulus
that initially caused no
behavioral response. However,
after becoming associated
with the unconditioned
stimulus eventually will trigger
the response produced by the
unconditioned stimulus itself.
Fear extinction
- a decline in
the conditioned fear response
caused by repeatedly
presenting the conditioned
stimulus without the feareliciting unconditioned
stimulus
- Give an example demonstrating the James-Lange theory, that expression of emotion
precedes and changes our perception of it.
- List the two main components of emotion and provide an example of each.
