NEUR 201: Emotion

Affective Neuroscience

seeks to understand the neural mechanisms that underlie emotion

Emotion

complex instinctive feelings produced by synthesizing environmental cues and external stimuli that alert an organism that some action may be required of them

Factors underlying emotion

enviornmental, bodily/physiological states, brain systems

James-Lange

bottom-up, requires autonomic specificity

Cannon-Bard

top-down

Schachter-Singer

two-factor, cognitive label: from prior knowledge and observing environmental cues

What did Darwin suggest about emotional facial expressions?

useful in conveying survival cues

What were Ekman’s seven categories of emotion?

anger, contempt, disgust, fear, happiness, sadness, surprise

Facial Action Coding System (FACS)

uses facial anatomy to differentiate the features that are characteristic of different expressions

Ekman 60 Faces Test (EK-60F)

test to assess facial emotions

Major Depressive Disorder and BPD’s reaction to facial cues:

have a lessened response to detect happiness in others

Dementia and Parkinson’s identify emotions as…

less intense

Papez circuit

essential for allostasis. one of the first scientists to ascribe emotions to a brain structure

Allostasis

regulates changes within internal environment to meet both the perceived and anticipated demands from the external environment.

Thalamus

first stop of papez circuit. deals with exteroception and interoception

[THALAMUS] Exteroception

sensations that result from stimuli located outside the body and is detected by exteroceptors

[THALAMUS] Interoception

a sense or awareness of changes occurring in internal state of body

Amygdala

processing the valence of emotional experiences that results in emotional memory formation. fear conditioning paradigm

[AMYGDALA] Positive Valence

happiness at birthday party

[AMYGDALA] Negative Valence

being bullied

[AMYGDALA] Emotional Learning

smell of food → hunger (hypothalamus); seeing kids get in line in cafe → hunger (amygdala)

Hypothalamus

initiates endocrine responses (hormone production) in conjunction with the pituitary gland. coordinates allostasis

[HYPOTHALAMUS] Reflexive Emotion

appetitive responses (energy), agnostic behaviors (defense, attack), reproductive mating instincts

Insular Cortex

appraises incoming sensory info to assign them a subjective feeling. contributes to interoception. strongly implicated in disgust

Orbitofrontal Cortex

input from hypothalamus and amygdala and hippocampus help assign conceptual meaning to sensory signals. input from cingulate cortex and hippocampus help use memories and if/then imagine scenarios to determine an emotional response

Dorsolateral Prefrontal Cortex

emotional regulation

Anterior Cingulate Cortex

inputs from orbitofrontal cortex, amygdala, and hippocampus assess value of interceptive info so conceptual meaning can be assigned. outputs to motor areas and hypothalamus coordinate behavioral and physiological response

Kluver-Bucy Syndrome

lesions to temporal lobes (amygdala, hippocampus, tracts in papez circuit)

Effects of Kluver-Bucy Syndrome

1. placidity (no fear or anger)

2. loss of feeding-related emotions (lack of satiety)

3. visual and tactile agnosia (inability to recognize faces or objects visually or with hands)

4. amnesia

5. hypermetamorphosis (compulsive exploring)

6. hyperorality (inappropriate fixation with using mouth)

Urbach-Wiethe’s Disease

rare autosomal recessive mutation of extracellular matrix protein 1 (aka lipid proteinosis)

Urbach-Wiethe’s Disease Causes

1. progressive destruction of amygdala (calcification of amygdala)

2. lack of fear/perception of threat, can’t recognize faces

3. can’t recognize fear in faces

4. hyaline-like material deposited in the skin, mucous membranes and brain

Urbach-Wiethe’s Disease Symptoms

hoarse voice, thickening and scarring of skin, beading around eyelids (muniliform blepharosis), and changes to teeth and mouth

SM

famous patient for Urbach-Wiethe’s Disease, didn’t show any fear to any fear inducing stimuli

Major Depressive Disorder Treatments

anti-depressants, deep brain stimulation, target monoamine NTs (monoamine oxidase inhibitors, tricyclic anti-depressants, SSRIs)

Monoamine NTs

released widely, including in brain regions of the Papez-circuit.