Emotions

James-Lange Theory

A theory proposing that emotion is the result of the perception of physiological responses to stimuli. Feeling component of emotion (3) comes from perceived pattern of bodily sensation (2) after experience of stimulus (1) 

Schachter-Singer Theory

A theory that emotions arise from cognitive appraisal of physiological responses in the context of external stimuli: Emotion that you feel is based on the context of the stimulus.

Cognitive appraisal of stimulus in context (3) determines category of emotions perceived by organism (1); not the physiological response (2) 

Mirror Neurons

Neurons that fire when we perform an action or when we observe someone else perform that action, linked to empathy.

Serotonin Depletion Hypothesis

People who have depression have lower levels of serotonin available for use  

• More about sensitivity to serotonin 

Seasonal Affective Disorder (SAD)

A type of depression that occurs at particular times of the year, often due to reduced sunlight exposure.

What are MAOIs? Side effects and useful for?

Medications that inhibit the enzyme monoamine oxidase, increasing levels of neurotransmitters in the brain.

Block enzyme that metabolizes monoamine neurotransmitters = those neurotransmitters are not getting broken down as much  

Potential fatal interactions 

• Adrenalin-like drugs 

• Foods that contain tyramine = monitor intake very closely otherwise it can get dangerous  

• Effective in those who are treatment resistant 

Serotonin Syndrome

Medication that build up high levels of serotonin in the body 

Symptoms: 

• Altered cognition 

• Agitation 

• Fever, chills, nausea, etc 

• Ataxia 

• Usually resolves in 24-48 hours after discontinuation 

Hypothalamus in Papez circuit

Receives interoceptive input from throughout the body, via the relays of the thalamus, which is then used to direct a number behavioral and physiological responses 

Amygdala in Papez circuit

Involved in emotional learning and fear.

Orbitofrontal Cortex in Papez circuit

• Assigning conceptual meaning to sensory info about the stimulus: Hypothalamus amygdala, hippocampus. 

• Sending info about stimulus and using memories we have about similar stimulus or situation and is also if/then. If I make this decision, what will happen? Decision and consequences 

• Tested people with what emotion everyone was feeling  

• Different cultures and places and the facial expressions were similar  

How is the idea of universal emotions supported? 

Role of PFC in depression

Atrophy = lower volume , Altered metabolic rates = how efficiently the PFC is using oxygen, sugar or any drugs that have been used, typically increased 

Hippocampus in depression

Atrophy

Role of Amygdala in depression

Increase in volume

Plasticity in depression

BDNF 

• Neurotropic  

• Less about neurotransmitters and more about plasticity