Neuropsychology of Emotion

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Neuropsychology of Emotion
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What is emotion?
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Three components of emotion

• Behavioral
• Physiological
• Experiential
• Subject quality
• cognition

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Behavioral

• Facial expressions
• Body language
• Language
• Anything that can be directly observed

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Physiological

• Change in autonomic nervous system
• Heart rate (cardiovascular)
• Respiration
• Sweat
• Pupil diameter
• Why do we have these?

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Experiential

• Subjective quality
• Emotions happen to us
• We experience them
• Cognitive
• How do you interpret the behavioral,
  physiological and subjective experiences
• Our personal explanations to ourselves

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Theories of emotion

• Physiological theories
• Cognitive theories

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Physiological

• James-Lange
• Emotions are our recognizing a change in our
  autonomic arousal level
• We see a car wreck, it causes our heart rate to
  climb, then we feel afraid
• Cannon-Baird
• Physiological response follows the feeling
• Heart pounds after we feel afraid

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Cognitive theories

• Schacter and Singer Two Factor Theory
• Physiological change
• Cognitive interpretation

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CNS and Emotion
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Behavioral

• Patients with lesions in the brain stem (medulla)
  have been reported to have uncontrolled crying
  (behavioral emotions)
• Not associated with feeling sad
• Dissociation between brain areas that control
  behavior and the other components of emotion

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Physiological Component?
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Hypothalamus

• Regulates hormonal system
• Control cardiovascular system
• Respiration
• Sweating
• Also appetitive behaviors
• Eating and drinking

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Experiential Component?
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Neocortex

• Limbic system

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Temporal Lobe

• Kluver-Bucy syndrome
• Tame
• Inappropriate sexual behavior
• Mouthing
• Loss of status in social hierarchy
• Loose affection too (dogs)
• Whats important?
• amygdala

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What does it do?

• Amygdala is made of several sub-nuclei
• Central nucleus (CN)
• Lateral nucleus (LN)
• Removal of either results in tameness
• Stimulation results in fear response
• startle
• avoidance

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LeDoux fear learning

• Classical conditioning of fear response
• Pair shock (UCS) with a tone (CS) and elicit
  freezing behavior (UCR)
• Eventually CS alone elicits freezing (CR)
• PTSD and anxiety disorders may involve a similar
  conditioning
• Recorded electrical activity and lesioned the
  amygdala (and other areas)

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Results

• LN of amygdala appears to be critical in learning
  the CR
• Damage to LN or disruption of LN activity
  prevents acquisition of CR in presence of UCR
• What does the LN do?
• Connects the auditory stimulus to fear circuits
  forming in cortex uses LTP

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Amygdala Studies in Humans

• Lesions usually result in calmness
• Failure to acquire fear conditioning
• Stimulation can result in aggressiveness
• Terminal Man
• PET studies
• Recall of highly emotional scenes from a movie gt
  right amygdala (RA) activity
• Frustrating problems gt RA
• Threatening words gt bilateral activation

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Threatening Words
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Role of the cortex laterality

• RH appears to play a more important role
• LH damage results in more depression
• RH damage more euphoria
• RH damage
• Problems judging facial expressions
• Problems determining and expressing emotion in
  voice
• a-prosodia
• Problems with comprehending humor
• Problems judging emotional situations

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Role of the frontal lobes

• Phineas Gage
• Personality changes, less inhibited
• Prefrontal Lobotomy
• Jacobsons chimp had fewer tantrums after frontal
  lobe removal
• Moinz (neuropsychiatrist) convinced neurosurgeons
  to try on humans
• Calmed patients and reduced compulsions

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What does this area do?

• Evidence suggests it has to do with translating
  personal consequences of behavior
• Patients can verbalize consequences, but dont
  tend to act
• e.g., if I dont go to work, I wont get paid

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Psychiatric Disorders

• Most have an emotional component

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Major Psychiatric Disorders

• Schizophrenia
• Depression
• Anxiety Disorders

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Traditional View

• Psychological disorders are due to environmental
  effects
• Faulty upbringing (Freudian)
• Increasing evidence that at least some disorders
  have a physiological cause
• At one level this is a false dichotomy
• As everything, including psychological problems,
  are based in the physiological brain

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Schizophrenia

• A serious mental disorder characterized by
  disordered thoughts, delusions, hallucinations
  and other bizarre behaviors
• 1 of population
• In the USA there are enough schizophrenics to
  populate the greater Boston area!

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Six criteria must be met

• critical symptoms delusions, hallucinations
  incoherence and blunted flat effect
• evidence of deterioration
• last at least 6 months
• (drugs may cause shorter similar symptoms)
• affective disorder if present must be secondary
• onset before age 45
• symptoms not due to known organic brain disorder
  (toxic effects or dementia)

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Positive and Negative Symptoms

• Positive
• Hallucinations
• Delusions
• Thought disorder
• Negative
• Flat affect
• Lack of speech
• Anhedonia (inability to experience pleasure)
• Social withdrawal

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What Causes Schizophrenia?

• Dopamine hypothesis
• Overactive dopamine system
• Neuroleptics (Haldol) are effective treatment for
  many
• Work by blocking dopamine receptors
• Dopamine Agonists (e.g., amphetamine)
• Aggravate schizophrenia
• In high doses can mimic schizophrenia
• Amphetamine psychosis

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Evidence

• Neuroleptics (Haldol) are effective treatment for
  positive symptoms for many
• Work by blocking dopamine receptors
• Dopamine Agonists (e.g., amphetamine)
• Aggravate schizophrenia
• In high doses can mimic schizophrenia
• Amphetamine psychosis

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But,

• dopamine works in many brain areas (e.g., motor
  system)
• Schizophrenics do not have motor problems
• Why?

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Dopamine Pathways
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Neuroleptics

• Work in both systems
• Result in side effects
• Tardive Dyskenisia -- movement disorder
  associated with too many DA receptors!
• Why?
• Treatment is usually to give more neuroleptics

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Modern anti-schizophrenic mediations

• Clozapine atypical
• Doesnt work at D2 receptors
• These are the ones in movement system
• Works at D4 and maybe D3

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D3 binding
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What causes negative symptoms?

• Neurological damage

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Ventricles
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How do you get Schizophrenia?

• Genetic hypothesis
• Environment hypothesis
• Combined effects

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Twin studies

• Twins reared apart
• Same incidence as twins reared together
• Greater incidence in identical than fraternal
• But, greater in monochorionic twins than
  dichorionic twins
• Why? What does this mean?

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Heritability
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Not 100 even in identical twins

• Multi-gene
• Genes only partly to blame
• Environmental stimulus

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Environmental

• Viral
• More prevalent in babies conceived in winter
  months
• Birth complications
• Especially in schizophrenics without family
  history

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Depression

• reactive
• endogenous or unipolar
• bipolar - manic/depression

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Reactive

• Normal depression
• Response to life events
• Usually passes

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Endogenous or Unipolar

• low, blue, despondent
• prolonged period of time
• no significant life event
• average age is 45 for first episode
• 13 months in length
• usually cycle
• two to three times more likely in women

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Bipolar - manic/depression

• Alternating periods of despondency and elation
• Effects men and women in equal numbers
• Elation may be characterized by delusions and
  grandiosity
• average age onset is 30
• depression lasts 6 months
• mania 2 months on average
• cycle rate varies average is 8 months without
  medication

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Cause?

• Genetic factor
• 10 times more like to have it if you have a close
  relative that does
• Concordance rate is 69 in identical twins and 13
  in fraternal
• Same if reared together as if reared apart
• Some evidence that bipolar may be due to a single
  dominant gene

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Treatment

• tricyclic antidepresents effective in 70 of
  unipolar
• prozac maybe even more (5-HT agonist)
• lithium carbonate effective against mania in
  bipolar
• ECT Meduna noticed that his epileptic depressed
  patients were better after seizures

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biogenic amine hypothesis

• norepinephrine or serotonin are
• under active in depression
• overactive in mania
• Drugs that block these transmitters cause
  depression
• Reserpine (blocks monoamine storage) elevates
  some schizophrenic symptoms and lowers blood
  pressure
• But causes depression