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Neuropsychology of Emotion

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Emotions are our 'recognizing' a change in our autonomic arousal level ... Anhedonia (inability to experience pleasure) Social withdrawal. What Causes Schizophrenia? ... – PowerPoint PPT presentation

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Title: Neuropsychology of Emotion


1
Neuropsychology of Emotion
2
What is emotion?
3
Three components of emotion
  • Behavioral
  • Physiological
  • Experiential
  • Subject quality
  • cognition

4
Behavioral
  • Facial expressions
  • Body language
  • Language
  • Anything that can be directly observed

5
Physiological
  • Change in autonomic nervous system
  • Heart rate (cardiovascular)
  • Respiration
  • Sweat
  • Pupil diameter
  • Why do we have these?

6
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

7
Theories of emotion
  • Physiological theories
  • Cognitive theories

8
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

9
Cognitive theories
  • Schacter and Singer Two Factor Theory
  • Physiological change
  • Cognitive interpretation

10
CNS and Emotion
11
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

12
Physiological Component?
13
Hypothalamus
  • Regulates hormonal system
  • Control cardiovascular system
  • Respiration
  • Sweating
  • Also appetitive behaviors
  • Eating and drinking

14
Experiential Component?
15
Neocortex
  • Limbic system

16
Temporal Lobe
  • Kluver-Bucy syndrome
  • Tame
  • Inappropriate sexual behavior
  • Mouthing
  • Loss of status in social hierarchy
  • Loose affection too (dogs)
  • Whats important?
  • amygdala

17
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19
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

20
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)

21
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

22
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

23
Threatening Words
24
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

25
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

26
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27
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

28
Psychiatric Disorders
  • Most have an emotional component

29
Major Psychiatric Disorders
  • Schizophrenia
  • Depression
  • Anxiety Disorders

30
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

31
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!

32
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)

33
Positive and Negative Symptoms
  • Positive
  • Hallucinations
  • Delusions
  • Thought disorder
  • Negative
  • Flat affect
  • Lack of speech
  • Anhedonia (inability to experience pleasure)
  • Social withdrawal

34
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

35
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

36
But,
  • dopamine works in many brain areas (e.g., motor
    system)
  • Schizophrenics do not have motor problems
  • Why?

37
Dopamine Pathways
38
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

39
Modern anti-schizophrenic mediations
  • Clozapine atypical
  • Doesnt work at D2 receptors
  • These are the ones in movement system
  • Works at D4 and maybe D3

40
D3 binding
41
What causes negative symptoms?
  • Neurological damage

42
Ventricles
43
How do you get Schizophrenia?
  • Genetic hypothesis
  • Environment hypothesis
  • Combined effects

44
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?

45
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46
Heritability
47
Not 100 even in identical twins
  • Multi-gene
  • Genes only partly to blame
  • Environmental stimulus

48
Environmental
  • Viral
  • More prevalent in babies conceived in winter
    months
  • Birth complications
  • Especially in schizophrenics without family
    history

49
Depression
  • reactive
  • endogenous or unipolar
  • bipolar - manic/depression

50
Reactive
  • Normal depression
  • Response to life events
  • Usually passes

51
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

52
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

53
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

54
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

55
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
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