Emotion Lecture 8

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Emotion Lecture 8

• Emotional experience and behaviour

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Stimulation amygdala can produce emotional
experience - amygdala may be sufficient to
produce experience

• Temporal lobe epilepsy (in Heilman et al., 2000)
• Changes in emotional behaviour and in emotional
  experience
• ictal symptoms (directly related to the seizure
  discharge during the seizure)
• postictal (directly after the seizure)
• interictal (between seizures)

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• Fear most common ictal emotional experience
• not simply fear of attack, experience seems to
  come by itself
• intensity and duration can vary
• sometimes accompanied by visceral sensations that
  normally go with fear
• e.g. palpitations, pallor
• may be associated with a fearful hallucination or
  memory

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Case J.V. The patient was a girl of 14 when
first seen. At the age of 7 she had a fright when
a man came up behind her. She ran across a meadow
to her brothers. Her mother remembered the story.
.. At 11 years she began to have epileptic
seizures in which she showed fright, screamed and
clung to people. .. During the period of her
fright she saw the above scene a little girl
identified as herself in the same meadow where
the event occurred, and she was filled with
terror lest she be struck or smothered from
behind.
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Stimulation amygdala can produce emotional
experience

• Ictal fear typically associated with
  abnormalities in amygdala (Cendes et al., 1994)
• more amygdala atrophy in patients with ictal fear
• ictal fear could stop after removal portions of
  the amygdala
• Feelings of fear can also be evoked by direct
  electrical stimulation of the brain (in Cendes et
  al., 1994)
• in particular amygdala and hippocampus

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• Ictal fear suggests role amygdala in generation
  of emotional experience (of fear), contrary to
  Anderson Phelps (2002)
• Ictal fear short episode and result of abnormal
  bursts of activity
• Anderson Phelps (2002) Amygdala damage has no
  effect on emotional experience assessed over much
  longer episodes
• amygdala activation may be sufficient to produce
  emotional experience

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During a few moments I feel a happiness that it
is impossible to realise at other times, and
other people can not image it. I feel a complete
harmony within myself and in the world, and this
feeling is so strong and so sweet that for a few
moments of this enjoyment one would readily
exchange ten years of ones life perhaps even
ones whole life. F. Dostoyevski
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Temporal lobe epilepsy

• Other ictal emotional experience
• Patients may experience feelings of loneliness or
  sadness
• Pleasant feelings (e.g. euphoria, completeness)
  are rare.
• Dostoyevskis epilepsy (Alajouanine, 1963)
• Anger/aggression very rare

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Emotions occurring with temporal lobes seizures
(or stimulation) are different from normal
emotions

• They arise suddenly, without context. No
  evaluation precedes emotion.
• Experienced emotions are probably reflection of
• function of stimulated area, and
• experiences and personality of patient

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Temporal lobe epilepsy

• Changes in emotional behaviour
• Ictal laughter (Heilman et al., 2000)
• laughter may be accompanied by mood changes, but
  that is not necessarily the case
• rare, not clear whether more common in patients
  with RH seizures or LH seizures
• Heilman et al. (2000) 2 studies, one found RH
  seizures in all 10 patients, the other found LH
  seizures in 7 out of 10 patients
• Sackheim et al. (1982) ictal laughter twice as
  likely with LH foci that RH foci
• Crying (dacrystic epilepsy) very rare
• Dissociations between behaviour and experience

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A girl who laughed and fell down (Bellman et
al., 2000)

• 6 year-old girl with unexplained and
  uncontrollable laughter and giggling lasting up
  to 5 minutes prior to epileptic seizure.
• Laughter was without actual enjoyment. This
  happened several times a day and also during the
  night.
• Lesion in temporal lobe was suspected (temporal
  lobe epilepsy)

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Amygdala lesions

• Changes in emotional behaviour (Aggleton Young,
  2000)
• Animal studies
• Kluver-Bucy syndrome
• hypersexuality, fear lost, oral exploration of
  objects, tendency to eat unusual things
• tameness, reduction in aggression
• affective blunting

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Changes in emotional behaviour following amygdala
lesions

• Humans
• Surgical treatment for epilepsy and behavioural
  disturbances
• patients often became calmer, less aggressive,
  not emotionless
• Brain damage
• lesions restricted to amygdala produce relatively
  mild behavioural changes
• patient SM slightly disinhibited, inappropriate
  remarks
• human form of Kluver-Bucy syndrome
• rare, extensive lesions also in medial
  temporal/frontal regions

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Frontal lesions changes in emotional behaviour

• Where is frontal lobes?
• dorsolateral PFC
• no agreement on involvement in emotion
• ventromedial PFC
• most strongly associated with emotions and
  changes in emotional behaviour
• impairments in anticipating future positive and
  negative consequences of behaviour
• orbital PFC
• effect lesions not always clearly distinguished
  from effect ventromedial PFC lesions

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Ventromedial frontal lesions

• Typical frontal behaviour can include
• disinhibited or socially inappropriate behaviour,
  impulsiveness, inappropriate sexual advances,
  euphoria, a tendency to make jokes at
  inappropriate moments (witzelsucht),
  irritability, aggressive.
• Mood and behaviour can change quickly and
  unpredictably
• Difficulties in anticipating future positive or
  negative consequence of own behaviour
• deficit emotion-related learning
• Performance on standard neuropsychological tests
  may be completely normal

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Phineas Gage

• from a responsible hard-working, energetic
  person, who was very good at organising his
  financial and personal affairs, he became
  impatient, rude, given to outbursts of anger and
  rage. He could no longer organise his life and
  work, and could not follow a coherent plan of
  action.
• lesions probably ventromedial, bilateral

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Elliot/EVR (Damasio, 1994)

• successful professional life and normal family
  life until age 35
• parts of ventromedial frontal cortex removed
  bilaterally for treatment of tumour
• became disorganised, changed jobs frequently and
  was fired from each of them, disastrous business
  investment, wife and children left him
• appeared unconcerned about his own fate
• very indecisive about relatively trivial things

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Anticipating future consequences of behaviour

• Gambling test
• patients with ventromedial lesions take more
  risks
• differences in skin conductance responses
• At the beginning of task, both frontal patients
  and controls display transient increases in skin
  conductance when turning a card from the risky
  deck (autonomic stress response)
• Eventually response becomes anticipatory in the
  control subjects, but not in the frontal patients

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Relationships between changes

• Effects frontal lesions (ventromedial)
• impaired recognition expressions
• indications for reduced intensity and frequency
  of emotional experience
• changes in emotional behaviour and in regulation
  of this behaviour
• possibly effects more severe with RH or
  bilateral lesions than with LH lesions

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Relationships between changes

• Impairments in recognising emotional expressions
  correlated with changes in the subjective
  experience of emotion (Hornak et al., 1996)
• Somatic marker hypothesis (Damasio, 1994)
• poor decision making is a consequence of the
  reduction in emotional reactivity and experience

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Somatic marker hypothesis

• reasoning and emotion not different domains
• emotions influence reasoning via somatic
  markers
• somatic marker memory of the bodily sensations
  of emotions experienced in a similar situation in
  the past
• markers act as alarm bell if outcome of action is
  possibly negative.
• markers help to sift options in decision making
• reduced emotional reactivity in ventral frontal
  patients, prevents benefit from somatic markers.

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Descartes error

• Descartes The body and the mind are separate and
  reason, a function of the mind, and emotion, a
  function of the body, are separate.
• Damasio Somatic marker hypothesis proposes that
  reason and emotion strongly influence each other
  emotion is crucial for proper reasoning and
  decision making.

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References

• Alajouanine, T. (1963). Dostoiewskis epilepsy.
  Brain, 86, 210-218.
• Anderson, A. Phelps, E. (2002). Is the human
  amygdala critical fro the subjective experience
  of emotion? Journal of Cognitive Neuroscience,
  14, 709-720
• Bellman, M. Pathan, A. Sinclair, L. (2000). A
  girl who laughed and fell down. Lancet, 355,
  2216.
• Cendes, F., Andermann, F., Gloor, P. et al.
  (1994). Relationship between atrophy of the
  amygdala and ictal fear in temporal lobe
  epilepsy. Brain, 117, 739-746. In Heavy Demand.
• Hornak, J., Rolls, E.T. Wade, D. (1996). Face
  and voice expressions identification in patients
  with emotional and behavioural changes following
  ventral lobe damage. Neuropsychologia, 34,
  247-261.