Cognitive Neuropsychiatry:

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Cognitive Neuropsychiatry The Normal Mind and
Brain Through the Lens of Disorder
Vaughan Bell
Departamento de Psiquiatría, Universidad de
Antioquia
Institute of Psychiatry, Kings College London
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Outline

• Cognitive neuropsychology
• Cognitive neuropsychiatry
• Delusions
• Hysteria
• Conclusions

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Phineas Gage

• A railroad worker in Vermont, known for his good
  character and responsible attitude.
• Suffered an injury in 1848 where a tamping iron
  was shot through his head when setting gunpowder
  to break rocks.
• He did not lose consciousness and he walked home.
• He was later seen by Dr Harlow who wrote up his
  case.

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Skull and Life Mask
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Damasio et al (1994) Reconstruction
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Effect on Gage
Dr Harlow reported He is fitful, irreverent,
indulging at times in the grossest profanity
capricious and vacillating, devising many plans
of future operation, which are no sooner arranged
than they are abandoned.
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Link to Function

• This was some of the first evidence that damage
  to specific areas of the brain could affect
  personality and behaviour.

• Later Paul Brocas autopsy on a patient with
  expressive aphasia found a specific lesion in the
  left frontal lobe, now known as Brocas area.

• This suggested language was not single function
  and could be linked to certain brain circuits.

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Trench Warfare and Scotoma
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Holmes (1916) Scotoma Lesion Map
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The Modern Era Begins

• Marshall and Newcombe (1966, 1973) ushered in the
  new era by studying dyslexia after brain injury.
• They used dissociations between different
  impairments to understand the cognitive structure
  of language.
• This approach has continued to the present day,
  focusing on impairments in relatively easy to
  measure concepts like memory, attention,
  language, perception and so on.

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Unknown Lands

• However, cognitive neuropsychology is not so good
  at dealing with other aspects of human
  psychology, such as
• Belief
• Free will
• Intentionality
• Body ownership
• Self-knowledge

• Delusion
• Passivity phenomena
• Hysteria
• Somatoparaphrenia
• Anosognosia

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Cognitive Neuropsychiatry

• So a new field was developed to
• Study how these functions break down to better
  understand the normal mind and brain.
• To explain mental disorders within models of
  normal neuropsychological function.
• Typically looks at symptoms rather than diagnoses.

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Freeman et al. (2002) model

• A psychological model of persecutory delusions.
• Almost entirely based on research with idiopathic
  psychosis patients.
• Using psychometric and cognitive measures.

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Precipitant
Anomalous experiences / arousal
Emotion Beliefs about self, world, others
Cognitive biases
Search for meaning
Selection of explanation
DELUSION
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Precipitant
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Langdon and Coltheart (2000)

• A cognitive model of belief formation.
• Largely based on patients with monothematic
  delusions, and often after brain injury.
• Using single case and double dissociation method
  of cognitive neuropsychology.

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Sensory information
Monitoring
Web of belief
Hypotheses
Prioritised list of explanations
Evaluation
Belief accepted
Belief rejected
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Sensory information
Monitoring
Web of belief
Hypotheses
Prioritised list of explanations
Evaluation
Belief accepted
Belief rejected
DELUSION
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Psychometrics

• Standardised questionnaires designed to reliably
  measure which experiences are typical in patients
  and the general population
• 10 of the general population score above the
  mean of psychotic inpatients on
• PDI (Peters et al., 2004) a measure of
  delusional thinking.
• CAPS (Bell et al., 2006) a measure of anomalous
  perceptual experiences.

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CAPS Frequency Distribution
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Cognitive Measures

• Bell et al. (2006b) reviewed differences between
  delusional patients, other psychiatric patients
  and controls
• Probabilistic reasoning (data gathering)
• Attributions for causes of events
• Attentional bias
• Attribution of memory source

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After Brain Damage

• Reviews of psychosis after brain damage also
  stress the importance of the temporal and frontal
  lobes.
• Psychosis has been found most commonly after
  damage to these areas in studies of
• Cerebrovascular accident (Starkstein et al.,
  1992)
• Tumour (Lisanby et al., 1998)
• Traumatic brain injury (Fujii and Ahmed, 2002)

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Neuroimaging

• Commonly finds frontal / temporal changes.

• The DTI literature indicates pathways connecting
  these areas are most commonly abnormal (Kubicki
  et al., 2007)

• Functional neuroimaging of delusions typically
  implicates frontal and temporal areas (Blackwood
  et al., 2001), although results can be task and
  delusion specific (e.g. Blakemore et al., 2000).

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Cognitive Modelling

• Computer models of delusions have existed since
  Colbys (1975) natural language simulation PARRY.
• Recent simulations tend to be based on
  connectionist models (Rolls et al., 2008).
• These are designed to perform a particular
  cognitive task
• and are then damaged to simulate the proposed
  neurobiological dysfunction.
• To see if they produce delusion-like behaviour.

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Neurocognitive Modelling

• We wanted to look at the causative role of the
  temporal cortices in anomalous experience.
• Used a paradigm from Brugger et al. (1993)
• Demo Here

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Bell et al. (2007)

• In reality, all patterns were completely random.
• Brugger et al. (1993) found that healthy
  participants who believe in telepathy were more
  likely to see meaningful information in visual
  noise.
• We did the same experiment, but controlled for
  anomalous experience in the 12 participants.

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Bell et al. (2007)

• Used transcranial magnetic stimulation on the
  vertex, left and right lateral temporal cortices
  before stimulus.
• TMS caused no significant effect on reaction time.

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Effect on detect responses

Sig main effect plt 0.05 Sig diff from left at
p lt 0.05
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Hysteria

• Now diagnosed as conversion disorder or
  dissociative disorder and typically based on
  three main assumptions (Miller, 1999)
• Symptoms are not adequately explained by tissue
  damage.
• The patient has no voluntary control over the
  symptom.
• They can be caused by the conversion of
  psychological distress into physical symptoms.

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Hysteria

• Can involve
• Paralysis
• Amnesia (psychogenic amnesia)
• Blindness / deafness
• Walking / gait problems (atasia-abasia)
• Loss of voice (psychogenic aphonia)
• Seizures (psychogenic non-epileptic seizures)
• and many others

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Hysteria and Dissociation

• The conversion hypothesis was originally an
  idea from Ferriar, popularised by Freud, but
  lacks evidence.
• There is more evidence for dissociation.
• Defined as the unconscious compartmentalisation
  of normally integrated mental functions (Janet,
  1887 Aybek et al., 2008).
• Recent evidence suggests that this
  compartmentalisation works by top-down
  attentional modulation.

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Neuropsychology of Dissociation

• EEG studies find that early sensory pathways are
  intact in hysterical sensory impairment
• but signals from higher level perception areas
  are abnormal (e.g. Xu et al., 2001).
• TMS studies of hysterical paralysis show that
  primary motor pathways are intact (e.g. Cantello
  et al., 2001).
• Neuroimaging typically shows functional decreases
  in areas linked to impairment with increases in
  prefrontal cortex activity (review in Bell et
  al., forthcoming)
• Suggesting inhibition at the cognitive level.

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Demo Here
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Distribution of Hypnotisability
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Hypnosis and Dissociation

• 19th century French neurologist Jean-Martin
  Charcot noted the similarities between the
  effects of hypnosis and hysteria.
• He noted that hypnosis could simulate and treat
  hysteria.

• He argued that hysteria occurred due to
  functional inhibitions of the motor cortex that
  were produced by a form of autosuggestion.

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Hypnosis and Hysteria

• Marshall et al. (1997) increases in frontal
  activity with motor cortex decrease in hysterical
  paralysis.
• Halligan et al. (2000) repeated the study but
  with someone with hypnotic paralysis and found
  remarkably similar pattern.
• Our research group is continuing to investigate
  hypnosis as a model of hysteria.

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Hypnosis and Hysteria

• As well as the functional similarities, it seems
  people with hysteria are more hypnotisable than
  the general population (review in Bell et al.,
  forthcoming)
• So we can use hypnosis to model hysteria
• and studying high hypnotisable people might give
  us a clue to susceptibility to dissociation.

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Imaging State Related Changes
Perfusion imaging using arterial spin labelling
High hypnotisables, hypnotised, absorption
correlation
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In Psychopathology Research

• There is now an increasing interest in hypnosis
  as a psychopathology research tool (Oakley,
  2006)
• For example, used to simulate
• Hysterical paralysis (Halligan et al., 2000)
• Peri-traumatic dissociation (Holmes et al., 2006)
• Delusions of alien control (Blakemore et al.,
  2003)
• Functional pain (Derbyshire et al., 2004)

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Conclusions

• Cognitive neuropsychiatry aims to understand
  mental disorder in terms of models of normal
  neuropsychological function.
• It also aims to study disorder as a window on to
  the normal mind and brain.
• This helps us understand the less easily
  accessible concepts like belief, free will,
  intentionality etc.
• We need to integrate phenomenology, psychology,
  cognitive science and neuroscience.