What do the frontal lobes do

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What do the frontal lobes do?

• Paul Fletcher
• Dept of Psychiatry
• Cambridge University
• pcf22_at_cam.ac.uk

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• As organisms evolve, their actions become more
  complex and idiosyncratic, their goals more
  remote in space and time, and their reasons or
  motives for attaining them more arcane, less
  transparent, more based on prior experience than
  instinctual need. Furthermore, action in general
  becomes more deliberate and voluntary. With this
  evolutionthe prefrontal cortex grows and so does
  its functional role.
• Joaquin Fuster, 1997

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• As organisms evolve, their actions become more
  complex and idiosyncratic, their goals more
  remote in space and time, and their reasons or
  motives for attaining them more arcane, less
  transparent, more based on prior experience than
  instinctual need. Furthermore, action in general
  becomes more deliberate and voluntary. With this
  evolutionthe prefrontal cortex grows and so does
  its functional role.
• Joaquin Fuster, 1997

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Lateral
Medial
Orbital
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Attention Volition Planning/strategy Monitoring In
hibition
Insight Volition Error monitoring Somatic
attention
Interference Suppression Mood Reward
processing Risk behaviour Decision-making
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What do the frontal lobes do?

• Why is this a difficult question?

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Frontal lobe tasks

• Wisconsin Card Sorting Test
• Stroop
• Cognitive estimates
• Hayling Sentence Suppression
• Multiple Errands
• Tower of London
• Gambling/Risk
• Dimensional Shifting
• Memory Attention
• Abstract Thought

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RED
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GREEN
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Frontal lobe tasks

• Wisconsin Card Sorting Test
• Stroop
• Cognitive estimates
• Hayling Sentence Suppression
• Multiple Errands
• Tower of London
• Gambling/Risk
• Dimensional Shifting
• Memory Attention
• Abstract Thought

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Frontal lobe tasks

• Wisconsin Card Sorting Test
• Stroop
• Cognitive estimates
• Hayling Sentence Suppression
• Multiple Errands
• Tower of London
• Gambling/Risk
• Dimensional Shifting
• Memory Attention
• Abstract Thought

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Frontal Lobe Processes

• Memory and Attention
• Volition
• Planning
• Strategy generation and implementation
• Monitoring/Error-checking
• Verification
• Inhibition
• Decision-making

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Frontal Lobe Syndrome

• Apathetic/Avolitional
• Disinhibited
• Judgement deficits
• Irritability
• Stimulus-bound behaviour

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Fundamental problems

• The processes we formulate to explain and
  challenge frontal lobe function are open to
  criticisms -
• Metaphorical
• Pseudo-insight through terminology
• Circularity
• You can tell a lot about someones personality
  from what theyre like
• Harry Hill
• Procrusteanism Simply inventing new tasks ...
  and then nominating them as measures of basic
  executive processes
• Baddeley 1998.
• Observations changed by nature of
  measurement/task
• I didnt realise how many ants spontaneously
  combust until I started to look at them closely
  through a magnifying glass on bright, sunny days
  
• Harry Hill
• Tasks soluble in multiple ways

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Fundamental problems

• The nature of processes is such that a task does
  not consistently engage a process nor does a task
  in the clinic translate easily to the real-world
  deficits.

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Frontal lobes as executives

• Not necessarily useful
• Non-routine
• Dynamic/adaptive
• Modulates existing functions
• Engender automaticity memory encoding?

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Frontal lobes as executives

• Not necessarily useful
• Non-routine
• Dynamic/adaptive
• Modulates existing functions
• Engender automaticity memory encoding?

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Fletcher et al, Cerebral Cortex, 2005
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What Bill said

• Shakespeare
• And thus the native hue of resolution /is
  sicklied oer with the pale cast of thought

• Shankly
• When youre through on goal and youre not sure
  which side of the keeper to put the ball, just
  pop it in the net and we'll discuss your options
  afterwards.'
• 'The problem with you son, is that your brains
  are all in your head.'

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Frontal lobes as executives

• Not necessarily useful
• Non-routine
• Dynamic/adaptive
• Modulates existing functions
• Engender automaticity memory encoding?

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Frontal lobes associated with non-routine
encoding proactive interference
Dolan and Fletcher, Nature, 1997
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Fletcher et al, NeuroImage 2000
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Frontal lobes as executives

• Not necessarily useful
• Non-routine
• Dynamic/adaptive
• Modulates existing functions
• Engender automaticity memory encoding?

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Fletcher et al, NeuroImage 2000
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Fletcher et al Nature Neurosci2001
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Study 1 Fletcher et al Nature Neurosci2001
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Freedman et al, Science, 2001
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Frontal lobes as executives

• Not necessarily useful
• Non-routine
• Dynamic/adaptive
• Modulates existing functions
• Engender automaticity memory encoding?

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Modulating behaviour
Sakai et al, Nature Neuroscience, 2002
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Fletcher et al, Cerebral Cortex, 2005
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Frontal lobes as executives

• Not necessarily useful
• Non-routine
• Dynamic/adaptive
• Modulates existing functions
• Engender automaticity memory encoding?

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Frontal lobes necessary to memory formation
dual task
Fletcher et al Brain, 1998
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Frontal lobes necessary to memory formation Dm
Effect
Did you see Word 3? Word 7? Word 1? Word 6? Word
2? Word 4? Word 8? Word 5?
Word 1
Word 2
Word 3
Word 4
Word 5
Fletcher et al, Cortex 2003
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Summary

• It is difficult to pronounce upon frontal lobe
  function, and hence dysfunction, because we have
  yet to elucidate, with confidence and
  credibility, the core processes to which they
  contribute.
• Neuropsychology and, latterly, functional
  neuroimaging have identified a number of
  principles that may tentatively point us in the
  right direction
• Non-routine, dynamic, modulatory, memory formation

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• As organisms evolve, their actions become more
  complex and idiosyncratic, their goals more
  remote in space and time, and their reasons or
  motives for attaining them more arcane, less
  transparent, more based on prior experience than
  instinctual need. Furthermore, action in general
  becomes more deliberate and voluntary. With this
  evolutionthe prefrontal cortex grows and so does
  its functional role.
• Joaquin Fuster, 1997