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What do the frontal lobes do

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Title: What do the frontal lobes do


1
What do the frontal lobes do?
  • Paul Fletcher
  • Dept of Psychiatry
  • Cambridge University
  • pcf22_at_cam.ac.uk

2
  • 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

3
  • 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

4
Lateral
Medial
Orbital
5
Attention Volition Planning/strategy Monitoring In
hibition
Insight Volition Error monitoring Somatic
attention
Interference Suppression Mood Reward
processing Risk behaviour Decision-making
6
What do the frontal lobes do?
  • Why is this a difficult question?

7
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

8
RED
9
GREEN
10
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

11
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12
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

13
Frontal Lobe Processes
  • Memory and Attention
  • Volition
  • Planning
  • Strategy generation and implementation
  • Monitoring/Error-checking
  • Verification
  • Inhibition
  • Decision-making

14
Frontal Lobe Syndrome
  • Apathetic/Avolitional
  • Disinhibited
  • Judgement deficits
  • Irritability
  • Stimulus-bound behaviour

15
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

16
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.

17
Frontal lobes as executives
  • Not necessarily useful
  • Non-routine
  • Dynamic/adaptive
  • Modulates existing functions
  • Engender automaticity memory encoding?

18
Frontal lobes as executives
  • Not necessarily useful
  • Non-routine
  • Dynamic/adaptive
  • Modulates existing functions
  • Engender automaticity memory encoding?

19
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20
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21
Fletcher et al, Cerebral Cortex, 2005
22
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23
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.'

24
Frontal lobes as executives
  • Not necessarily useful
  • Non-routine
  • Dynamic/adaptive
  • Modulates existing functions
  • Engender automaticity memory encoding?

25
Frontal lobes associated with non-routine
encoding proactive interference
Dolan and Fletcher, Nature, 1997
26
Fletcher et al, NeuroImage 2000
27
Frontal lobes as executives
  • Not necessarily useful
  • Non-routine
  • Dynamic/adaptive
  • Modulates existing functions
  • Engender automaticity memory encoding?

28
Fletcher et al, NeuroImage 2000
29
Fletcher et al Nature Neurosci2001
30
Study 1 Fletcher et al Nature Neurosci2001
31
Freedman et al, Science, 2001
32
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33
Frontal lobes as executives
  • Not necessarily useful
  • Non-routine
  • Dynamic/adaptive
  • Modulates existing functions
  • Engender automaticity memory encoding?

34
Modulating behaviour
Sakai et al, Nature Neuroscience, 2002
35
Fletcher et al, Cerebral Cortex, 2005
36
Frontal lobes as executives
  • Not necessarily useful
  • Non-routine
  • Dynamic/adaptive
  • Modulates existing functions
  • Engender automaticity memory encoding?

37
Frontal lobes necessary to memory formation
dual task
Fletcher et al Brain, 1998
38
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
39
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

40
  • 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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