Chapter 14: The Frontal Lobes

- Anatomy
    - Comprises all the tissue in front of the central sulcus
    - 20% of the neocortex
    - Made up of several functionally distinct regions
        - Motor
        - Premotor
        - Prefrontal 
        - Motor is area 4 and premotor includes areas 6 and 8

    - In humans- lateral premotor area has expanded as Broca's area has developed 
- Functions of the premotor cortex 
    - Functions to select the movements to be executed 
    - Area 8- stimulus directed movements
    - Area 8A- internally directed movements
- Functions of the prefrontal cortex 
    - Controls the cognitive process so that the appropriate movements are selected at the correct place and time 
    - Internalized memory of what has just occurred- short-term memory 
        - Use to refer to a neural record of recent events 
- Asymmetry of frontal lobe function
    - Functionally asymmetrical 
    - Left frontal lobe has a preferential role in language-related movements
    - Right frontal lobe plays a greater in other movements
        - Ex. facial expression
- Symptoms of frontal lobe lesions
    - Damage to the primary motor cortex associated with a chronic loss of the ability to make fine, independent finger movements
    - Removal of the supplementary motor cortex results in a disruption of nearly all voluntary movements 
        - Rapid recovery
        - Only permanent disability is in the performance of rapidly alternating movements of the hands and fingers 
    - Alterations in voluntary eye gaze 
    - People with strokes involving Broca's area impaired in their ability to use verbs and produce appropriate grammar 
    - Interferes with divergent thinking 
    - Certain loss of spontaneity of speech
    - Problem following rules
    - Making strategies
- Phineas Gage
    - Damage to frontal lobe 
    - Nasty and mean after the damage
    - Autopsy revealed deep scaring of the orbital part of both frontal lobes
        - more extensive on the right

Images: http://www.lea-test.fi/en/vistests/pathways/images/pathway3.jpg, http://www.theplatform.info/utility/image?id=145&w=150&h=0&hash=8d11c7b0649a4fbed45933f6b1bec893

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