Frontal lobe

  1. Function of the frontal lobe
    • Motor: Primary motor area 4, secondary: motor area 6
    • Volitional eye movements: Mediated by the frontal eye field, Saccadic eye movements depend on the integrity of this system
    • Speech and language   
    • Motivational behaviour  
    • Working memory 
    • Attention
    • Social behaviour  
    • Self awareness
    • Self regulation
    • Executive function
  2. Disturbances on motor function
    • No voluntary movement/poor fractionalization of movement 
    • Abnormal muscle tone (spasticity)      
    • Release of primitive reflexes (grasp, suck, bite reflexes)     
    • Sphincter control   
    • Ventral prefrontal cortex – affective
    • Dorsolateral prefrontal cortex – cognitive
  3. Disturbances to frontal lobe on volitional eye movements
    Frontal lobe lesions can produce an alteration in voluntary eye gaze in relation to scanning the visual field appropriately
  4. Disturbances to frontal lobe on language
    Expressive aphasia: the inability to perform the verbal expression of language. Non-fluent output
  5. Orbitofrontal cortex lesion
    • Social convention
    • Tend to have disinhibited, impulsive, inappropriate behaviour
    • Poor social judgement 
    • Impulsive decision making
    • Lack of consideration for impact of their behaviour      
    • Lack of empathy
    • Apathy, disinterestedness
    • Distractibility, restlessness    
    • Personal changes
  6. Ventral and polar motor cortex lesions
    • Self regulation
    • Damage to these areas may result in such significant changes that the person is not considered to be the same person
    • Inability to regulate behaviour according to internal goals and constraints  
    • Lack of insight – lack of real understanding of problems and inability to act with one’s own interest in mind, despite knowing what to do and at least verbalising an intent to change
  7. Medial frontal motor cortex lesions
    • Apathetic, indifferent
    • Motor apathy: reduced gesturing, reduced verbal output, preservation
    • Cognitive apathy: decreased curiosity, altered interest in learning, deducing and drawing logical conclusions, poor abstraction and categorization
    • Affective apathy: diminished vocal inflection, reduced facial expression of internal emotional states
    • Emotional apathy: reduced social interest, diminished affection, disinterest
    • Motivational apathy: Reduced initiative
  8. Dorsolateral frontal cortex lesions
    • Stategy formation and executive function
    • Loss of mental flexibility    
    • Apathy 
    • Personality changes  
    • Aboulia
    • Lack of ability to plan or sequence actions or tasks
    • Poor working memory for verbal information (if left hemisphere) or spatial information (if right hemisphere)
Card Set
Frontal lobe
Terms etc.