WK13 Reading Voluntary Behaviour & Frontal Lobes

• Voluntary movement


  A movement made when carrying out an intended act, even if the specific movements are not intended
• Involuntary movement


  A movement that does not occur as part of an intended act
• Types of involuntary movements


  • Reflexive movements
  • Passive movements caused by external forces
  • Active movements not part of an intended act
• Voluntary vs involuntary movements


  Experienced differently - voluntary movements feel like you are doing them, involuntary feel caused by external forces
• Learned involuntary behaviours can occur in Pavlovian conditioning
• Habitual behaviours


  Acquired behaviours mediated by direct stimulus-response connections, often experienced as involuntary
• Goal-guided behaviours


  Behaviours carried out to achieve a desired outcome, under control of that outcome
• Goal-guided behaviours correspond to human experience of voluntary behaviour
• Automatic behaviours can be voluntary or involuntary
• Highly practiced behaviours can become so automatic they are almost reflexive or habitual, even if originally voluntary
• Anarchic hand syndrome


  • Patient's left hand would do things without their intention or control, e.g. grabbing their throat, undoing buttons they had just done up
• Anarchic hand syndrome was first documented by Kurt Goldstein in the early 20th century
• Anarchic hand syndrome


  Condition where one hand behaves in a way that achieves specific outcomes, like undoing buttons or picking up objects, without any intention on the part of the patient
• Goldstein was a resident physician at the Psychiatric Hospital of the University of Königsberg and it was here that he encountered an extraordinary patient known only by her initials, HM2
• HM2 claimed that her left hand had grabbed her by the throat and tried to throttle her, and that it was continually doing things that she didn't want it to
• HM2 would get angry and frustrated with her hand and often resorted to hitting it or talking sternly to it in an attempt to stop it behaving in an unwanted fashion
• Goldstein's account of the strange claims and behaviour of his patient was the first time such a case had been documented, and it would be thirty-seven years until another was described
• Since then, several more cases have been reported with the common feature that only one hand is affected and it moves in a way that achieves specific outcomes, like undoing the buttons on a shirt or picking up an object, but without any intention on the part of the patient
• Patients do not experience these actions as self-generated, let alone as voluntary, and they are unable to stop them unless they grab the affected hand with their unaffected one
• Anarchic hand syndrome


  Condition where the affected limb behaves as if it had a mind of its own, with normal tactile and propriosensory feeling, and no paralysis
• Anarchic hand syndrome occurs when a particular region of the frontal lobes, known as the supplementary motor area (SMA), is damaged, with the damage restricted to one hemisphere

  
• Damage to the SMA in both hemispheres does not result in the person having two anarchic hands, but instead they exhibit something called utilization behaviour
• Utilization behaviour


  Spontaneous performance of object-appropriate actions when the person sees an object, regardless of time, context or ownership
• Patients exhibiting utilization behaviour do not report that their behaviour is unwanted or unwilled and usually do not realize that their behaviour is inappropriate
• In patients with SMA damage, sensory (usually visual) messages are activating the circuits involved in the production of actions appropriate for things that are seen, and this activation elicits the behaviour in an involuntary, reflex-like fashion
• Normally, there are inhibitory processes at work that prevent sensory activity from eliciting the response, but damage to the SMA reduces or eliminates this inhibition, allowing the stimulus to elicit the response involuntarily
• Volition


  The releasing of relevant stimulus-response circuits from inhibition, allowing the stimulus to elicit the response, which is experienced as voluntarily performing the action
• Much well-learned human behaviour incorporates sensorimotor connections overlaid by an intentional system (or systems) mediated by the frontal cortex