Amnesia

Amnesia


Amnesia refers to a deficit in memory. It can be anterograde or retrograde and the two can occur simultaneously.

Anterograde amnesia refers to the inability to create new memories (the inability to transfer new information from the short-term to the long-term store). Although the exact mechanism is not understood it is thought to be due mainly to damage to the hippocampus.

Retrograde amnesia refers to a loss of memory for information that was acquired prior to the onset of the amnesia (the traumatic insult e.g. a head injury). Episodic memory is more likely to be effected than semantic.

Dissociative amnesia results from a psychological cause as opposed to direct damage to the brain.

Amnesia is typically associated with damage to the following:

  • medial temporal lobe
  • hippocampus
  • midline diencephalon