Anatomy, see Fig. 2-8, 2-9, 2-10

  1. Episodic memory, experience of remembering
    1. The explicit recollection of incidents that occurred at a particular time and place in one's personal past
    2. Medial or inner parts of temporal lobes, including the hippocampal formation,
      1. damage -> greatly impairs the acquisition of new episodic memories
    3. Prefrontal cortex,
      1. Damage -> great difficulty in remembering when and where recent events occurred
    4. Frontal cortex
      1. Damage -> source amnesia
    5. PET study, for a typical image see Fig. 2-11
      1. Right frontal regions greater activation - episodic retrieval
      2. Left frontal regions greater activation - episodic encoding, see Fig. 2-12
      3. Medial temporal lobe - both encoding and retrieval, see Fig. 2-13
        1. activations of hippocampal region associated with
          1. encoding memories - primarily in the rostral portions
          2. retrieval memories - primarily in the caudal portions
  2. Semantic memory, experience of knowing
    1. General knowledge of facts and concepts that is not linked to any particular time and place
    2. Medial temporal lobe
  3. Dissociation between Episodic memory and Semantic memory
    1. Patient K.C.
      1. Damage to medial temporal and frontal regions
      2. Unable to recollect a single episode from any time in his entire life yet possessed extensive semantic knowledge of facts and concepts
    2. A patient
      1. Damage to anterior sectors of the temporal lobe
      2. Could remember specific past episode, but had great difficulty understanding the meaning of common words and had lost knowledge of historical events
    3. Elderly patients with syndrome of semantic dementia
      1. Reduced metabolic activity of and structural atrophy in the anterior and lateral regions of the temporal lobe.
      2. Poor knowledge of the properties of specific objects, yet intact episodic memory
  4. The time-limited function of medial temporal memory system: storage or retrieval?
    1. Amnesia
      1. retrograde (backward-acting) amnesia
        1. lost of memory for information learned before the amnesia-inducing brain injury
      2. anterograde (forward-acting) amnesia
        1. lost of memory for information learned after the amnesia-inducing brain injury
    2. Retrograde amnesia can not be simply described as a retrieval deficit
      1. memory acquired just prior to the amnesic episode can not be recovered
    3. Medial temporal system is not repository of long term memory
      1. one can identify a time after learning when damage had no effect on memory
    4. Current view
      1. Medial temporal memory system initially binds together the distributed sites in neocortex that together represent the memory of a whole event.
      2. This low-capacity, fast system permits the acquisition and storage, and for a period it provides a basis for retrieving the full representation.
      3. At time passes, the burden of long-term memory storage is assumed fully by neocortex.