L9 Episodic Memory pt. 2

• Retrieval:

  • Retrieval is less affected by divided attention than encoding, which suggests an automatic component to memory retrieval.
• What is the second way of retrieving information in episodic memory?

  Effortful retrieval: If you are not given a strong retrieval cue then the hippocampus cannot retrieve memories very well, hence it is required for free recall.

  The frontal system can generate better retrieval cues that the hippocampus can use to generate a memory.

  Frontal systems can also monitor and eliminate errors in memory retrieval.
• Evidence from Korsakoff patients (amnesia associated with frontal lesions):

  Recall is more affected than recognition. They sometimes suffer from confabulation.
• What is the first way of retrieving information in episodic memory?

  Automatic retrieval: the hippocampus can retrieve information relatively automatically with strong retrieval cues.

  Memories often ‘pop out’. These can be false memories and confabulation, and the hippocampus cannot correct itself.

  Allows memory retrieval under divided conditions.

  Supports recognition memory better than free recall.
• What is the role of the frontal system?

  • It is the boss of the hippocampal memory system
  • Controls the information that is presented to the hippocampus at encoding (by directing attention)
  • Initiates and guides retrieval
  • Monitors information that is retrieved from the hippocampus
• What is encoding specificity?

  The effectiveness of a retrieval cue depends on how well it relates to initial encoding.
• Testing effect - explained by encoding specificity:


  • Studying only/ cramming helps you recall more in the short term
  • however testing yourself helps your recall more in the long-term
• False memories are remembered due to:

  Errors in encoding and errors in retrieval
• Memory distortion at encoding:

  Episodic memory for faces is better for your own race than cross-race. This is because encoding is better for more familiar faces.

  Study: Asian and Caucasian ptps made perceptual decisions about Asian and Caucasian faces. In each trail a target face was in the centre of the screen for 250 ms, and after a 1s delay, two faces presented side by side. Ptps clicked which matched the target photo.

  
• The retrieval Induced forgetting paradigm study:

  1. Ptps study words from two categories - food and animals.
  2. Then they practice a subset of words from the first category i.e. the first three words.
  3. Recall test - memory is worse for the non-practiced words from the first category than for the second category even though they were studied for the same length of time.

  Over time, the induced forgetting goes away.
• Induced forgetting could be a possible mechanism for repression.