L5: Amnesia and Memory Systems III
NON-DECLARATIVE MEMORY (cont.)
Repetition priming = Processing a stimulus facilitates subsequent processing of that stimulus in the future.
ANOTHER FORM OF UNCONSCIOUS MEMORY.
Become faster and more accurate processing a stimulus the second time round. Also creates a bias in the response in future.
Bias – Eg. Once you’ve seen the stimulus of a bear and talk about/observe it, if you’re given a task like ‘Name any word starting
with the letter bea--,’ you are now biased/inclined to say ‘bear’ and before due to the prior exposure of that stimulus.
Identifying fragmented objectlearning a PERCEPTUAL STRUCTURE INSTANTLY. (Different to procedural memory as this is
instantly acquired and related to how you perceive an object, whereas procedural memory requires repeated practise of a
particular task to learn it).
o The response can be instant, even after a brief encounter with stimulus. Results show that all you need is one
exposure to the stimulus and you can recognise the form quickly/accurately the second time.
o In this task, even the AMN patients are improving overtime, and there is only a small difference between the no.
errors made between the control and AMN patients.
o AMN patients unconsciously remember the forms/fragmented objects (they don’t remember doing the task before,
yet they show significant improvement overtime).
Priming is LONG LASTING the perceptual response can be retained for a long period of time. (eg. years later)
OFTEN PERCEPTUALLY SPECIFIC
o The way the object is presented affects the priming process. Eg. If you first heard the word ‘bear’ and repetition
priming occurred, then the next time you were given the task to complete the word ‘bea---‘ the effect of the priming
would be SEVERELY REDUCED. If there are any changes occurring in the perceptual structures/circumstances across the repetitions, the repetition priming is severely reduced as it is very sensitive to a precise perceptual
Very resistant to forgetting, like procedural memory.
PERCEPTUAL REPRESENTATION SYSTEM (Endel Tulving and Schacter 1990)
o Separate memory system that controls perceptual structure priming
o Stores structural-perceptual descriptions of objects and word forms.
o Priming reflects refinement of neural representations and computations within this system.
o Relies on sensory cortices (patient and fMRI data) (eg. Visual perceptions depend on visual cortex, hearing depends
on auditory cortex etc.)
o Independent of hippocampus, unconscious (Evidence: Intact in anterograde amnesia patients with dysfunctional
Real life example of Repetitive Priming: Cryptomnesia = Plagiarism that occurs without the plagiariser’s conscious
awareness or intention.
o Plagiarism can occur unintentionallunconscious influence of implicit memory.
o eg. George Harrison – My sweet Lord and The Chiffons – He’s so Fine.
o Evid. suggests that priming lasts for years DECLARATIVE/CONSCIOUS MEMORY
Episodic vs semantic memory