L4: AMNESIA AND MEMORY SYSTEMS II
~ LONG TERM MEMORY ~
Mirror Drawing in H.M.
Each day after his first attempt, he thinks he’s never done the task before, but he improves
dramatically everyday Less errors per attempt.
THIS SHOWS THAT HE HAS NO CONSCIOUS INSIGHT INTO THIS LEARNING. So learning can
occur independent of the hippocampus. (Remember his hippocampus was removed).
o Long lasting, resistant to forgetting. Like riding a bike.
o Often have no insight into how they learnt how to do the task
o Eg. Typing, driving, playing an instrument
o Requires highly complex movements and sequences of steps gradually become
automatic and we don’t even need to think about it.
o “practice makes perfect” Need to engage in task yourself.
o Eg. Cooking, tying your shoes, using a phone.
o Slowly building learning process.
o Gradually acquired. Rigid and inflexible. Enables you to automate procedures.
Problem is when modification of those habits is required ->hard to break the habit.
“Force of habit” Difficult to reprogramme proc. Memory and even to return back to
Conscious vs. Unconscious Memory
Nondeclarative Memory = You are NOT CONSCIOUSLY aware of what you have learned and
you CANNOT VERBALISE it. Includes procedural memory. INDEPENDENT OF HIPPOCAMPUS.
Declarative Memory = You are CONSCIOUSLY AWARE of what you have learned and you
CAN VERBALISE it. Includes memory for personal events and facts.
Severely impaired in individuals with anterograde amnesia eg. HM Measuring Memory:
o Explicit memory task = specifically asks the participant to report information in their
memory. Direct method of testing memory. General questions, not just personal qs.
What did you eat for breakfast?
Is the population of Perth larger than Sydney?
o Implicit memory task = Shows learning without specifically instructing the articipant
to rely on memory. Doesn’t require participant to be conscious that they’re using
their memory at all.
Eg. Mirror-task H.M. Not directly demonstrating memory ability.
Proc. memory is gradual and cumulative and can only be learned from the performance of a
task. (Person needs to actively engage in the task in order to learn it). Unconscious. Long-
o Rigid and inflexible.
Weather pred. task. Tricky task that must be guessed several times over
time to get the hang of it and therefore predict the weather correctly.
IMPLICIT MEMORY TASK:
You end up knowing how to predict the weather, but you are not
consciously aware of how to do it This is proc. memory and it enables you
to not just learn motor skills, but to learn complex, highly probabilistic
stimulus response relationships in the presence of feedback.
Counterintuitive (Not what common sense would dictate) form of memory.
Proc. memory must be independent of hippocampus as AMN (severe
anterograde amnesia) individuals and control patients have similar success
rates in predicting the weather. So AMN individuals are just as capable as
the control group in learning complex stimulus response associations
gradually with feedback. Remember that they do not remember actually
performing the tasks, so they have no conscious insight into what they have
learned. EXPLICIT MEMORY TASK:
Multiple choice qs about the task asked. This tests the individual’s
familiarity/conscious experience, memory and understanding of the game.
Control group has a SIGNIFICANTLY higher percentage of qs correct. AMN patients
have a significantly lower percentage of qs correct. This shows how AMN patients
can’t even remember doing the task, and that they have unconsciously learned how
to predict the weather. So they have this ‘RESIDUAL memory’.
How is it that individuals with AMN have this residual, procedural memory?
1. SCEPTIC: Single System alternative?
Maybe these implicit memory tasks testing procedural memory are just easier, and
so even the AMN patients can successfully complete the tasks their success has
nothing to do with a whole other memory system in the brain.
AMN patients have residual memory ability.
Since there is some residual learning in anterograde amnesia, maybe implicit
memory tasks are just easier.
Implicit memory tasks may reveal any residual memory an individual has due to its
simplistic/easy nature. Because the implicit task is so easy (eg. Mirror drawing), it is