Chapter 11 Flashcards
Learning, memory, and amnesia
Sensory memory (amount of time and number of item it can hold, consciousness of the process, what does it hold)
A Few seconds after the stimulus left our environment, almost illimited capacity, unconscious process, holding sensory information/impression
Short-term/working memory (amount of time and number of item it can hold, consciousness of the process, what does it hold, and the difference between the two types)
15 secondes, 5-9 items at a time, conscious process holding information you are paying attention to, working memory is what we call a short term memory that we can manipulate/reorganize
Long-term memory (what does it hold, amount of time and number of item it can hold)
Holding informations that has been consolidated, has an illimited storage, and the amount of time it can hold a memory depends on how well the consolidation process was made, but could be forever.
When memories are in the long-term memory they are in an ____ state, when they are in the short-term memory they are in a _____ state.
Inactive and active
What is the consolidation process? (What and how, and how long it takes)
Making new memories stables by strengthening them often with repetition, or how important the information is. Many things will play a role in consolidation. It can take up to many years, about 3 years for the memories to be fully consolidated without being disturbed.
What is the process of retrieval?
When we think of a memory - Bringing a memory from an inactive state in our long-term back to an active stsate in our short-term
Subsystems of the longterm memory + conscious or unconscious?
Explicit/Declarative memory conscious, containing semantic and episodic memory
Implicit/Non-declarative memory unconscious, containing procedural memory, classical conditioning, and priming
Semantic vs episodic
Facts and language vs own personal experiences
Procedural memory?
Memory for skills and actions that cannot efficiently be explained verbally, moment/process of learning cannot be recalled
Classical conditioning
Unconscious learning process associating a neutral stimulus (no particular response) with a significant stimulus (response inducing)
Unconditioned Stimulus (UCS)
Stimulus that naturally triggers a response without prior learning
Conditioned Stimulus (CS)
Stimulus that initially doesn’t trigger any response but can with classical conditioning
Unconditioned Response (UCR)
Natural response to an unconditioned stimulus
Conditioned Response (CR)
Learned response to the conditioned stimulus
The Little Albert experiment (Process, Problems)
- Infant Albert is presented to a rat (neutral stimulus)
- Albert is presented to a loud sound (significant stimulus/UCS) that scares him - UCR
- Every time Albert was reaching for the rat, the loud sound was played - Paring of the two stimulus
- Albert is now scared of rats (now CS) - CR
What is the problem with the little Albert experiment?
It is underestimating the importance of classical conditioning in our lives and how it is constantly guiding our actions.
What is priming?
The unconscious influence of previous knowledge and experiences on how we respond to other things.
Types of amnesia and what they are
Retrograde - Impairment in memories that happened prior to the event impairing memory
Anterograde - Impairment in new memories after the event impairing memory
Why after a head injury is it important to know the length of the retrograde amnesia?
Gives a good indication on the severity of the injury
Hebb’s theory (What and what does it explain)
Memories are stored in the short-term memory (seconds or minutes) in a reverberating loop of neural activity, keeping the memory alive. This constant recall leads to physiological changes at synapse level, leading to long term storage, that will be strengthen over time (over years) to stabilize the memory.
What does Hebb’s theory explains?
Explaining why interference of this process can result in retrograde memory loss
What is the name of the study done on animal to prove Heeb’s theory?
Animal study of electroconvulsive shock (ECS)
Animal study of electroconvulsive shock (ECS) process
Familiarization: rats in a box with an empty niche for 10min a day 5 days.
Learning trial: Water is placed in the niche and rats learn where it is located
ECS treatment: different groups had different time intervals (10 seconds, 1 minute, 10 minutes, 1 hour, or 3 hours) to interfere with memory consolidation and two control groups: one did not receive shocks, one did not have the learning trial.
Recall test: rats are placed back in the box to see if they remember the water
What were the results of the Animal study of electroconvulsive shock (ECS)
Rats who received ECS soon after learning (10 seconds to 10 minutes) showed retrograde amnesia and forgot where the water was, they went to the water as often as the control group who did not have the learning trial.
ECS applied later (1 hours) had less impact on memory.
ECS applied 3 hours later had no memory loss and when as much as the group that was not shocked, they went directly to the water.
What are the problems of the Animal study of electroconvulsive shock (ECS)
Testing memory with thirsty rats in a box could not be directly applied to humans. Also, the human brain is much more complex and the consolidation process takes much longer.
Human study with electroconvulsive shock (ECS) process
- Before the treatment, patients were tested on their memory of TV showed that aired only one season from different years (1-3, 4-5, 6-7, 8-9, 10-17 years prior)
- After the treatment, patient were tested again on these shows
Results and conclusion of the human study with electroconvulsive shock (ECS)
For very old shows (10-17 years), patients performed equally well before and after ECS - memories were well consolidated.
For recent shows (1-3 years), patients performed much better before receiving ECS, - memories of recent shows were still in the process of consolidation and stabilization.
For shows between 4-9 years old, patient performed similarly before and after ECS
Conclusion: The study showed that memories take at least 3 years to become consolidated enough to resist neurological damage from ECS. This suggests that human memory consolidation is a fragile process that lasts longer than in rats.
What is the name of the theory stating that memories can be altered?
Reconsolidation theory
Explain more in detail the reconsolidation theory.
When the memory is retrieved back from it’s inactive state into the shot-term memory, it can be modified or altered before being reconsolidated.
Application of the reconsolidation theory in patient with PTSD.
Patients are learning to stay in a relaxation state when retrieving the memories, altering the physiological body response when the memory comes back up, because the brain will have reconsolidated this memory as less traumatic.
Medication can also be used to help the relaxation process, but less effective because the patient was less involved in the process and his own mental reaction did not change.
why is the patient H.M. case so important?
It helped us understand the different memory systems (explicit vs implicit, consolidation vs retrieval) and the importance of specific structures in the brain for memory (like medial temporal lobes)
What resection did H.M. had, where is it, and was is it containing?
Resection of the medial temporal lobes bilaterally, containing the hippocampus, the amygdala, and the rhinal cortex - Inner regions to the temporal lobe containing the hippocampus, the amygdala, and the cortex around it.
Where did we think memories were stored before H.M.’s case and what did we think or the hemispheres roles?
We thought that memory was all over the brain and that the right hemisphere was a spare hemisphere for the brain.
What were the after effects of H.M.’s retrograde memory?
Mild amnesia from 2 years prior to the surgery.
What were the after effects of H.M.’s anterograde memory?
Severe impairment. Unable to form most type of new memories
Explicit: Was gravely impaired because the process of consolidation was impaired.
1. He could not form new episodic memories.
2. He could learn to a certain extend new facts and words (semantic memory).
3. He had difficulty with mental time travel - describing/imagining past and futur events, giving vague and generic descriptions.
Why did H.M. had impairment in mental time travel?
The neural networks involved in memory consolidation that was gravely impaired are overlapping with the neural network we use to imagine future events.
Who was the main neurologist working on this case?
Branda Milner
Why is Branda Milner important?
- She was able to show that the different subtypes of memories (implicit and explicit) had different neural networks, showing that even with one impaired, the other one can work just fine.
- She demonstrated that the entirety of the frontal lobe is essential to learn from feedback and to integrate it, adjusting your behaviour accordingly.
- She was the first to show that the right hemisphere was not the spare tire, but was important for many cognitive functions.
- She had the intelligence to take existing tests and modify them to dissociate different memory subtypes.
- She is the inventor of neuroscience!
What was shown in the assessment of H.M.’s explicit memory?
- His short-term was within normal limits
- His consolidation process was greatly impaired in the verbal and visuo-spatial domaine
What were the different tests done to assess H.M.’s memory?
Digit span test, digit span test +1, block-tapping memory-span test, and block-tapping memory span test +1
What is the digit span test, process, scoring, and H.M’s result?
Assessing the short-term memory’s capacity by making the patient repeat a digit sequence, and increasing the length by one digit till a mistake is made.
The length of the longest sequence correctly repeated is the capacity of the verbal short-term memory.
H.M. was able to do this test within normal limits
What is the digit span test +1, process, scoring, and H.M.’s results?
Assessing the process of verbal memory consolidation and how well information can be transferred for short-term to long-term memory.
After assessing the verbal short term capacity with the standard test, a new sequence is presented exceeding by 1 the short-term capacity.
If unsuccessful, the same sequence is repeated to provide an opportunity for consolidation.
Successful completion of the test demonstrates consolidation into the long-term memory
H.M. was never able to accomplish this test.