long term memory complete Flashcards
what is semantic knowledge
general world knowledge that humans have accumulated throughout their life
2 basic facts about memory and the NS
in order for there to be a memory, there has to be a physical change in the NS
diff parts of brain are responsible for diff types of memory, nonetheless, memory is quite pervasive in the nervous system, hard to find a part of the NS that doesn’t have some capacity for learning and memory
we make an alaogy of memory to computer systems because both share an
common underlying representation, in the case of memories in the NS, that representation is in the connections between neurons , and how strong those connections are
___ maintenance for short term memory
______ storage for long term memories
Active maintenance for short term memory
Passive storage for long term memories
3 differences between computers and our brains in this analogy
parts of machines that store memories are physically distinct from the parts that do the actual work (processing) hard drives vs central processing unit for example - NOT how the NS works,
in a computer you can have a pattern of 1s and 0s and copy it from place to place easily through cloud email etc, same pattern means the same thing, in the brain you can’t move memories around in the same way, the meaning of a memory, as encoded by connections between neurons is fundamentally tied to which neurons we are talking about,
In a computer primary way memories are accessed is based on their location - you look info up by specific physical location on a chip or disc, in Human Memory - accessed based on a cue - based on its content
4 processes required for memory to work
Encoding - has to be encoded into the brian in a way that can be put into memory
Consolidation - initial coding often changes over time if we keep a memory around
Storage - at some point the memory is stored, hopefully sticks around
Retrieval - accessing info from stored information traced
Reconsolidation - possible reorganization of memory traces after retrieval. Can get rewritten from retrieving it,
how do we use dissociation to look at the extent to which one system or the other can be damaged
If you are able to show damage to one part of the brain is associated with one process, damage to another part is associated to a diff process - gives you evidence that they are 2 different systems
memory span tasks test _____
short term memory
list learning task test ____
long term memory
how does the memory span task work
you have a sequence of words and the example here is 3 words - time, base, offer. Your job is to try to recite them back in the same order as accurately as you can. Number of words cna differ but that is the basics of the task - immediate recall in correct order
how does the list learning task work
you hear a longer sequence of words (10) and then you are to recall them and it can be in ANY ORDER, if you don’t get them all right you get to hear them all again, try to recite them again, do it until you can recite the whole list correctly
what is a single dissociation
a patient who is impaired on one task but not all, is a Single Dissociation
explain the partial damage argument for dissociations
maybe there is only one system being used to perform BOTH tasks, and maybe this patient has partial damage to that system - because the short term memory task is Harder than the long term one the partial damage has led to a drop in performance on the harder tasks - but is intact enough to complete the easier one
explains the single diss without saying there must be 2 distinct brain systems
explain the compensation argument for single dissociations
maybe the damage knocked out a single system that would normally be used for both tasks - but because the short term task is harder, the participant has found a way to compensate for the easier task but not for the harder one
what brain damage did HM have
temporal lobes bilaterally
what gives us the Double Dissociation
This crossover pattern with 2 patients with damage to 2 distinct brain areas with opposite patterns of impairment on 2 tasks gives us our
short term vs long term mmeory - which has more capacity
Short term memory is extremely LIMITED (7 words in task)
wheres LT is massive in comparison (20000 words in vocab)
short and long term memory are represented in different ways
LT memory seems to be based on the strength of connections between neurons as well as NUMBER of connects
ST is represented by WHICH neurons are currently active in the brain - sometimes neurons can maintain that activity for at least a few seconds
different physical bases in the brain for these two - current activity VS structural connections
what is the perceptual identification task and what type of memory is it used to test
used for implicit memory
study phase - words are flashed on a screen for 2 secs each, one after the other -
test - identify the word as fast as you can - some you have seen before some are new - is it easier to ID the ones you have seen before
what memory type was the word recognition task test
Explicit
study phase you see 24 words flashed for 2 seconds each
test phase - you are again get a mix of old and new words at random, each word appears on screen and stays as long as you need in order to respond yes it was in first phase or no it is a new word - here you are explicitly asked if they are new words or if you already saw them.
how does the MS patient do in the explicit word recognition task and the implicit perceptual identification task
Now by comparison you can look at the performance of MS patient (damage to right occipital lobe) they do NOT show a priming effect in perceptual id task they are impaired, BUT they are able to Explicitly recall the words as well as the control group
they have a Single Dissociation between Implicit and Explicit Memory
not neough to prove anything
how do the amnesia patients do on the explicit word recogniton task
they are impaired on the explicit word recognition task, but show a priming effect if anything larger effect as it helps them more
how is the double dissociation shown in the implicit and explicit tasks
we put the MS patient and the Amnesia patient together - they both have damage to different places - strong evidence that implicit and explicit memory are distinct processes that depend on diff parts of the brain
explicit memory
declarative, things we can remembr and bring to mind
the two kinds of non assocaitive memory are
habituation and sensitization
describe habituation
response decreasing with repetiton
hearing the fan until you get used to it
describe sensitization
response to unchanging stimulus repeated becomes increased over time
someone rubs your hand and it starts to hurt
what does sensitization involve - pathway
sensory motor reflex pathways
what is presynaptic depression
the neural basis behind Habituation
sensory neuron fires the same AP every time it is touched, releases less NT over time causing the EPSP goes down if the presynaptic motor neuron becuase less receptors take up the NT
presynaptic facilitation
neural basis of sensitization
AP of sensory neuron stays the same, but over time it releases MORE neurotransmitters, causing the EPSP in the motor neuron to increase
