Chapter 7: Consolidating Memory Flashcards
what is the consolidation of memory?
the physiological process of memories moving from fragile STM to stable LTM
memory consolidation is what type of change?
-observable structural change
-synaptic consolidation
-system consolidation
what is synaptic consolidation?
the physical neural change at the synapse
what is system consolidation?
change in the organization of the neural networks involved in memory
forming a new memory
-anything can become a new memory
the brain is made up of many interconnected neurons, and new experiences and cognition are a result in the organized firing of new networks of neurons (memory)
it is a unique combination of hundreds to thousands of coordinated neurons
more in depth explanation of synaptic consolidation
-some neurons will communicate to each other for the first time
when two neurons form a new connection few neurotransmitters are released, and firing rates are much slower. This leads to weak encoding a retrieval for new connections.
neural growth proteins are then released which cause protein synthesis
BUT
when you repeatedly use the neural network (encoding and retrieval) growth proteins continue to be released and this causes a stronger neurotransmitter signal and long term potentiation
what is long term potentiation?
when fewer neurotransmitters are needed to produce a strong signal
in depth explanation of system consolidation
when new experiences/cognition happens the hippocampal neurons communicate with the rest of the brain to begin an neural network (encoding)
if cognition continues (thru working memory) the new network will become stronger and lead to long term potentiation
what are the two models of hippocampal involvement in system consolidation?
- standard model:
after encoding becomes so strong, the hippocampus has no role in that LTM retrieval - multiple trace model
the hippocampus continues to help with retrieval even once encoding has become strong
what was Viskontas (2009)
measured fmri activity of the hippocampus while recalling recent and older memories
-HC was active for all recent LTM retrieval (pre long term-potentiation)
-HC after 1 week for episodic memory retrieval-the multiple trace model worked for episodic memories, but the standard model was consistent for semantic memories
**remember patient KC (hippocampal damage)
what is a way consolidation can be disrupted?
-electroconvulsive therapy
-concussions or other trauma
-drugs
what is electroconvulsive therapy used for?
electrically induces seizures as a way to treat depression
what was Lisbany (2000)
Studied memory around ECT treatment
-retrograde amnesia for events right before ECT treatment started
-anterograde amnesia for events right after ECT treatment
physical damage to neurons in a memory network stops ___________.
consolidation
what type of damage would cause anterograde amnesia?
damage to the hippocampus
what type of damage would cause retrograde amnesia?
damage to cerebral network for a given memory
what are concussions?
-mild traumatic brain injuries (TBI)
-rapid movement deforms the brain or causes it to strike against the skull
-immediate effects are consistent with poor cognition (slurred speech, blurred vision, confusion, poor attention, loss of memory)
the loss of memory from concussions comes from…
a disruption of the hippocampus to cerebrum network
long term memory consolidation occurs ________.
gradually
at first long term memory consolidation is very…but becomes…
fragile
it is very susceptible to interruption especially in the first 3-6 hours
robust with time
becomes less susceptible to memory loss
when a TBI occurs, graded amnesia is common, what types of amnesia are often experiences?
-retrograde memory loss is common for recent events (the last few seconds, or anything that happened before long term potentiation)
-loss of memory for distant events is less common (months in the past, or events after long term potentiation)
(look at the liklihood of forgetting graphic)
the first time we move info from STM to LTM is called…
initial encoding
when LTM is loved back to stm to be used then stored back in LTM is is…
retrieved then re-encoded
when an LTM is retrieved, the brain treats it like…
brand new sensory info
it becomes an STM all over again, but it allows your working memory to start using that information again
initial encoding is the most ________ type of memory
accurate
primary source info
when memory is reconsolidated it becomes ______ ___________.
less accurate
it moves from robust LTM to fragile STM
secondary source info
(the LTM has been changed, even though we arent rlly aware of it)
Hmm I think marks new car was a sportscar with X rims, then your brain encodes that as new sensory info even if it isn’t correct)
is is possible to lose LTM during __________.
reconsolidation
what was Nader (2000)
-found that the antibiotic (anisomycin) can be used to stop neural protein synthesis
-injected anisomycin into the spinal fluid of rats
-created a fear LTM in rats by shocking them when playing a sound
-split into a control and 3 different conditions following that”
Control:
Day 1: associated shock and pain
Day 2: nothing
Day 3: played tone=rat freezes
Condition 1:
Day 1: injected anisomycin, associated shock and pain
Day 2: nothing
Day 3: played tone=NO freeze reponse
(prevented initial consolidation, no STM to LTM)
Condition 2:
Day 1: associated shock and pain
Day 2: injected anisomycin
Day 3: played tone=rat freezes
(anisomycin without LTM,, has no effect on LTM)
Condition 3
Day 1: associated shock and pain
Day 2: tone plays=rat freezes, inject anisomycin
Day 3: tone played=no freeze response
(anisomycin during LTM retrieval, preventing STM to LTM reconsolidation)
what is PTSD?
a disorder involving traumatic memories of threatening events
usually results in intrusive thoughts and physiological reactivity
what are intrusive thoughts?
unwanted recall of events
what is physiological reactivity?
distressing physiological response to memory of event (hear rate, sweat rate)
how can reconsolidation of memory be applied to therapy?
using drugs to alter reconsolidation, or other activities (tetris)
what is Lyadurai (2018)
tetris study
participants currently in the ER for car accidents were asked to recall the event (LTM to STM)
group 1-played Tetris for 20 min while waiting
group 2-journaled their experience in the ER for 20 min
then followed up a week later, the patients who played tetris suffered from 1/3 of the number of intrusive thoughts about the crash
when events recalled from LTM to STM, the tetris interrupted STM/WM of event, therefore, less STM to LTM reconsolidation
What was Brunet (2008)
Propanolol (medication) used to turn down fight or flight
PTSD patients were given propanolol during recall of traumatic event, then audio sessions were recorded
what is the primary effect of propanolol?
-the initial traumatic event consolidation
(high stress STM - high stress LTM)
-session with propanolol
(high stress LTM - high stress STM)
(with propanolol (low stress STM) - low stress LTM)
-future recall of event
(low stress LTM - low stress STM)
what is the secondary effect of propanolol?
less stress leads to weaker consolidation
what was McGaugh (1990)
rats given epinephrine (stress hormone) within 30 min of memory task
-no dose = normal memory
-low dose = 60% better memory
-high dose = 90% worse memory
some stress is good for memory too much is bad and not enough is alright but not great
what was Hupbach (2007)
participants were shown a bag of 20 objects
-on day 2…group 1 was shown a second bag of objects, group 2 was reminded of day 1 objects and then shown a second bag of objects
when participants came back into the lab on day 3, they were asked to recall the Day 1 objects:
-groups 1 incorrectly recalled 5% of the day 2 objects
-group 2 recalled 24% of the day 2 objects
Day 1 - First Bag
day 1 STM-LTM
Day 2- Second Bag
day 1- LTM - STM
day 2-STM - LTM
Day 3-first bag recall
day 1 + day 2 LTM-STM
what is Gais (2006)
participants learned a list of words then were tested a day later
they found that the only variable that mattered was how soon the participant was able to sleep after learning the words
this is because sleep prevents any new information from interrupting encoding, and helped with physiological consolidation too
