Episodic and Semantic Memory Flashcards
Memory Consolidation
● Semantic and episodic memories are subject to a consolidation period a time window during which new memories are vulnerable and easily lost
● Consolidation: the process of strengthening the stability of stored information.
- Stabilize memories
- Incorporate new memories with old ones
- Different types of consolidation (we will start with one type)
Episodic Memory and the Hippocampus
Two current theories, though no clear answer yet:
- View 1 - Standard Consolidation Theory
- View 2 - Multiple Trace Theory
View 1 - Standard consolidation theory
The hippocampus is involved in the encoding of episodic or semantic memories but its involvement fades with time, as memories are stored (“consolidated”) in the cortex
View 2 - Multiple Trace Theory
The hippocampus is involved in the encoding of episodic and semantic
memories but its involvement in semantic memory fades with time, as
memories are stored (“consolidated”) in the cortex BUT** the hippocampus continues to be involved in episodic memory in perpetuity**
same for sematic different from episodic between this theory and the oth
multiple trace theory
● According to multiple trace theory, when an event is experienced, it
can be stored as an episodic memory by a group of neurons in the
hippocampus and the cortex
● Each time that memory is retrieved, the retrieval itself becomes a new
episodic memory “trace”
so what are the difference between the theory
the main one is that for Standard Consolidation Theory the hippocampus is not as significant across time as for the Multiple Trace Theory
know how to draw
Pattern of Episodic Memory Loss
slides
Amnesia Data
Earlier studies show data consistent with view 1 (standard consolidation theory), which shows “temporally graded” amnesia, but later studies show
data consistent with view 2 (multiple trace theory), that is, “flat” amnesia.
what can be happening is that each of this theories were tested in different labs
Evidence: Neuroimaging (Photo Study)
- looked at photos (new or old)
- ‘i have seen this thing before/person’’
- 3 days and then 3month later
- after 3 days they say they recognized with pretty specifc details - really remenbering
- after 3 months there was more variability peoples responses, when they remenber seeing that image the hippocampus is active even after 3 monsth
- but if they say thy remenber a little bit (with not much detail) the hippocampus is not activitated
result: if the memory have to do with episodic memory the hippocampuse will be activated if its sematic not as much
another way of looking: as u memory is more specififc the hippocampus is activated more but along time, as ur remenbering becomes less specic and becomes more of fact that u know í remener i know this’ (episodic to semetic memory) the hippocampus is not as activated
Most of the cases we have discussed involve damage that occurred late in
life. What about damage that occurs early in life?
Developmental Amnesia
method:
* used neuroimaging
participants:
* demage sustain during birth
* 2/3 lack of oxygen around birth for short period of time
* lead to demage to the brain and specifically the hipocampse(its sensitive) - early in life
* their brain demage went undetected
* when they enterted school adults become aware something was off (it took some time to be discovered)
observation
* their hippocamouse is smaller then ther control group - volume loss (just in this area)
memory performence:
- asked to draw something they never seen before
- they do well if they copy (with the image near by)
- but if the image is taken away and they have to remnebr how to draw , they do poorly (while the control group does well)-
key points of the study:
- they have poor episodic memory
- their languague,sematic memory tends to be intect
- they have smaller brain
why is this imporatant ?
because it highlights the difference between episodic memory is not intact and sematic memory is - they get by at school while they have a demage hippocampsu
in adults both are impared-
a potetioal reason as to why this happens
- maybe in infaces becomes more focal( not neceseesarly true)
- maybe when teh demage is in early on in life the brain re-organizes it self
if the hippo is necessary initially for acquisition for both semetic and episodic memory, then the pattern of developmental amenisia should not occur - unless placity is a thing
writte a summary about developmental
This study shows that episodic memory is connected to the hippo but the semantic memory might not be as when the brain was demaged as a child only the episodic memory was affected
This is true unless brain plasticity plays a role on this, where both memories are related to the hippo but when demaged the brain re-organized itself ( so other parts of the bran becomes more important for semetic)
