Beth Part 2 Flashcards
Tulving
Episodic has events- easily forgotten amd better when young, affected in amnesia. Semantic has facts but not time and placed learnt, more durable as consolidated, better when old. KC had amnesia, no episodic memory but semantic fine as remembered how to change tire but not where he learnt it. Personal semantic knowledge like knew was in crash but couldn’t remember it -from others
Single vs double dissociation
KC example of single dissociation - not enough as episodic may be esp vulnerable or people may show issues in both so may not be separated
Semantic dementia
Semantic impaired but episodic fine, type of fronto temporal dementia. Loss of indertsandinf of words and objects. Damage next to hippo (fusiform and entrohinal) episodic fine e.g. can describe holiday. Graham 2000: shown pic then a set of pics W identical image within, or then shown set of different images showing the same objects e.g. red phone now blue phone. If know concept-ps could id both but when don’t they can id identical object but not diff picture
Hippo and anterior temporal lobe
Hippo has episodic but ATL has extraction of similarities between experiences to create concepts e.g. semantic memory - difference between episode and concept
Different learning systems- hippo and cortex - mclelland 95
Hippo has fast learning, binds elements of episodes, few neurones (sparse coding) so memories can be separated. Neocortex has slower learning, similar dewatered coded strongly for semantic learning which prevents catastrophic interference (loss of old memories when new learnt)
Squire - episodic then semantic theory /opposing tulving as separate systems
Hippo time limited so transfers to neocortex. Kim and fanselow 92: inhibition of protein synthesis to stop changes in ltp disrupts memory for 1 hour (memory leaves hippo), when given hippo lesion after 2 weeks of learning, still remember 50%, if right after remember nothing, if 28 days, remembers almost everything but not 100%.
Temporal gradients
In amnesia events are not remembered after injury, better childhood memories- same as AD graham and hodges 97. Reverse temp gradient in SD as better recent memories as still in hippo. Cormack and O’Connor 83: older memories retrieved more so rely on semantic (remember what’s said not what actually happened) older more in neocortex
Encoding
Impaired in amnesia so have impaired learning of new events, retrieval also impaired for events just before injury but not childhood as in neocortex. Over time, connections go to neo as take out unnecessary
Consolidation
REM used in consol of motor skills, Marshall 2016: electrical stim that enhances slow wave sleep boosts verbal learning in declarative memory but skill memory unchanged. Friedrich 2014: babies 9-18m who napped for 1.5hrs after learning were better at generalising word meaning beyond example as erp diff for known vs unknown words
Reactivation in humans
From the rat maze okeefe: when asleep, the hippo neurones were reactivated in the series from the actions they just did. Deikelmann 2011: ps learnt card locations and presented W odours. Odours re presented during sleep as olfactory doesn’t turn off and brain reactivates the card memory
Two challenges to episodic then semantic theory
Hippo still reencodes during retrieval (creates traces)-multiple trace theory nadel and moscovitch (hippo still used for old memories). Theory says Hippo needed to form memories but in dev amnesia bilateral hippo damage so have poor verbal and non learning but iq, wm and semantic fine just didn’t recall where/when learnt, 44% reduced hippo. So may be scale and not all transferred out of hippo- may be bc entorhinal and peri may have semantic
