Lecture 6: Creativity, semantic memory and age Flashcards
What is GIST?
Gist is centrally shared concepts around a semantic memory.
Chronologically older memories: we lose the episodic specific details, however remember the cooccuring themes that happened e.g may not be able to remember what you had for breakfast last week but remember features about it
What does research say about the impact of sleep on gist?
Sleep facilitates abstraction of gist info as well as the integration across multiple memories
What does the ioTa model stand for
Information overlap to abstract
What does the ioTa model explain?
It explains how the specific physiology of slow wave sleep (SWS) in combo with the replay of memories could assist consolidation by transferring memories from ST to LT cortical representations
Explain what the ioTa says about overlapping replay
The overlap in memory reactivation can occur simultaneously or sequentially
When memories are overlapped simultaneously, the neurons which code for shared memory components are more strongly activated - this means that during SWS when downscaling occurs, these memories have stronger formations are less likely to be downscaled
When memories are overlapped sequentially, the neurons which cde for the shared memory components are more strongly activated - potential from the 2nd will build from the potentiation from the first and so on
How does overlapping replay lead to schemas?
Multiple bouts of reactivation in different combinations could act with downscaling so abstract networks of connected neural nodes form more detailed/accurate representations between different experiences creating a schema
Explain how the ioTa says we can add to existing schemas
Work in rats has shown that memories conforming to an existing schema are added to the neocortex quicker - no longer needing the hippocampus
When you activate a new memory with additional features relating to an existing schema, all nodes are activated a the same time and therefore the connections are strengthened and less likely to be downscaled during SWS
How do you know when a schema has become integrated?
Activation of a single node triggers the schema
What is a schema?
An adaptive, generalisable, associative memory network
What is the taxonomy of memory
Declarative (explixit)
WM, episodic, semantic
Non-declarative (implicit)
Priming, procedural, conditioning, non associative
What is semantic memory?
Memory for knowledge about the world e.g Paris is the capitol of France (do not remember when we learnt this)
How are semantic memories are formed (ioTa theory?
Episodic memories are processes in the medial temporal lobe overtime and through reactivation they evolve and become more semantic and represented in the cortical
What is synaptic homeostasis?
Global downscaling of recently potentiated synapse during SWS
In rats, where we can look at the surface area of the synapse (related to strength), if animals can sleep these surfaces reduce and can actually grow stronger if they cannot sleep
Connections which are not strong are more likely to be downscaled during SWS
Describe Hemies et al study design
Created 2 schemas that were very similar -crab vs ants or cell types vs cell organelles
Ppts were trained in just 1 schema, then taught novel information (1/2 relating to schema they learned, 1/2 not relating to the schema - consolidated knowledge)
Spent the night in the lab
Taught more facts in the morning (unconsolidated knowledge)
Ppts were then tested on all they learned (consolidated and unco
Hemies et al study results (schema vs non schema)
Knowledge relating to the schema was remembered better than knowledge not relating to the schema
This benefit increased over night: having 24 hours led to a greater schema advantage
This was associated with spindle density (which is associated with replay) = the higher spindle density the more schema advantage to memory
