Reorginisational Theory Flashcards
Who made this theory
Crick and Mitchison in 1983
Main statement
That the main function of dreams is to reorganise to improve memory storage
What is the theory based on
The concept of reverse learning which they state happens in REM sleep
Why do dreams occur according to this theory
Because they are a side effect of the decluttering process during sleep
Basis of REM statment
That the cortex becomes overloaded with information during the day so during REM sleep unwanted memories are deleted to improve organisation and make space for new memories
What is the two categories of memories
Adaptive and parasitic
What are adaptive memories
Memories that have useful information
What are parasitic memories
Memories that are not useful and just waste resources
What occurs during REM sleep according to this theory
The reverse learning of parasitic memories
What was the idea of parasitic memories based on
Computer simulations
What was the buildup of memories causing
Obsessional thoughts and hallucination and that REM sleep is where we delete these memories
Evidence against
Rasch and Born in 2013 who found that REM sleep counteracted participants actively suppressing memories and that they actually recalled these memories better after sleep which refuted the idea that REM sleep removes unwanted memories
Evidence for
Saletin et al in 2011 found that sleep only protects items with instructed future relevance while sacrificing those without future relevance which supports the idea that sleep strengthens adaptive memories while pruning parasitic memories
What evidence did Crick and Mitchison present
They studied which animals experienced REM sleep and their brain size and found that animals with no REM sleep had far larger brains which suggested they are not as efficient as our because of the absence of REM sleep
What are the weakness of this theory
They did not have many human participants instead choosing to use computer simulations as evidence and because of that the results are not applicable to the wider human population
It does not explain why dreams have a narrative and make sense often, this refutes the idea that random memories are recalled when destroyed
It understimates the capacity of the human brain
If REM sleeps primary function is to remove unwanted memories it does not explain why babies have a high percentage of their sleep being REM as they should not have as much memories to remove
