Crick & Mitchison's Reorganisational Theory of Dreaming

Question 1

the theory suggests that the function of dreams is to…

Answer 1

make the most of our ability to store memories

Question 2

since the brain’s storage capacity is limited, some memories are…

Answer 2

deleted overnight to use storage space efficiently

Question 3

reverse learning

Answer 3

learning can be undone during sleep

Question 4

as memories are activated during sleep…

Answer 4

a random selection of thoughts are turned into a dream

Question 5

categories of memories

Answer 5

• adaptive
• parasitic

Question 6

adaptive memories

Answer 6

useful memories

Question 7

parasitic memories

Answer 7

useless memories that waste space

Question 8

species with large brains in proportion to body size…

Answer 8

lack REM sleep

Question 9

pruning of memories during REM allows brains to…

Answer 9

be smaller and more efficient

Question 10

neural network computer programmes

Answer 10

• became overloaded, so an unlearning system had to be created
• C&M suggested that the same thing happens in the brain

Question 11

evidence against reorganisational theory: Walker et al. (finger tapping)

Answer 11

using a finger tapping task, they found that sleep helps memories to become reliably encoded

Question 12

evidence against reorganisational theory: Medrick et al. (nap benefits)

Answer 12

for a perception task, a 90 min nap had the same benefits as a full night’s sleep, showing that sleep helps to strengthen memories

Question 13

evidence against reorganisational theory: Seehagen et al. (babies)

Answer 13

when babies were learning a new task, those who had had a nap showed better recall than those who had not, showing that sleep facilitates information processing

Question 14

weaknesses (3)

Answer 14

• based on computer models and lacks research on humans
• research on dolphins cannot be generalised to humans
• doesn’t explain why dreams have a narrative