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4 Dec 2025
•
Understanding Crick and Mitchison's (1983) Theory of Sleep and Dream Organization
Tyra-Angel
@xt_ang_studyx
1 / 3
Crick and Mitchison's Reorganisation Theory
Think of your brain like a smartphone that's running out of storage - that's exactly how Crick and Mitchison viewed memory in 1983. Their reorganisation theory suggests we dream to delete useless information and make room for what actually matters.
The theory works like this: during REM sleep, your brain acts as a filter, sorting through the day's experiences. It keeps adaptive memories (useful stuff that helps you survive) and deletes parasitic memories (pointless or harmful thoughts that waste mental resources).
This process is called reverse learning - essentially undoing unnecessary connections formed during the day. Crick and Mitchison believed parasitic memories could lead to obsessions and hallucinations if left unchecked, so REM sleep serves as your brain's overnight cleanup crew.
Quick Tip: The theory is based on information consolidation - imagine your brain defragmenting like a computer, organising files and deleting junk to run more smoothly.
Strengths of the Theory
The reorganisation theory isn't just theoretical speculation - it's backed by some solid research that makes it worth taking seriously. Heber et al. (2004) found that slow wave sleep can boost learning by up to 25%, which supports the idea that sleep reorganises our cognitive abilities.
Real-world evidence strengthens this theory too. People with primary insomnia show significant drops in concentration, memory, and problem-solving skills - exactly what you'd expect if sleep reorganisation wasn't happening properly.
Sleep deprivation studies like Peter Tripp's famous experiment demonstrate serious cognitive decline after just a few days without sleep. This suggests our brains genuinely need that overnight maintenance period to function effectively.
Remember: The theory explains why REM sleep exists and provides a clear evolutionary advantage - more efficient memory storage means better survival chances.
Weaknesses and Modern Challenges
Despite its appeal, the reorganisation theory faces some serious criticism from modern sleep research. The biggest problem? It's based on computer models that don't capture the complexity of human cognition - your brain isn't actually like a hard drive with limited storage.
Recent evidence suggests our brains might have unlimited storage capacity, which would make the whole "deleting memories" premise unnecessary. Even more problematic, current research shows sleep consolidates rather than deletes memories, directly contradicting Crick and Mitchison's core claim.
PTSD patients present the strongest counter-evidence - they experience repetitive nightmares that make traumatic memories worse, not better. If REM sleep deleted harmful memories, these patients should improve with more sleep, but they don't.
Rasch and Born (2013) found that people who tried to suppress memories before sleeping actually remembered them better afterwards, and that sleep improves creative thinking rather than limiting it.
Key Point: Modern memory consolidation theory by Axmacher suggests sleep strengthens and organises memories rather than deleting them, supported by EEG studies showing active memory transfer during sleep.
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Understanding Crick and Mitchison's (1983) Theory of Sleep and Dream Organization
Tyra-Angel
@xt_ang_studyx
Ever wondered why we dream and forget so much of what happens during our sleep? Crick and Mitchison's reorganisation theory suggests we dream to delete unnecessary memories and make our brains work more efficiently, like defragmenting a computer.
Crick and Mitchison's Reorganisation Theory
Think of your brain like a smartphone that's running out of storage - that's exactly how Crick and Mitchison viewed memory in 1983. Their reorganisation theory suggests we dream to delete useless information and make room for what actually matters.
The theory works like this: during REM sleep, your brain acts as a filter, sorting through the day's experiences. It keeps adaptive memories (useful stuff that helps you survive) and deletes parasitic memories (pointless or harmful thoughts that waste mental resources).
This process is called reverse learning - essentially undoing unnecessary connections formed during the day. Crick and Mitchison believed parasitic memories could lead to obsessions and hallucinations if left unchecked, so REM sleep serves as your brain's overnight cleanup crew.
Quick Tip: The theory is based on information consolidation - imagine your brain defragmenting like a computer, organising files and deleting junk to run more smoothly.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Strengths of the Theory
The reorganisation theory isn't just theoretical speculation - it's backed by some solid research that makes it worth taking seriously. Heber et al. (2004) found that slow wave sleep can boost learning by up to 25%, which supports the idea that sleep reorganises our cognitive abilities.
Real-world evidence strengthens this theory too. People with primary insomnia show significant drops in concentration, memory, and problem-solving skills - exactly what you'd expect if sleep reorganisation wasn't happening properly.
Sleep deprivation studies like Peter Tripp's famous experiment demonstrate serious cognitive decline after just a few days without sleep. This suggests our brains genuinely need that overnight maintenance period to function effectively.
Remember: The theory explains why REM sleep exists and provides a clear evolutionary advantage - more efficient memory storage means better survival chances.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Weaknesses and Modern Challenges
Despite its appeal, the reorganisation theory faces some serious criticism from modern sleep research. The biggest problem? It's based on computer models that don't capture the complexity of human cognition - your brain isn't actually like a hard drive with limited storage.
Recent evidence suggests our brains might have unlimited storage capacity, which would make the whole "deleting memories" premise unnecessary. Even more problematic, current research shows sleep consolidates rather than deletes memories, directly contradicting Crick and Mitchison's core claim.
PTSD patients present the strongest counter-evidence - they experience repetitive nightmares that make traumatic memories worse, not better. If REM sleep deleted harmful memories, these patients should improve with more sleep, but they don't.
Rasch and Born (2013) found that people who tried to suppress memories before sleeping actually remembered them better afterwards, and that sleep improves creative thinking rather than limiting it.
Key Point: Modern memory consolidation theory by Axmacher suggests sleep strengthens and organises memories rather than deleting them, supported by EEG studies showing active memory transfer during sleep.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Most popular content: Rem Sleep
Most popular content in Psychology
Most popular content
English - inspector calls quotes and analysis
Quotes from every main character
English Literature10
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user