1. Harvard Medical School Beth Israel Deaconess Medical Center Boston, MA Sleeping on a Problem: Where Insight is Expected Robert Stickgold

2. Insight “The sudden appearance in conscious awareness of a new and useful relationship among previously known information” “The sudden appearance in conscious awareness of a really big new and useful relationship among previously known information” Questions:  How does the nonconscious brain find these relationships?  How does it identify them as valuable?  How does it bring them into conscious awareness?  Should we only consider the “really big” ones?

3. “Really Big?” Normal science: "Curiosity demands that we ask questions, that we try to put things together and try to understand [them]... In this way we try gradually to analyze all things, to put together things which at first sight look different, with the hope that we may be able to reduce the number of ‘different things’ and thereby understand them better.” Richard Feynman (1963) "The Feynman lectures on physics"

4. “Really Big?” ”Scientific revolutions are inaugurated by a growing sense... that an existing paradigm has ceased to function adequately in the exploration of... nature.” Entrenchment reduces possibility of shifting Thomas Kuhn (1962) "The Structure of Scientific Revolutions"

5. Or Not So Big? Piaget proposed that children learn by constructing a model of the world built of “schemas” that explain how parts of the world work. Assimilation (like normal science) integrates new perceptual information into innate or personally developed schemas (“robins”) (Children are biased to fit data into schemas) (Piaget, 1981)

6. Or Not So Big? When assimilation fails (“penguins”) accommodation modifies the schemas “to fit reality” (Piaget & Inhelder, 1969, p. 6) So, big or small, the process of insight is probably fundamentally the same.

7. Sleep & Insight Insight, then, whether related to large or small discoveries, is a special case of Piagetian accommodation in which the process occurs outside of conscious awareness. Obviously, this process of accommodation (and insight) is defined by the innate wiring and functional plasticity of the human brain. The processes of brain plasticity necessary for Piagetian accommodation, and hence for insight, may be most daringly activated, not during wake, but during sleep.

8. There are Different Kinds of Sleep

9. A Good Night’s Sleep 11 PM1 AM3 AM5 AM7 AM Wake I/REM II III IV Sleep onset Stage 2 NREM SWS REM sleep

10. Sleep Physiology EEG Wake Stage 2 Stage 4 REM 2 sec EOG Stage 1 Stage 2 REM EMG Wake Stage 4 REM

11. Neuromodulation Varies Across the Wake-Sleep Cycle Active Wake ACh NE 5-HT Quiet Wake SWSREM Ach:acetylcholine (scopolamine, belladonna) NE:norepinephrine (MAO inhibitors, cocaine) 5HT:serotonin (Prozac, LSD)

12. Regional Activation in REM Sleep

13. Hippocampal-Neocortical Dialog Neocortex Hippocampus

14. There are Different Kinds of Memory

15. Sleep Alters Associative Memory Systems Cindi Rittenhouse Jen Holmes Beth Schirmer Lauri Scott Semantic Priming (580 ms) thief wrong (560 ms) rightwrong paperwrong (600 ms)

16. 0.01 0.17 0.01 Weak Strong msec 0 10 20 30 REM NREM PM

17. Sleep Enhances Insight Number Reduction Task 11449494114494941144949411449494 1441991 Ulrich Wagner Jan Born Wagner et al. (2004) Nature 427: 352

18. Development of Insight Wake/ Night Wake/ Day Sleep/ Night 0% 20% 40% 60% Subjects gaining insight Improvement in speed (ms) 0 100 200 Solvers Non-solvers SWS 11449494114494941144949411449494 1914419 9

19. Ina Djonlagic Andy Rosenfeld Mark Gluck Sleep Calculates the Rules

20. ?!? Probabilistic Learning Card 1 Card 2 Card 3 Card 4 80%60%40%20%

21. Practice & Sleep Enhance Performance 0 2 4 6 8 10 12 14 p = 0.01 Observation Improvement (% of trials) Wake Sleep Feedback p = 0.06

22. Weather Forecasting & REM Sleep 15% 17% 19% 21% 23% 25% 5565758595 Post-Training Performance (% of optimal) REM Sleep (%) r = 0.70 p = 0.008

23. Jessica Payne Ruth Propper Daniel Schacter Word Lists DoorHouseLedge GlassOpenBreeze PaneFrameCurtain ShadeView Sleep Enhances the Gist

24. 12-Hour Deterioration 15 0 -15 -30 -45 -60 Critical lures Studied words * % Change (relative to 20 min Wake Sleep *

25. 5 15 25 35 10152025 SWS (%) Words Recalled Morning Recall r = - 0.47 p = 0.03

26. 60 Nap 0 10 20 30 40 50 01020304050 SWS (min) words Morning & Nap Recall r = - 0.47 p = 0.03 Overnight words SWS (min) 0 40 10 20 30 50 100 40 60 80 120 r = - 0.54 p = 0.037

27. Creative Intrusions WordList PlateCup SpoonCup Fuzzy Swirl BloodDoctor Rough? Smooth? Soft? Mountain??

28. 0% 20% 40% Wake Percent of Intrusions Sleep Creative Intrusions

29. New Experiences are Replayed at Sleep Onset Hypnagogic dreams Erin Wamsley Karen Emberger Laura Babkes

30. Alpine Racer II 14 out of 16 players (88%) 14 out of 16 players (88%) 42% of first night reports contain skiing imagery 42% of first night reports contain skiing imagery 3 out of 3 controls who only watched 3 out of 3 controls who only watched

31. Alpine Racer Images “ “I keep seeing all the places where I fall- like, hit the walls. It’s kind of annoying; and then my legs fly up in the air.” (SEC) “I can sort of feel the motions of the game but more not really seeing it.” (MLC) “I envisioned myself skiing, and for a second there it felt like I was skiing backwards - something I used to attempt when I was younger.” (CMD)

32. Delayed Onset Reporting } REPORTS Standard protocol 023456781 } Math problems REPORTS Delayed onset 023456781

33. Insights Without Insight "I felt like I was sort of sliding downhill again. And, um... there were instructions and a person and uh, I don't know." (JAV, rpt 6) "I was having a rather vivid image as though I was moving forward through some kind of a forest... I was moving forward very stiffly. Um, my entire upper body was incredibly straight... it felt almost as if I was moving forward on a conveyor belt, and, without my legs actually moving." (MAM, rpt 8) "I felt as though I was falling downhill. And I was dreaming about like instructions to a young king or something." (JAV, rpt 4)

34. The Biology of Insight The discovery of “insights” is aided by: Shutting down logical (DLPFC) processing Shutting down episodic memory replay (HC) Enhancing error detection (ACC, MOFC) Enhancing weak associations, and thereby … Enhancing the recognition of accommodations that expand our understanding of the world

35. The Biology of Insight All of which occurs during REM Sleep! Thus sleep, and REM sleep in particular, may not only represent a model system for the processes involved in insight … But may actually represent a brain state which evolved, in part, to facilitate the discovery of insights.