Altered states

1. Altered states A backwards, but important, look at consciousness

2. The mystery of consciousness • Something we all know intimately, but can’t define? • So hard to pin down, many don’t even try • How about – a person’s awareness of everything that is going on around him or her at any given moment • We try to understand it by looking at ourselves when it is altered

3. Intro to sleep • To look at sleep in the proper context, let’s examine our timing mechanisms • They promote efficiency by making sure that we are at our best during daylight when we can use our vast visual capacities • Ensured by our circardian rhythm a pattern of activity/inactivity of about 24 hrs

4. the circadian rhythm • Originates in the hypothalamus in its suprachiasmatic nucleus which signals the pineal gland to release melatonin • Calibrated by the sun but not dependent on it • Thrown out of whack by jet lag, shift work, or other major disruptions to our routine • Are you (or will you be) a morning person?

5. We all sleep. Why? • Repair and Restoration – we sleep to let the body to recover from the exertions of the day • After all, our abilities and mood typically falter without it • We also are more likely to get sick • But our level of activity doesn’t correlate with our need and some fare well with little

6. Why sleep? ii • Evolutionary/Conservation – evolutionary forces led us to adopt regular patterns of activity and inactivity to protect us and conserve energy • We do save 10-25% of energy • Also prey animals sleep much less • But no one will dispute that some repair goes on while we sleep

7. Why sleep? iii • Learning – we strengthen neuronal connections that serve as the basis of learning as we sleep Progress in understanding complex problems often only comes after sleep Also, the hippocampus mints new neurons only as we sleep

8. The stages of sleep • Researchers have investigated sleep through the simultaneous use of : • 1)Electroencephalographs (EEGs) which measure electrical activity within the brain, and • 2) Polysomnographs which measure eye movements.

9. Sleep stages ii • As we sleep our brains and, eventually, the movements our eyes follow regular stages • Stage 1 –brain is slowing down, as shown by short but choppy waves on the EEG; our eyes are inert • Stage 2 – 4 waves slow gradually and become increasingly rhythmic, indicating less activity, eyes still inactive

10. The rem stage • After Stage 4, we move back through Stages 3 and then 2, but instead of then going into Stage 1, we enter into …. • REM sleep in which our eyes suddenly move about, as if we were awake, and our brain waves become fast and choppy like Stage 1 • These cycles run for about 90 minutes

11. Rem sleep • Discovered by researchers at both Stanford and in France in the 1950’s, REM sleep had a number of fascinating qualities: • 1) While sleeper’s eyes and brains are active the major muscle are virtually paralyzed, thus the tag Paradoxical sleep • 2) When aroused, people described vivid dreams,

12. Rem ii 3) We all dream though some never recall them, 4) dreams are in real time andin color, 5) REM composes 20-25% of our sleep, 6) time in REM lengthens as the night goes on, 7) sleepers experience genital arousal, and 8) we need less as we age.

13. Why rem? We are not sure, but if we take it away… a) It attempts to return relentlessly, and b) as soon as it does we see the REM rebound, c) we become irritable and anxious, and .

14. Rem and learning • If we are denied REM we do not learn as well or as quickly. • If we spend a lot of time learning, we spend more time in REM. • REM improves memory storage ( in concert with the hippocampus?) • As stated earlier, REM facilitates tightening neuronal connections.