Altered statesAltered states

A backwards, but important, look A backwards, but important, look at consciousnessat consciousness

The mystery of consciousnessThe mystery of consciousness

Something we all know intimately, but can’t Something we all know intimately, but can’t define?define?

So hard to pin down, many don’t even trySo hard to pin down, many don’t even try How about – How about – a person’s awareness of a person’s awareness of

everything that is going on around him or everything that is going on around him or her at any given momenther at any given moment

We try to understand it by looking at We try to understand it by looking at ourselves when it is alteredourselves when it is altered

Intro to sleepIntro to sleep

To look at sleep in the proper context, let’s To look at sleep in the proper context, let’s examine our timing mechanismsexamine our timing mechanisms

They promote efficiency by making sure that They promote efficiency by making sure that we are at our best during daylight when we we are at our best during daylight when we can use our vast visual capacitiescan use our vast visual capacities

Ensured by our Ensured by our circardian rhythmcircardian rhythm a pattern a pattern of activity/inactivity of about 24 hrsof activity/inactivity of about 24 hrs

the circadian rhythmthe circadian rhythm

Originates in the Originates in the hypothalamus hypothalamus in its in its suprachiasmatic nucleus suprachiasmatic nucleus which signals the which signals the pineal gland pineal gland to releaseto release melatonin melatonin

Calibrated by the sun but not dependent Calibrated by the sun but not dependent on iton it

Thrown out of whack by jet lag, shift work, Thrown out of whack by jet lag, shift work, or other major disruptions to our routineor other major disruptions to our routine

Are you (or will you be) a morning person?Are you (or will you be) a morning person?

We all sleep. Why?We all sleep. Why?

Repair and Restoration – Repair and Restoration – we sleep to let the we sleep to let the body to recover from the exertions of the body to recover from the exertions of the dayday

After all, our abilities and mood typically After all, our abilities and mood typically falter without it falter without it

We also are more likely to get sickWe also are more likely to get sick But our level of activity doesn’t correlate with But our level of activity doesn’t correlate with

our need and some fare well with littleour need and some fare well with little

Why sleep? iiWhy sleep? ii

Evolutionary/Conservation – Evolutionary/Conservation – evolutionary evolutionary forces led us to adopt regular patterns of forces led us to adopt regular patterns of activity and inactivity to protect us and activity and inactivity to protect us and conserve energyconserve energy

We do save 10-25% of energyWe do save 10-25% of energy Also prey animals sleep much lessAlso prey animals sleep much less But no one will dispute that some repair But no one will dispute that some repair

goes on while we sleepgoes on while we sleep

Why sleep? iiiWhy sleep? iii

Learning – Learning – we strengthen neuronal connections we strengthen neuronal connections that serve as the basis of learning as we sleepthat serve as the basis of learning as we sleep

Progress in understanding complex problems often Progress in understanding complex problems often only comes after sleeponly comes after sleep

Also, the Also, the hippocampus hippocampus mints new neurons only as mints new neurons only as we sleepwe sleep

The stages of sleepThe stages of sleep

Researchers have investigated sleep Researchers have investigated sleep through the simultaneous use of :through the simultaneous use of :

1)1)Electroencephalographs Electroencephalographs (EEGs) (EEGs) which measurewhich measure electrical activity electrical activity within the brainwithin the brain, , andand

2) 2) Polysomnographs Polysomnographs which which measure measure eye movements. eye movements.

Sleep stages iiSleep stages ii

As we sleep our brains and, eventually, the As we sleep our brains and, eventually, the movements our eyes follow regular stagesmovements our eyes follow regular stages

Stage 1 –brain is slowing down, as shown Stage 1 –brain is slowing down, as shown by short but choppy waves on the EEG; our by short but choppy waves on the EEG; our eyes are inerteyes are inert

Stage 2 – 4 waves slow gradually and Stage 2 – 4 waves slow gradually and become increasingly rhythmic, indicating become increasingly rhythmic, indicating less activity, eyes still inactiveless activity, eyes still inactive

The rem stageThe rem stage

After Stage 4, we move back through After Stage 4, we move back through Stages 3 and then 2, but instead of then Stages 3 and then 2, but instead of then going into Stage 1, we enter into ….going into Stage 1, we enter into ….

REM sleep REM sleep in which our eyes suddenly in which our eyes suddenly move about, as if we were awake, and our move about, as if we were awake, and our brain waves become fast and choppy like brain waves become fast and choppy like Stage 1 Stage 1

These cycles run for about 90 minutesThese cycles run for about 90 minutes

Rem sleepRem sleep

Discovered by researchers at both Stanford Discovered by researchers at both Stanford and in France in the 1950’s, REM sleep had and in France in the 1950’s, REM sleep had a number of fascinating qualities:a number of fascinating qualities:

1) While sleeper’s eyes and brains are 1) While sleeper’s eyes and brains are active the major muscle are virtually active the major muscle are virtually paralyzed, thus the tag paralyzed, thus the tag Paradoxical sleepParadoxical sleep

2) When aroused, people described vivid 2) When aroused, people described vivid dreams,dreams,

Rem iiRem ii

3) We all dream though some never recall them,3) We all dream though some never recall them,

4) dreams are in 4) dreams are in real time real time andand in color,in color,

5) REM composes 20-25% of our sleep,5) REM composes 20-25% of our sleep,

6) time in REM lengthens as the night goes on,6) time in REM lengthens as the night goes on,

7) sleepers experience genital arousal, and7) sleepers experience genital arousal, and

8) we need less as we age. 8) we need less as we age.

Why rem?Why rem?

We are not sure, but if we take it away…We are not sure, but if we take it away… a) It attempts to return relentlessly, and a) It attempts to return relentlessly, and

b) as soon as it does we see the b) as soon as it does we see the REM REM rebound,rebound,

c) we become irritable and anxious, andc) we become irritable and anxious, and..

Rem and learningRem and learning

If we are denied REM we do not learn as If we are denied REM we do not learn as well or as quickly.well or as quickly.

If we spend a lot of time learning, we spend If we spend a lot of time learning, we spend more time in REM.more time in REM.

REM improves memory storage ( in concert REM improves memory storage ( in concert with the hippocampus?)with the hippocampus?)

As stated earlier, REM facilitates tightening As stated earlier, REM facilitates tightening neuronal connections. neuronal connections.