Consciousness What is it? Can we look at it directly?

The mystery of consciousness  Something we all know intimately, but can’t define?  So hard to pin down, many don’t even try  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

sleep  Circadian rhythms - patterns of activity/inactivity of about 24 hrs. –Sleep Wake Cycle  Shared by all living things to aid adaptation

the circadian rhythm  Originates in the hypothalamus  Calibrated by the sun but not dependent on it

We all sleep, Why?  Repair and Restoration  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

Why sleep? ii  To learn – neuronal connections strengthen  We solve tough problems easier  Our hippocampus mints new neurons

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

Sleep stages ii  As we sleep our brains and, eventually, the movements of our eyes follow regular stages  Stage 1 –brain is slowing down  Stage 2 – 4 waves slow gradually and become increasingly rhythmic, indicating less activity, eyes still inactive

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

Rem sleep  Discovered by researchers at both Stanford and in France in the 1950’s, REM sleep has a number of fascinating qualities:  1) While the sleeper’s eyes and brain are active, the major muscles are virtually paralyzed, thus the tag REM paralysis  2) When aroused, people describe vivid dreams,

Rem ii 3) We all dream though some never recall them, 3) We all dream though some never recall them, 4) dreams are in real time and in color, 4) dreams are in real time and 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, and 7) sleepers experience genital arousal, and 8) we need less as we age. 8) we need less as we age.

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 REM rebound, b) as soon as it does we see the REM rebound, c) but early claims of paranoia have proved exaggerated. c) but early claims of paranoia have proved exaggerated..

Rem and learning  If we are denied REM we do not learn as well or as quickly.  If we have a rough day emotionally, we need more REM sleep,  REM improves memory storage ( in concert with the hippocampus?)  REM facilitates forming neuronal connections.

Sleep Disorders  Insomnia – the inability to fall, stay or profit from sleep tactics to prevent tactics to prevent 1) stay away from bed if not tired 1) stay away from bed if not tired 2) beds are for sleeping 2) beds are for sleeping 3) avoid alcohol, sleeping drugs 3) avoid alcohol, sleeping drugs 4) stick to a regular schedule 4) stick to a regular schedule

More Sleep Trouble  Sleep apnea - temporary halt in breathing while sleeping can cause serious problems can cause serious problems  Narcolepsy – falling into REM sleep during the day without warning don’t drive dreaming don’t drive dreaming