-
-
restorative sleep
species with higher metabolic rates sleep more
-
adaptive sleep
- amount of sleep depends on:
- availability of food
- safety considerations
- ->predators and animals that can hide, sleep a lot
- -> animals without shelter and feed often sleep little
-
performance after deprivation
- performance declines in shift workers
- long-term deprivation, performance declines at night and recovers during the day
-
night time accidents
- driving accidents peak at 2am
- ->Chernobyl meltdown
- ->exxon valdez oil spill
-
eastward travel
- west coast teams playing in the east
- staying up late vs. going to bed early
-
circadian rhythm
- rhythm about a day in length
- main biological clock is suprachiasmoatic nucleus (SCN)->lesioning SCN in rats abolishes 24 hr rhythms of sleep, activity, body temp and drinking
- ->SCN entrained to day-night cycle by zeitgebers "time-givers" (most important is light)
-
melatonin
- secreted by pineal gland
- hormone that induces sleep
-
ultradian rhythms
- shorter than a day in length->hormone production, urinary outputs, alertness, day dreaming and EEG activity follow this
- ->basic rest and actvity cycle is 90-100 min. longcycle extends into sleep, with 90 min. variations in arousal
-
EEG waves
- awake: miss of Alpha and Beta waves
- sleep stage 1: theta waves
- sleep stage 2: sleep spindles and K-complex
- sleep stage 3 and 4: delta waves
after stage 4 sleeper moves through stages in reverse, not returning to stage one, instead entering REM
-
EEG waves
- delta: 1-4 Hz
- theta: 4-8 Hz
- alpha: 8-13 Hz
- beta: 13-30 Hz
- gamma: 30-90 Hz
DONT TRUST ALL BAD GIRLS
-
EEG waves:
- sleep spindles
- stage 2: brief bursts of 12-14Hz waves
- k-complex
-
Rapid Eye Movement
- REM
- eyes dart back and forth horizontally
- most dreaming occurs during this
- non-rem dreams are less vivid
- promotes neural development->50% of sleep in infancy
- encourages differentiation, maturation and myelination in higher brain center
-
activation-synthesis hypothesis
- dreams area by-product
- forebrain combines info from brainstem
- invlved memory consolidation and sensory input
- ->doesn't include "meaning" in dreams
-
reverse learning hypothesis
brain achieves efficiency by purging memories during REM sleep
-
preoptic area of the hypothalamus
- regulates temperature, inhibits arousal areas
- ->locus coeruleus and raprie nuclei
- ->warmth induces sleep
-
sleep and consciousness
- lucid dreamers are semi-conscious
- sleepwalkers in non-REM sleep can drive a car and eat
-
consciousness
- state: a person is conscious or unconscious
- indicates a sense of awareness of something
- varies in level
- ->coma, sleep, alert wakefulness
- altered states
- ->hypnosis, trances, meditative states
- most researchers agree that consciousness involves:
- ->awareness (content)
- ->attention (process)
- ->a sense of self
-
brain areas involved in awareness
- prefrontal cortex (relationship between stimuli)
- hippocampus (declarative learning)
- parietal lobes (locating objects in space for combining features into a conscious whole)
-
binding characteristics of awareness
- synchronization of neural activity
- ex: moving object synchronizaes between V1 and V5 (movement)
-
attention
- process involves focusing on some neural inputs to exclusion of others
- ACC plays executive role in allocating attention
- ->20% of ACC neurons increase or decrease firing during attention-demanding tasks->ACC active during stroop test (color test)
-
sense of self
- identity (I)
- sense of agency, attribution/effect to self
- mirror recognition studies
- ->sense of self develops about 15 months in age
- some animals can recognize selves in a mirror as well
|
|
