Physiological Psychology 41363
Outline 9
I. Sleep/Movement
A. Sleep
1. How do we study sleep
a. Electroencephalogram (EEG)- measures brain waves
b. Electrooculogram (EOG) - eye movements
c. Electromyogram (EMG) - muscle activity
first night phenomenon
II. Stages of sleep EEG
A. During wakefulness, alpha and beta activity
B. Stage 1 sleep - characterized by theta waves
C. Stage 2 sleep - contains theta waves, sleep spindles, and K complexes
D. Stage 3 sleep - some delta wave activity
E. Stage 4 sleep - more delta activity
F. REM sleep - dramatic change in EEG, eyes rapidly dart back and forth, and EMG
becomes silent - also called paradoxical sleep: vivid dreams: penile erections and
vaginal secretion
Each sleep cycle lasts about 90min with typically 4-5 periods of 20-30 min of REM sleep
III. Theories of why we sleep
A. Recuperative sleep - sleep is necessary to recuperate
B. Circadian rhythms - we have evolved a mechanism that encourages us to sleep when we
are not engaged in promoting our survival, or when it is most dangerous
zeitgebers - environ cues that trigger circadian rhythms
IV. Sleep deprivation
A. sleep deprivation studies find few ill effects of deprivation
B. Animal studies have had slightly diff findings
V. Selective sleep deprivation - some evidence for restoration hypothesis
VI. Sleep disturbances - 2 types
1. Insomnia - inability to initiate or maintain sleep: sleep apnea - cessation of breathing
2. Hypersomnia - excessive sleep or sleepiness
narcolepsy - repeated brief daytime sleep attacks
cataplexy - sudden loss of muscle tone during wakefulenss
VII. Brain areas involved in sleep
A. Suprachiasmatic nucleus (SCN) of the hypothalamus- responsible for circadian rhythms.
-SCN seems to have its own clock intrinsic to all neurons of the SCN
B. Reticular activating system in the brain stem (medulla) - stimulation produces arousal
C. Three neurotransmitter systems - norepi and Ach in the locus coeruleus: and serotonin
in the raphe nuclei
Movement
A. Three types of muscles
1. Skeletal muscle - muscles that move us
-two major movements of skeletal muscle involve
-flexion
-extension
a. Skeletal muscle contains a number of specialized structures
- extrafusal muscle fibers
- alpha motor neurons: alpha motor neuron and muscle fibers are referred to as a
motor unit
-bundle of myofibrils which are made up of actin and myosin - responsible for
muscular contraction
-muscle spindles - sensory organs that are sensitive to muscle length: Golgi
tendon organs sensitive to stretch
2. Smooth muscle - controlled by autonomic NS
3. Cardiac muscle - found in heart
B. Control of movement in brain
1. Motor cortex
-principle input to motor cortex comes from frontal association cortex
C. Four different pathways for motor cortex control of movement
1. Corticospinal- lateral coticospinal tract controls distal parts of limbs - hands and fingers,
feet and toes: ventral corticospinal tract (upper legs and trunk)
2. Corticobulbar - facial movements
3. Rubrospinal tract - movement of forearm and hands that are independent of trunk
movements
4. Ventromedial - trunk and proximal limb muscles: posture, coordinating body movements
with eye movement, and automatic functions like sneezing respiration etc
D. Disorders of movement
1. Apraxia - inability to execute a learned movement
-Limb apraxia
-Constructional apraxia
E. Brain regions involved in movement
1. Basal ganglia
2. Cerebellum
3. Reticular formation