CHAPTER 4

I. Psychological States and levels of Arousal

II. Sleep defined

A. Stages of sleep (Rechtschaffen & Kales, 1968, criteria)

SWS = slow wave sleep, REM = rapid eye movement, HR = heart rate, RR = respiration rate, BP = blood pressure

III. Sleep disturbances

A. Types of sleep deprivation

1. Total - absence of sleep
2. Partial - reduced sleep duration
3. Selective - absence of particular sleep stages

B. Sleep onset
Performance during stage 1 sleep to a simple task

C. Sleep disruptions and recovery

1. Exercise - appears to depend upon exercise intensity/duration

SWS increased after exercise to exhaustion, but recovery night following exercise no different than baseline.

2.Disrupted sleep

a. performance effects

3.Shiftwork - SWS preserved at expense of stage 1 & REM; day sleep onset slower and duration shorter than night sleep.

IV. Dreaming

A.Frequency - dreams occur in both REM and NREM sleep, but are more commonly reported after REM (60-90%) than NREM (7-54%)

B.Content - classified according to reports after waking

1.prelucid - most bizarre, emotional, irrational dreams that lead to a critical attitude toward the dream (characterized by high amplitude alpha (relative to individual subjects waking alpha activity) differs from lucid and nonlucid)
2.lucid - feelings of control and participation, more realistic than prelucid, and may evolve from prelucid, but unclear whether prelucidity is a prerequisite (more common during REM than NREM) (characterized by high amplitude alpha near beginning and low alpha near waking )
3.nonlucid - mundane & realistic (characterized by low alpha activity throughout)

V. Sleep "learning"
- Seems to depend upon the person, the material, and the stage of sleep.

- Even for very simply types of learning such as habituation effects are not large. Some subjects show habituation of autonomic responses to simple tone stimuli during stage 2 sleep but not generally during REM. Generally no EEG (K complex) habituation during either stage 2 or REM. Better habituation may be found when subjects are first habituated to stimuli (stimuli made meaningful) during waking, then exhibit dishabituation followed by habituation during sleep.

- May be some learning of meaningful of verbal material presented during stages 1 or 2 (with alpha). Better (or faster) recognition or faster relearning of sentences or words accounting for about 20% of the variance across 11 studies reviewed by Aarons (1976). Material presented repetitively to motivated subjects during stages of sleep with high alpha activity appears to be important.

VI. Sensation, Perception, and Attention

Most studies use alpha blocking (supression, same as beta enhancement) as DV. Historically, there has been much interest in alpha blocking because it was the first EEG response that was found to be sensitive to manipulation of external stimili (light onset).

A.Sensation

1.Stimulus Threshold - threshold is minimum level of detectable stimuli energy. Threshold for auditory stimuli was found to be lower during alpha than nonalpha by Bohdanecky et al. (1984).
2.Stimulus Complexity - alpha supression increases as stimulus complexity increases (Christie et al., 1972).

B. Perception

1.Discrimination - alpha supression increases as auditory discrimination difficulty increases (Wang et al., 1975).

C. Attention

1.Intake/rejection - Ray and Cole (1985) more alpha occurred during rejection than during intake in both hemispheres, more right than left hemisphere alpha during rejection
2.Vigilance and signal detection - O'Hanlon and Beatty (1977?) showed that detection of simulated radar stimuli depended upon EEG frequency. Performance decreased over the watch while beta decreased and alpha and theta increased. (More under operant conditioning)

 

VII. Conditioning of EEG

A. Classical conditioning

1. Definition of paradigm

Braggio and Putney (1980) examined individual differences in UCR magnitude, UCS intensity, perceived UCS intensity, and awareness as factors affecting conditioned alpha blocking.

 

B.Instrumental or Operant Conditioning

Theoretical foundation of biofeedback. Control bodily responses through by monitoring (usually visual or auditory) feedback based upon value of the to-be controlled physiological response. In operant conditioning, "reward" (reinforcer) is provided when response in evident.

- Nowlis and Kamiya (1970) demonstrated subjects could increase and decrease amount of alpha, and recorded their strategies.

- Beatty (1972) found that subjects could increase alpha equally well with feedback or with information on strategies.

- Beatty et al. (1974) found that detection of simulated radar stimuli depended upon theta control. Performance decreased when theta was increased, and performance increased when theta was decreased.