Psychology Chapter on Consciousness

Consciousness

• Operational definition: If a person is conscious of a stimulus, they can report being aware of it.
• Masking: A stimulus is presented briefly, followed by an interfering stimulus, preventing conscious perception.
• Flash suppression: Other visual distractions are presented to prevent conscious perception of a target stimulus.
• Binocular rivalry: Two different images are presented to each eye, resulting in alternating perception of each image.
• Brain processes stimuli unconsciously: This occurs even without conscious perception, helping to evaluate their importance.
• Consciousness of a stimulus: Is an all-or-none process, either the brain activity spreads strongly or it doesn't.
• Conscious experience of a stimulus: Is constructed slightly after the stimulus itself, rather than simultaneously.
• Brain scans: Suggest consciousness in unresponsive patients.
• Conscious decision to act: Brain activity responsible for the movement starts before the conscious decision is reported.
• Possible function of conscious thought: To prepare for future actions when a similar situation arises.

Sleep and Dreams

• Sleep: Is not a state of unconsciousness but a state of reduced or altered consciousness.
• Sleep stages: People cycle through stages 1 to 4 and back through stages 3 and 2 to 1 again.
• Electroencephalogram (EEG): Measures brain activity during sleep.
• Polysomnograph: Combines EEG measurement with a simultaneous measurement of eye movements.
• Sleep spindles: Seen in stage 2, waves of activity that are important for memory storage.
• REM sleep: A special stage with high brain activity and relaxed muscles, often associated with dreaming.
• Dream content: More dreams are threatening than pleasant.
• Lucid dreaming: A state where part of the brain is awake and another part asleep.
• Nightmares: Unpleasant dreams.
• Night terrors: Causes the sleeper to awaken screaming and sweating.
• Insomnia: Subjectively unsatisfactory sleep.
• Apnea: No breathing during sleep.
• Narcolepsy: Sudden attacks of sleepiness during the day.
• Orexin: Important for maintaining long periods of wakefulness.
• Circadian rhythms: Even in unchanging environments, people become sleepy in cycles of approximately 24 hours.
• Suprachiasmatic Nucleus: A brain structure that generates the circadian rhythm of sleep and wakefulness.
• Morning and evening people: Some people are more alert early in the day, others are more alert later in the day.
• Jet lag: A period of discomfort and inefficiency when internal clock is out of phase with new surroundings.
• Brain mechanisms of circadian rhythms: Sunlight does not generate the rhythm, but does reset it.
• Need for sleep: Serves many functions, including energy conservation and strengthening memories.
• Sleep-deprived people: Have difficulty maintaining attention.
• Periodic Limb Movement Disorder: Prolonged creepy-crawly sensations in legs, accompanied by repetitive leg movements.
• REM Behavior Disorder: Failure to inhibit muscular activity during REM sleep, resulting in actions during dreams.

Explore the fascinating concepts of consciousness in psychology. This quiz covers operational definitions, masking techniques, binocular rivalry, and unconscious brain processes related to stimulus perception. Test your understanding of how our conscious experiences are formed and the scientific investigations around them.