Overview

• Early psychologists such as William James, author of the first psychology textbook, were very interested in consciousness.

• The historical discussion about consciousness centers on the competing philosophical theories of dualism and monism.

• Dualists believe humans (and the universe in general) consist of two materials: thought and matter.

• Psychologists define consciousness as our level of awareness about ourselves and our environment.

Levels of Consciousness

• The mere exposure effect occurs when we prefer stimuli we have seen before over novel stimuli, even if we do not consciously remember seeing the old stimuli.

• Another fascinating phenomenon that demonstrates levels of consciousness is blind sight.

• The concept of consciousness consisting of different levels or layers is well established.

• Conscious level- The information about yourself and your environment you are currently aware of.

  • Your conscious level right now is probably focusing on these words and their meanings.

• Nonconscious level- Body processes controlled by your mind that we are not usually (or ever) aware of.

  • Right now, your nonconscious is controlling your heartbeat, respiration, digestion, and so on.

• Preconscious level - Information about yourself or your environment that you are not currently thinking about (not in your conscious level) but you could be.

  • If I asked you to remember your favorite toy a child, you could bring that preconscious memory into your conscious level.

• Subconscious level - Information that we are not consciously aware of but we know must exist due to behavior.

  • The behaviors demonstrated in examples of priming and mere exposure effect suggest some information is accessible to this level of consciousness but not to our conscious level.

• Unconscious level - Psychoanalytic psychologists believe some events and feelings are unacceptable to our conscious mind and are repressed into the unconscious mind.

  • Many psychologists object to this concept as difficult or impossible to prove.

Sleep

Sleep Cycle

• Part of our circadian rhythm is our sleep cycle.

• Our sleep cycle is our typical pattern of sleep.

• Researchers using EEG machines can record how active our brains are during sleep and describe the different stages of sleep we progress through each night.

• The period when we are falling asleep is called sleep onset.

  • This is the stage between wakefulness and sleep.

• While we are awake and in stages 1 and 2, our brains produce theta waves, which are relatively high-frequency, low-amplitude waves.

• In stage 2, the EEG starts to show sleep spindles, which are short bursts of rapid brain waves.

• Stages 3 and 4, which are sometimes called delta sleep (also called slow-wave sleep) because of the delta waves that exist during these stages.

  • Delta sleep seems to be very important in replenishing the body’s chemical supplies, releasing growth hormones in children, and fortifying our immune system.

• As we reach stage 1, our brain produces a period of intense activity, our eyes dart back and forth, and many of our muscles may twitch repeatedly.

  • This is REM—rapid eye movement.

  • This sleep stage is sometimes called paradoxical sleep since our brain waves appear as active and intense as they do when we are awake.

Sleep Disorders

• Insomnia is far and away the most common sleep disorder, affecting up to 10 percent of the population.

  • An insomniac has persistent problems getting to sleep or staying asleep at night.

  • Insomnia is usually treated with suggestions for changes in behavior: reduction of caffeine or other stimulants, exercise at appropriate times (not right before bedtime) during the day, and maintaining a consistent sleep pattern.

• Narcolepsy occurs far more rarely than insomnia, occurring in less than 0.001 percent of the population.

  • Narcoleptics suffer from periods of intense sleepiness and may fall asleep at unpredictable and inappropriate times.

• Sleep apnea may be almost as common as insomnia and, in some ways, might be more serious.

  • Apnea causes a person to stop breathing for short periods of time during the night.

Dreams

• Dreams are the series of storylike images we experience as we sleep.

• Some people remember dreams frequently, sometimes more than one per night, while others are not aware of whether we dream or not.

Sigmund Freud

• Considers dream an important tool in his therapy.

• Freudian psychoanalysis emphasizes dream interpretation as a method to uncover the repressed information in the unconscious mind.

• Manifest content is the literal content of our dreams.

• Latent content, which is the unconscious meaning of the manifest content.

• Freud thought that even during sleep, our ego protected us from the material in the unconscious mind (thus the term protected sleep) by presenting these repressed desires in the form of symbols.

• The activation-synthesis theory of dreaming looks at dreams first as biological phenomena.

  • Researchers know that our minds are very good at explaining events, even when the events have a purely physiological cause.

• Split-brain patients sometimes make up elaborate explanations for behaviors caused by their operation.

• According to this theory, dreams, while interesting, have no more meaning than any other physiological reflex in our body.

• The information-processing theory of dreaming falls somewhere in between the Freudian and activation-synthesis theories.

  • This theory points out that stress during the day will increase the number and intensity of dreams during the night.

Drugs

• Psychoactive drugs alter brain (and body) chemistry and consciousness.

  • These drugs change behavior and cognition due to physiological processes and drug expectations.

  • If they think they took the drug, they may experience some of its effects, according to research. (Like the placebo effect.)

• Blood-brain barrier - the brain is protected from harmful chemicals in the bloodstream by thicker walls surrounding the brain’s blood vessels.

• Agonists - The drugs that mimic neurotransmitters.

• Antagonist - The drugs that block neurotransmitters.

• Stimulants - Speed up body processes, including autonomic nervous system functions such as heart and respiration rate.

• Depressants slow down the same body systems that stimulants speed up.

• Hallucinogens (also sometimes called psychedelics) do not necessarily speed up or slow down the body.

• Reverse tolerance is a phenomenon in which a person needs to consume more of a substance to achieve the same effect as before.

  • It is most commonly seen with drugs and alcohol, but can also occur with other substances.

• Opiates such as morphine, heroin, methadone, and codeine are all similar in chemical structure to opium, a drug derived from the poppy plant.