Biological Approach The biological approach in psychology emphasizes that both the similarities and differences among individuals can be comprehensively understood through the lens of biological factors. This perspective posits that behavior, cognition, and emotions arise from the workings of the brain as well as the influences of hormones, genetics, and evolutionary processes.
Sleep & Dreaming Notes ## Background for Dement & Kleitman Study Important foundational information and context related to the research by Dement and Kleitman on sleep and dreaming, which likely includes their methodology, findings, and implications.
Waking Consciousness ## Consciousness Consciousness is defined as our awareness of ourselves and our environments. This can include both the external environment and internal states. ### Altered States Altered states of consciousness can manifest in various forms, which may include experiences induced by sleep, hypnosis, meditation, or psychoactive substances. An example provided in the transcript is a metaphor indicating reliance on the brain to maintain balance while navigating life.
Sleep and Dreams ## Circadian Rhythm Circadian rhythms are regular physiological patterns that occur on a 24-hour cycle, notable examples being the sleep-wake cycle and fluctuations in body temperature. ## Ultradian Rhythms Ultradian rhythms refer to biological cycles that recur more frequently than once every 24 hours, such as heart rate variability and appetite regulation. ## Sleep Sleep is described as a periodic, natural, reversible loss of consciousness. The measurement of sleep activity and brain function during sleep is conducted using an Electroencephalogram (EEG).
Brain Waves and Sleep Stages In the context of non-REM (Rapid Eye Movement) sleep:
- Beta Waves indicate awake consciousness.
- Alpha Waves suggest a relaxed state.
- Hallucinations can occur upon transitioning into sleep, characterized by false sensory experiences such as a sensation of falling.
- Theta Waves are observed in Stage 1, representing light sleep.
- Sleep Spindles feature in Stage 2, displaying bursts of brain activity.
- Delta Waves manifest in Stages 3-4, consisting of large, slow waves indicative of deep sleep.
Stages in a Typical Night’s Sleep A typical sleep cycle occurs approximately every 90 minutes, cycling through stages 1 through 4 and REM sleep. The relationship between sleep stages and hours of sleep demonstrates a fluctuating pattern throughout the night, with delta waves dominant during deep sleep and REM characterized by increased brain activity.
REM Sleep REM (Rapid Eye Movement) sleep is a recurring stage of sleep, typically occurring every 90 minutes. Characteristics include vivid dreaming, lucid dreaming, and nightmares. This phase is known as "paradoxical sleep" because, although the body muscles are generally relaxed and immobilized, other bodily systems are actively functioning. Notable physiological changes during REM sleep include increased heart rate, rapid and irregular breathing, and genital arousal, with EEG readings similar to those of an awake state.
Stages in a Typical Night’s Sleep Visualization The slide depicts the progression of sleep across hours in terms of the minutes spent in specific stages (4 and REM), illustrating the decreasing time in Stage 4 sleep and increasing time in REM sleep as the night progresses.
Sleep Deprivation ## Effects of Sleep Loss The consequences of sleep deprivation encompass several adverse effects, including:
- Fatigue
- Impaired concentration and cognitive function
- A depressed immune system increasing vulnerability to illness
- A heightened risk of accidents due to decreased alertness
Sleep Disorders ## Night Terrors Night terrors occur within two or three hours after falling asleep, usually in Stage 4, predominantly affecting children. Symptoms include high arousal and panic without recall of dreams.
Somnambulism Also known as sleepwalking, somnambulism occurs in Stage 4 sleep and is more prevalent in children, often running in families. Stressful events can contribute to its occurrence.
Insomnia Insomnia denotes persistent difficulties with falling asleep or maintaining sleep throughout the night.
Narcolepsy Narcolepsy is characterized by uncontrollable sleep attacks that may occur at inappropriate times, occasionally involving REM sleep features.
Sleep Apnea Sleep Apnea entails repeated interruptions of breath during sleep, which can lead to momentary awakenings and disrupt normal sleep patterns.
Sleep Paralysis Sleep Paralysis occurs during the transitional states between waking and sleeping, accompanied by an inability to move or speak.
Dream Theory ## As Information Processing This theory suggests that dreaming may play an essential role in consolidating memories. It is common for dreams to focus on mundane aspects of daily life.
Activation Synthesis The activation synthesis theory postulates that dreams are a result of random electrical impulses in the brain, leading to the creation of nonsensical dream narratives.
REM Rebound REM rebound refers to the phenomenon where there is an increase in REM sleep following periods of REM sleep deprivation, indicating the body's attempt to regain balance in sleep architecture.
Sleep Across the Lifespan Sleep patterns and needs change significantly over a person's life:
- Infancy: Average of 16 hours of sleep, marked decrease in REM sleep duration.
- Childhood (Years 1-5): Average sleep declines to around 14 hours.
- Adolescence (Ages 6-23 months): Average sleep further decreases to about 10-12 hours.
- Adulthood and Old Age (Ages 19-90 years): Total sleep time decreases, with ongoing reductions in REM sleep as age progresses.