[Crash Course] Psychology IX&X Other types of consciousness IX Dreams and Sleeps Sleep: a periodic, natural, reversible and near total loss of consciousness. But sleep is just another state of consciousness.

The meanings of sleep: -Part of it probably has to do with simple recuperation, allowing our neurons and other cells to rest and repair themselves. -Sleep also supports growth, because that's when our pituitary gland release growth hormones. -Plus, sleep has all kinds of benefits for mental function, like improving memory, giving our brains time to process the events of the day, and boosting our creativity.

Electroencephalograph (EEG): machine that measures the brain's electrical activity.

Rapid eye movement (REM): a recurring sleep stage during which vivid dreams commonly occur. A perplexing period when the sleeping brain is buzzing with activity, even tough the body is in a deep slumber.

Four distinct stages of sleep: -REM (Rapid Eye Movement) -NREM-1 (Non-Rapid Eye Movement) -NREM-2 -NREM-3

Say you're just going to bed. All day your endocrine system has been releasing “awake” hormones like cortisol. But with nightfall comes, the release of sleepy melatonin hormones from the pineal gland. Your brain is relaxed, but still awake, a level of activity that EEGs measure as alpha waves. You're feeling sleepy, your breath slows, and suddenly you are asleep. This exactmoment is clearly evident on an EEG reading, as those alpha waves immediately transition to the irregular non-Rapid Eye Movement stage one (NREM-1) waves. At this stage you might experience hypnagogic sensations, those brief moments when you feel like you're falling, and your body jerks, startling you. As you relax more deeply, you move into NREM-2 stage sleep, as your brain starts exhibiting bursts of rapid brain wave activity called sleep spindles. You're now definitely asleep, but you could still be easily awakened. NREM-3 comes with slow rolling delta waves. You can have brief and fragmentary dreams in the first three stages of sleep, but eventually you'll get to the most important stage: FULL REM SLEEP. That famous stage of sugarplum slumber that makes eyeballs go nuts, grants vivid visual dreams, and provided the namesake for a certain famous rock band. That whole sleep cycle repeats itself every 90 minutes or so, transitioning back and forth between the stages of sleep.

Lack of sleep is terrible for your health, mental ability, and mood. In fact, it's a predicator for depression and has been linked to things like weight gain, as your hunger-arousing and -suppressing hormones get out of whack. Sleep deprivation also causes immune system suppression, and slow reaction time.

Sleep disorder: -Insomnia, which is persistent problems of falling or staying asleep. -Narcolepsy, whose sufferers sometimes experience brief, uncontrollable attacks of overwhelming sleepiness, called 'sleep attacks'. -Sleep apnea, causes the sleeper to temporarily stop breathing until their decreased oxygen levels wake them up. -REM sleep behaviour disorder -Night terrors, spurring increased heart and breathing rates, screaming and thrashing that's seldom remembered upon waking. Most common in children under seven. Occurs during NREM-3, like sleepwalking and sleeptalking. -Nightmares. Occur during REM.

What's the purpose of dreaming? Oneirology: 'Oneiros' is the Greek for 'dream'. The study of dreams is a mix of neuroscience and psychology.

Theories: -Freud proposed in his 1900 Interpretation of Dreams that our dreams offer us wish-fulfilment. He thought a dream's manifest content, the stuff you remember in the morning was a sort of censored and symbolic version of whatever inner conflict was really going on in that dream's unconscious, or latent, content. [Lack scientific chops] -The Information Processing Theory. Our dreams help us sort out and process the day's events and fix them into our memories. -The Physiological Function Theory. Dreaming may promote neural development and preserve neural pathways by providing the brain with stimulation. When our brain is stimulated, they expand their connections more. -The Cognitive Development Theory. Dreams are part of our cognitive development, they draw on our knowledge and understanding of the world, mimicking reality, engaging those same brain networks that light up when we daydream. -The Neural Activity Theory. REM sleep triggers neural activity, and dreams are accidental side-effects.

X Altered state of consciousness -Hypnosis: a calm, trance-like state during which you tend to have heighted concentration and focus, and in which you're typically more open to suggestion. It is when you're fully conscious in the clinical sense, but also not in what you'd consider a normal waking state. Hypnosis cannot make you act totally against your will, nor is hypnosis a reliable way to enhance the recall of deeply buried memories. But it can increase your suggestability. —As a social influence, they act in the role of being hyponotised. —A special dual-processing state of 'split consciousness' called Dissociation. Detachment from your surroundings which can range from mild spacing out all the way up to a total loss of your sense of yourself. —Help us to adaptive dissociative capacity that we all seem to have. -Hallucinations. -Use drugs. The more you use a substance, legal or illegal, the less you feel its effects as your tolerance grows. That's your brain chemistry adapting to offset the drug effect in a process called neuroadaptation, and soon you'll risk a physical and/or psychological addiction to the substance you choose, or the substance that chose you.

The placebo effect: They also work by tapping into the psychological component, in other words, the user's expectations about what substance might mean. Like, if you really believe that drinking tequila makes you more aggressive and I give you a virgin margarita, your mere expectation of getting all surly and aggro may actually lead you to punch someone in the neck.

3 catogeries of psychological substances: -Dpressants, like alcohol, tranquillisers and opiates, they bring the mellow, slow body functions and suppress neural activity. For example, alcohol, acts as a disinhibitor, impairing your brain's judgement areas, while reducing your self-awareness and self-control. And then because alcohol disrupts memory formations you may wake up wondering where one of your eyebrows went. Similar to booze, tranquillisers or barbiturates, depress nervous system activity and may be prescribed to ease anxiety or insomnia. Opiates, depress nervous system and envelop the brain in a fog of no-pain bliss. The thing is, if a brain keeps getting flooded with outside opiates, it will eventually stop brewing its own natural pain killing neurotransmitters endorphins. The resulting withdrawal is particularly nasty.

-Stimulants, excite neural activity and speed up body functions, bring up your energy, self-confidence and changing your mood. Legal: caffeine, nicotine, and prescription amphetamines. Illegal: street amphetamines, meth, ecstasy and cocaine. So, when those neurotransimitters are excessively activiated, they can become temporarily depleted, which is what causes that agitated, depressive crash that users often feel.

-Hallucinogens, which come in a variety of plant and fungal forms, and synthetic forms like LSD or lysergic acid diethylamide. Also called psychedelics, these drugs distort perceptions and evoke sensory images in the absence of actual sensory input. Without the use drugs, there are lots of involuntarily ways to hallucinate. Neurological disturbances spur hallucinations of one kind or another.