psych ch 5-6

Consciousness

Your immediate awareness of your surroundings and yourself.

Stream of conciousness

A continuing flow of changing thoughts. Proposed by William James.

Functions of consciousness

Information processing, survival and learning new tasks

Inattentional blindness

Inability to notice even obvious stimuli when our attention is focused on another stimulus.

Attentional spotlight

Selectively attending to a very limited aspect of all incoming sensory information.

Change blindness

Failing to notice a change in a stimulus that you are attending to.

Dual processing

Information is often simultaneously processes on separate conscious and unconscious tracks in the brain. Supported by split brain and brain damage case studies.

Blindsight

A lack of awareness of objects in the visual field. Common after damage to certain visual cortex areas. Typically, person still acts aa though the objects are present, but is unaware of it.

What track

A visual track that requires awareness to identify objects. Located in the temporal lobe.

Where track

Visual track that guides moment to moment actions with or without awareness. Found in the parietal lobe.

Cerebral cortex

Has certain areas for awareness and attention to particular classes of stimuli, but when we are awake and asleep the whole cortex is active to some degree. Although, amount of activity increases with higher levels of attention and awareness.

Thalamus

Directs sensory information to higher cortical areas. If damaged, transmission and response to sensory information is altered. Can cause coma like conditions.

Intralaminar nucleus

Nuclei in the thalamus that is important for awareness. It is connected to the reticular formation, which is important for sleep pathways.

Preconciousness

Distinct level of awareness in which information can become readily available to consciousness if needed

State in which familiar behaviours occur

Preconscious state

Automatic behaviours

Tasks that involve little awareness. Can be done in a Preconscious state

unconscious state

Distinct state in which information is not easily accessible to conscious awareness. Has roots in freud’s psychoanalytical theory.

Freuds psychoanalytical theory

Suggests that emotional trauma keeps important memories in the unconscious, where they cannot be accessed, but can be hinted at in conscious thoughts and behaviours.

Explicit memory

Pieces of information that we recall consciously

Implicit memory

Types of knowledge that we are unable to consciously recall but that we can nevertheless use to guide behaviour

Sleep

Periodic, natural, reversible loss of consciousness. Includes some awareness of self and environment. Distinct from medically induced unconsciousness or hibernation.

Circadian rhythm

A cycle that repeats roughly every 24 hours.

Sleep-wake cycle

A circadian rhythm involving states of consciousness and unconsciousness. Influenced by external stimuli and out innate biological clock.

External stimuli are removed from circadian rhythyms

The cycles tend to drift, starting later and lasting longer each day, exceeding 24 hour cycles.

Entrainment

Synchronization of circadian rhythms to the external twenty four hour light-dark cycle.

Pineal gland

A structure near the thalamus that secretes melatonin

Melatonin

A hormone that induces sleep. Most abundant during dark hours.

Suprachiasmatic nucleus (SCN)

A bundle of neuronal cell bodies located in the hypothalamus that acts as a biological clock. Receives input from the optic nerve". Activated by light exposure, suppressing melatonin release.

Length of a sleep cycle

90-100mins, consisting of 5 stages. Occurs 4/5 times each night.

Sleep Stage 1

Transitional stage into sleep, lasting about 5 minutes. Alpha waves transition to theta waves. The heart rate and blood pressure decreases. Can cause hypnagogic states or myclonic jerks.

Hypnagogic states

States in which you are more susceptible to hallucinate or experience altered perceptions different from reality.

Myclonic jerks

Sudden and brief involuntary movements of the muscle.

Sleep Stage 2

Stage that is harder to wake from, lasting 15-20 minutes. Muscles relax. Sleep spindle emerge in EEG.

Sleep spindles

Burts of rapid brain waves, common in stage 2.

Sleep Stage 3

A deeper sleep stage lasting 5-10 minutes. Theta waves and delta waves are present.

Sleep Stage 4

The deepest stage lasting 20-30 minutes. A very slow heart rate, the brain and body are totally relaxed. Eeg shows delta waves. Sleep walking or bed wetting could occur.

K complex

A large brain waves that suppresses cortical arousal, allowing stage 2 to transition into stage 3. Known as the largest single event generated in human brain electrical activity.

Rapid Eye Movement (REM) sleep

Sleep state that is very difficult to awaken. EEG resembles an awake state with eye movement, increase of HR and BP, dreams and muscle paralysis. Often called paradoxical sleep.

REM length during night

Duration Increases as the night progresses, spending more time with each sleep cycle.

REM rebound

Duration spent in REM increases after a period of REM deprivation. Evidence of the human biological need for REM.

Sleep debt

The body keeps a running tab of our nightly sleep amounts and creates a cumulative record. A deficit is common, of about 25-30 hours.

Effects of sleep debt

Increased stress hormones, body fat storage, ageing effects, suppressed immunity, reduced longevity, irritability, bad concentration, depression, increased accidents.

Adaptive theory

The idea that sleeping serves a protection function, reducing dangerous night activities.

Growth theory

The idea that sleep promotes growth, as HCG is secreted during deep sleep and children sleep more than adults.

Restorative theory

The idea that sleep allows for recovery from use during the day. Supported by the fact that sleep debt compromises immune function by reducing free radicals.

Memory theory

The idea that sleeping serves allows for memories to be stores from the days events.

Creative thinking theory

The idea that sleeping serves encourages new and innovative thoughts, supported by dreaming.

When do dreams occur

In REM, if the brain is awake enough.

Lucid dreams

Dreams in which we are aware that we are dreaming, and can even test to see if it is true.

Common dream plots

Most contain negative emotions and contain the days events, old memories, unsuccessful tasks, etc. Most are not sexual.

Information processing theory

The idea that dreams help us sort out the days events and store memories. Supported by the fact that if we are awakened in REM, performance of learned tasks is hindered, especially motor tasks.

Activation synthesis theory

Observations of the brainstem activating certain cortex areas and the limbic system during REM led to the idea that dreams are the result of the brain trying to make sense of randomly triggered sensations and emotions. It is thought that this brain reactivation in REM can help strengthen and maintain existing connections that are not often activated.

Insomnia

Most common sleep disorder involving a difficulty going to sleep, staying asleep, or frequently waking early. Caused by stress, drugs, pain and depression

Sleep apnea

Second common sleep disorder where a person repeatedly stops breathing during the night. Characterized by snoring, can lead to cardiac arrest. Causes chronic sleep deprivation and neuro degeneration.

Natcolepsy

Sleep disorder characterized by excessive daytime sleepiness. Can cause a person to suddenly fall into REM sleep during the day, lasting up to 15 mins. Could be caused by genetic factors or an orexin deficiency.

Orexin

A neuropeptide produced in the lateral hypothalamus that stabilizes the transition between REM and wakefulness. Also important for food intake. Deficiencies can cause type 1 narcolepsy.

Night terrors

A sleep disruption that can occur in stages 3 or 4. Often experienced by adolescents, waking in a panic, then returning to sleep and forgetting the event. Resolved by adolescence

Hypnosis

Altered state of consciousness with heightened suggestibility, deep relaxation and intense focus.

Process of hypnosis

Begins with an induction, imploring the subject to relax or focus on an object. Followed by a suggestion, prompting the subject to experience a particular thing or behave a certain way.

Characteristic of hypnotizable people

Susceptible to suggestion and highly imaginative with rich fantasy lives.

Impact of hallucination

Can help with pain management and healing (positive thinking).

Social influence theory

The idea that hypnotized people are just role playing, acting in ways that are expected of them by the hypnotist or a crowd. An extension of conformity or obedience. Supported by the fact that many behaviours induced can be produced without hypnosis and that is motivation for being hypnosis reduced, the subjects are less responsive.

Divided consciousness theory

the idea that hypnosis involves a splitting of consciousness and attention to one aspect of an experience (the suggestion). Supported by the observations that subjects will carry out behaviours in cue when alone and that tasks that are typically difficult can be performed well when hypnotized.

Stroop test

A psychological assessment that involves stating the color that a word is spelt in, not what the words read. Difficult usually, but hypnotized people can excel at it.

Anterior cingulate cortex

Area of the brain involved with conflicting information. Activity is reduced under hypnosis, explaining potential success in stroop test.

Psychoactive drugs

Chemicals that affect consciousness and behaviour.

Physical dependence

A physiological need for a drug, marked by unpleasant withdrawal symptoms reflecting the opposite of the drugs function.

Psychological dependence

A psychological desire to use a drug, for a desired psychological state or to remove a negative state

Addiction

A compulsive craving for the use of a drug despite adverse consequences that are known.

Tolerance

Following repeated drug use, effect can become diminished. Higher doses may be needed to produce the same previous effect.

Withdrawal

Syndrome resulting from termination of drug use after physical dependence. Symptoms are the opposite of those initially produced by the drug, causing a rebound effect.

Agonist

Drug that binds to receptor sites and mimics neurotransmitters

Antagonist

Binds to receptors and block neurotransmitters from binding.

Depressants

Drugs that dampen neural activity. Examples inclue alcohol, sedative hypnotics, barbiturates and opiates

Stimulants

Drugs that enhance neural activity. Examples include caffeine, nicotine, cocaine, amphetamine, and ecstasy

Hallucinogens

Drugs with mixed effects on neural activity, distorting its functions. Examples include LSD and THC

Alcohol

CNS depressant that inhibits widespread areas of the brain by enhancing GABA levels. Initially, judgement and behaviour limitation is inhibited, leading to a phase of excitement caused by by disinhibition. After, sedation is felt at higher levels.

Very high alcohol doses

Suppresses the vomit reflex and respiration by acting on the medulla. Can lead to death.

Sedative hypnotics

Benzodiazepines, including valium, xanax and ativan. Enhances GABA levels. Used to treat anxiety in the form of anxiolytics or to treat insomnia. Dangerous with alcohol.

Opiates

Includes morphine, codeine, heroin, methadone, and oxycodone. Activates opiod receptors in the brain to produce a blissful pleasure. High abuse and overdose potential. Repeated use causes a decline in endorphin production in the brain,

Opiate receptors

Structures that typically bind endorphins in the brain, produces an analgesia effect, blocking pain.

Fentanyl

An opiate that is most common today, often the cause of overdoses. Created and sold on the street.

Caffeine

Stimulant that is the most used psychoactive substance. Blocks adenosine for 3-4 hours. Can cause tolerance and withdrawal effects.

Nicotine

Stimulant that causes quick release of epinephrine and norepinephrine, causing alertness and arousal. Stimulates acetylcholine receptors, creating a calming effect. Can cause tolerance and withdrawal. Highly addictive.

Cocaine

Stimulant derived from the coca leaf that blocks dopamine reuptake, leading to intense euphoria and a sense of well being. Fast tolerance, withdraw, can cause depletion of neurotransmitters, causing a crash.

Amphetamines

Stimulant that is manufactured, increasing energy and alertness by increasing dopamine. Causes reuptake transporters to run in reverse. Was prescribed for ADHD, weight loss, narcolepsy, decongestion. Now known as adderall or dexedrine.

Methamphetamines

Stimulant that is a crystal like powder substance produced in labs. Causes dopamine release, crating a high of up to 8 hours. Large crash afterward, reduces dopamine production. Highly addictive

Ephedrine

A compound common in cough medication that can be broken down by acetone or chloroform to make methamphetamine.

Ecstasy (MDMA)

Stimulant and a mild hallucinogen, producing a euphoria and social intimacy urges for ¾ hours by causing dopamine release. Can cause death by dehydration, depression due to serotonin depletion, memory problems and sleep issues in the LD Cycle.

LSD (lysergic acid diethylamide)

hallucinogen that causes a common pattern of hallucinations. At its peak, people fell seperated from the body and in a vivid dreamlike state. Blocks serotonin receptors. Can cause flashbacks to the high a long period after the trip.

Marijuana

Hallucinogen with the active ingredient THC, which can stay in the body for moth or more after use. Causes relaxrion, reduced inhibition, can produce a high, amplifies sensitivity to many sensws. Can reduce nausea and impair motor coordination, perceptual skills and time estimations.

How does marijuana cause memory impairment

It interferes with the recall of events by hastening loss of brain cells, causing a reduced hippocampal volume. Also can depress testosterone and sperm levels. Associated with psychosis.

Endocannabinoids

Endogenous chemicals that bind to CB1 receptors in the brain to stop pre synaptic cells from producing a neurotransmitter, typically glutamate. Similar in structure to THC.

Mesolimbic pathway

Route from the ventral tegmental area of the midbrain to the nucleus accumbens and cortex, involved in the reward/pleasure pathway. Abused and activated most by psychoactive drugs.

Sensation

The act of using sensory systems to detect environmental stimuli. External energy is transduced until internal neural signals.

Perception

The act of recognizing and identifying internalized sensory stimuli.

Sensory systems

Visual, auditory, somatosensory, gustatory, olfactory, kinaesthetic and vestibular.

Transduction

The process of converting an external physical stimulus into neural impulses.

Sensory receptor cells

Specialized cells that convert a form of environmental stimuli into neural impulses.

Absolute threshold

The smallest amount of a stimulus that can be detected atleast 50% of the time.