Sleep Stages and Brain Waves

• Sleep consists of a loss of consciousness, but not the absence of being awake
• Characteristics include immobility, posture, diminished responsiveness, and reversibility
• Reasons for sleep are not entirely known
• Sleep is a state of altered consciousness

Sleep Stages and Brain Waves

• Sleep stages are measured using an EEG (electroencephalogram)

• Muscle activity is measured with an electromyogram

• Eye movements are measured with electro-oculogram.

• Each wave has a frequency and amplitude

• Gamma waves range from 32-100 Hz

• Beta waves range from 13-32 Hz

• Alpha waves range from 8-13 Hz

• Theta waves range from 4-8 Hz

• Delta waves range from 0.5-4 Hz

• The amount of delta activity/amplitude determines sleep quality

• Awake: exhibits alpha and beta activity, high frequency, and low amplitude

• Stage 1: exhibits theta activity, high frequency, and low amplitude

• Stage 2: has sleep spindles

• Stage 3: delta activity appears

• Stage 4: continuous delta waves, larger amplitude (many neurons firing at once)

• REM: exhibits theta and beta activity, very similar to waking activity (higher frequency lower amplitude)

REM vs Slow Wave Sleep

• REM sleep includes rapid EEG waves, muscular paralysis, rapid eye movements, penile erection or vaginal secretion, and vivid dreams
• Slow wave sleep includes slow EEG waves, lack of muscular paralysis, slow or absent eye movements, lack of genital activity, and banal dreams
• Less delta occurs per cycle and more REM sleep
• REM sleep mostly occurs at the end of the night

Sleep Stage Characteristics

• Awake: irregular pattern, beta activity (15-30Hz) for alert, alpha activity (8-12Hz) for relaxed
• Individuals feel drowsy shifting from alert to relaxed wakefulness
• Stage 1: theta activity (3.5-7.5Hz)
• Transition of wakefulness to sleep, with EMG showing muscles still active, and EOG showing gentle eye movements
• Eyes slowly open and close and the person falls asleep.
• Stage 2: spindles (small spikes) in EEG activity, sleep is deeper.
• Stage 3: delta activity appears (< 3.5Hz), reduced muscle tone on EMG
• Slow wave sleep, and sleep is even deeper with less responsiveness to stimuli.
• Stage 4: continuous delta waves
• Very deep slow wave sleep, which is reached within 1 hour.
• REM: EEG shifts through stages 3, 2, and 1 with rapid EEG.
• Show rapid eye movements on EOG, and loss of muscle tone (but hands and feet occasionally twitch) on EMG
• Heartbeat is irregular, breathing shallow causing vivid dreaming.

Sleep Deprivation and Restriction

• Sleep deprivation (Total Sleep Deprivation or TSD) leads to a delta rebound, with more Delta sleep rather than a larger amount of sleep next night Also there is a little bit of REM rebound
• Losing only REM leads to REM rebound
• Lower sociality and optimism increases one's irritability and fatigue
• Substantial lapses occur in attention (microsleeps), vigilance (maintain focus on something for a period of time), alertness, reaction time via the Parietal Lobe
• Impaired executive function is affected through judgement, planning, concentration, productivity, self-control, high level performance as related to the Prefrontal Cortex (PFC).
• Hyperphagia (more eating) and impaired memory formation is possible from deprivation
• Sleep restriction has similar symptoms, with increased rates of depression, suppressed immune system, and increased risk of cardiovascular disease, heart attacks, and stroke.
• Accumulation of wastes in the brain is associated with dementia accumulated following excessive nights of low sleep, creating a sleep debt.
• A 2013 Gallup poll found that 40% of Americans get 6 hours or less of sleep per night
• Individuals perform best if they are sleeping 7 hours a day, showing the lowest mortality rates and highest cognitive function

Brain Areas Related to Sleep

• REM Sleep: Acetylcholine neurons in the pons are responsible for generating REM sleep and activate the cerebral cortex (dreaming), midbrain (tectum - eye movement of REM), and descending inhibitory signal to paralyze
• Slow wave sleep: Brain stem, especially serotonin; Basal forebrain, especially GABA; and Preoptic area of hypothalamus, especially GABA
• If the preoptic area is destroyed, an animal sleeps less, but if stimulated, the animal becomes drowsy and falls asleep.

Circadian Rhythms

• Circadian rhythm or biological clock operates on a roughly 24 hour biological clock
• Includes blood sugar, melatonin, body temperature, and arousal, which could be altered by age and experience
• Every cell has its own circadian rhythms, which is controlled by the suprachiasmatic nucleus in hypothalamus (the master clock) Outside environmental cues (zeitgebers) synchronize (like light)
• Bright morning light activates proteins in the eye that trigger SCN
• Light suppresses melatonin release from the pineal gland
• Social jet lag: exposes one to a new rhythm and adjusts the brain cycle, which can be disrupted during weekends
• When SCN is damaged, humans become free running with cells each with its own clock, slowly falling out of sync resulting in 90-minute sleep cycles
• Ultradian (<day) and infradian (>day) rhythms can occur

Potential Mechanisms of Restoration in Sleep

• Developed a protective role to prevent wandering around and dangerous activity
• Conserves energy by saving ~120 calories
• Restores and repairs damaged neurons while modifying neural connections for improving both NREM and REM memory while promoting creative problem solving.
• Pituitary gland secretes growth hormone during sleep and muscle development, especially in the glymphatic system
• Empties metabolic wastes using glia, and acts as a lymphatic system. Glia shrink nearly 50 percent during sleep and pulsing them creates flow of wastes
• Delta waves result from this movement.

Sleep Disorders

• Insomnia: the inability to start or maintain sleep over at least 3 nights
• A primary predictor is stress
• Sleep apnea is breathing obstructions, and can cause insomnia
• Narcolepsy: difficulty maintaining wakefulness and rapidly transitioning in a sleepy state
• Cataplexy: has paralysis but is still conscious exhibiting sudden muscle weakness or paralysis triggered by emotions, and also a feature of narcolepsy
• Sleepwalking occurs in stage 4 as a not narrative, with usually just most common motions during the day
• Difficult to wake and heritable
• Sleep talking occurs in REM dreams but usually other stages
• Night terrors are not nightmares; the individual is not really dreaming of anything but afraid - don't wake them
• REM Behaviour disorder: the brain no longer inhibits muscles, acting out our REM dreams
• Strong predictor of future neurodegenerative disorders such as Parkinson's or Ley-Body dementia
• Enuresis is bed-wetting during Stage 4
• Exercise regularly, not in the late evening (late afternoon is best) Avoid caffeine after early afternoon avoid food/drink near bedtime Relax before bedtime using low levels of light while choosing non arousing thoughts such as multiplication

Dreams

• Dreams are different forms of consciousness, a different simulation based on brain noise and a sequence of images, emotions, etc.
• Are mostly of ordinary events and everyday experiences, anxiety content, misfortune, with familiar details of life, and REM dreams which are vivid, emotional, bizarre
• Dreams with negative event or emotion: 8 in 10 dreams, and dreams with sexual imagery: 1/10 in men, 1/30 in women
• Dreams incorporating previous days' experience are most common

Dream Theories

• Freud's Wish-fulfillment: dreams provide a "psychic safety valve" - expressing otherwise unacceptable feelings
• Lacks any scientific support with many ways dreams are interpreted, and the dream content is most often negative in nature.
• Information-processing: dreams help us sort out the day's events and consolidate our memories, but fails to explain why we sometimes dream about things we have not experienced and about past events.
• Physiological Function: regular brain stimulation from REM sleep may help develop and preserve neural pathways, which fails to explain why we experience meaningful dreams.
• Activation-synthesis: REM sleep triggers neural activity that evokes random stimuli and memories, which our sleeping brain weaves into narrative, where the individual's brain is weaving the stories, which still tells us something about the dreamer.
• Cognitive Development: dream content reflects dreamers' level of cognitive development-their knowledge and understanding, dream simulate our lives, including worst care scenarios but does not propose an adaptive function of dreams
• Activation synthesis: dreams are not for any specific reason but rather a product of brain noise

Memory

• Memory has persistence of learning over time.
• Recall retrieves information into consciousness
• Recognition happens without recall
• Also has relearning
• More deeply learned information on day 1 reduces time to relearn on day 2

3-Stage Information Processing Model of Memory

• External events flow into sensory memory which is fleeting , working/short term memory, then long term memory
• Encoding (sensory memories to working or working to long term)
• Storage
• Retrieval (pulling back from long term to working memory)
• Automatic processing: processes and encodes external events automatically to long term memory storage and bypasses consciousness. Connectionism information processing model says that all three processes are happening amongst multiple pathways
• There is not a single working memory rather hearing/sight might have different memory storages
• Long term memory is stickier, and has different modalities like contain sight memory and hearing memory
• Multitrack parallel processing; processing is happening across many modalities across many different tracks Reactivating connections between neurons such that when you reactivate these connections, you remember the memory
• N-back test: participants are told to recall the nth back number

Dual Track Memory System

• Explicit memories are conscious and declarative, able to be verbally expressed, and can be improved with repetition
• Implicit memories are nondeclarative and form through automatic processes and bypass consciousness

Amnesia

• Retrograde amnesia: lost memories from before (usually just more recent memories)
• Anterograde amnesia: no longer able to make new memories

Patient HM - Seizures

• Bilateral medial temporal lobectomy (removed medial temporal lobe)
• Resulted in anterograde amnesia with some retrograde amnesia
• Brenda Milner studied HM
• Digit span task: memorise a string of numbers. HM had a magic number 7+-2 in working memory
• Consolidation: moving things from working memory to long term memory; a type of encoding
• HM could not consolidate, but working memory was still intact
• Hippocampus - HM was still able to form some types of long term memories Mirror-drawing test: using a mirror image to draw something
• Learning habits and skills is on a different tract
• Pavlovian conditioning: Learn to associate things with each other
• Priming: exposure to a stimulus can influence how we respond to a subsequent stimulus (e.g. soap)

Two Memory Systems

• Automatic processing (implicit memories or nondeclarative memory) can create memories without conscious recall

• Are processed in cerebellum and basal ganglia

• Space, time and frequency (where you ate dinner yesterday), motor and cognitive skills (riding a bike), and classical conditioning (reaction to dentist's office)

• Effortful processing (explicit memories or declarative memory) create memories with conscious recall

• are processed in the hippocampus and frontal lobes Semantic memory (facts and general knowledge/this chapter's concepts) and episodic memory (personally experienced events/family holidays)

• Sensory memory is the first stage of forming explicit memories They trigger immediate, fleeting capture, and activation of sensory systems Iconic memory: picture memory Echoic memory: sound memory. Short term memory/working memory has varying capacity

• Decays rapidly without rehearsal (within a few seconds)

• WM Capacity: maximum amount of information one can accurately retrieve from WM (5-9 items)

• Ability to read, verbal numerical communication, fluid intelligence, and long term memory is linked to capacity of working memory Strategies improve memory formation via Chunking or putting information into manageable sizes of units, Mnemonics, Hierarchies where one arranges information vertically/broad categories, and Spaced study and self assessment

• Massed practice is cramming and only benefits short term memory and an artificial sense of confidence

• Distributed practice or spaced out practice, and testing effect via practicing retrieval with teaching, practiced testing, and turning retrieval into a skill.

• Making material personally meaningful increases memory retention

• Levels of processing:

• Shallow processing: encoding information on the most basic level (e.g. letters, structure, phonetic, the way something sounds, etc.)

• Deep processing: semantic level (e.g. what does it mean?)

SQ3R Method

• Survey
• Question; generate possible questions
• Read
• Retrieve/recite; rehearsing
• Review Retaining information in the brain
• Past research: the brain is a hard drive; this is no longer thought to be true today because information is not stored in a single place and it is all interconnected New findings: perception, language, emotions, etc. require neuronal interconnections
• Recall is not a perfect tape, but rather a reconstruction and a simulation, a top down process.
• Reconsolidation: makes memories labile. Memories are laid down differently every time they reconsolidate

Emotions and Memory

• Flashbulb memories: significant events that create a vivid memory
• Emotions trigger hormone production (neuromodulators such as norepinephrine) from locus coeruleus across the whole brain, priming the brain for making memory

Retrieval and Cues

• Priming: triggering an association with memory before the second stimuli is introduced
• Context-dependent memory: remember something better if the context is present during both encoding/retrieval (encoding specificity)
• State-dependent memory: Internal conditions such as feeling sleepy or moody etc. which is a mood congruent memory
• Serial position effect
• Primacy effect: one most likely to learn information when it is learned first
• Recency effect: only really important if tested shortly after learning it
• Forgetting happens at every single stage of information processing
• Only some information in working memory is encoded
• Sometimes memories cannot be retrieved due to retrieval failure

Forgetting and the Two-Track Mind

• Two categories of tracts: conscious and non conscious
• Encoding failure
• Storage decay
• Retrieval failure
• Interference
• Proactive: older memories make it harder to remember new information
• Retroactive: new learning disrupts learning of old information
• Motivated forgetting
• Repressed memories

Memory Construction Errors

• Misinformation effect: usually corrupted by misleading information used in eyewitness memory
• Memories are be biased by the questions
• The recollection of children ofent accuratley recall events, but they also often create false events via their simulations and what they understand of the world
• Avoid leading questions
• Imagination Effect: repeats and imagines fake actions/events to cause misleading memories
• Reconsolidation Effect: the laying down memories from longterm storage can lead to distortion of the memory

Types of Learning

• Associative learning (classical conditioning): Learn associations between things - when an event occurs, one expects another event connecting two different things to each other
• Consequences (operant conditioning): Certain actions lead to certain consequences
• Cognitive learning: acquiring mental information

Classical Conditioning

• Involves: Unconditioned Stimulus, Neutral Stimulus, Conditioned Stimulus, Conditioned Response
• Neutral and Unconditioned Stimulus must be paired
• Can generalize to be more sensitive to certain situations or discriminate between situations and stimuli
• Temporal contiguity: For maximal classical conditioning, the UCS is presented almost immediately after the NS; tightly connected in time
• Exception includes food Conditioned response does not have to be exactly the same as Unconditioned response, but rather preparatory.
• Genetically predisposed to certain types of learning. For example, food and poisonous is much more easier to learn than a light and then poison

Operant Conditioning

• A type of learning that results in reinforcement of an action and vice versa as it Puts a cat into a box to pull Cat Lever to open the door.
  • Lever pulls increases the frequency of opening the door by the cat.
• Can lead to certain reinforcers being provided: giving something positive (reward) that reinforces a behaviour or taking away a negative stimulus that reinforces a behaviour
• Shaping guides our behaviour to be closer and closer to the desired behaviour
• Classical Conditioning is often automatic and involuntary.
• Operant Conditioning is behavior and consequences based and often operates on the environment

Reinforcement Schedules

• Continuous, or reinforced every time, or Partial Intermittent, reinforced at certain intervals.
• Positive punishment: adding aversive stimulus/condition
• Negative Punishment: is a drawing away of a positive and desired stimulus
• The goal of Punishment: is to make a subject preform an action, in response, this is often suppressed, and not preformed.

Operon's Conditioning Legacy

• Showed Discounted importance of cognition with little effect on reinforcement schedules; Biological influences constrains what stimuli and responses can easily be associated with while:
• Cognitive influences develops an expectation that CS signals the arrival of US, with animals developing an Expectation of reinforcement.
• Evidence with cognitive learning, and learning with no external reward.

Observational Learning

• Can learn by watching others do the same thing with mirroring of other behaviours; such as the bobo doll experiment increasing aggression
• Mirror Neurons are fired upon when observing an action from someone else
• Actions are mimicked and used
• Shown to be related to prosocial effects with kind behavioural mimicing

Cognition

• Thoughts and thought process. An aspect of cognition is consciousness with mental organisations.
• Schemas relate a concept to the categories they appear in, where as Prototypes are ideal representations of a schema.
• Rationality is developed with behaviour that is helpful, to us
• Logic is used in ways to come to a conclusion (aristotle) with logical fallacies.
• Often do base decisions on logic and rationality Kahneman & Tversky (1981) neuroeconomics: -Show 2 options, where 1 is a subset of another, this is often chosen even through its lower probability; shown to be higher through population; conjunction affect. This is often rectified with real world application
• The wasp affect is often used.

Problem Solving

• Is often achieved through the use of Algorithms. Which are a procedure to guarantee a solution, in computers often achieved through a series of small commands
• These are limited in scope and speed
• Heuristics are often used to assist with decision
• These generally work and are more rational but do not guarantee a solution
• They are prone to bias: Including Affect, Anchoring, Authority, and Availability bias, Effort, and Framing.

Examples of Memory and Bias

• Affect: feelings/emotions, a kind of intuition
• Anchoring: compare values to previous values like later prices
• Authority: asking experts
• Availability: how much is available to our memory.
• Problem solving strategies- often limited by a mental set that is often frozen within an intuition.

Insight and Thought

• Insight may be limited by analysis and habit
• Be sensitive to cognitive inflexibility: such as the Dunning-Kruger (ineptitude leading excessive confidence)
• One needs to work to break beliefs.

Creativity and Logic

• Can be seen as opposition to logic and often comes randomly
• High correlation to positive Aptitude, memory, divergent thinking.
• Divergent thinking: spreading out and expanding the number of possible solutions
• Expertise and skills give flexibility in creativity.

Animal Consciousness

• Explored through schematics with Alex the parrot; ability to display insight, and conceptualise solutions to hard problems.
• Evidence that other animals also have some sort of tool culture

Language Structure

• Language consists of - spoken, written, or signed signs in combination, which connects us together and evolves faster than us
• Language, however is often not shared with animals
• Language components include: phonemes (the sound of a language), Morphemes (the sounds of a language in word sense) and grammar (system of rules that govern language as a whole)
• Semantics; the meaning of sounnds Receptive language: Babies can here sounds after 4 weeks, with the ability break sounds after 7 Productive Language:
• Productive babble after 4 months, using the tongue to formulate.
• At 10 months, start to lose the ability to hear non nativelanguages.
• By age 5, syntax is learnt.

Language and Brain

• Humans are predisposed to grammar and syntax, and can make pidgin languages even with little understanding With deaf speakers, and their sign language. Children use: Statistical learning: Using context to understand new words.
• Limited by grammatically incorrect sentence and language.

Language Areas

• 2 primary areas are the Broca's area (left hemisphere) which is responsible for is important in writing and grammar.
• Second is the Broca's area
• With this if there is a word salad, it can be attributed to the Broca area: production of speech is okay but the sentences don't make any sense
• Brain speech zones are widespread not localized.

Thought and Language

• Linguistic determinism and language relation determine basic ideas to thought
• Whorf's linguistic determinism hypothesis - Language determines our basic ideas and thoughts to thought.
• Determinisim too far: We have an inner monotone.
• Bilingual advantages can increase ability to inhibit irrelevant information and filter information.
• Visualising can assist with increasing the rate of visualising sucess, or reduce it in some cases.