Study Notes for Introductory Psychology

INTRODUCTORY PSYCHOLOGY

Course Information

  • Course: PSYC-1100

  • Instructor: Yao

Today's Topics

  • Sleep

  • Arousal

  • States of consciousness

  • Dreaming

  • Sleep disorders

  • Language

  • Language disorders

MEMORY: DECLARATIVE (EXPLICIT) EPISODIC MEMORIES

Overview of Episodic Memories

  • Episodic Memories:

    • Depend on the hippocampus:

    • A structure in the limbic system, heavily involved in the formation of new memories.

    • Critical for encoding specific experiences or contexts.

    • Neurons in the hippocampus called place cells:

    • Encode information about location (context).

    • Contextual Information:

    • Stored and associated with episodic memories, enhancing memory retrieval.

BIOLOGICAL RHYTHMS

Introduction

  • The body has various biological rhythms that govern physiological functions.

  • Biological Rhythms:

    • Defined as periodic fluctuations in physiological functioning.

    • Example:

    • Alertness peaks in the morning and decreases towards night.

Circadian Rhythms

  • Circadian Rhythms:

    • 24-hour biological cycles observed in humans and many species due to the day-night cycle.

    • Common rhythms typically last around 24 hours.

The Suprachiasmatic Nucleus (SCN) & Pineal Gland

Role in Sleep Regulation

  • SCN:

    • Located in the hypothalamus, receives light input through the retina.

    • Signals the pineal gland to suppress melatonin release in response to light.

  • Melatonin:

    • Hormone secreted by the pineal gland that regulates sleep-wake cycles.

Impact of Light on Melatonin Release

  • Exposure to light (especially blue light from screens) inhibits melatonin production, leading to difficulties in sleep.

JET LAG & Sleep Cycles

Jet Lag

  • Jet Lag:

    • Results from rapid travel across time zones, causing circadian rhythms to become out of sync with real-time.

    • Disrupts sleep until the body adjusts to the new schedule.

STUDYING SLEEP: ELECTROPHYSIOLOGY

Consciousness

  • Consciousness: Awareness of internal and external stimuli.

  • Historically measured through Electroencephalogram (EEG):

    • Device that records electrical activity of the brain via electrodes attached to the scalp.

Brain Waves and Mental States

Brainwave Patterns

  • EEG yields various brainwave patterns, each associated with specific mental states, characterized by:

    • Amplitude: Height of the wave.

    • Frequency: Cycles per second, indicating wave speed.

Types of Brain Waves

  • Identified categories of human brainwaves:

    • Gamma (32-100 Hz): Highest frequency, involved in higher mental activity.

    • Beta (13-32 Hz): Associated with normal waking thought, alertness, and problem-solving.

    • Alpha (8-13 Hz): Reflects relaxation and meditation; prominent when eyes are closed.

    • Theta (4-8 Hz): Associated with light sleep.

    • Delta (0.5-4 Hz): Indicates deep sleep; characterized by slow, high-amplitude waves.

POLYSOMNOGRAPHY (PSG)

Sleep Measurement Techniques

  • Polysomnography (PSG):

    • Comprehensive sleep study measuring multiple physiological factors, typically EEG, EMG (muscle activity), and EOG (eye activity).

    • Essential for assessing sleep patterns and identifying sleep disorders.

SLEEP STAGES AND CYCLES

Overview of Sleep Stages

Sleep Stages

  • Various stages of sleep are monitored through PSG:

    • Stage 1: Transition from wakefulness to sleep.

    • Stage 2: Characterized by sleep spindles; a deeper sleep.

    • Stage 3: Deep sleep (SWS), marked by delta waves.

    • REM Sleep: Resembles waking state; characterized by muscle paralysis and vivid dreaming.

Characteristics of Each Stage

  • Stage 1:

    • Transitional phase (5-10 minutes, easy to awaken).

    • Characterized by alpha and theta waves.

  • Stage 2:

    • Eye movement stops, muscle activity decreases.

    • Contains sleep spindles and K-Complexes, believed to enhance memory and quality of sleep.

  • Stage 3 (SWS):

    • Deepest stage, primarily occurring in the first half of the night.

    • Delta waves are predominant; crucial for restorative processes in the body.

  • REM Sleep:

    • Also known as paradoxical sleep due to brain activity resembling wakefulness.

    • Characterized by rapid eye movements, muscle atonia, and vivid dreaming.

Hypnogram and the Sleep Cycle

  • The hypnogram illustrates different sleep stages across the night.

  • Trends in healthy adults:

    • People cycle through sleep stages approximately every 90 minutes.

    • Length of SWS decreases while REM periods lengthen throughout the night.

DREAMING & SLEEP DISORDERS

Overview of Dreaming

  • Dreams are more vivid during REM sleep due to heightened brain activity.

  • Can originate from any sleep stage, but non-REM dreams are less coherent and emotional.

The 'Day-Residue' Effect

  • Recent experiences often influence dream content, known as the day-residue effect.

  • Modern research indicates dreams stem from daily activities and emotions.

Causes of Dreaming

Activation-Synthesis Hypothesis

  • Proposed by J. Allan Hobson: Dreams arise from brain attempts to synthesize random neural activities during REM sleep.

  • Suggests dreams assist with emotional regulation and memory consolidation.

Counterarguments and Evidence

  • Mark Solms conducted studies that showed patients with brainstem damage still dream, challenging the activation-synthesis hypothesis.

Types of Sleep Disorders

  • Variety of disorders disrupt normal sleep cycles, including:

    • REM Behaviour Disorder: Absence of muscle paralysis during REM sleep, causing people to act out dreams.

    • Somnambulism (Sleepwalking): Performing activities while asleep, often during non-REM sleep.

    • Narcolepsy: Characterized by excessive daytime sleepiness and sudden sleep episodes.

    • Sleep Apnea: Recurrent pauses in breathing during sleep, leading to fragmented sleep.

    • Insomnias: Difficulty falling asleep or remaining asleep.

    • Nightmares and Night Terrors: Hallucinations during sleep associated with fear and distress.

SPECIFIC SLEEP DISORDERS

Somnambulism (Sleepwalking)

  • Disorder in which individuals perform activities while asleep, often during Stage 3 (SWS).

  • Can be triggered by factors like stress or sleep deprivation.

  • Sleepwalkers typically lack memory of their actions and require guided assistance back to bed.

REM Behaviour Disorder (RBD)

  • RBD involves acting out dreams due to lack of normal muscle paralysis.

  • Causes include degeneration of the pontine inhibitory area (PIA).

Threat Simulation Theory

  • Suggests dreams may have an evolutionary purpose of rehearsal for dealing with potential conflicts or threats.

  • Proposed by Antti Revonsuo.

Narcolepsy

  • Chronic disorder marked by sudden sleep episodes.

  • Cataplexy may also occur, leading to instant loss of muscle tone.

Nightmare Disorder

  • Characterized by vivid, distressing dreams, often causing the person to wake.

  • Usually occurs during REM sleep and can disrupt sleep patterns, often influenced by stress or trauma.

Night Terrors

  • Abrupt episodes of intense fear during sleep, common in children, typically during non-REM sleep.

  • Characterized by screaming and thrashing; individuals wake with little to no recollection.

Sleep Apnea

  • Caused by repeated interruptions in breathing, leading to excessive daytime sleepiness.

  • Often treated with Continuous Positive Airway Pressure (CPAP) therapy, which assists breathing during sleep.

Insomnia

  • Difficulty in falling asleep, staying asleep, or experiencing refreshing sleep.

  • Treatment may involve cognitive-behavioral therapy or medication to improve sleep hygiene.

Fatal Familial Insomnia

  • Rare genetic disorder leading to severe sleep disturbances and cognitive decline.

  • Ultimately results in death within 0-2 years due to the inability to sleep.

LANGUAGE

Units of Language

Morphemes

  • Defined as the smallest units of meaning, which can include:

    • Root words (e.g., "friend").

    • Prefixes (e.g., "un").

    • Suffixes (e.g., "ly").

  • Example: The word "unfriendly" has three morphemes.

Phonemes

  • Defined as the smallest units of sound in a given language.

Critical Periods in Language Development

Early Language Acquisition

  • Year 1:

    • Critical for language development; children start to utter words typically between 10-13 months.

  • 1 year – 18 months:

    • Vocabulary expands from 3 to 50 words; receptive vocabulary exceeds productive vocabulary.

  • 18 months – 5 years:

    • Vocabulary can grow from 50 words to an average of 10,000.

    • Children demonstrate fast mapping, linking words to concepts after a single exposure.

    • Development of metalinguistic awareness occurs toward school age.

Is Language Unique to Humans?

  • Attempts have been made to teach language to other species, such as chimpanzees.

  • Evidence suggests that while they can learn a limited set of symbols, human children far surpass this capacity rapidly in weeks or months.

Theories of Language Acquisition

Behaviorism

  • B.F. Skinner proposed that language is learned through imitation, reinforcement, and conditioning, where parents reinforce correct language use.

Nativist Theories

  • Noam Chomsky critiqued Skinner's theory, suggesting humans possess an innate Language Acquisition Device (LAD) that facilitates language learning.

  • He noted that children generate novel sentences that indicate deeper linguistic understanding beyond imitation.

Language in the Brain

Discoveries of Paul Broca

  • Paul Broca identified that damage to a specific region of the brain affects speech production.

  • Broca's Area: Responsible for language production; damage causes Broca's Aphasia, where comprehension remains intact, but fluency is impaired.

Discoveries of Carl Wernicke

  • Carl Wernicke identified a region of the brain associated with language comprehension.

  • Damage to Wernicke’s Area results in Wernicke’s Aphasia, where comprehension is impaired while speech remains fluent but nonsensical.

Additional Notes

  • Both Broca's and Wernicke's areas highlight the specialization of brain functions related to specific aspects of language.

  • Understanding these areas is crucial for diagnosing and treating language disorders in clinical psychology.