PSYC 104 Exam 2 Study Guide: Biological Psychology, Sensation & Perception, and Consciousness

Chapter 3: Biological Psychology

Section 3.1: Neuroimaging and Brain Function

This section covers the main techniques used to study brain structure and function, as well as the concepts of spatial and temporal resolution in neuroimaging.

• Structural Neuroimaging: Techniques that visualize the anatomy of the brain (e.g., CT, MRI).

• Functional Neuroimaging: Techniques that measure brain activity (e.g., PET, fMRI, EEG, MEG).

• Brain Stimulation: Includes Transcranial Magnetic Stimulation (TMS) and Transcranial Direct Current Stimulation (tDCS), which can temporarily enhance or disrupt brain function.

• Spatial Resolution: The ability to distinguish small details in brain structure or activity. fMRI and PET have good spatial resolution.

• Temporal Resolution: The ability to track changes in brain activity over time. EEG and MEG have good temporal resolution.

• Localization of Function: The concept that specific brain areas are responsible for specific functions, demonstrated by lesion and imaging studies.

• Caution: Overemphasizing localization can ignore the brain's networked and distributed processing.

Section 3.2: Neurons and Neurotransmission

This section explains the structure and function of neurons, the process of neural signaling, and the role of neurotransmitters.

• Parts of a Neuron: Dendrites (receive signals), Soma (cell body), Axon (transmits signals), Myelin Sheath (insulation), Axon Terminals (release neurotransmitters), Synaptic Vesicles (store neurotransmitters), Synapse (gap between neurons).

• Neural Signaling Steps:

  1. Resting Potential: The neuron's stable, negative charge when inactive.

  2. Threshold of Excitation: The level of stimulation required to trigger an action potential.

  3. Action Potential: A rapid electrical impulse that travels down the axon.

  4. Absolute Refractory Period: A brief period after an action potential when a neuron cannot fire again.

• Neurotransmitter Communication: Neurotransmitters are released into the synapse, bind to receptor sites on the next neuron, and trigger a response.

• Types of Neurotransmitters: Examples include dopamine, serotonin, acetylcholine, GABA, glutamate, etc.

• Psychoactive Drugs:

  • Agonists: Enhance neurotransmitter activity (e.g., morphine).

  • Antagonists: Inhibit neurotransmitter activity (e.g., antipsychotics).

• Neural Plasticity: The brain's ability to change and adapt. Occurs through:

  • Development (growth, synaptogenesis, pruning, myelination)

  • Learning (experience-dependent changes)

  • Injury (takeover of function, neurogenesis, stem cells)

Section 3.3: Brain Structure and the Nervous System

This section describes the major brain regions, their functions, and the organization of the nervous system.

• Cerebral Cortex Lobes:

  • Frontal (planning, movement, problem-solving)

  • Parietal (sensory processing)

  • Temporal (hearing, memory)

  • Occipital (vision)

  Damage to Lobes: Can result in deficits such as aphasia, agnosia, or loss of motor control.

• Forebrain Regions: Basal ganglia (movement), limbic system (emotion, memory), hypothalamus (homeostasis).

• Midbrain, Brainstem, Cerebellum: Midbrain (sensory relay), Pons and Medulla (basic life functions), Cerebellum (coordination).

• Peripheral Nervous System:

  • Somatic (voluntary control)

  • Autonomic (involuntary control):

    • Sympathetic (emergency, 'fight or flight')

    • Parasympathetic (rest and digest)

• Spinal Reflex: Automatic response to stimuli, processed in the spinal cord.

Section 3.4: Hormones and the Endocrine System

This section explains the role of hormones and how the endocrine system differs from neurotransmission.

• Hormones: Chemical messengers released by glands, travel through the bloodstream, and affect distant organs.

• Endocrine System: Network of glands (e.g., pituitary, adrenal) that secrete hormones.

• Difference from Neurotransmitters: Hormones act more slowly and over longer distances than neurotransmitters.

Section 3.5: Genetics and Behavior

This section covers the basics of genetic material and how genes influence traits and behavior.

• Genetic Material: DNA (deoxyribonucleic acid), Chromosomes (structures containing DNA), Genes (segments of DNA coding for traits).

• Dominant vs. Recessive: Dominant genes mask the effects of recessive genes.

• Genotype vs. Phenotype: Genotype is genetic makeup; phenotype is observable traits.

• Behavioral Genetic Designs:

  1. Family studies

  2. Twin studies

  3. Adoption studies

Chapter 4: Sensation and Perception

Section 4.1: Basic Concepts in Sensation and Perception

This section introduces the processes of sensation and perception, thresholds, and the role of attention.

• Sensation: Detection of physical energy by sense organs.

• Perception: Interpretation of sensory input.

• Transduction: Conversion of physical energy into neural signals.

• Sensory Adaptation: Reduced sensitivity to constant stimulation.

• Absolute Threshold: Minimum stimulus intensity detected 50% of the time.

• Just Noticeable Difference (JND): Smallest detectable difference between stimuli; related to Weber's Law ($\frac{\Delta I}{I} = k$).

• Signal Detection Theory: Framework for distinguishing signal from noise; outcomes include hit, miss, false alarm, correct rejection.

• McGurk Effect: Interaction between hearing and vision in speech perception.

• Synesthesia: Blending of senses (e.g., seeing colors when hearing music).

• Selective Attention: Focusing on specific stimuli while ignoring others.

• Inattentional Blindness: Failure to notice unexpected stimuli when attention is elsewhere.

• Binding Problem: How the brain integrates information from different sensory modalities.

Section 4.2: Vision

This section details the properties of light, the anatomy of the eye, and theories of color vision.

• Light Properties: Amplitude (brightness), Wavelength (color/hue).

• Eye Anatomy:

  • Cornea: Focuses light.

  • Lens: Adjusts focus (accommodation).

  • Retina: Contains photoreceptors (rods and cones).

  • Fovea: Central point of sharpest vision, high density of cones.

  • Blind Spot: Area with no photoreceptors where optic nerve exits.

• Rods vs. Cones: Rods (low light, peripheral vision), Cones (color, detail, concentrated in fovea).

• Myopia: Nearsightedness; Hyperopia: Farsightedness.

• Theories of Color Vision:

  • Trichromatic Theory: Three types of cones (red, green, blue).

  • Opponent-Process Theory: Pairs of opposing colors (red-green, blue-yellow).

  • Dual Process Theory: Combines both theories.

• Feature Detector Cells: Neurons in V1 that respond to specific visual features.

Section 4.3: Hearing (Audition)

This section explains the properties of sound, ear anatomy, and theories of pitch perception.

• Sound Properties: Amplitude (loudness), Frequency (pitch), Complexity (timbre).

• Human Hearing Range: 20 Hz to 20,000 Hz.

• Ear Anatomy:

  • Outer Ear: Pinna, ear canal.

  • Middle Ear: Ossicles (malleus, incus, stapes).

  • Inner Ear: Cochlea, basilar membrane.

• Basilar Membrane: Vibrates in response to sound, crucial for pitch perception.

• Theories of Pitch Perception:

  • Place Theory: Pitch determined by location of vibration on basilar membrane.

  • Frequency Theory: Pitch determined by rate of nerve impulses.

• Types of Deafness:

  • Conductive: Problems with outer/middle ear.

  • Nerve (Sensorineural): Damage to inner ear or auditory nerve.

Section 4.4: Smell (Olfaction) and Taste (Gustation)

This section describes the chemical senses and their neural pathways.

• Olfaction: Sense of smell; uses olfactory receptors.

• Gustation: Sense of taste; uses taste buds (chemoreceptors).

• Five Basic Tastes: Sweet, sour, salty, bitter, umami.

• Anosmia: Loss of sense of smell.

• Flavour: Combination of taste and smell; orbitofrontal cortex integrates these senses.

Section 4.5: Somatosensory, Proprioceptive, and Vestibular Systems

This section covers touch, body position, and balance senses.

• Somatosensory System: Processes touch, temperature, pain, and body position.

• Main Components: Touch, temperature, pain, proprioception.

• Skin Layers: Epidermis, dermis, hypodermis.

• Mechanoreceptors: Respond to mechanical pressure or distortion.

• Withdrawal Reflex: Automatic response to painful stimuli.

• Proprioceptive System: Senses body position; uses muscle spindles, Golgi tendon organs, joint receptors.

• Vestibular System: Senses balance and spatial orientation; located in inner ear (semicircular canals).

Section 4.6: Perceptual Organization

This section explains how the brain organizes sensory input into meaningful patterns.

• Parallel Processing: Simultaneous processing of multiple aspects of a stimulus.

• Bottom-Up Processing: Analysis begins with sensory receptors; example: recognizing a letter by its features.

• Top-Down Processing: Guided by experience and expectations; example: reading messy handwriting using context.

• Gestalt Principles: Rules for organizing sensory input:

  1. Proximity

  2. Similarity

  3. Continuity

  4. Closure

  5. Symmetry

  6. Figure-ground

Chapter 5: Consciousness

Section 5.1: Sleep and Circadian Rhythms

This section covers biological rhythms, sleep stages, and sleep disorders.

• Circadian Rhythm: 24-hour biological cycle regulating sleep and wakefulness.

• Sleep Deprivation: Impairs cognitive function, mood, and health.

• REM vs. Non-REM Sleep: REM (rapid eye movement, vivid dreams, muscle paralysis); Non-REM (stages 1-4, less vivid dreams).

• Five Stages of Sleep: Progress from light to deep sleep, then REM; characterized by different brain waves (e.g., theta waves in stage 1).

• Sleep Disorders:

  • Insomnia: Difficulty falling or staying asleep.

  • Narcolepsy: Sudden sleep attacks.

  • Sleep Apnea: Breathing interruptions during sleep.

  • Night Terrors: Sudden arousal and fear during sleep.

• Lucid Dreaming: Awareness of dreaming while in a dream.

Section 5.2: Theories of Dreaming

This section reviews major theories explaining why we dream and how dreams are generated.

• Dream Protection Theory: Freud's idea that dreams guard sleep by disguising wishes.

• Manifest Content: The literal storyline of a dream.

• Latent Content: The hidden psychological meaning of a dream.

• Activation-Synthesis Theory: Dreams result from the brain's attempt to make sense of random neural activity.

• Neurocognitive Theory: Dreams reflect cognitive development and everyday concerns.

• Dream Continuity Hypothesis: Dreams are continuous with waking thoughts and concerns.

Section 5.3: Hypnosis

This section explains hypnosis, its processes, and main theories.

• Hypnosis: Altered state of consciousness with increased suggestibility.

• Theories:

  • Dissociation Theory: Hypnosis causes a split in consciousness.

  • Sociocognitive Theory: Effects of hypnosis are due to social and cognitive influences.

• Myths vs. Realities: Hypnosis does not give superhuman abilities or force people to act against their will.

Section 5.4: Drugs and Consciousness

This section discusses substance use disorders, drug categories, and their effects.

• Substance Use Disorder: Maladaptive pattern of substance use leading to impairment or distress.

• Drug Abuse Phenomena: Withdrawal, physical dependence, tolerance.

• Risk Factors: Sociocultural influences, personality traits, expectations, genetics.

• Drug Categories:

  • Depressants: Alcohol, benzodiazepines (reduce CNS activity).

  • Stimulants: Nicotine, cocaine, amphetamines (increase CNS activity).

• Effects: Depressants cause relaxation and drowsiness; stimulants increase alertness and energy.