Biological Bases of Behavior Summary

Broca's and Wernicke's Areas

  • Paul Broca (1861): Discovered link between Broca's area (in left frontal lobe) and speech (expressive aphasia).
  • Carl Wernicke: Found Wernicke's area (in left temporal lobe) involved in comprehension (receptive aphasia).

Brain Imaging Techniques

  • Lesions and Ablation: Help study functions resulting from brain damage.
  • CAT (CT) Scan: Creates x-ray images; shows brain lesions.
  • MRI: Uses magnetic fields and radio waves to generate images.
  • EEG: Measures electrical activity in the brain.
  • PET: Produces images based on metabolic activity.
  • fMRI: Measures brain activity through changes in blood oxygenation.
  • MEG: Measures magnetic fields created by neural activity.

Nervous System Structure

  • Central Nervous System: Brain + spinal cord.
  • Peripheral Nervous System: Somatic (voluntary) + autonomic (involuntary).
  • Autonomic Nervous System: Sympathetic (stress response) + parasympathetic (calming response).

Brain Organization

  • Triune Brain Model: Differentiates three brain systems:
    • Reptilian brain (brainstem): Homeostasis, instincts.
    • Old mammalian brain (limbic system): Emotion, memory.
    • New mammalian brain (neocortex): Higher cognitive functions.

Brain Functions and Areas

  • Medulla: Heart rate, breathing.
  • Pons: Sleep regulation, communication between brain areas.
  • Cerebellum: Coordination, balance.
  • Hippocampus: Long-term memory formation.
  • Cerebral Cortex: Higher-order processing and sensory information.

Neuron Structure & Function

  • Neuron: Basic unit of nervous system.
  • Dendrites: Receive information.
  • Axon: Transmits impulses; covered by myelin sheath.
  • Neurotransmitters: Chemicals that transmit signals across synapses (e.g., dopamine, serotonin).
  • Action Potential: Electrical impulse triggered when neuron is stimulated.

Endocrine System

  • Glands: Secrete hormones (e.g., pituitary, thyroid, adrenal).
  • Hormones: Chemical messengers affecting various functions (e.g., metabolism, stress).

Genetics and Behavior

  • Nature vs. Nurture Debate: Examines heredity influence vs. environment on behavior.
  • Heritability: Genetic influence on traits.
  • Genetic Conditions: Examples include Down syndrome, Klinefelter's syndrome, Tay-Sachs disease.

Levels of Consciousness

  • Preconscious: Easily accessible memories.
  • Nonconscious: Automatic bodily functions.
  • Unconscious: Repressed thoughts and feelings.
  • Sleep Cycle: Includes NREM and REM stages with distinct EEG patterns.

Sleep Disorders

  • Insomnia: Difficulty in sleep initiation or maintenance.
  • Narcolepsy: Sudden sleep attacks.
  • Sleep Apnea: Breathing interruptions during sleep.

Hypnosis and Meditation

  • Hypnosis: Altered consciousness with heightened suggestibility.
  • Meditation: Techniques for concentration and calmness.

Psychoactive Drugs

  • Depressants: Slow CNS activity (e.g., alcohol).
  • Stimulants: Increase CNS activity.
  • Hallucinogens: Alter perception and mood (e.g., LSD).