ap psych unit 1-2?

BIOLOGICAL BASES OF BEHAVIOR
UNIT 2 Overview

  • The biological bases of behavior link the nervous and endocrine systems to psychological processes.

Nervous System Overview

  • Central Nervous System (CNS): Brain and spinal cord.

  • Peripheral Nervous System (PNS): Nerves outside CNS.

    • Somatic: Voluntary movements.

    • Autonomic: Involuntary functions, further divided into:

    • Sympathetic: Fight or flight response.

    • Parasympathetic: Rest and digest.

Structure of the Brain

  • Hindbrain: Medulla (vital functions), Pons (connective), Cerebellum (movement, balance).

  • Midbrain: Sensory integration, alertness (reticular formation).

  • Forebrain: Higher functions, includes:

    • Thalamus: Sensory relay.

    • Hypothalamus: Regulates hunger, thirst, temperature, circadian rhythms.

    • Amygdala: Emotions (fear, pleasure).

    • Hippocampus: Memory formation.

Brain Lobes

  • Frontal Lobe: Logic, reasoning, motor control (motor cortex, Broca's area).

  • Parietal Lobe: Sensory information (sensory cortex).

  • Occipital Lobe: Visual processing (visual cortex).

  • Temporal Lobe: Auditory processing, language comprehension (Wernicke's area).

Neuron Structure

  • Components: Dendrites (receive), Soma (cell body), Axon (transmit), Myelin Sheath (insulate), Node of Ranvier (propagate), Axon Terminals (release neurotransmitters).

Neural Communication

  • Electrochemical Transmission: Neuron goes from resting state (polarized, e.g., -70 ext{mV}) to action potential (depolarization to +40 ext{mV} with Na+ influx) then refractory period.

  • All-or-Nothing Principle: Neuron fires completely or not at all.

Neurotransmitters

  • Acetylcholine (ACH): Muscle action, learning, memory (deficits: Alzheimer's).

  • Dopamine: Movement, emotion (low: Parkinson's; high: Schizophrenia).

  • Serotonin: Mood, sleep, appetite (low: depression).

  • Norepinephrine: Attention, stress response (fluctuating: depression, anxiety).

  • GABA: Inhibitory (low: anxiety).

  • Glutamate: Excitatory (excess: excitotoxicity/strokes).

  • Endorphins: Natural painkillers.

Influence of Drugs on Neurotransmitters

  • Agonists: Mimic neurotransmitters.

  • Antagonists: Block neurotransmitters.

  • Reuptake inhibitors: Prevent reabsorption (e.g., SSRIs).

Split-Brain Research

  • Study of corpus callosotomy patients; highlights hemisphere specialization:

    • Left Hemisphere: Verbal, language.

    • Right Hemisphere: Non-verbal, spatial.

Genetic Influences on Behavior

  • Genetics impact individual differences; twin studies show heritability. Chromosomal abnormalities affect development.

Endocrine System

  • Glands release hormones (regulated by hypothalamus/pituitary) affecting growth, metabolism, mood. Key glands: Adrenal (adrenaline), Gonads (sex hormones).

Important Figures in Neuropsychology

  • Roger Sperry, Michael Gazzaniga: Split-brain research.

  • Paul Broca, Carl Wernicke: Brain language areas.