Biological Basis of Behavior Study Guide Notes

T H E B R A I N:

Limbic System

  • Function: Emotion and memory.

  • Includes: Amygdala, hippocampus, hypothalamus, thalamus, and pituitary gland.

  • Mnemonic: "PATHH(Pituitary gland, amygdala, thalamus, hypothalamus, hippocampus)."

Pituitary Gland

  • Function: Master gland; controls other glands + growth.

  • Example: Releases growth hormone during sleep.

Amygdala

  • Function: Fear and aggression.

  • Mnemonic: "Amy stole your dollar" – you're angry and scared!

Thalamus

  • Function: Sensory relay station (except smell).

  • Mnemonic: "Thal–a–BUS" — like a bus hub that sends messages to different parts of the brain.

Hypothalamus

  • Function: Hunger, thirst, body temperature, and sex drive.

  • Mnemonic: "Hippos Fight For Food" – Hunger, Fight or Flight, Feeding, Fornication.

Hippocampus

  • Function: Memory formation.

  • Mnemonic: "You’d never forget a hippo on campus."

Lobes of the Cerebral Cortex

  • Frontal: Judgment, planning, movement.

    • Location: Forehead

  • Temporal: Hearing, memory

    • Location: Both sides of the back of your ears

  • Occipital: Vision.

    • Location: Behind the eyes

  • Parietal: Touch, body position.

    • Location: Top of the head

Cerebellum

  • Function: Balance, coordination.

  • Mnemonic: "Sarah the ballerina" (Cerebellum = balance).

Medulla/Brain Stem

  • Function: Basic functions (breathing, heartbeat).

  • Mnemonic: "Medusa stops your heart!"

Corpus Callosum

  • Function: Connects left and right hemispheres.

  • Mnemonic: “Call someone to connect hemispheres.”

Left vs. Right Hemisphere

  • Left: Logic, language.

  • Right: Creativity, spatial.

Broca’s Area

  • Function: Speech production.

  • Damage: Can’t talk but understands.

  • Mnemonic: “Broca = Broken speech.”

Wernicke’s Area

  • Function: Language comprehension.

  • Damage: Talk nonsense.

  • Mnemonic: “What?” when you hear Wernicke.

EEG (Electroencephalogram)

  • Function: Detects electrical activity in the brain.

  • Use: Sleep studies, epilepsy.

Nervous System

  • Central vs Peripheral

    • Central (CNS): Brain + spinal cord.

    • Peripheral (PNS): Everything else.

    • Glial cells: the growth of developing neurons helps provide nutrition, gets rid of wastes of neurons, and forms an insulating sheath around neurons that speeds conduction.

  • Autonomic vs Somatic

    • Autonomic: Automatic (heart rate, digestion).

    • Somatic: Voluntary movement.

  • Sympathetic vs Parasympathetic

    • Sympathetic: Fight or flight.

    • Parasympathetic: Rest and digest.

    • Mnemonic: "Sympathy for stress, Para for peace."

  • Nervous vs Endocrine

    • Nervous: Fast, electrical.

    • Endocrine: Slow, hormonal.

  • Brain Plasticity: Although specific regions of the brain are associated with specific functions, if one area is damaged, the brain can reorganize to take over its function.

Parts of the Neuron

  • Synapse: Gap between neurons.

  • Dendrites: Receive signals.

  • Cell Body (Soma): Life of the cell.

  • Axon: Sends messages.

  • Myelin Sheath: Insulates axon, speeds up signal.

  • Axon Terminal: Releases neurotransmitters.

Neuron Movement

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

  • Depolarization: Positive ions enter; neuron fires.

  • Refractory Period: Resets before firing again.

  • Resting Potential: Negative charge inside the neuron.

  • Reuptake: Reabsorption of neurotransmitters.

  • Threshold: Minimum to trigger firing.

  • Sensory Neurons: Take in info.

  • Interneurons: Process info.

  • Motor Neurons: Send commands out.

Hormones (GLAMO)

  • Ghrelin: Hunger inducer.

  • Leptin: Hunger suppressant.

  • Adrenaline: Fight or flight.

  • Melatonin: Sleep.

  • Oxytocin: Bonding, love, lactation.

Neurotransmitters (SAND EGGS)

  • Neurotransmitters are chemicals stored in structures of the terminal buttons called synaptic vesicles.

  • Agonists may mimic a neurotransmitter and bind to its receptor site to produce the effect of the neurotransmitter.

  • Antagonists block a receptor site, inhibiting the effect of the neurotransmitter or agonist.

  • Serotonin: Mood

    • Mnemonic: "Stabilizer” – stay serene

  • Acetylcholine: Movement

    • Mnemonic: "A for Action"

  • Norepinephrine: Alertness

    • Mnemonic: "No rest = norepinephrine"

  • Dopamine: Pleasure

    • Mnemonic: "Dope = feel good"

  • Endorphins: Pain relief

    • Mnemonic: "End pain"

  • GABA: Inhibitory

    • Mnemonic: "GAbariar – slows down"

  • Glutamate: Excitatory

    • Mnemonic: "Gluta go!"

  • Substance P: Pain

    • Mnemonic: "P for pain"

Drugs

  • Stimulants: Speed up (caffeine, cocaine).

  • Depressants: Slow down (alcohol).

  • Hallucinogens: Distort perception (LSD).

  • Opioids: Pain relief (morphine).

  • Tolerance: Need more for the same effect.

  • Withdrawal: Symptoms when stopping.

Sleep

  • Circadian rhythm is a natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours.

  • Stages

    • nREM 1: Light sleep, falling sensation.

    • nREM 2: Sleep spindles, transition.

    • nREM 3: Deep sleep, delta waves.

    • REM: Dreaming, paradoxical (active brain, paralyzed body).

  • Theories:

    • Activation-Synthesis: Dreams = random brain activity.

    • Consolidation: Sleep solidifies memories.

  • Disorders:

    • Sleep Apnea: Breathing stops.

    • Insomnia: Trouble falling/staying asleep.

    • Narcolepsy: Sudden sleep attacks.

    • REM Behavior Disorder: Acting out dreams.

    • Somnambulism: Sleepwalking (nREM 3).

The Eye

  • Retina: Detects light.

  • Cornea: Protects and focuses light.

  • Lens: Focuses the image.

  • Pupil: Controls light entry.

  • Cones: Color vision.

  • Rods: Low-light vision.

  • Blind Spot: No receptors.

  • Accommodation: Lens changes shape.

  • Nearsighted: Can’t see far.

  • Farsighted: Can’t see close.

Theories of Color Vision

  • Trichromatic: 3 colors (RGB).

  • Opponent Process: Opposing colors (red-green, blue-yellow).

The Ear

  • Outer Ear → Middle Ear → Inner Ear

  • Cochlea: Converts sound to neural signals.

  • Pitch: Frequency.

  • Amplitude: Volume.

  • Conduction Deafness: Mechanical issue.

  • Sensorineural Deafness: Inner ear/nerve issue.

Smell (Olfaction)

  • Processed directly, not through the thalamus.

  • Tied closely with memory.

Taste (Gustation)

  • 6 Tastes: Sweet, Sour, Salty, Bitter, Umami, Oleogustus (fatty).

  • Taste Buds: Detect chemicals.

  • Smell & taste are connected.

Touch

  • Skin Receptors: Pressure, temperature, pain.

  • Gate Control Theory: Spinal "gate" opens for pain signals.

  • Phantom Limb: Feeling in a missing limb.

Balance

  • Vestibular Sense: Inner ear, balance.

  • Kinesthetic Sense: Position/movement of body parts.

Sensation

  • Absolute Threshold: Minimum detectable.

  • JND (Just Noticeable Difference): Smallest detectable change.

  • Sensory Adaptation: Get used to constant stimuli.

  • Weber’s Law: The Change needed is proportional.

  • Sensory Interaction: Senses influence each other.

  • Synesthesia: Mixing senses.

  • Transduction: Sensory input → neural signal.

  • Behavioral geneticists study the role played by our genes and our environment in mental ability, emotional stability, temperament, personality, interests, and so forth; they look at the causes of our differences.

  • Dual processing refers to processing information on conscious and unconscious levels at the same time.