Biological Bases of Behavior Lecture Notes

Overview

• Connection between environment, hereditary traits, and psychological being.
• Psychology relates to the entire body, including endocrine and nervous systems.
• Focus on the brain, sleep, dreaming, and the impact of drugs.

Key Questions

• Is our mind biological?
• Is our mind separate from our body?
• Where is our identity located - heart, brain, or body?

Neural Anatomy

• Biological psychologists study the link between body, mind, and behavior.
• Neurons: Create pathways for communication within the body.
  • Structure of a Neuron:
    • Dendrites: Receive messages from previous neurons.
    • Cell Body/Soma: Neuro-cell’s life center, attached to dendrites.
    • Axon: Long middle section, covered by the Myelin Sheath for faster message travel.
    • Terminal Branches: End of the neuron, where neurotransmitters pass through the synapse to next neuron.

Neural Communication

• Too many neural signals can cause a seizure; too few can lead to depression.
• Neurons fire when a specific threshold is reached.
• Polarization: Neuron's inside is negatively charged relative to the outside.
• Depolarization/Action Potential: Sodium ions enter, reversing the negative charge.
• Refractory Period: Post-stimulation period when a neuron can’t be stimulated.
• Synapse: Gap where neurotransmitters are exchanged and recycled.
• All-or-none response of neurons; more neurons firing = more intense sensations.

Neurotransmitters

• Dopamine: Linked to movement, learning, motivation, pleasure.
  • Imbalance: Tremors, ADHD, Parkinson’s, psychosis, schizophrenia.
• Serotonin: Influences mood, hunger, sleep, aggression.
  • Imbalance: Depression.
• Acetylcholine: Muscle action, learning, memory.
  • Imbalance: Alzheimer’s.
• Norepinephrine: Alertness, arousal.
  • Imbalance: Depression.
• GABA: Inhibitory neurotransmitter.
  • Imbalance: Seizures, insomnia, anxiety.
• Glutamate: Excitatory neurotransmitter.
  • Imbalance: Seizures, migraines.
• Other Terms:
  • Epinephrine: Triggers adrenal response in danger.
  • Agonist: Mimics neurotransmitters.
  • Antagonist: Blocks neurotransmitters.

Nervous System

• Central Nervous System (CNS): Brain and spinal cord.
• Peripheral Nervous System (PNS): All other nerves.
  • Sympathetic Functions: Arousal, fight or flight.
  • Parasympathetic Functions: Calming, rest and digest.

Brain Functionality

• Cerebral Cortex: Complex functions handled.
  • Four lobes: Frontal, Parietal, Occipital, Temporal.
  • Left Hemisphere: Language, details, thoughts.
  • Right Hemisphere: Wholistic ideas, feelings.
  • Corpus Callosum: Connects hemispheres.
• Brain Stem: Essential functions like heartbeat, breathing.
• Limbic System: Emotions, memory.

Sleep and Dreaming

• Consciousness: Awareness of self and environment.
• Circadian Rhythm: 24-hour body cycle.
• Sleep Stages: Cycle through various stages including REM.
• Function of Sleep: Memory building, problem solving, bodily repair.
• Sleep Disorders: Insomnia, narcolepsy, sleep apnea.

Hypnosis and Drugs

• Psychoactive Drugs: Affect mind and behavior.
  • Depressants: Reduce neural activity.
  • Stimulants: Increase neural activity.
  • Hallucinogens: Affect serotonin balance.
• Addiction involves tolerance, withdrawal, and can be physical or psychological.