Introduction to Psychology - The Biology of Mind

Psychology and Biology Connection

• Psychological phenomena are rooted in biological processes.

• Psychological, biological, and social factors interplay in influencing behavior.

• Humans viewed as biopsychosocial systems.

Historical Perspectives

• Plato: Mind located in the head.

• Aristotle: Mind located in the heart.

• Gall: Phrenology connects brain regions with mental abilities.

• 1800s: Localization of various brain functions proposed by Gall.

Neuroplasticity

• Brain adapts and reorganizes throughout life.

• New neural pathways formed based on experience.

Nervous System

• Functions: Transmits information within the body.

• Key Components:

  • Neurons: cells that transmit messages.

  • Dendrites: extensions that receive messages.

  • Axon: transmits messages away from cell body.

  • Glial Cells: nourish and protect neurons; assist in memory and learning.

  • Synapse: connection point between neurons.

Neural Communication

• Action Potential: electrical signal that travels down the axon.

• Resting Potential: polarized state of neurons.

• Refractory Period: recovery phase post-neuron firing.

• Threshold: minimum stimulus needed for action potential.

• All-or-Nothing Response: neuron either fires completely or not at all.

• Neurotransmitters: chemicals that bridge synapses, influencing behavior.

• Reuptake: absorption of neurotransmitters back into the sending neuron.

Key Neurotransmitters and Functions

• Acetylcholine: muscle action, learning, memory.

• Dopamine: movement, mood, attention, emotion.

• Serotonin: mood and arousal regulation.

• Norepinephrine: alertness and arousal.

• GABA: major inhibitory neurotransmitter.

• Glutamate: major excitatory neurotransmitter; crucial for memory.

Impact of Drugs on Communication

• Drugs can alter synaptic transmission.

• Many addictive substances affect the dopamine system directly or indirectly.

• Example: Alcohol effects on neuronal communication.