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Psychology & Neuroscience
How the Brain Works
Lobes, functions, and how neurons power the mind
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The brain is the control center of the nervous system, coordinating thoughts, emotions, movement, memory, and body regulation. It matters because every perception, decision, and behavior depends on networks of neurons communicating with each other. Psychology studies how these brain processes connect to mental life and observable actions. Understanding how the brain works helps explain learning, stress, attention, habits, and mental health.
Key Facts
- Neurons communicate using electrical impulses and chemical neurotransmitters.
- A typical resting neuron has a membrane potential of about -70 mV.
- Action potentials are all-or-none signals that travel along axons.
- Signal speed can increase when axons are covered by myelin.
- Learning changes the brain through neuroplasticity, especially by strengthening or weakening synapses.
- Reaction time = response time - stimulus onset time.
Vocabulary
- Neuron
- A neuron is a specialized nerve cell that receives, processes, and sends information through electrical and chemical signals.
- Synapse
- A synapse is the small gap where one neuron communicates with another cell using neurotransmitters.
- Neurotransmitter
- A neurotransmitter is a chemical messenger that carries signals across a synapse.
- Cerebral cortex
- The cerebral cortex is the outer layer of the brain involved in perception, language, memory, reasoning, and voluntary movement.
- Neuroplasticity
- Neuroplasticity is the brain's ability to change its connections and activity patterns in response to learning, experience, or injury.
Common Mistakes to Avoid
- Thinking each brain region does only one job is wrong because most behaviors depend on networks that include several regions working together.
- Confusing electrical signals with neurotransmitters is wrong because electrical impulses travel within a neuron, while neurotransmitters carry messages between neurons.
- Assuming people use only 10 percent of the brain is wrong because brain imaging shows that many regions are active across normal daily tasks.
- Treating memory like a video recording is wrong because memories are reconstructed and can change when recalled, updated, or influenced by new information.
Practice Questions
- 1 A student reacts to a visual stimulus at 0.42 s after it appears. If the stimulus appeared at 0.10 s on the timer, what is the student's reaction time?
- 2 A nerve signal travels 12 m in 0.15 s. What is the signal speed in m/s?
- 3 A person practices a piano sequence every day for a month and becomes faster and more accurate. Explain how neuroplasticity and synapses help account for this improvement.