Neuroscience · Lesson 02
Sensation and Movement
From physical energy to perception, then from intention to action.
Learning targets
By the end of this lesson, you can
- Trace how sensory receptors transduce physical energy into neural signals.
- Describe why perception is an active inference rather than a literal recording.
- Outline the complementary roles of cortex, basal ganglia, and cerebellum in action.
Core mechanism
The brain interprets, not merely receives
Receptors convert light, pressure, sound, and chemicals into patterns of neural activity. The nervous system then combines those patterns with context, expectations, and goals. What you perceive is a useful construction constrained by evidence.
Illustrated scene card
Worked scene: catching a cup
Observation: Vision estimates its path, motor areas prepare a reach, the cerebellum compares expected and actual movement, and touch updates the grip.
Why it matters: The response is a loop, not a command sent once. Sensory feedback and prediction continually refine action.
Retrieval practice
Retrieve before you review
Answer aloud or on paper first. Then reveal the feedback and repair any gaps.
- What does sensory transduction mean?
- Why can two people notice different details in the same scene?
- Which structure is especially important for calibrating movement from error signals?
Professor’s noteConfidence is a feeling. Retrieval is evidence.
Lesson summary and completion
What to retain
It is the conversion of physical energy into changes in neural signaling. Perception combines sensory evidence with attention, prior knowledge, context, and current goals. The cerebellum is especially important for comparing predicted and actual movement and refining coordination.
Save your reading and continue when ready. All retrieval and physical practice in this extended lesson is optional; reading completion does not record a passing test or professional competence.
Ready to continue? The reading action is always available here. This is a reading position, not proof of understanding. Nothing advances automatically.