Sensory Adaptation vs. Sensory Amplification

Sensory Adaptation

• Definition: Change over time in the responsiveness of a sensory receptor to a constant stimulus.
• Process: Downregulation of a sensory receptor in response to a constant stimulus.
• Example:
  • Placing a hand on a table initially activates pressure receptors in the hand.
  • These pressure receptors send signals to the brain when there is a change in pressure.
  • Over time, if the pressure remains constant (like the hand resting), the receptors stop sending signals.
  • The brain eventually ignores the constant stimulus, which is why you might forget your hand is on the table.
• Importance: Prevents overstimulation of cells, which can be harmful and lead to cell death.
  • Example: Pain receptors activated by capsaicin, too much stimulation can lead to cell death.

Sensory Amplification

• Definition: Upregulation of a sensory signal in response to a stimulus.
• Process: Increases the strength of a signal sent to the brain.
• Example:
  • A single ray of light can trigger a cascade of molecular events in a photoreceptor.
  • This cascade amplifies the signal as it is transmitted to the brain.
  • One molecule can activate multiple others, leading to a larger response.

Key Points

• Adaptation helps prevent sensory overload and cell damage.
• Amplification increases the sensitivity and awareness of the brain to certain stimuli.
• Both processes are essential for managing sensory information and maintaining cellular health.