| Feature | Sensation | Perception |
|---|---|---|
| Nature | Biological / Physiological | Psychological / Cognitive |
| Input | Physical energy (Light, Sound) | Neural signals / Mental concepts |
| Processing | Bottom-up (Data-driven) | Top-down (Concept-driven) |
| Goal | To detect presence of stimuli | To assign meaning to stimuli |
The Absolute Threshold is the minimum stimulation needed to detect a particular stimulus 50 percent of the time. It defines the boundary of our sensory capabilities.
The Difference Threshold (or Just Noticeable Difference) is the minimum difference between two stimuli required for detection 50 percent of the time. According to Weber's Law, this difference is a constant proportion rather than a constant amount.
Sensory Adaptation is the diminished sensitivity that occurs as a consequence of constant stimulation. This allows our attention to shift toward informative changes in the environment rather than being overwhelmed by unchanging background noise.
Identify the Actor: If a question describes a biological structure (like the retina or cochlea) reacting to energy, it is likely discussing sensation. If it describes a person 'recognizing,' 'interpreting,' or 'expecting,' it is discussing perception.
Check for Context: Questions involving 'perceptual sets' or 'context effects' are always testing top-down processing, as they rely on the brain's prior knowledge to influence the current experience.
Common Confusion: Do not confuse sensory adaptation with habituation. Adaptation is a physiological change in the receptors (sensation), while habituation is a cognitive decrease in response to a repeated stimulus (perception/learning).