Perception

Perception is the process through which sensory inputs are organized, interpreted, and consciously experienced. It involves interactions between sensory data and brain processing.

Perception includes both bottom-up and top-down processing.

In bottom-up processing, sensory receptors detect external cues and relay this information to the brain for interpretation. For example, facial expressions like smiles or furrowed brows are noticed at a party, and the brain pieces these clues together to determine emotions such as happiness or sadness.

Conversely, top-down processing uses prior knowledge, expectations, and experiences to interpret the sensory inputs. For example, if a black cellphone is misplaced, the search involves looking for an object of a specific size and color, such as a black phone, in likely places like the counter or coffee table. The likelihood of finding the phone depends on the prior knowledge of its color, shape, and possible locations. 

Sensory adaptation allows the brain to manage the overwhelming amount of sensory information it receives, such as learning to ignore the continuous hum of a refrigerator while working in the kitchen or the feel of clothing on the skin while performing regular activities.