Once the brain has made sense of what it perceives, it decides in a flash whether action is necessary: A loud honk on the street leads me to jump onto the saving sidewalk, a hiss in the grass leads me to turn toward the source of the noise and avoid being bitten by the snake. A honk in a soccer stadium, on the other hand, is unlikely to elicit a specific response from me; the hiss of a fizzy drink bottle being opened is more likely to elicit attention when it is absent.
If the control center deems actions necessary, it sends the appropriate request to the respective parts of the body – the feet jump, the hand jerks away or towards, the eyes open or are squinted. Whether a reaction is successful and what happens afterwards, about it the brain is informed then again by the appropriate sense organs.
Perception in the view of the sciences
What perception is, how it works, why and how it can be disturbed or deceived, what role it plays for us or for other areas (for example, advertising) – these aspects are illuminated in many fields, such as psychology, medicine (especially sensory and neurophysiology), physics and chemistry, but also philosophy and sociology. In psychology, a variety of different disciplines and approaches exist in this regard – here is a selection:
- Psychophysics: looks for mathematically describable relationships between the physical properties of a stimulus and the subjective sensation triggered by it.
- Gestalt psychology: tries to find regularities according to which stimuli are selected and organized by the brain; these laws underlie, for example, many optical illusions.
- Cognitive perceptual psychology: studies experimentally the mutual influences of perception, memory, thinking, and action control; the computational approach uses computer models for this purpose that attempt to replicate the performance of the perceptual system.
- Developmental psychology: deals with the development of behavior; a partial aspect of this is also how (infant) perception develops.
- Ecological theory of perception: assumes that perception aims to identify in an object the benefit it has for concrete action.
- Neuropsychology: fairly recent field of work that uses instrumental techniques to measure brain activities associated with perceptual processes.
