Perception. Direct approaches: the ecological approach Author: Elena Pasquinelli [INSTNICOD] Contributors: none Current version (on 2006-01-20) The ecological approach to perception and action originated in the work of J. J. Gibson (see [Gibson, 1966]), who claimed that the perceiving organism and its environment form a system, and that perception is an achievement of the system; thus, the input is defined by the overall system, notably including the motor activities through which the organism enters in contact with the surrounds. No intermediary steps or representations are necessary in order to achieve perception. To this effect the theory introduces the notion of ‘ambient array’. Ambient arrays are structured by specific animalenvironment settings and constitute what is directly perceived. Ambient arrays are higher order properties, as the changing patterns of light that are typical of an animal approaching to an object or, vice-versa, of an object approaching to the animal: for instance, a global change in the pattern of light is specific of self-motion, local change against a stationary background is specific to object motion. The specific patterns of optic flow (the patterns of light structured by particular animal-environment settings, available to a point of observation) that are identified as relevant in guiding activity are called “invariants”. Invariants are what organisms directly perceive. There is no space for knowledge in the direct picking-up of invariants. The invariants an organism is sensitive to are not necessarily the ones the experimenter is expecting, the ones that are named in the linguistic description of the task (as the measurable weight and length of an object). As such, they must be discovered empirically. The muscular system for instance is sensitive to variations in the resistance an object opposes to being moved, and the invariant quantities (the inertia tensor) that can be individuated for describing this resistance appear to be well suited to explain all the phenomena of the dynamic perception of object, included the so-called illusions.
References: Gibson, J. J. (1962). Observations on active touch. Psychological Review, 69(6). Gibson, J. J. (1966). The senses considered as perceptual systems. Boston: Houghton Mifflin Company. Gibson, J. J. (1979). The ecological approach to visual perception.: Houghton Mifflin Co. Stoffregen, T. A., & Bardy, B. G. (2001). On Specification and the Senses. Behavioral and Brain Sciences, 24(1). Turvey, M., Shaw, R. E., Reed, E. S., & Mace, W. M. (1981). Ecological Laws of Perceiving and Acting: In Reply to Fodor and Pylyshyn. Cognition, 9, 237-304.
Related items: Active perception Array Dynamic touch Perception. Direct and indirect approaches Invariances
Related External Links: none
