"Affordance" refers to whatever it is in the environment that contributes to the kind of interaction that occurs. Gibson developed an interactionist view of perception which focuses on the thinker dynamically interacting with the world (Chemero A. , 2013). The concept of affordances is intertwined with ability in that the affordances which the environment offers are relative to the organism that perceives them. Gibson introduced a framework for studying perception, introducing the concept of distal objects, informational medium, proximal stimulation and perceptual object (Gibson, 1979). The reason we perceive is to recognise the affordances the environment is offering to us as humans. As adaptive organisms we only perceive what is necessary to survive. .
To carry out action based on affordances it is necessary to use an effector such as a hand to grasp an object. The affordances of the object are only limited by the ability of the perceiver. The size of the perceiver in relation to an object determines the affordances of the particular object in the given situation. A chair offers a human adult the affordance to sit, stand or lean on it, lift it off the ground or tuck it under a table. The affordances a chair offers a cat are significantly different. It affords the cat to climb on it, lie under it or lie down on it. The relationship between objects and the perceiver are the potential interactions the item affords the perceiver (Greeno.G.J, 1994). There are an infinite number of ways an action can be performed. As adaptive organisms we have degrees of freedom which allow us the opportunity to move in many different ways if the optimal way to move ever becomes inadequate in any given situation. Spatial perception is modulated by the size of the body and the energy expenditure required to carry out the action. The motor system chooses the optimum action which has the most efficient energy expenditure.