ABSTRACT
In order to successfully move about in the world and respond to its permanent challenges, we have to rapidly make sense of our multifarious and fast-changing environment. To do so, we create an internal mental representation of the stimuli that are immediately present in our surroundings. Any given external object in the environment, the distal stimulus (e.g., a stone) is not processed as such, but is represented in the organism as a physical stimulation pattern on the senses, the proximal stimulus (e.g., the pattern of light on the retina reflected by the stone). Perception is the transformation of the proximal stimulus into a percept, the accessible, subjective, reportable experience that takes the form of an activation of a certain category in the mind (e.g., the accessible visual experience of the stone). How we perceive our environment is thus profoundly shaped by categorisation. When we categorise a stimulus, we group certain objects or concepts as equivalent or analogous, thereby reducing the information complexity of the external world. At the same time, a lot of information about the stimulus is inferred due to its association with a category. The act of categorisation is therefore critical to cognition (see Harnad, 2005) and allows us to give meaning to the world.
