Encoding general knowledge

The typical adult can expect to call upon an extensive store of general knowledge relating to the scenes and events occurring in the surrounding world. The contents of this store will mainly have been acquired via direct perception of the environment but a significant proportion will also have been acquired, less directly, through communication with others or as a result of reflecting on past acquisitions. Whatever its source, knowledge of the manner in which the properties of external events cluster together enables us to set the daily round of activity against a background of contextual information that invests it with meaning. An encounter with a heavy woven fabric, if categorised as a “carpet”, leads to the expectation that the item belongs on the floor and can be walked upon with impunity. Had the categorisation followed a different course, say, the item had been classed as a “tapestry”, we would expect to find it hung on the wall and kept well out of harm’s way. In each case, a perceptual parsing of the object in question generates a structural description which is then used to select whichever category provides the best fit. The net result is that the flow of experience becomes channelled into known and familiar territory.