Memory can be defined as, `the process by which we receive, encode, organise, store and retrieve information'. (Grivas et al, 1999) Our memory, although vast in capacity, is necessarily selective, as memory of every single stimulus encountered would quickly become unworkable. There are several models which explain the processes involved in forming memory, notably Atkinson and Shiffrin's (1971) information processing (multi-store) view, the working memory model (Baddeley and Hitch, 1983) and the levels of processing model (Craik and Lockhart, 1972).

The Information Processing model of memory (Atkinson and Shiffrin, 1971) describes three interdependent, unitary memory systems, in each of which the processes of encoding (conversion of information), storage (retention of information), and retrieval (recovering of information) take place. The first system, Sensory Memory, retains information in its original form long enough for us to decide, though not consciously, whether or not it should be further processed. Sensory memory is an exact copy of...