Part II of this book comprises four chapters dealing with the relationship between phonological short-term storage and the other processes involved in the retention of verbal information. All four chapters report data from individual case studies of shortterm memory patients. They emphasize that immediate retention of verbal material involves more than one level of representation and attempt to specify how these different levels contribute.
Phonological storage is not carried out in a single isolated system (see, e.g., Monsell, 1984; Barnard, 1985). The storage system responsible interacts with low-level (acoustic, nonphonological) components (see Berndt & Mitchum, chapter 5; Campbell, chapter 11). Within the phonological level, interrelated input and output subcomponents may be distinguished (see Campbell, chapter 11; Howard & Franklin, chapter 12) and possibly also lexical and prelexical ones (see Saffran & Martin, chapter 6). At a higher level of processing, interactions with lexical–semantic (Saffran & Martin, chapter 6) and syntactic–semantic (Butterworth, Shallice, & Watson, chapter 8) systems with longterm memory properties may occur. Finally, short-term memory tasks also involve highly controlled executive subcomponents (see Baddeley, chapter 2; McCarthy & Warrington, chapter 7; Craik, Morris, & Gick, chapter 10; Crain, Shankweiler, Macaruso, and Bar-Shalom, chapter 18). The discussion of the relationships of the phonological short-term store with other functional components of mental functions is of course not confined to this part, but may be found, in a variety of theoretical approaches, in most chapters of the book. This may be taken as an indication of the highly interactive nature of the system.