As an inextricable component of the ‘cognitive leap’ in the evolution of modern human thinking (Coolidge & Wynn, 2009), working memory (WM) has attracted enormous research interest from multiple disciplines in cognitive science since the inception of the seminal model of Baddeley and colleagues (Baddeley, 1986, 2007; Baddeley & Hitch, 1974). These waves of research have been accompanied by the propagation of a dozen WM models (Miyake & Shah, 1999) and inherent controversies and heated debates about the nature, structure and functions of the WM construct (Baddeley, 2007, 2012; Cowan, 2014). This chapter, which is divided into four sections, reviews these lines of interdisciplinary WM research in cognitive science. In the first section, an evolutionary perspective is used to trace the development of the WM concept. The following section summarizes the differences and commonalities of the major theoretical models of WM in cognitive psychology, culminating in nomothetic and consensual characterizations of the construct. The third section widens the interdisciplinary scope by incorporating neuropsychological evidence corroborating these unified theories of WM. The last section concludes the chapter by recapitulating the key characterizations of the WM construct that lend theoretical support to the integrated framework of WM proposed in this book.

Evolution of WM and the Standard Model

The concept of WM can be traced back to as early as William James’s (1890) demarcation of ‘primary memory’ and ‘secondary memory’ (Logie et al., 2007). According to James, primary memory (synonymous with today’s concept of short-term memory, STM) temporarily stores a limited amount of information that is consciously accessible for use in higher-level cognitive activities. This temporarily stored information is then either displaced by new information and forgotten, or transferred via (sub-vocal) rehearsal to a secondary or long-term memory (LTM) that presumably has unlimited storage capacity. In a similar vein, Hebb (1949) suggested that STM was the result of the temporary activation of neural connections between clusters of cells, while LTM resulted from permanent synaptic changes (also see Andrade, 2014: 93).