Individual differences in working memory capacity and what they tell us about controlled attention, general fluid intelligence, and functions of the prefrontal cortex

Engle, R. W., Kane, M. J., & Tuholski, S. W. (1999). Individual differences in working memory capacity and what they tell us about controlled attention, general fluid intelligence, and functions of the prefrontal cortex. In: A. Miyake & P. Shah. Models of Working Memory: Mechanisms of Active Maintenance and Executive Control. Cambridge: Cambridge University Press. pp. 102-134. doi: http://dx.doi.org/10.1017/CBO9781139174909.007.

Engle, Kane and Tuholski describe a working memory model to explain individual differences in performance of WM tasks, and their relation to General Fluid Intelligence (gF) and controlled attention. Working Memory is defined as a system of procedures and skills used to activate and maintain long-term memory traces above threshold, as well as limited-capacity controlled attention. Thus, Working Memory capacity is not about memory limitations per se, but rather about the limits of sustained attention in the face of distraction and interference during tasks. Engle et al.’s model includes the short-term memory and central executive components described in other models. Importantly, the central executive is responsible for achieving activation through controlled processing, maintaining activation and blocking interference. Encoding, maintenance and grouping skills transform novel information into something familiar to be retained for longer periods in the focus of attention (for example, chunking numbers in a numerical span). This last component can be of many types (phonological, visual, spatial, auditory, etc.) and can vary according to attentional demands and individual differences.

According to Engle et al., controlled attention is the key feature of WM linking it to higher level processing. Evidence is reviewed showing that Working Memory tasks are uniquely associated with gF even when differences in short-term memory have been taken into account. Consistent with this view, working memory has been linked to learning in many studies, and has been the focus of specific interventions.

Blogger: Gabriela Hora is working as a volunteer research assistant in the LWM lab.