Working memory, short-term memory, and general fluid intelligence: A latent-variable approach.

Abstract

A study was conducted in which 133 participants performed 11 memory tasks (some thought to reflect working memory and some thought to reflect short-term memory), 2 tests of general fluid intelligence, and the Verbal and Quantitative Scholastic Aptitude Tests. Structural equation modeling suggested that short-term and working memories reflect separate but highly related constructs and that many of the tasks used in the literature as working memory tasks reflect a common construct. Working memory shows a strong connection to fluid intelligence, but short-term memory does not. A theory of working memory capacity and general fluid intelligence is proposed: The authors argue that working memory capacity and fluid intelligence reflect the ability to keep a representation active, particularly in the face of interference and distraction. The authors also discuss the relationship of this capability to controlled attention, and the functions of the prefrontal cortex.

Does working memory training have to be adaptive?

“…We chose the complex span paradigm, which is a well-established measure of WM capacity (cf. Conway et al, 2005), as well as an excellent predictor for reasoning (e.g., Engle, Tuholski, Laughlin, & Conway, 1999;Süß, Oberauer, Wittmann, Wilhelm, & Schulze, 2002). Moreover, in our recent study mentioned above , we found that training with complex span tasks was more effective than training with other tasks of WM capacity in terms of transfer to untrained WM and reasoning tasks.…”

Spatial maps in frontal and prefrontal cortex

“…The contents of working memory are often viewed as an activated subset of information from long-term memory, with the focus of attention determining what information becomes active (Cowan, 1988;Engle et al, 1999). Such a model does not require that the attentional controller, perhaps DLPFC, actually represents the information.…”

Prefrontal cortex and sensory cortices during working memory: quantity and quality

“…Despite the vast storage in human long-term memory, WM has been demonstrated to have a capacity limited by the number of items [8,9] and this is strongly correlated with general cognitive ability [10,11] . Recent advances in studying visual WM have shown a precision limit of representations in WM besides the capacity limit [12][13][14][15][16] .…”

“…However, with regard to WM the role of the delay activity in sensory cortices has been thought to differ from that of the PFC. The former has been thought to represent and store selective sensory information and the latter has been considered to exert attentional bias and cognitive control over the former (see reviews [6,7] ).Despite the vast storage in human long-term memory, WM has been demonstrated to have a capacity limited by the number of items [8,9] and this is strongly correlated with general cognitive ability [10,11] . Recent advances in studying visual WM have shown a precision limit of representations in WM besides the capacity limit [12][13][14][15][16] .…”