D. Zach Hambrick

Bio: D. Zach Hambrick is an academic researcher from Michigan State University. The author has contributed to research in topics: Cognition & Short-term memory. The author has an hindex of 2, co-authored 2 publications receiving 2221 citations.

Working memory span tasks: A methodological review and user’s guide

Abstract: Working memory (WM) span tasks—and in particular, counting span, operation span, and reading span tasks—are widely used measures of WM capacity. Despite their popularity, however, there has never been a comprehensive analysis of the merits of WM span tasks as measurement tools. Here, we review the genesis of these tasks and discuss how and why they came to be so influential. In so doing, we address the reliability and validity of the tasks, and we consider more technical aspects of the tasks, such as optimal administration and scoring procedures. Finally, we discuss statistical and methodological techniques that have commonly been used in conjunction with WM span tasks, such as latent variable analysis and extreme-groups designs.

THEORETICAL AND REVIEW ARTICLES Working memory span tasks: A methodological review and user's guide

Abstract: Other than standardized instruments, such as intelligence test batteries, working memory (WM) span tasks, such as the counting span, operation span, and reading span tasks, are among the most widely used measurement tools in cognitive psychology. These tasks have come to prominence not only for their methodological merit, but also because theoretical advances in the study of human behavior since the cognitive revolution have placed WM as a central construct in psychology. Methodologically, WM span tasks have proven to be both reliable and valid measures of WM capacity (WMC), which we will document below. However, the larger factor in accounting for their increased use is simply that WM has become a widely useful, scientifically fruitful construct. It plays an important role in contemporary global models of cognition (e.g., J. R. Anderson & Lebiere, 1998; Cowan, 1995), and it is purportedly involved in a wide range of complex cognitive behaviors, such as comprehension, reasoning, and problem solving (Engle, 2002). Also, WMC is an important individual-differences variable and accounts for a significant portion of variance in general intellectual ability (Conway, Cowan, Bunting, Therriault, & Minkoff, 2002; Conway, Kane, & Engle, 2003; Engle, Tuholski, Laughlin, & Conway, 1999; Kane et al., 2004; Kyllonen, 1996; Kyllonen & Christal, 1990; Sus, Oberauer, Wittmann, Wilhelm, & Schulze, 2002). Furthermore, neuroimaging and neuropsychological studies have revealed that WM function is particularly dependent on cells in the prefrontal cortex of the brain, which has traditionally held a prominent status in the biological approach to studying complex goal-directed human behavior (Kane & Engle, 2002). A diverse set of researchers is now using WM as a construct in research programs, as well as measures of WMC

Is working memory training effective? A meta-analytic review

Abstract: It has been suggested that working memory training programs are effective both as treatments for attention-deficit/hyperactivity disorder (ADHD) and other cognitive disorders in children and as a tool to improve cognitive ability and scholastic attainment in typically developing children and adults. However, effects across studies appear to be variable, and a systematic meta-analytic review was undertaken. To be included in the review, studies had to be randomized controlled trials or quasi-experiments without randomization, have a treatment, and have either a treated group or an untreated control group. Twenty-three studies with 30 group comparisons met the criteria for inclusion. The studies included involved clinical samples and samples of typically developing children and adults. Meta-analyses indicated that the programs produced reliable short-term improvements in working memory skills. For verbal working memory, these near-transfer effects were not sustained at follow-up, whereas for visuospatial working memory, limited evidence suggested that such effects might be maintained. More importantly, there was no convincing evidence of the generalization of working memory training to other skills (nonverbal and verbal ability, inhibitory processes in attention, word decoding, and arithmetic). The authors conclude that memory training programs appear to produce short-term, specific training effects that do not generalize. Possible limitations of the review (including age differences in the samples and the variety of different clinical conditions included) are noted. However, current findings cast doubt on both the clinical relevance of working memory training programs and their utility as methods of enhancing cognitive functioning in typically developing children and healthy adults.

What are the differences between long-term, short-term, and working memory?

Abstract: In the recent literature there has been considerable confusion about the three types of memory: long-term, short-term, and working memory. This chapter strives to reduce that confusion and makes up-to-date assessments of these types of memory. Long- and short-term memory could differ in two fundamental ways, with only short-term memory demonstrating (1) temporal decay and (2) chunk capacity limits. Both properties of short-term memory are still controversial but the current literature is rather encouraging regarding the existence of both decay and capacity limits. Working memory has been conceived and defined in three different, slightly discrepant ways: as short-term memory applied to cognitive tasks, as a multi-component system that holds and manipulates information in short-term memory, and as the use of attention to manage short-term memory. Regardless of the definition, there are some measures of memory in the short term that seem routine and do not correlate well with cognitive aptitudes and other measures (those usually identified with the term "working memory") that seem more attention demanding and do correlate well with these aptitudes. The evidence is evaluated and placed within a theoretical framework depicted in Fig. 1.

For whom the mind wanders, and when: an experience-sampling study of working memory and executive control in daily life.

Abstract: An experience-sampling study of 124 undergraduates, pretested on complex memory-span tasks, examined the relation between working memory capacity (WMC) and the experience of mind wandering in daily life. Over 7 days, personal digital assistants signaled subjects eight times daily to report immediately whether their thoughts had wandered from their current activity, and to describe their psychological and physical context. WMC moderated the relation between mind wandering and activities' cognitive demand. During challenging activities requiring concentration and effort, higher-WMC subjects maintained on-task thoughts better, and mind-wandered less, than did lower-WMC subjects. The results were therefore consistent with theories of WMC emphasizing the role of executive attention and control processes in determining individual differences and their cognitive consequences.