Jill T. Shelton

The relationships of working memory, secondary memory, and general fluid intelligence: working memory is special.

Recent efforts have been made to elucidate the commonly observed link between working memory and reasoning ability. The results have been inconsistent, with some work suggesting that the emphasis placed on retrieval from secondary memory by working memory tests is the driving force behind this association (Mogle, Lovett, Stawski, & Sliwinski, 2008), whereas other research suggests retrieval from secondary memory is only partly responsible for the observed link between working memory and reasoning (Unsworth & Engle, 2006, 2007). In the present study, we investigated the relationship between processing speed, working memory, secondary memory, primary memory, and fluid intelligence. Although our findings show that all constructs are significantly correlated with fluid intelligence, working memory-but not secondary memory-accounts for significant unique variance in fluid intelligence. Our data support predictions made by Unsworth and Engle (2006, 2007) and suggest that the combined need for maintenance and retrieval processes present in working memory tests makes them special in their prediction of higher order cognition.

Do Children "DRM" Like Adults? False Memory Production in Children

The Deese/Roediger-McDermott (DRM) paradigm was used to investigate developmental trends in accurate and false memory production. In Experiment 1, DRM lists adjusted to be more consistent with childrens vocabulary were used with 2nd graders, 8th graders, and college students. Accurate and false recall and recognition increased with age, but semantic information appeared to be available to all age groups. Experiment 2 created a set of child-generated lists based on the free associations by a group of 3rd graders to critical items. The child-generated associates were different from those generated by adults; long and short versions of the child-generated lists were therefore presented to 2nd, 5th, and 8th graders and college students in Experiment 3. Second graders exhibited few false memories, whereas 5th graders were similar to adults in low-demand conditions and more similar to younger children in high-demand conditions. Findings are discussed in terms of developmental changes in automatic and effortful processing and the use of semantic networks.

A group-administered lag task as a measure of working memory

The purpose of the present studies was to evaluate the utility of a group-administered version of the n-back, or lag task. Experiments 1 and 2 describe the construction of the task and reveal that the modified lag task (MLT) produces the same performance trends as have been observed in individually administered versions of the lag task; performance decreased significantly as lag conditions increased in difficulty. Experiments 3 and 4 established convergent validity by comparing the MLT to another common working memory task, the operation—word span task, as well as the updated version of this task, the automatic operation span task. The results showed that MLT performance was significantly correlated to scores on both measures. These experiments provide important details about the MLT as a measure of working memory, in a group- or individual-administration setting.

Evaluation of embedded malingering indices in a non-litigating clinical sample using control, clinical, and derived groups

Although recent findings have indicated that a portion of college students presenting for psychoeducational evaluations fail validity measures, methods for determining the validity of cognitive test results in psychoeducational evaluations remain under-studied. In light of this, data are needed to evaluate utility of validity indices in this population and to provide base rates for students meeting research criteria for malingering and to report the relationship between testing performance and the level of external incentive. The authors utilized archival data from: (i) a university psychological clinic (n = 986) and (ii) a university control sample (n = 182). Empirically supported embedded validity indices were utilized to identify retrospectively suspected malingering patients. Group performance, according to invalidity and the level of incentive seeking, was evaluated through a series of multivariate mean comparisons. The current study supports classifying patients according to the level of incentive seeking when evaluating neurocognitive performance and feigned/exaggerated deficits.

Goal-neglect links Stroop interference with working memory capacity

Relationships between Stroop interference and working memory capacity may reflect individual differences in resolving conflict, susceptibility to goal neglect, or both of these factors. We compared relationships between working memory capacity and three Stroop tasks: a classic, printed color-word Stroop task, a cross-modal Stroop, and a new version of cross-modal Stroop with a concurrent auditory monitoring component. Each of these tasks showed evidence of interference between the semantic meaning of the color word and the to-be-named color, suggesting these tasks each require resolution of interference. However, only Stroop interference in the print-based task with high proportions of congruent trials correlated significantly with working memory capacity. This evidence suggests that the relationships observed between Stroop interference and working memory capacity are primarily driven by individual differences in the propensity to actively maintain a goal.