The effect of abstract inter-chunk relationships on serial-order control.

Hierarchical control is often thought to dissect a complex task space into isolated subspaces in order to eliminate interference. Yet, there is also evidence from serial-order control tasks that our cognitive system can make use of abstract relationships between different parts (chunks) of a sequence. Past evidence in this regard was limited to situations with ordered stimuli (e.g., numbers or positions) that may have aided the detection of relationships and allowed gradual learning and hypothesis testing. Therefore, we used a modified task-span paradigm (with no ordered elements between tasks) in which participants performed memorized sequences of tasks that were encoded in terms of separate chunks of three tasks each. To allow examination of learning effects, each sequence was "cycled" through repeatedly. Importantly, we compared sequences whose chunks were governed by a common, abstract grammar with sequences whose chunks were governed by different grammars. Experiment 1 examined the effect of relationships between shared-element chunks (e.g., ABB-BAA vs. ABB-BAB), Experiment 2 and 3 between different-element chunks (e.g., ABA-CDC vs. ABA-CCD), and Experiment 4 examined second-order relationships (e.g., ABA-ABB--CDC-CDD vs. ABA-ABB--CDC-CCD). Robust evidence in favor of beneficial effects of abstract inter-chunk relationships was obtained across all four experiments. Importantly, these effects were at least as strong in initial cycles of performing a given sequence as during later cycles, suggesting that the cognitive system operates with an "expectation of abstract relationships," rather than benefitting from them through gradual learning. We discuss the implications of these results for models of hierarchical control.

What's so hard about hierarchical control? Pinpointing processing constraints within cue-based and serial-order control structures.

Most task spaces require a hierarchical structure, where decisions on one level are contingent on previous decisions made on one or more higher levels. While it is a truism that increasing the number of hierarchical levels makes it harder to solve a given task, the exact nature of this "number-of-levels" effect is not clear. On the one hand, processing costs might be strictly "local," incurred only when higher-level settings need to be updated, while otherwise lower-level decisions are insulated from the presence of higher-level settings (local updating costs with ballistic control). On the other hand, maintaining and integrating more complex hierarchical structures could require overall greater representational resources, negatively affecting each individual decision within the represented task space (global integration/maintenance costs). Further, navigation through hierarchical structures can be guided either through prompts in the environment (cue-based), or through sequential plans (serial-order based), with potentially distinct maintenance and updating demands. In two experiments, we assessed performance as a function of hierarchical level and format (serial-order vs. cue-based). Model comparisons showed that the pattern of costs in the serial-order format was consistent with a global maintenance/integration account. In contrast, in the cue-based format, costs arose at updating points and when one additional relevant level beyond the current decision was relevant, while additional levels produced no further costs. This overall constellation of costs can be explained by assuming that each decision requires checking the immediately relevant higher-level context for that decision. For cue-based control, this context involves the "next-level-up" rule, whereas in the serial-order format, each trial requires updating of the current position within the sequence, which in turn requires integration across all relevant hierarchical levels.

Age differences in the recovery from interruptions.

We tested the hypothesis that there is an age-related deficit in the recovery from interruptions. This hypothesis is based on the idea that it is more difficult for old than for young adults to establish a focused state after working memory has been "opened up" through an interruption. Old (N = 95) and young adults (N = 94) performed competing nondominant and dominant primary tasks (selecting either exogenously or endogenously cued targets) in alternating, single-task blocks that were occasionally interrupted through trials with unrelated math tasks. As predicted, after interruptions, older adults showed increased and prolonged recovery costs, as well as generally larger endogenous/exogenous and conflict effects in blocks that contained interruptions. Individual differences in working memory (WM) capacity did not produce comparable results, suggesting that the interruption-based deficits were specific to aging. In addition, the theoretically important, paradoxical cost asymmetry (i.e., larger interruption costs for the dominant exogenous than for the nondominant endogenous task) was stronger in old than in young adults. These results provide novel insights about the interplay between WM and long-term memory during task control, as well as the origin of age differences in task-set selection. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Does conflict resolution rely on working memory?

Theoretical considerations and results from individual differences studies suggest that working memory and conflict resolution are interrelated functions. Yet, there is little direct evidence suggesting that they actually share common cognitive resources. To study how overcoming conflict influences the maintenance of working memory representations and vice versa, we conducted 4 experiments using a dual-task paradigm in which both working memory load and level of conflict were independently manipulated. Participants performed an auditory Stroop task ("high" or "low" spoken in high/low pitch), which was presented during the retention period of a visual change detection task (Experiments 1-4) or simultaneously with the working memory encoding phase (Experiment 2-4). Across the 4 experiments, we found no consistent interaction between level of conflict and working memory load on working memory performance, although there was evidence in 2 of the 4 experiments for a small effect on auditory Stroop accuracy (but not on response times). These findings present at best weak evidence for the hypothesis that the maintenance of task goals in working memory is critical for successful conflict resolution. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A Comparison of Physicians' and Nurse Practitioners' Use of Race in Clinical Decision-Making.

Objective: The debate over use of race as a proxy for genetic risk of disease continues, but little is known about how primary care providers (nurse practitioners and general internal medicine physicians) currently use race in their clinical practice. Our study investigates primary care providers' use of race in clinical practice. Methods: Survey data from three cross-sectional parent studies were used. A total of 178 nurse practitioners (NPs) and 759 general internal medicine physicians were included. The outcome of interest was the Racial Attributes in Clinical Evaluation (RACE) scale, which measures explicit use of race in clinical decision-making. Predictor variables included the Genetic Variation Knowledge Assessment Index (GKAI), which measures the providers' knowledge of human genetic variation. Results: In the final multivariable model, NPs had an average RACE score that was 1.60 points higher than the physicians' score (P=.03). The GKAI score was not significantly associated with the RACE outcome in the final model (P=.67). Conclusions: Physicians had more knowledge of genetic variation and used patients' race less in the clinical decision-making process than NPs. We speculate that these differences may be related to differences in discipline-specific clinical training and approaches to clinical care. Further exploration of these differences is needed, including examination of physicians' and NPs' beliefs about race, how they use race in disease screening and treatment, and if the use of race is contributing to health care disparities.

Nurses' Use of Race in Clinical Decision Making.

PURPOSE: To examine nurses' self-reported use of race in clinical evaluation. DESIGN: This cross-sectional study analyzed data collected from three separate studies using the Genetics and Genomics in Nursing Practice Survey, which includes items about use of race and genomic information in nursing practice. The Racial Attributes in Clinical Evaluation (RACE) scale was used to measure explicit clinical use of race among nurses from across the United States. METHODS: Multivariate regression analysis was used to examine associations between RACE score and individual-level characteristics and beliefs in 5,733 registered nurses. FINDINGS: Analysis revealed significant relationships between RACE score and nurses' race and ethnicity, educational level, and views on the clinical importance of patient demographic characteristics. Asian nurses reported RACE scores 1.41 points higher than White nurses (p < .001), and Black nurses reported RACE scores 0.55 points higher than White nurses (p < .05). Compared to diploma-level nurses, the baccalaureate-level nurses reported 0.69 points higher RACE scores (p < .05), master's-level nurses reported 1.63 points higher RACE scores (p < .001), and doctorate-level nurses reported 1.77 points higher RACE scores (p < .01). In terms of clinical importance of patient characteristics, patient race and ethnicity corresponded to a 0.54-point increase in RACE score (p < .001), patient genes to a 0.21-point increase in RACE score (p < .001), patient family history to a 0.15-point increase in RACE score (p < .01), and patient age to a 0.19-point increase in RACE score (p < .001). CONCLUSIONS: Higher reported use of race among minority nurses may be due, in part, to differential levels of racial self-awareness. A relatively linear positive relationship between level of nursing degree nursing education and use of race suggests that a stronger foundation of knowledge about genetic ancestry, population genetics and the concept "race" and genetic ancestry may increase in clinical decision making could allow nurses to more appropriately use of race in clinical care. Integrating patient demographic characteristics into clinical decisions is an important component of nursing practice. CLINICAL RELEVANCE: Registered nurses provide care for diverse racial and ethnic patient populations and stand on the front line of clinical care, making them essential for reducing racial and ethnic disparities in healthcare delivery. Exploring registered nurses' individual-level characteristics and clinical use of race may provide a more comprehensive understanding of specific training needs and inform nursing education and practice.