Students' decisions to switch between categories or stay within them are related to practice classification performance.

How exemplars are ordered - blocked or interleaved - can play a critical role in later classification performance. Even so, when students self-regulate their learning, they typically block their study by choosing to stay within the same category on subsequent trials. Our goal was to evaluate the degree to which such decisions to stay within a category are influenced by performance on the previous practice trial. In five experiments, participants learned to classify categories of rocks by completing practice classification trials, receiving feedback, and making decisions about what to study on the next practice trial. The rate of stay choices was influenced by feedback type, a preceding familiarity trial, and location in the list. Most importantly, stay rates were low following correct classification demonstrating a preference to interleave study. By contrast, stay rates substantially increased following incorrect classification. Thus, practice classification performance and subsequent study decisions during complex categorical learning tasks can be strongly related.

Judgments of learning enhance recall for category-cued but not letter-cued items.

Making immediate judgments of learning (JOLs) during study can influence later memory performance, with a common outcome being that JOLs improve cued-recall performance for related word pairs (i.e., positive reactivity) and do not impact memory for unrelated pairs (i.e., no reactivity). The cue-strengthening hypothesis proposes that JOL reactivity will be observed when a criterion test is sensitive to the cues used to inform JOLs (Soderstrom et al., Journal of Experimental Psychology: Learning, Memory, and Cognition, 41 (2), 553-558, 2015). Across four experiments, we evaluated this hypothesis with category pairs (e.g., A type of gem - Jade) and letter pairs (e.g., Ja - Jade). Participants studied a list comprised of both pair types, made (or did not make) JOLs, and completed a cued-recall test (Experiments 1a/b). The cue-strengthening hypothesis predicts greater positive reactivity for category pairs than for letter pairs, because making a JOL strengthens the relationship between the cue and target, which is more beneficial for material with an a priori semantic relationship. Outcomes were consistent with this hypothesis. We also evaluated and ruled out alternative explanations for this pattern of effects: (a) that they arose due to overall differences in recall performance for the two pair types (Experiment 2); (b) that they would also occur even when the criterion test is not sensitive to the cues used to inform JOLs (Experiment 3); and (c) that JOLs only increased memory strength for the targets (Experiment 4). Thus, the current experiments rule out plausible accounts of reactivity effects and provide further, converging evidence for the cue-strengthening hypothesis.

Microfluidic single-cell scale-down bioreactors: A proof-of-concept for the growth of Corynebacterium glutamicum at oscillating pH values.

In large-scale bioreactors, gradients in cultivation parameters such as oxygen, substrate, and pH result in fluctuating cell environments. pH fluctuations were identified as a critical parameter for bioprocess performance. Traditionally, scale-down systems at the laboratory scale are used to analyze the effects of fluctuating pH values on strains and thus process performance. Here, we demonstrate the application of dynamic microfluidic single-cell cultivation (dMSCC) as a novel scale-down system for the characterization of Corynebacterium glutamicum growth using oscillating pH conditions as a model stress factor. A detailed comparison between two-compartment reactor (two-CR) scale-down experiments and dMSCC was performed for one specific pH oscillation between reference pH 7 (~8 min) and disturbed pH 6 (~2 min). Similar reductions in growth rates were observed in both systems (dMSCC 21% and two-CR 27%) compared to undisturbed cultivation at pH 7. Afterward, systematic experiments at symmetric and asymmetric pH oscillations, between pH ranges of 4-6 and 8-11 and different intervals from 1 to 20 min, were performed to demonstrate the unique application range and throughput of the dMSCC system. Finally, the strength of the dMSCC application was demonstrated by mimicking fluctuating environmental conditions of a putative large-scale bioprocess, which is difficult to conduct using two-CRs.

Older and younger adults' revision of health misconceptions.

Although ample younger adult research has detailed effective strategies for revising misconceptions, research with older adults is less extensive. Older adults may be less able to correct errors in knowledge due to age-related changes in cognition, but it is also possible that older adults' revision of misconceptions has been limited by methodologies which do not provide adequate support for correction. In two experiments, we examined how older and younger adults revise health-related misconceptions when provided with cognitive support in the form of explicit detailed feedback and an immediate test. Older and younger adults in Experiment 1 answered true/false health statements, received feedback with a detailed explanation of the correct response, took an additional test on the same statements immediately following the initial test, and completed a final test 1-week later. Older and younger adults corrected a similar proportion of misconceptions immediately and maintained most of those revisions across a 1-week delay. In Experiment 2, older adults corrected the same proportion of misconceptions on the final test regardless of whether or not they received a test immediately following feedback. Overall, older adults revised health misconceptions as effectively as did younger adults but variables influencing correction (e.g., belief in feedback) may differ.

Development and application of a cultivation platform for mammalian suspension cell lines with single-cell resolution.

In bioproduction processes, cellular heterogeneity can cause unpredictable process outcomes or even provoke process failure. Still, cellular heterogeneity is not examined systematically in bioprocess research and development. One reason for this shortcoming is the applied average bulk analyses, which are not able to detect cell-to-cell differences. In this study, we present a microfluidic tool for mammalian single-cell cultivation (MaSC) of suspension cells. The design of our platform allows cultivation in highly controllable environments. As a model system, Chinese hamster ovary cells (CHO-K1) were cultivated over 150 h. Growth behavior was analyzed on a single-cell level and resulted in growth rates between 0.85 and 1.16 day-1 . At the same time, heterogeneous growth and division behavior, for example, unequal division time, as well as rare cellular events like polynucleation or reversed mitosis were observed, which would have remained undetected in a standard population analysis based on average measurements. Therefore, MaSC will open the door for systematic single-cell analysis of mammalian suspension cells. Possible fields of application represent basic research topics like cell-to-cell heterogeneity, clonal stability, pharmaceutical drug screening, and stem cell research, as well as bioprocess related topics such as media development and novel scale-down approaches.

Dynamic Environmental Control in Microfluidic Single-Cell Cultivations: From Concepts to Applications.

Microfluidic single-cell cultivation (MSCC) is an emerging field within fundamental as well as applied biology. During the last years, most MSCCs were performed at constant environmental conditions. Recently, MSCC at oscillating and dynamic environmental conditions has started to gain significant interest in the research community for the investigation of cellular behavior. Herein, an overview of this topic is given and microfluidic concepts that enable oscillating and dynamic control of environmental conditions with a focus on medium conditions are discussed, and their application in single-cell research for the cultivation of both mammalian and microbial cell systems is demonstrated. Furthermore, perspectives for performing MSCC at complex dynamic environmental profiles of single parameters and multiparameters (e.g., pH and O2 ) in amplitude and time are discussed. The technical progress in this field provides completely new experimental approaches and lays the foundation for systematic analysis of cellular metabolism at fluctuating environments.

Beliefs about memory decline in aging do not impact judgments of learning (JOLs): A challenge for belief-based explanations of JOLs.

The cue-utilization framework (Koriat, 1997) and the analytic processing theory (Dunlosky, Mueller, & Tauber, 2015) identify people's beliefs about their memory as central to how judgments of learning (JOLs) are made. This assumption is supported by ample evidence. However, researchers have almost exclusively explored the impact of participants' beliefs about the materials or the learning task, and none have evaluated the impact of beliefs about a person on JOLs. Thus, to inform JOL theory, we evaluated the degree to which JOLs are related to the belief that "memory declines with aging in adulthood." In seven experiments, college-aged participants studied words, made JOLs, and took a memory test. Participants made JOLs predicting memory performance for an average younger adult (i.e., 18-21 years old) or for an average older adult (i.e., 65+ years old). Most important, beliefs about aging in adulthood were not always sufficient to produce cue effects on JOLs, which contrasts with expectations from the aforementioned theories. An important challenge for future research will be to discover factors that moderate belief effects. To guide such explorations, we discuss possible explanations for why beliefs about aging would have demonstrated little to no relationship with people's JOLs.

Monitoring of learning for emotional faces: how do fine-grained categories of emotion influence participants' judgments of learning and beliefs about memory?

Researchers have evaluated how broad categories of emotion (i.e. positive and negative) influence judgments of learning (JOLs) relative to neutral items. Specifically, JOLs are typically higher for emotional relative to neutral items. The novel goal of the present research was to evaluate JOLs for fine-grained categories of emotion. Participants studied faces with afraid, angry, sad, or neutral expressions (Experiment 1) and with afraid, angry, or sad expressions (Experiment 2). Participants identified the expressed emotion, made a JOL for each, and completed a recognition test. JOLs were higher for the emotional relative to neutral expressions. However, JOLs were insensitive to the categories of negative emotion. Using a survey design in Experiment 3, participants demonstrated idiosyncratic beliefs about emotion. Some people believed the fine-grained emotions were equally memorable, whereas others believed a specific emotion (e.g. anger) was most memorable. Thus, beliefs about emotion are nuanced, which has important implications for JOL theory.

Reaching for the limits in continuous-flow dielectrophoretic DNA analysis.

The efficient purification and analysis of topological DNA variants is mandatory for many state-of-the-art molecular medicine technologies, like gene- and cancer-therapy as well as plasmid vaccination. In this work, we exploit dielectrophoresis (DEP) for a fast and efficient continuous-flow separation and analysis that goes beyond the standard methods of gel electrophoresis and capillary electrophoresis. The aim of this work was to reach for the limits in dielectrophoretic analysis of DNA regarding the size resolution and the topological conformation. A continuous-flow analytical separation of analyte mixtures of small linear DNA-fragments (10.0 kbp, 8.0 kbp, 6.0 kbp, and 5.0 kbp) and topological DNA variants (linear and supercoiled conformation) was investigated. We present a world record in the minimal size difference of 16.7% of DNA samples that can be resolved in a dielectrophoretic continuous-flow separation. Moreover, we demonstrate for the first time a microfluidic continuous-flow separation of DNA molecules based on their topological conformation. Since dielectrophoresis is virtually label-free, it offers a fast in-process quality control with low consumption, e.g. for the production of gene vaccines.

Children's agenda-based regulation: The effects of prior performance and reward on elementary school children's study choices.

The main goal of the current experiments was to examine the influence of monitoring and reward on elementary school children's study decisions. First and third graders studied names for 10 animals (e.g., "The elephant's name is Suzy") and then were given a cued recall test on which they were shown the animal and needed to recall the name. Next, they were given an opportunity to restudy the animal-name pairs, and some of these pairs were slated to earn a reward (a sticker) if correctly recalled. In Experiment 1, both groups of children were (a) more likely to restudy previously unrecalled pairs than previously recalled pairs and (b) more likely to restudy pairs that were slated to receive a reward. In Experiment 2, we further explored children's use of reward using a forced-choice selection task. Namely, during selection, pairs were presented in dyads where one pair was slated for a reward and the other pair was not, and the children could choose only one pair from each dyad for restudy. Both first and third graders chose to restudy pairs slated for a reward. Thus, even young elementary school children consider both rewards and performance monitoring when regulating their learning.

The concreteness effect on judgments of learning: Evaluating the contributions of fluency and beliefs.

Researchers have often determined how cues influence judgments of learning (JOLs; e.g., concrete words are assigned higher JOLs than are abstract words), and recently there has been an emphasis in understanding why cues influence JOLs (i.e., the mechanisms that underlie cue effects on JOLs). The analytic-processing (AP) theory posits that JOLs are constructed in accordance with participants' beliefs of how a cue will influence memory. Even so, some evidence suggests that fluency is also important to cue effects on JOLs. In the present experiments, we investigated the contributions of participants' beliefs and processing fluency to the concreteness effect on JOLs. To evaluate beliefs, participants estimated memory performance in a hypothetical experiment (Experiment 1), and studied concrete and abstract words and made a pre-study JOL for each (Experiments 2 and 3). Participants' predictions demonstrated the belief that concrete words are more likely to be remembered than are abstract words, consistent with the AP theory. To evaluate fluency, response latencies were measured during lexical decision (Experiment 4), self-paced study (Experiment 5), and mental imagery (Experiment 7). Number of trials to acquisition was also evaluated (Experiment 6). Fluency did not differ between concrete and abstract words in Experiments 5 and 6, and it did not mediate the concreteness effect on JOLs in Experiments 4 and 7. Taken together, these results demonstrate that beliefs are a primary mechanism driving the concreteness effect on JOLs.

Why is knowledge updating after task experience incomplete? Contributions of encoding experience, scaling artifact, and inferential deficit.

Knowledge updating occurs when people learn about the impacts of variables on memory after experiencing their effects. For instance, judgments of learning (JOLs) for encoding strategies (e.g., imagery and repetition) show no difference during a first study-test trial; however, during a second trial, JOLs better reflect the benefits of the more effective strategy. Although this outcome indicates some knowledge updating, JOLs on a second trial rarely update to reflect the full impact of a given variable. We investigated several explanations for this incomplete updating. Evidence using prestudy JOLs from Experiments 1 and 2 disconfirmed the encoding-disrupts-updating (EDU) hypothesis, which is that the experience of encoding items on the second trial disrupts the use of new knowledge in making JOLs. In Experiment 3, we used binary JOLs to evaluate whether the lack of updating is an artifact of people not wanting to use extreme ratings, which accounted for some-but not all-of the incomplete updating. Finally, in Experiment 4, immediately after the test on the initial trial, participants received feedback about how many items they had recalled for each level of the focal variable, and their JOLs on the second trial still showed incomplete updating. Taken together, the evidence suggests that incomplete knowledge updating on JOLs arises from multiple factors, including a scaling artifact and the deficient use of accurate knowledge when making JOLs.

Prior knowledge is more predictive of error correction than subjective confidence.

Previous research has demonstrated that, when given feedback, participants are more likely to correct confidently-held errors, as compared with errors held with lower levels of confidence, a finding termed the hypercorrection effect. Accounts of hypercorrection suggest that confidence modifies attention to feedback; alternatively, hypercorrection may reflect prior domain knowledge, with confidence ratings simply correlated with this prior knowledge. In the present experiments, we attempted to adjudicate among these explanations of the hypercorrection effect. In Experiments 1a and 1b, participants answered general knowledge questions, rated their confidence, and received feedback either immediately after rating their confidence or after a delay of several minutes. Although memory for confidence judgments should have been poorer at a delay, the hypercorrection effect was equivalent for both feedback timings. Experiment 2 showed that hypercorrection remained unchanged even when the delay to feedback was increased. In addition, measures of recall for prior confidence judgments showed that memory for confidence was indeed poorer after a delay. Experiment 3 directly compared estimates of domain knowledge with confidence ratings, showing that such prior knowledge was related to error correction, whereas the unique role of confidence was small. Overall, our results suggest that prior knowledge likely plays a primary role in error correction, while confidence may play a small role or merely serve as a proxy for prior knowledge.

Assigned value improves memory of proper names.

Names are more difficult to remember than other personal information such as occupations. The current research examined the influence of assigned point value on memory and metamemory judgements for names and occupations to determine whether incentive can improve recall of proper names. In Experiment 1 participants studied face-name and face-occupation pairs assigned 1 or 10 points, made judgements of learning, and were given a cued recall test. High-value names were recalled more often than low-value names. However, recall of occupations was not influenced by value. In Experiment 2 meaningless nonwords were used for both names and occupations. The name difficulty disappeared, and value influenced recall of both names and occupations. Thus value similarly influenced names and occupations when meaningfulness was held constant. In Experiment 3 participants were required to use overt rote rehearsal for all items. Value did not boost recall of high-value names, suggesting that differential processing could not be implemented to improve memory. Thus incentives may improve memory for proper names by motivating people to engage in selective rehearsal and effortful elaborative processing.

General knowledge norms: updated and expanded from the Nelson and Narens (1980) norms.

The Nelson and Narens (Journal of Verbal Learning and Verbal Behavior 19:338-368, 1980) general knowledge norms have been valuable to researchers in many fields. However, much has changed over the 32 years since the 1980 norms. For example, in 1980, most people knew the answer to the question "What is the name of the Lone Ranger's Indian sidekick?" (answer: Tonto), whereas in 2012, few people know this answer. Thus, we updated the 1980 norms and expanded them by providing new measures. In particular, we report two new metacognitive measures (confidence judgments and peer judgments) and provide a detailed report of commission errors. Each of these measures will be valuable to researchers, and together they are likely to facilitate future research in a number of fields, such as research investigating memory illusions, metamemory processes, and error correction. The presence of substantial generational shifts from 1980 to 2012 necessitates the use of updated norms.

Microfluidic single-cell scale-down systems: introduction, application, and future challenges.

Performance losses during the scaling-up of bioprocesses from the laboratory to the production scale are common obstacles caused by the formation of concentration gradients in bioreactors. To overcome these obstacles, so-called scale-down bioreactors are used to analyze selected large-scale conditions and are one of the most important predictive tools for the successful transfer of bioprocesses from the lab to the industrial scale. In this regard, cellular behavior is usually measured as an averaged value, neglecting possible cell-to-cell heterogeneity within the culture. In contrast, microfluidic single-cell cultivation (MSCC) systems offer the possibility of understanding cellular processes on a single-cell level. To date, most MSCC systems have a limited choice of cultivation parameters that are not representative of bioprocess-relevant environmental conditions. Herein, we critically review recent advances in MSCC that allow the cultivation and analysis of cells under dynamic (bioprocess-relevant) environmental conditions. Finally, we discuss what technological advances and efforts are needed to bridge the gap between current MSCC systems and the use of these systems as single-cell scale-down devices.

Protocol to perform dynamic microfluidic single-cell cultivation of C. glutamicum.

Here, we present a protocol for the design, fabrication, and usage of a polydimethylsiloxane (PDMS)-based chip for dynamic microfluidic single-cell cultivation of Corynebacterium glutamicum. We describe steps for flow profile establishment and biological preparation. We then detail time-lapse imaging to observe reactions of C. glutamicum to repeated environmental changes in the range of seconds. This system can be adapted to other organisms with a cell wall and soluble non-gaseous environmental factors like nutrients. For complete details on the use and execution of this protocol, please refer to Täuber et al..1.

Emerging Trends in Research on Self-Regulated Learning and Implications for Education: An Introduction to the Special Issue.

Students in higher education face a multitude of challenges when gaining and refining their knowledge [...].

Teaching older adults to use retrieval practice improves their self-regulated learning.

Retrieval practice can reduce associative memory deficits for older adults but they underutilize this potent learning tool during self-regulated learning. The current experiment investigated whether teaching older adults to use retrieval practice more can improve their self-regulated learning. Younger and older adults made decisions about when to study, how often to engage in retrieval practice, and when to stop learning a list of medication-side effect pairs. Some younger and older adults received instructions before learning that emphasized the mnemonic benefits of retrieval practice over restudying material and described how to schedule retrieval practice to learn to a goal criterion level. This minimal intervention was effective for improving both younger and older adults' associative memory. These data indicate that a simple strategy for improving older adults self-regulated learning is to provide them with instructions that teach them how to use criterion learning to schedule their retrieval practice for to-be learned material.

Does Interactive Imagery Influence the Reactive Effect of Judgments of Learning on Memory?

Making judgments of learning (JOLs) while studying is a useful tool for students to evaluate the status of their learning. Additionally, in associative learning contexts, JOLs can directly benefit learning when the to-be-learned information is related. One explanation for this reactive effect is that making JOLs strengthens the associative relationship, leading to enhanced memory performance when a test relies on that relationship (e.g., cued-recall tests). In the present research, we evaluated whether having students make interactive mental images-another strategy that can increase the strength of a cue-target relationship-impacts the reactive effect of JOLs on learning. Students studied word pairs that were related and unrelated. Half of the students were instructed to form a mental image of the words interacting, whereas the other half were not. Additionally, in each group half of the students made a JOL for each pair, whereas half did not. Following a short delay, students completed a cued-recall test. Consistent with prior research, students who made JOLs remembered more related word pairs than did students who did not. By contrast, students who made JOLs recalled fewer unrelated word pairs than did students who did not. Moreover, although students who formed interactive images demonstrated enhanced memory relative to students who did not, interactive imagery did not impact the reactive effect of JOLs. These outcomes are informative for existing theory of JOL reactivity. Specifically, JOLs may only benefit learning of associative information when it has a pre-existing semantic relationship (e.g., related word pairs) and not when that that relationship is created by the learner (e.g., by forming interactive images).