Mental health during COVID-19: College students' need for structure

Objective: College students made the unprecedented shift to remote learning during the COVID-19 pandemic, potentially contributing to escalating anxiety, depression, and suicide. This loss of structure may be a driving factor in students' distress. We examined the relationship between students' mental health, perceived need for structure, and five stressors related to COVID-19. Participants: Students (N = 1319, 76.3% female, 79.8% White) at a southeastern university responded to a survey in spring 2020. Methods: Participants answered questions about global anxiety and depression, suicide, perceived need for structure, and COVID-19 related stressors. Results: Participants reported increased anxiety and depression and elevated suicidality compared to previous studies of student mental health. Findings indicated that the stressors and lack of structure added unique variance toward predicting anxiety and depression. Conclusions: As COVID-19's consequences persist, counseling centers and other stakeholders are urged to work together in providing support for students' mental wellness and stress management.

The role of maintenance and disengagement in predicting reading comprehension and vocabulary learning

This study uses a novel framework based on work by Shipstead, Harrison, and Engle (2016) that includes measures of both working memory capacity and fluid intelligence in an attempt to better understand the processes that influence successful reading comprehension at the latent level. Further, we extend this framework to a second educationally relevant ability: second-language vocabulary learning. A large sample of young adults received a battery of working memory, fluid intelligence, language comprehension, and memory updating tasks. The results indicate that individual differences in reading comprehension and vocabulary learning benefit from the ability to maintain active information, as well as to disengage from no longer relevant information. Subsequently, we provide an interpretation of our results based on the maintenance and disengagement framework proposed by Shipstead et al. (2016). (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Working Memory Capacity and Fluid Intelligence: Maintenance and Disengagement

Working memory capacity and fluid intelligence have been demonstrated to be strongly correlated traits. Typically, high working memory capacity is believed to facilitate reasoning through accurate maintenance of relevant information. In this article, we present a proposal reframing this issue, such that tests of working memory capacity and fluid intelligence are seen as measuring complementary processes that facilitate complex cognition. Respectively, these are the ability to maintain access to critical information and the ability to disengage from or block outdated information. In the realm of problem solving, high working memory capacity allows a person to represent and maintain a problem accurately and stably, so that hypothesis testing can be conducted. However, as hypotheses are disproven or become untenable, disengaging from outdated problem solving attempts becomes important so that new hypotheses can be generated and tested. From this perspective, the strong correlation between working memory capacity and fluid intelligence is due not to one ability having a causal influence on the other but to separate attention-demanding mental functions that can be contrary to one another but are organized around top-down processing goals.

Do the effects of working memory training depend on baseline ability level?

There is a debate about the ability to improve cognitive abilities such as fluid intelligence through training on tasks of working memory capacity. The question addressed in the research presented here is who benefits the most from training: people with low cognitive ability or people with high cognitive ability? Subjects with high and low working memory capacity completed a 23-session study that included 3 assessment sessions, and 20 sessions of training on 1 of 3 training regiments: complex span training, running span training, or an active-control task. Consistent with other research, the authors found that training on 1 executive function did not transfer to ability on a different cognitive ability. High working memory subjects showed the largest gains on the training tasks themselves relative to the low working memory subjects-a finding that suggests high spans benefit more than low spans from training with executive function tasks. (PsycINFO Database Record

What item response theory can tell us about the complex span tasks

Working memory capacity is an important construct in psychology because of its relationship with many higher-order cognitive abilities and psychopathologies. Working memory capacity is often measured using a type of paradigm known as complex span. Some recent work has focused on shortening the administration time of the complex span tasks, resulting in different versions of these tasks being used (Foster et al., 2015; Oswald, McAbee, Redick, & Hambrick, 2015). Variations in the complex span tasks, such as the number of set sizes, can lead to varying power to discriminate individuals at different ability levels. Thus, research findings may be inconsistent across populations due to differing appropriateness for the ability levels. The present study uses a combination of item response theory and correlational analyses to better understand the psychometric properties of the operation span, symmetry span, and rotation span. The findings show that the typical administration of these tasks, particularly the operation span, is not suitable for above average ability samples (Study 1; n = 573). When larger set sizes are added to the tasks (Study 2; n = 351), predictive validity and discriminability is improved for all complex span tasks, however the operation span is still inferior to the spatial tasks. The authors make several conclusions about which tasks and set sizes should be used depending on the intended population, and further suggest avoiding the standard-length operation span for average or higher ability populations. (PsycINFO Database Record

A Neurodegenerative Disease Sleep Questionnaire: principal component analysis in Parkinson's disease

Sleep disturbances are common in many neurodegenerative diseases and may include altered sleep duration, fragmented sleep, nocturia, excessive daytime sleepiness, and vivid dreaming experiences, with occasional parasomnias. Although representing the "gold standard," polysomnography is not always cost-effective or available for measuring sleep disturbance, particularly for screening. Although numerous sleep-related questionnaires exist, many focus on a specific sleep disturbance (e.g., restless legs, REM Behavior Disorder) and do not capture efficiently the variety of sleep issues experienced by such patients. We administered the 12-item Neurodegenerative Disease Sleep Questionnaire (NDSQ) and the Epworth Sleepiness Scale to 145 idiopathic Parkinson's disease patients. Principal component analysis using eigenvalues greater than 1 suggested five separate components: sleep quality (e.g., sleep fragmentation), nocturia, vivid dreams/nightmares, restless legs symptoms, and sleep-disordered breathing. These results demonstrate construct validity of our sleep questionnaire and suggest that the NDSQ may be a useful screening tool for sleep disturbances in at least some types of neurodegenerative disorders.

Working memory training may increase working memory capacity but not fluid intelligence

Working memory is a critical element of complex cognition, particularly under conditions of distraction and interference. Measures of working memory capacity correlate positively with many measures of real-world cognition, including fluid intelligence. There have been numerous attempts to use training procedures to increase working memory capacity and thereby performance on the real-world tasks that rely on working memory capacity. In the study reported here, we demonstrated that training on complex working memory span tasks leads to improvement on similar tasks with different materials but that such training does not generalize to measures of fluid intelligence.

No evidence of intelligence improvement after working memory training: a randomized, placebo-controlled study

Numerous recent studies seem to provide evidence for the general intellectual benefits of working memory training. In reviews of the training literature, Shipstead, Redick, and Engle (2010, 2012) argued that the field should treat recent results with a critical eye. Many published working memory training studies suffer from design limitations (no-contact control groups, single measures of cognitive constructs), mixed results (transfer of training gains to some tasks but not others, inconsistent transfer to the same tasks across studies), and lack of theoretical grounding (identifying the mechanisms responsible for observed transfer). The current study compared young adults who received 20 sessions of practice on an adaptive dual n-back program (working memory training group) or an adaptive visual search program (active placebo-control group) with a no-contact control group that received no practice. In addition, all subjects completed pretest, midtest, and posttest sessions comprising multiple measures of fluid intelligence, multitasking, working memory capacity, crystallized intelligence, and perceptual speed. Despite improvements on both the dual n-back and visual search tasks with practice, and despite a high level of statistical power, there was no positive transfer to any of the cognitive ability tests. We discuss these results in the context of previous working memory training research and address issues for future working memory training studies.

Working Memory Capacity and Visual Attention: Top-Down and Bottom-Up Guidance

Previous studies have indicated that working memory capacity (WMC) is related to visual attention when selection of critical information must be made in the face of distraction. The present study examines whether WMC-related differences in flanker task performance might be decreased by displays that are designed to support bottom-up guidance of attention. Participants were required to respond to a centrally located target while ignoring a peripheral flanker. In one condition, bottom-up support was provided by embedding the target in a row of zeros. In another condition, the zeros were removed, thus emphasizing the role of top-down attention in selecting spatially defined information. It was found that the inclusion of zeros led to the elimination of WMC-related flanker effects. We conclude that bottom-up attentional guidance can attenuate the role of WMC in selective attention.

Developmental variation in cytochrome P450 expression in Papilio polyxenes in response to xanthotoxin, a hostplant allelochemical

Although developmental variation in activity and inducibility is typical of cytochrome P450 monooxygenases (P450s) in insects, the adaptive significance of such variation is often unclear, in part because the natural function of insect P450s is rarely known. In this study, we examined developmental variation in expression of CYP6B1 and CYP6B3 in Papilio polyxenes, the black swallowtail. Enzymes encoded by these genes have been implicated in the metabolism of xanthotoxin, a furanocoumarin characteristic of the apiaceous hostplants of P. polyxenes. In each life stage-egg, five larval instars, pupa, and adult-we examined individuals exposed to foliage with and without supplemental xanthotoxin. For each stage, we conducted enzyme assays to estimate xanthotoxin metabolism, Northern analysis to detect constitutive and induced mRNA levels, and RT-PCR amplification and Southern analysis to differentiate among P450 genes expressed. Inducible xanthotoxin metabolism, previously reported in fifth instars, was observed in four of five larval stages but was absent or undetectable in all stages that do not feed on foliage; the highest levels of activity were in early larval instars. The same pattern was observed in both Northern and RT-PCR gel blot analyses. In inducible larval stages, inducibility of CYP6B1 transcripts by xanthotoxin was greater than the inducibility of CYP6B3 transcripts. These findings support earlier suggestions that these two P450s contribute to xanthotoxin metabolism in this species and that expression of these P450 genes is regulated in an adaptive fashion with respect to probability of exposure to hostplant toxins over the course of development.

CYP6B3: a second furanocoumarin-inducible cytochrome P450 expressed in Papilio polyxenes

Cytochrome P450 monooxygenases in the larvae of Papilio polyxenes (black swallowtail) (Lepidoptera: Papilionidae) are capable of detoxifying linear and angular furanocoumarins found in their host plants. The CYP6B1 locus, which is transcriptionally induced in these larvae in response to xanthotoxin, encodes a P450 that principally metabolizes linear furanocoumarins such as xanthotoxin and bergapten. We have now cloned CYP6B3 cDNA derived from a second locus that is evolutionarily related to the CYP6B1 locus. Reverse transcription-PCR Southern analyses have demonstrated that CYP6B3 transcripts are expressed in response to a wider range of linear and angular furanocoumarins but at lower abundance than CYP6B1 transcripts. Whereas CYP6B1 transcripts are expressed at a low detectable level in uninduced control larvae and at high levels in xanthotoxin-induced larvae, CYP6B3 transcripts are nearly undetectable in control larvae and are highly induced by xanthotoxin and bergapten (linear furanocoumarins) as well as by angelicin and sphondin (angular furanocoumarins). The fact that these two CYP6B loci are differentially regulated by these four furanocoumarins indicates that P. polyxenes has adapted to the presence of the wide range of furanocoumarins in its host plants by diversifying its P450 isozyme structure and its furanocoumarin-responsive regulatory cascades.

Trisporic acid biosynthesis in separate plus and minus cultures of Blakeslea trispora: identification by Mucor assay of two mating-type-specific components

Separate plus and minus cultures of Blakeslea trispora synthesize small amounts of trisporic acids under specific conditions. These amounts are expressed as a percentage of the trisporic acids (50 mg/liter of medium) synthesized by mixed plus-minus cultures in 5 days. Plus cultures, without additives from minus cultures, synthesize 0.1% trisporic acids. Plus cultures synthesize 0.4% trisporic acids when stimulated by M-factor, a mating-type-specific component synthesized by minus cultures. Minus cultures, without additives from plus cultures, do not synthesize even 0.0001% trisporic acids. Minus cultures synthesize 1% trisporic acids when stimulated by P-factor, a mating-type-specific component synthesized by plus cultures. Minus cultures synthesize M-factor when stimulated by pi, a component synthesized by plus cultures. We speculate that (i) minus cultures synthesize a component, mu, which stimulates P-factor synthesis in plus cultures, and (ii) both M-factor and P-factor are precursors of trisporic acids.