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Working memory encompasses the limited incoming information that can be held in mind for cognitive processing. To date, we have little information on the effects of bilingualism on working memory because, absent evidence, working memory tasks cannot be assumed to measure the same constructs across language groups. To garner evidence regarding the measurement equivalence in Spanish and English, we examined second-grade children with typical development, including 80 bilingual Spanish–English speakers and 167 monolingual English speakers in the United States, using a test battery for which structural equation models have been tested – the Comprehensive Assessment Battery for Children – Working Memory (CABC-WM). Results established measurement invariance across groups up to the level of scalar invariance.
Bipolar disorder (BD) is a leading cause of disability and is linked to cognitive and functional impairment, increased mortality from cardiometabolic disorders and bipolar disorder suicide. Few studies in sub-Saharan Africa have explored cognitive dysfunction in bipolar disorder. Our study explores the cognitive characteristics in a bipolar patient cohort in Nigeria and assesses its association with clinical and demographic variables.
40 participants from the Bipolar Disorder Longitudinal Study, at baseline, were included in the pilot study of the BiDiLos-Ng. Using a cross-sectional design, cognitive function was assessed using the Screen for Cognitive Impairment in Psychiatry. Multiple linear regression models were used to explore associations between dependent and independent variables.
Cognitive impairment was present in 41% of the bipolar cohort, it was not associated with the frequency of mood episodes, and higher educational level was associated with higher verbal fluency test scores (p = 0.02). Being in employment (p = 0.03), younger age (p = 0.00), and lower YMRS score (p = 0.006) were associated with higher working memory test scores.
The presence of mania symptoms during the euthymic phase of BD was associated with cognitive impairment. Executive function and working memory were linked to better academic and occupational attainment.
Child maltreatment impacts approximately one in seven children in the United States, leading to adverse outcomes throughout life. Adolescence is a time period critical for the development of executive function, but there is little research examining how abuse and neglect may differently affect the developmental trajectories of executive function throughout adolescence and into young adulthood. In the current study, 167 adolescents participated at six time points from ages 14 to 20. At each time point, adolescents completed behavioral tasks measuring the three dimensions of executive function (working memory, inhibitory control, and cognitive flexibility). Neglect and abuse in early life (ages 1–13) were reported at ages 18–19. Unconditional growth curve models revealed age-related improvement in all three executive function dimensions. Conditional growth curve models tested the prospective effects of recalled neglect and abuse on the developmental trajectories of executive function. The results revealed that neglect was associated with developmental changes in working memory abilities, such that greater levels of neglect during ages 1–13 were associated with slower increases in working memory abilities across ages 14–20. These findings highlight the adverse consequences of early neglect experiences shown by delayed working memory development during adolescence into young adulthood.
An important issue in second-language acquisition concerns the role of explicit information (EI) and how it is affected by individual differences. The present study explored this question through a partial replication and extension of Fernández (2008: Experiment 2), which investigated the effects of EI in processing instruction (PI) for the Spanish present subjunctive. This replication compared training with EI (PI) to training without it (structured input; SI). In addition to methodological changes that balance the amount of exposure between groups, this study also includes a control group that received exposure to the target form (C+). Extending the original study, we also assessed the durability of training and whether its effects interact with individual differences in working memory (WM). Results indicate advantages for the PI group during training, supporting Fernández’s conclusions. Immediate post-tests show advantages for the PI group that are not sustained on delayed post-tests. Analyses also indicate benefits for higher WM but only for the PI and C+ groups, although this was only sustained for the C+ group. Thus, findings indicate that when paired with SI, EI and high WM may influence the initial learning of the Spanish subjunctive, but their influence may dissipate over time.
Using archival data from 106 children with and without DLD who spoke two dialects of English, we examined the independent contributions of vocabulary, morphological ability, phonological short term memory (pSTM), and verbal working memory (WM) to exact sentence recall, ungrammatical repetition, and incorrect tense production. For exact repetitions on simpler sentences, performance of the DLD group was predicted by morphological ability, pSTM and WM, while that of the TD group was predicted by vocabulary and sometimes pSTM. On complex sentences, performance of the DLD group was predicted by morphological ability, and the TD group was predicted by pSTM and WM. For ungrammatical repetitions and incorrect tense, morphological ability was a factor for both groups, with WM also affecting the DLD group for ungrammatical production. Thus, sentence recall taxes multiple resources, with more and different factors being taxed at lower levels of complexity for children with DLD than those without.
The present experimental studies shed light on effects of implicit prosodic cues on anaphora resolution as well as on how these differ both within and between L1 and L2 speaker groups. In two self-paced reading studies, L1 and L2 participants read poem-like texts that contained anaphoric ambiguity. These stimuli were designed to include a rhyming scheme and meter that were either regular or disrupted. We expected a rhyme cue on a nonsubject pronoun antecedent (in the regularly metered and rhyming version of the texts) to induce competition effects in L1 speakers and cause them to adapt their interpretative preferences and processing strategies; yet, for L2 speakers we hypothesized that effects would either not be observed or that they would be attenuated. Additionally, we examined whether comprehender-dependent factors would modulate effects in each group. We tested both L1 and L2 participants on memory-related tasks. We also measured L1 speakers’ print exposure and L2ers’ proficiency in English. Results revealed L1–L2 dissimilarities in interpretative preferences and reading behavior, as L2 speakers were not equally sensitive to the prosodic cues introduced. The examination of memory-related measures provided evidence of within-group differences and between-group parallels: higher working memory in both groups modulated anaphora resolution, although for L2 speakers there was no additional influence of context.
This chapter introduces the key concepts and major theoretical accounts of cognitive control (e.g., conflict monitoring, the expected value of control) that seek to answer fundamental questions about the control mechanisms, the recruitment of control resources, the selection of task-relevant processes, and the prevention of interference. Although some of the theories focus more on the regulatory processes, while others on the evaluative mechanisms, most of them complement each other. Essential questions, such as the sources of capacity limitations, the continuum between control and automaticity, cognitive flexibility as a marker, the effects of contextual changes, and individual differences in both behavioral performance and neural activity are critically discussed throughout the chapter. The most widely used behavioral paradigms and their outcome measures (e.g., congruency effects, intrusion cost, switching cost, practice effects, post-error slowing and post-error reduction of interference) are presented and linked to different conceptual constructs.
This chapter discusses cognitive individual differences that affect learning processes and outcomes of second language. It answers broad questions such as Why do some learners seem to have such an easy time learning a second language? and Why do some learners sound like a first-language speaker but others don’t? The chapter examines how our cognitive abilities influence our learning, and how we might be able to improve our learning even if we have lower cognitive skills in some areas. Specific individual differences include general intelligence, working memory, and language learning aptitude (phonemic coding ability, grammatical sensitivity, rote memorization). The chapter then examines how cognitive individual differences mediate the impact of second language instruction, that is, aptitude–treatment interaction. The chapter includes less-investigated individual differences as well, such as neurodiversity, autism, ADHD, and dyslexia. The chapter concludes with learning strategies and pedagogical recommendations that help counter the negative impacts that cognitive individual differences have on second language learning.
To examine whether objective sleep parameters are associated with cognitive function (CF) in patients with major depressive disorder (MDD) with chronic insomnia (CI) and whether the severity of these disorders is related to CF.
Method
Thirty patients with MDD with CI attending a tertiary care institution underwent two consecutive nights of polysomnographic (PSG) recording and a battery of neuropsychological tests, which included episodic memory, sustained attention, working memory, and executive function. The severity of MDD and CI was assessed by clinical scales. We examined the relationship between PSG parameters and CF, as well as whether the severity of the disorders is related to CF.
Results
Linear regression analysis revealed that total sleep time (TST) was positively associated with higher learning and recall of episodic memory, as well as better attention. Slow-wave sleep (SWS) showed a positive association with better working memory. Furthermore, wake after sleep onset (WASO) was negatively associated with episodic memory and lower attention. No significant relationships were found between the severity of MDD or CI with CF.
Conclusion
Both sleep duration and depth are positively associated with several aspects of CF in patients with MDD with CI. Conversely, a lack of sleep maintenance is negatively related to CF in these patients. These findings could help identify modifiable therapeutic targets to reduce CF impairment.
In processing their two languages, bilinguals have to selectively attend to the target language and reduce interference from the non-target language. This experience may have specific cognitive consequences on Executive Functions (EF) through bilingual language processing. Some studies found cognitive consequences in executive functioning skills. However, other studies did not replicate these findings or found a bilingual disadvantage. The aim of this study was to test for the cognitive consequences of bilingualism in EF among a large number of young adults using a latent variable approach, to rule out non-EF task differences as an explanation for inconsistency across studies. Also, we were interested in testing the EF structure using the Confirmatory Factor Analysis (CFA) approach. The results did not support a cognitive consequence of bilingualism and also the EF structure was the same for both groups. We discuss other possible variables that might contribute to the mixed results across studies.
People with schizophrenia (PSZ) are impaired in attentional prioritization of non-salient but relevant stimuli over salient distractors during visual working memory (VWM) encoding. Conversely, guidance of top–down attention by external predictive cues is intact. Yet, it is unknown whether this preserved ability can help PSZ encode more information in the presence of salient distractors.
Methods
We employed a visuospatial change-detection task using four Gabor patches with differing orientations in 66 PSZ and 74 healthy controls (HCS). Two Gabor patches flickered which were designated either as targets or distractors and either a predictive or a non-predictive cue was displayed to manipulate top–down attention, resulting in four conditions.
Results
We observed significant effects of group, salience and cue as well as significant interactions of salience by cue, group by salience and group by cue. Across all conditions, PSZ stored significantly less information in VWM than HCS. PSZ stored significantly less non-flickering than flickering information with a non-predictive cue. However, PSZ stored significantly more flickering and non-flickering information with a predictive cue.
Conclusions
Our findings indicate that control of attentional selection is impaired in schizophrenia. We demonstrate that additional top–down information significantly improves performance in PSZ. The observed deficit in attentional control suggests a disturbance of GABAergic inhibition in early visual areas. Moreover, our findings are indicative of a mechanism for enhancing attentional control in PSZ, which could be utilized by pro-cognitive interventions. Thus, the current paradigm is suitable to reveal both preserved and compromised cognitive component processes in schizophrenia.
Numerous studies have shown a decrease in executive functions (EF) associated with aging. However, few investigations examined whether this decrease is similar between sexes throughout adulthood. The present study investigated if age-related decline in EF differs between men and women from early to late adulthood.
Methods:
A total of 302 participants (181 women) aged between 18 and 78 years old completed four computer-based cognitive tasks at home: an arrow-based Flanker task, a letter-based Visual search task, the Trail Making Test, and the Corsi task. These tasks measured inhibition, attention, cognitive flexibility, and working memory, respectively. To investigate the potential effects of age, sex, and their interaction on specific EF and a global EF score, we divided the sample population into five age groups (i.e., 18–30, 31–44, 45–54, 55–64, 65–78) and conducted analyses of covariance (MANCOVA and ANCOVA) with education and pointing device as control variables.
Results:
Sex did not significantly affect EF performance across age groups. However, in every task, participants from the three youngest groups (< 55 y/o) outperformed the ones from the two oldest. Results from the global score also suggest that an EF decrease is distinctly noticeable from 55 years old onward.
Conclusion:
Our results suggest that age-related decline in EF, including inhibition, attention, cognitive flexibility, and working memory, becomes apparent around the age of 55 and does not differ between sexes at any age. This study provides additional data regarding the effects of age and sex on EF across adulthood, filling a significant gap in the existing literature.
Historically, numerous studies have supported a male advantage in math. While more recent literature has shown that the gender gap is either decreasing or non-significant, a gender difference remains for higher level math (high school and college) (Hyde et. al. 1990; Casey et. al. 1995). It is known that both cognitive and non-cognitive factors influence math performance. There is little evidence for gender differences in working memory (Miller & Bichsel, 2004), which is a key predictor for mathematics. There is, however, evidence for gender differences in the non-cognitive domain, including math anxiety, with females having higher levels (Miller & Bichsel, 2004; Goetz, et. al. 2013). This study evaluates gender differences in both standardized and everyday math performances, and the way that cognitive and non-cognitive factors impact math. The study is focused on a very understudied group with high levels of math difficulty, namely community college students. We expected to find gender differences in math, and expect these to be in part accounted for by gender differences in strong mathematical predictors, particularly non-cognitive factors.
Participants and Methods:
Participants included 94 community college students enrolled in their first math class (60 female; 34 male). Participants were administered the Kaufman Test of Educational Achievement - 3rd edition (KTEA3): Math Computation (MC) and Math Concepts Application (MCA) subtests, as well as an original Everyday Math (EM) measure which assessed their math ability in the context of common uses for math (e.g., financial and health numeracy). Additional measures included math anxiety, self-efficacy, and confidence. Finally, complex span working memory tasks were administered to assess verbal and spatial working memory. Analyses were performed using correlation and regression to examine relationships between the cognitive and non-cognitive variables and standardized and everyday math measures.
Results:
Correlations showed that all cognitive and non-cognitive variables are significantly correlated with all three math measures (all p < .05). There were no significant gender differences for any of the math measures, nor the working memory, or non-cognitive measures. Regression showed that across all three math outcomes, math anxiety and verbal working memory are significantly predictive of math performance. Overall R2 values were significant (range 27% to 37%, all p < .001). Working memory and math anxiety were unique predictors in all three regressions (all p < .05), but other non-cognitive variables such as self-efficacy did not show unique prediction (all p >.05).
Conclusions:
There was no evidence for gender differences on any studied variable. This stands in contrast to prior studies, although few studies have included community college students. On the other hand, both cognitive and non-cognitive factors were complimentary in the prediction of math outcomes, which is consistent with prior work. Among non-cognitive predictors, math anxiety was particularly prominent. This study clarifies prior conflicting work regarding gender differences, and highlights the role of both math anxiety and working memory as relevant for multiple math outcomes.
Cognitive training is a non-pharmacological intervention aimed at improving cognitive function across a single or multiple domains. Although the underlying mechanisms of cognitive training and transfer effects are not well-characterized, cognitive training has been thought to facilitate neural plasticity to enhance cognitive performance. Indeed, the Scaffolding Theory of Aging and Cognition (STAC) proposes that cognitive training may enhance the ability to engage in compensatory scaffolding to meet task demands and maintain cognitive performance. We therefore evaluated the effects of cognitive training on working memory performance in older adults without dementia. This study will help begin to elucidate non-pharmacological intervention effects on compensatory scaffolding in older adults.
Participants and Methods:
48 participants were recruited for a Phase III randomized clinical trial (Augmenting Cognitive Training in Older Adults [ACT]; NIH R01AG054077) conducted at the University of Florida and University of Arizona. Participants across sites were randomly assigned to complete cognitive training (n=25) or an education training control condition (n=23). Cognitive training and the education training control condition were each completed during 60 sessions over 12 weeks for 40 hours total. The education training control condition involved viewing educational videos produced by the National Geographic Channel. Cognitive training was completed using the Posit Science Brain HQ training program, which included 8 cognitive training paradigms targeting attention/processing speed and working memory. All participants also completed demographic questionnaires, cognitive testing, and an fMRI 2-back task at baseline and at 12-weeks following cognitive training.
Results:
Repeated measures analysis of covariance (ANCOVA), adjusted for training adherence, transcranial direct current stimulation (tDCS) condition, age, sex, years of education, and Wechsler Test of Adult Reading (WTAR) raw score, revealed a significant 2-back by training group interaction (F[1,40]=6.201, p=.017, η2=.134). Examination of simple main effects revealed baseline differences in 2-back performance (F[1,40]=.568, p=.455, η2=.014). After controlling for baseline performance, training group differences in 2-back performance was no longer statistically significant (F[1,40]=1.382, p=.247, η2=.034).
Conclusions:
After adjusting for baseline performance differences, there were no significant training group differences in 2-back performance, suggesting that the randomization was not sufficient to ensure adequate distribution of participants across groups. Results may indicate that cognitive training alone is not sufficient for significant improvement in working memory performance on a near transfer task. Additional improvement may occur with the next phase of this clinical trial, such that tDCS augments the effects of cognitive training and results in enhanced compensatory scaffolding even within this high performing cohort. Limitations of the study include a highly educated sample with higher literacy levels and the small sample size was not powered for transfer effects analysis. Future analyses will include evaluation of the combined intervention effects of a cognitive training and tDCS on nback performance in a larger sample of older adults without dementia.
HSCT is increasingly used for curative therapy for patients with high risk hematologic diseases. Existing research regarding the neurocognitive impact of HSCT on pediatric patients is notably variable. One area of identified risk is attention/working memory (WM) [Perkins et al., 2007]. The current study examines the degree to which difficulties in attention/WM are present prior to HSCT, as assessed using parent-report of working memory and cognitive tests of attention span and working memory.
Participants and Methods:
Participants were 19 children and adolescents ages 6-17 years (M= 9.63, SD= 3.22) who were enrolled in a prospective longitudinal study monitoring neurocognitive outcomes in children undergoing HSCT. Participants were eligible for this study if they were 2-18 years old at the time of transplant and had a diagnosis that qualified for an allogenic HSCT. Participants were ineligible if they had a pre-HSCT developmental delay, were non-English speaking, and had a prior HSCT or prior CAR T-cell therapy. Participants were 53% female and 95% Caucasian. Diagnoses in the current study sample included acute lymphoblastic leukemia (n=10), acute myeloid leukemia (n=8), and myelodysplastic syndrome (n=1).
Measures included were the Working Memory Index score from the Behavior Rating Inventory of Executive Function (BRIEF; Gioia et al., 2000) and the Digit Span subtest from the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV; Wechsler, 2003) and the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV; Wechsler, 2008).
Results:
Mean scores on parent-reported WM scores and cognitive measures of attention/WM fell within normal limits, including the Digit Span Total score (M = 48.42, SD= 6.33), Digit Span Forward score (M = 47.28, SD = 9.9.83), and Digit Span Backward score (M = 48.94, SD = 6.31). However, further analyses suggested that between 11-32% of patients had scores falling at least one standard deviation below the mean on these measures, with more than half of the sample (52.6%) identified with at least one measured weakness in attention and WM. The most commonly identified weakness (33.3% of patients) was Digit Span Forward. Correlations between parent-reported WM issues and cognitive measures of attention and WM were generally strong, with parent report of WM significantly correlated with the Digit Span Total score (r(18)= -0.52, p=.02) and the Digit Span Forward score (r(18) = -0.51, p=.03). No correlations were found between Digit Span Backward and other measures of attention and WM.
There were no significant differences in WM scores between patients with ALL and AML. Additional analyses will examine potential contribution of medical factors (e.g., pre-HSCT treatment) to pre-HSCT performance on measures of attention and WM.
Conclusions:
These results suggest that, prior to undergoing HSCT, pediatric patients present with attention and WM issues. This finding has implications for research related to neurocognitive outcomes in HSCT, indicating the need to obtain pre-HSCT cognitive data in this area in order to fully understand potential change after HSCT. In addition, providers may need to consider adapting communication methods with patients during their transplant stay, given potential attention and WM issues within this population.
As part of the Research Domain Criteria (RDoC) initiative, the NIMH seeks to improve experimental measures of cognitive and positive valence systems for use in intervention research. However, many RDoC tasks have not been psychometrically evaluated as a battery of measures. Our aim was to examine the factor structure of 7 such tasks chosen for their relevance to schizophrenia and other forms of serious mental illness. These include the n-back, Sternberg, and self-ordered pointing tasks (measures of the RDoC cognitive systems working memory construct); flanker and continuous performance tasks (measures of the RDoC cognitive systems cognitive control construct); and probabilistic learning and effort expenditure for reward tasks (measures of reward learning and reward valuation constructs).
Participants and Methods:
The sample comprised 286 cognitively healthy participants who completed novel versions of all 7 tasks via an online recruitment platform, Prolific, in the summer of 2022. The mean age of participants was 38.6 years (SD = 14.5, range 18-74), 52% identified as female, and stratified recruitment ensured an ethnoracially diverse sample. Excluding time for instructions and practice, each task lasted approximately 6 minutes. Task order was randomized. We estimated optimal scores from each task including signal detection d-prime measures for the n-back, Sternberg, and continuous performance task, mean accuracy for the flanker task, win-stay to win-shift ratio for the probabilistic learning task, and trials completed for the effort expenditure for reward task. We used parallel analysis and a scree plot to determine the number of latent factors measured by the 7 task scores. Exploratory factor analysis with oblimin (oblique) rotation was used to examine the factor loading matrix.
Results:
The scree plot and parallel analyses of the 7 task scores suggested three primary factors. The flanker and continuous performance task both strongly loaded onto the first factor, suggesting that these measures are strong indicators of cognitive control. The n-back, Sternberg, and self-ordered pointing tasks strongly loaded onto the second factor, suggesting that these measures are strong indicators of working memory. The probabilistic learning task solely loaded onto the third factor, suggesting that it is an independent indicator of reinforcement learning. Finally, the effort expenditure for reward task modestly loaded onto the second but not the first and third factors, suggesting that effort is most strongly related to working memory.
Conclusions:
Our aim was to examine the factor structure of 7 RDoC tasks. Results support the RDoC suggestion of independent cognitive control, working memory, and reinforcement learning. However, effort is a factorially complex construct that is not uniquely or even most strongly related to positive valance. Thus, there is reason to believe that the use of at least 6 of these tasks are appropriate measures of constructs such as working memory, reinforcement learning and cognitive control.
Working memory is a vital construct in efficient verbal memory encoding (Cotton & Ricker, 2021). Working memory is impacted by attentional capacities (Riccio, Cohen, Garrison, & Smith, 2005). Mood symptoms impact efficient information processing and consolidation of memory (Hubbard, 2016; Lukasik, 2019). This study examines self-reported symptoms of depression, anxiety, and stress as possible moderators of the relationship between working memory and a verbal list-learning task.
Participants and Methods:
Archival data from 415 adults (Mage= 56.10, SD=18.05; Medu= 15.5 SD=2.2; 53% female; 73% white) were collected at an outpatient clinic. Sex and race were not available in a small percentage of cases included in analyses. The Wechsler Adult Intelligence Scale 4th Edition Digit Span subtest was given to assess attention and working memory. Although Digit Span Forward is a measure of simple attention, not working memory, it was included in initial analyses because the subtest was given as a whole. The three components of Digit Span total, Forward, Backward, and Sequencing were also investigated separately, with the two latter scores being better representations of working memory. Learning was assessed via the California Verbal Learning Test (CVLT-II) total T-Score (Trials 1-5). Mood was assessed via the Depression Anxiety and Stress Scales (DASS-42).
Results:
Results of a hierarchical linear regression showed a significant effect between total Digit Span performance and total learning on the CVLT-II in the Block 1 (F(3, 411)=14.383, p =<.001 , AR2=.095). Standardized beta weights and p-values for Digit Span Forward, Backward, and Sequencing were (ß=-.50, p=.374), (ß= .159, p=.009), and (ß=.210, p<.001) respectively. In Block 2, when the DASS variables were introduced, the model remained significant F(3,408)=2.602, p=.05 , AR2=.017). The DASS anxiety and stress subscales had significant beta weights in the model (ß=-.172, p=.015) and (ß=.144, p=.039) respectively, with depression being insignificant (ß=--.023, p=.724).
Conclusions:
Mood symptoms have been shown to be an important consideration when assessing working memory and verbal learning performance (Massey, Meares, Batchelor, & Bryant, 2015). Present results demonstrate that when accounting for working memory, anxiety and stress were significant predictors of performance on a measure of verbal learning. Additionally, as the components best representing working memory, Digit Span Sequencing and Backward were significantly correlated with verbal learning, whereas a measure best representing simple attention, Digit Span Forward, was not significantly correlated with verbal learning.
Research examining dietary fat in relation to physical and cognitive health is mixed. Generally, it has been hypothesized that polyunsaturated fatty acids (PUFAs) have vascular, anti-inflammatory, and neuroprotective effects1,2,3. Monounsaturated fatty acids (MUFAs) commonly occur with saturated fatty acids (SFA) in certain foods, and some research suggests that consumption is associated with increased vascular risk4; however, there is limited research examining combined MUFAs and SFAs consumption from traditional Western diet foods (e.g., pizza, desserts) compared to animal (e.g., butter, cow milk, salmon) and plant products (e.g., coconut oil, cocoa butter). Furthermore, much of the research examining dietary components/supplementation and cognition is in older adult or at-risk samples, with limited research examining the relationships among middle-aged and cognitively unimpaired adults. We present preliminary data from an ongoing pilot study.
Participants and Methods:
39 middle-aged (40-65 years, inclusive) cognitively unimpaired individuals were recruited from the community. The Food Frequency Questionnaire (Short-Form; SF-FFQ) was used to calculate diet components and servings during a “typical week.” Attention and working memory were measured using trial one of the California Verbal Learning Test - Third Edition (CVLT-III), Oral Trail Making Test Part B, Number Span (forward and backward), Stroop Color and Color-Word trials. Genetic and other plasma-based data for 25 participants have also been obtained, and analysis is in progress; we plan to analyze these additional components in greater detail once we have achieved our target sample size.
Results:
Nonparametric correlation analyses revealed no significant relationships between total dietary fat (as measured by the SF-FFQ) and cognitive performance, which included CVLT Trial 1 (r = .28, p = .09), Oral Trail Making Test Part B (r = .02, p = .89), Number Span Forward (r = .18, p = .27) and Number Span Backward (r = -.04, p = .83), Stroop Color trial (r = -.10, p = .56), and Stroop Color-Word trial (r = -.09, p = .58). Notably, however, data is continuing to be collected and these relationships will be examined further with additional data.
Conclusions:
While total fat consumption was expected to be associated with attention and working memory measures, correlations revealed nonsignificant relationships. Notably, there are important limitations to consider, as other expected relationships based on previous research findings/theoretical relationships (e.g., positive correlation between waist-to-hip ratio and fat consumption) were lacking. A primary limitations of this study included a small sample size of cognitive and physically healthy middle-aged adults. Regardless, these relationships should be explored further with a greater and more diverse sample size.
Converging evidence across languages suggests that the word length effect (WLE; rate of number of syllables, phonemes, or pronunciation times per word) significantly contributes to estimates of verbal working memory (WM) capacity limits in the storage phase, but not in the manipulation phase (i.e., word length effect decay), of WM. Direct examination of the WLE on verbal WM performance within monolingual Spanish-speakers has not been reported. We investigated the psychophysical mechanisms of capacity consumption in Spanish-speakers across three syllabic word length rates to clarify the relative contributions of the WLE to storage (digit span forward) versus manipulation (digit span backward) memory phases within one language of monolingual speakers.
Participants and Methods:
Monolingual Spanish-speaking adults (N = 84) born in Latin American countries and age 18-65 completed testing over Zoom. Inclusion criteria required proficiency in the Spanish-language; exclusion criteria were bilingualism, multilingualism, TONI-4 IQ < 85, or history of head injury/LOC. A within-group design measured the WLE across three cognitive load conditions in the forward and backward directions of the digit span test varying in Spanish syllabic word length: the Mexican WAIS-IV Digit Span Test (“Standard Load”), and two modified measures with either a ∼20% decrease (“Low Load”) or ∼20% increase (“High Load”) in total syllables/digit relative to the Standard Load.
Results:
A reverse WLE was observed on syllable accuracy percentage task performance (p < 0.01), such that longer word length led to higher capacity limits during storage WM. A WLE, not decay, was found on both raw score (p < .001) and syllable accuracy percentage (p < 0.01) task performances during manipulation WM, where longer word length led to lower capacity limits.
Conclusions:
The reverse WLE was attributed to higher-order, executive-function cognitive strategies (such as chunking) that superseded negative word length effects. A larger syllabic discrepancy during manipulation WM could have superseded executive-function strategies, rendering a traditional WLE. Our study contributed more precise capacity estimates and clearer understanding of successful WM performance within monolingual, Latin American-born Spanish-speakers, helping to reduce cultural disparities in neurocognitive and neuropsychological research. Future studies may extend these findings to examine how WM capacity resources can be harnessed to improve memory strategies in clinically-applied settings with Spanish-speaking populations.
Cognitive deficits in patients diagnosed with schizophrenia are a core feature of the disorder. There are currently no treatments for these cognitive deficits. Our aim was to examine and compare patterns of increased versus decreased activity in the central executive network (CEN), salience network (SN), and default mode network (DMN) between healthy controls (HCs) and patients diagnosed with schizophrenia (SZs) as well as to explore the influence of task load on these networks between HCs and SZs.
Participants and Methods:
Analyses focused on a secondary dataset comprising Blood Oxygen-Level Dependent (BOLD) data collected from 25 HCs and 27 SZs who completed a working memory (WM) task (N-back) with 5 load conditions while undergoing functional magnetic resonance imaging (fMRI). Region of interest (ROI) data were analyzed using linear mixed-effects models.
Results:
Group activation differences were found in the posterior salience network (pSN), default mode network (DMN), dorsal default mode network (dDMN), and ventral default mode network (vDMN) showing greater activity for SZs. Specifically, pSN, DMN, dDMN, and vDMN all showed increased activity in SZs compared to HCs. The curve of brain activity was consistent between HCs and SZs with the exception of the vDMN, where HCs show greater activation at modest mental workload (quadratic curve) and SZs showed greater brain activation at lower mental workload (linear). In the CEN, there were no group differences, and the response curve was the same for both groups.
Conclusions:
These group differences demonstrate network difference between HCs and SZs and could show value in treatments targeting cognitive deficits in SZs from a large-scale brain network connectivity perspective. Future studies are needed to confirm these results with larger sample size in order to examine potential subtleties of interactions between these networks.