Measures Of Processing Speed Research Articles

Patterns of proactive interference in CVLT-II: evidence of a low-organized, disorganized, and highly organized learning style

ABSTRACT Objective Previous studies have interpreted proactive interference (PI) either as indicating executive dysfunction or a normal process indicating deep level encoding. We investigated these competing models of PI in a large clinical sample using cluster analyses. We expected to find clusters defined by high PI but otherwise characterized by either EF impairment or of good memory performance. Method File records of 731 patients with neurological or psychiatric disorders were analyzed. PI-scores, false positive recognition errors, and semantic organization scores on the California Verbal Learning Test-II (CVLT-II) were subjected to cluster analyses. Clusters were compared regarding buildup and release from PI, memory performance and strategy measures, measures of intelligence, EF, and processing speed. Results The analyses revealed six analyzable clusters. Two clusters showed no buildup of PI and normal release from PI. Discriminability was impaired both in List A and B. Learning acquisition and speeded measures of EF were reduced. One cluster showed both buildup of PI and problems with releasing from PI, and particularly impaired discriminability of List B. Semantic organization was low. Learning consolidation and EF speeded measures were impaired. Two other clusters showed buildup of PI, but no problem with release. Learning was highly organized, and they showed good memory and normal neuropsychological performance. Conclusions Results shows differentiation between a low organized EF dysfunction pattern with no PI, a disorganized PI pattern also indicating EF dysfunction and a highly organized pattern where PI seems to be the price to pay for high effort put into the learning process.

A - 174 The Clinical Utility of RBANS Coding Compared to WAIS-IV PSI in Community Dwelling Older Adults.

Fatigue and cognitive performance are important considerations in assessment with older adults. Utilization of a shorter cognitive battery may provide similar results to lengthier batteries in older adults diagnosed with various degenerative diseases (Mooney et al., 2007). Studies have identified implications for both normative and abnormal cognitive decline with regard to task-related fatigue (Campbell et al., 2022; Hess & Knight, 2021). When examining processing speed and mental fatigue, research has identified strong associations in clinical populations (Andreasen et al., 2010; Hess & Knight, 2021; Banerjee et al., 2020). The current study compares longer and shorter measures of cognitive processing speed in a community dwelling older adult sample. bThe current sample consists of 60 community dwelling participants (female n = 54; Caucasian n = 52); mean education 13.83years; mean age = 76years. Measures: Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Coding; Wechsler Adult Intelligence Scale Fourth Edition (WAIS-IV) Symbol Search (SS) and Coding (CD) subtests. Linear regression identified that 82.7% of the variance in RBANS Coding was accounted for by WAIS-IV SS and CD (Adjusted R Squared = 0.827). The specific correlations for RBANS Coding were strong for SS (r = 0.794, p < 0.001) and CD (r = 0.907, p < 0.001). RBANS Coding appears to map on strongly to the WAIS PSI in community dwelling older adult populations. RBANS Coding may be considered as an alternative to longer measures of processing speed due to the strong correlation to better established PSI measures on the WAIS.

A - 103 Persistent Longitudinal Differences in Cognition between Men and Women with Parkinson's Disease.

Cross-sectional studies of Parkinson's disease (PD) patients have identified cognitive differences between men with PD (MPD) and women with PD (WPD) at single time points. WPD generally outperform MPD on global cognition, memory, executive functions, verbal fluency, and processing speed measures, whereas MPD perform better on visuospatial tasks. Little is known about sex-based differences in PD cognition longitudinally. This study examined neurocognitive profiles in WPD, MPD, and health controls (HC) over three years. Participants were 26 PD (16 WPD, 10 MPD) and 51 HC (28 females, 23 males). Age (M = 60.70, SD = 7.89) and education (M = 15.07, SD = 2.77) were consistent across groups. PD mean disease duration was 4.04years (SD = 4.56), with samples matched for disease duration and severity. At baseline and three-year follow-up, neuropsychological measures of attention, memory, language, visuospatial, and executive functions were completed. Repeated measures ANOVAs with Bonferroni correction examined differences between samples over time controlling for age and education. In both PD and control groups, women outperformed men on measures of verbal learning and verbal memory over time. WPD also performed significantly better than MPD in verbal and visual working memory and semantic fluency tasks at baseline and at 3-year follow-up. In contrast, MPD outperformed WPD on visuospatial perception at both time points, with remaining measures being similar. Results build upon earlier cross-sectional studies and confirm that WPD have persisting, comparative strengths in verbal memory, working memory and semantic fluency in contrast to visuospatial perception for MPD in early disease stages.

B - 62 The Clinical Utility of the BAI Compared to the GAI in Community Dwelling Older Adults.

Given the potential impact anxiety may have on cognitive performance, the current study explored the relationship of both the Beck Anxiety inventory (BAI) and the Geriatric Anxiety Inventory (GAI) to cognitive performance in community dwelling older adults. Specifically, the correlation of anxiety and depression symptomatology to performance on measures of executive functioning and processing speed was explored (Dorekamp & Vik, 2018; Najimi et al., 2015; Vytal et al., 2012). Archival data from a sample of 60 community dwelling older adult participants (female n = 54; White n = 52), with an average education of 13.83years and an average age of 76years were included. The BAI and GAI were used to determine anxiety levels. Processing speed and executive functioning were assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Coding subtest and Trail Making Test B respectively. Data was analyzed using Pearson's R product moment correlations. Pearson's R product moment correlations were significant between the BAI and RBANS Coding (r = -0.328; p = 0.011), Trails B (r = 0.295; p = 0.023), and the GAI (r = 0.268; p = 0.04). However, the GAI was only significantly associated with the BAI. While both the BAI and GAI are well established measures of anxiety in older adults, the BAI appears to be more sensitive to the effects of anxiety on executive functioning and processing speed in community dwelling older adults. Future directions related to exploration of severity and potential cut scores will be discussed.

B - 98 Interactive Effects of Sleep Apnea and Depression Symptoms on Cognition in Older Adults.

This study examined interactions between symptoms of sleep apnea and depression in predicting cognition in healthy older adults. From the Memory and Aging Project (Rush Alzheimer's Disease Center, Rush University, 2019), the sample consisted of 3345 community dwelling older adults including 2552 women (76.3%) and 1093 men (23.7%) with an average age of 80years. Measures included the Berlin Questionnaire (for sleep apnea symptoms, Center for Epidemiological Studies Depression Scale, and neuropsychological measures of semantic memory, visuospatial ability, and processing speed. ANOVAs indicated significant main effects of depression on visuospatial ability, processing speed, and semantic memory (p's < 0.001), and no main effect for sleep apnea. However, when sleep apnea was analyzed between those with any depressive symptoms versus those without, significant interactions were found for visuospatial ability, processing speed, and semantic memory (ps < 0.05). Sleep apnea symptoms had a detrimental effect on visuospatial skills (p = 0.027) only when any depression symptom was present. In contrast, sleep apnea symptoms predicted slower processing speed when depressive symptoms were not present (p = 0.001) Similarly, depression symptoms had a greater negative effect on semantic memory for those who reported no sleep apnea symptoms compared to those who did (p = 0.016). There seems to be differential main and interactive effects of sleep apnea symptoms and depression on semantic memory, visuospatial ability, and processing speed. Clinicians may need to consider even mild symptoms of sleep problems and depression if they suspect changes in these cognitive domains in older adults.

B - 51 The Relationship between Delusional Thinking and Processing Speed in Community Adults.

Adults diagnosed with a psychotic disorder demonstrate heterogeneous neurocognitive performances, though the relationship between delusions and neurocognition among nonclinical adults remains largely unstudied. This study addressed this gap by examining how nonclinical delusional thinking impacts processing speed and speeded inhibition. Participants included an adult community sample who completed a neuropsychological battery through the Nathan Kline Institute's Rockland Project. The 1111 participants were 36% male, ages 18-85 (M = 47, SD = 17.97), and 76% White, 16% Black, and 5% Asian. Delusional thinking was assessed using the total score on the 21-item Peters et al. Delusions Inventory. Processing speed and speeded inhibition were assessed using age-adjusted scores from the Delis-Kaplan Executive Function System (D-KEFS) Trail Making Test (TMT) and Color-Word Inhibition Test (C-WIT). Linear regression analyses were conducted to assess whether delusional thinking predicted performance on TMT and C-WIT tests. Greater delusional thinking predicted poorer performance on TMT tests of Number Sequencing (R2 = 0.005, p = 0.023), Number-Letter Sequencing (R2 = 0.005, p = 0.018), and Motor Speed (R2 = 0.005, p = 0.021). For performance on Letter Sequencing and all C-WIT tests, there were no statistically significant relationships with delusional thinking. Results indicated that faster psychomotor processing speed, not visual processing speed, was significantly associated with lower delusional thinking in a community sample. Therefore, it may be particularly useful to include measures of psychomotor processing speed when assessing individuals with delusional symptoms. A replication study with greater variability in delusional thinking may elucidate the relationship between delusional thinking and cognitive functioning in nonclinical populations.

A - 173 Symbol Match Validity at the Montefiore Memory Disorder Centers.

To demonstrate the validity of the Symbol Match in a diverse clinical setting. To improve detection of cognitive impairment in older primary care patients, our team developed the 5-Cog, a 5-minute cognitive assessment and decision tree paradigm that can be administered by non-clinicians. The Symbol Match is a new 90-second oral symbol and digit substitution task that is one of the three tests in the 5-Cog that assesses processing speed and executive function. 50 participants (66% female; 44% Hispanic, 38% Non-Hispanic Black; 36% evaluated in Spanish) with a mean age of 77.84 ± 7.3, and 12 ± 4.7 mean years of education. Participants were recruited following clinical evaluations at the Montefiore Memory Disorder Centers and had confirmed clinical diagnoses of dementia, mild cognitive impairment (MCI), or subjective cognitive concerns (SCC). Symbol Match scores were significantly different (p < 0.001) between participants with SCC (N = 5, M = 48 ± 9.7), MCI (N = 14, M = 31.7 ± 14.3), and dementia (N = 28, M = 9.6 ± 11.5). Age (p = 0.004) and education (p < 0.001) were correlated with Symbol Match score in the overall sample. Symbol Match scores were significantly different between the 3 disease states (p < 0.001) even when controlling for age and education. The Symbol Match was highly correlated (r = 0.843, p < 0.001) with the Symbol Digit Modalities Test (SDMT), an established neuropsychological measure of processing speed and executive function. This study provides initial validation of the Symbol Match and its utility in a clinical population. Further research on psychometric properties and construct validity of this new tool is needed.

Bilingual neurocognitive resiliency, vulnerability, and Alzheimer's disease biomarker correlates in Latino older adults enrolled in the Health and Aging Brain Study - Health Disparities (HABS-HD).

The effects of bilingualism on neuropsychological test performance in bilinguals with and without cognitive impairment are not well-understood and are relatively limited by small sample sizes of Latinos. Using analysis of covariance (ANCOVA), we explored patterns of cognitive performance and impairment across a large sample of community-dwelling bilingual and monolingual Latino older adults with (n=180) and without (n=643) mild cognitive impairment (MCI) enrolled in HABS-HD. Bilinguals demonstrated cognitive resiliency in the form of significantly better performance on the Trail Making Test and Digit Symbol Substitution Test, observed across the cognitively unimpaired and MCI groups. In contrast, bilinguals demonstrated cognitive vulnerability in the form of significantly poorer performance and higher impairment rates on phonemic fluency in the MCI phase, only. Follow-up analyses revealed less balanced bilinguals demonstrated poorer performance and higher impairment rates on this measure, supported by lower levels of plasma Aβ 42/40. Patterns of cognitive performance and impairment differ as a function of bilingualism. Bilingualism must be considered when evaluating cognitive and biomarker outcomes in Latino older adults. Latino bilinguals perform better on measures of processing speed and coding.Latino bilinguals with MCI demonstrate cognitive vulnerability in verbal fluency.Less balanced bilinguals demonstrate greatest vulnerability anchored by Aβ42/40.

Cognitive enrichment and education quality moderate cognitive dysfunction in black and white adults with multiple sclerosis.

To examine the extent to which three sociobehavioral proxies of cognitive reserve-years of education, education quality, and cognitive enrichment-differ in their prediction of cognitive performance among Black and White people with MS (PwMS). 82 PwMS (Black n=41, White n=41) underwent a neurological examination and a neuropsychological evaluation that included tests of word recognition (Wechsler Test of Adult Reading) as well as measures of verbal memory, visuospatial memory, and processing speed (the Brief International Cognitive Assessment for MS; BICAMS). Participants rated their lifetime engagement in various cognitively-enriching activities (Cognitive Reserve Scale). For the full sample, education quality and cognitive enrichment were more strongly associated with cognitive performance than were years of education. Cognitive enrichment was not associated with cognitive performance among participants with high education quality. In contrast, among participants with low education quality, cognitive enrichment was strongly associated with cognitive performance, suggesting that high engagement in cognitively-enriching activities provided similar protection to high education quality. Furthermore, among Black participants, cognitive enrichment and educational quality moderated the relationship between disability level and cognitive performance. In contrast, among White participants, cognitive enrichment did not provide additional protection beyond the buffering effect of education quality. PwMS can successfully build reserve through multiple routes, including formal education or informal cognitive enrichment. Treatment for MS should incorporate cognitively-enriching activities to build resilience against cognitive decline, particularly for members of marginalized racial/ethnic groups, who are at greatest risk for poor health outcomes, and for whom years of education may not best reflect education quality.

Multivariate examination of embedded indicators of performance validity for ADHD evaluations: A targeted approach

This study investigated the individual and combined utility of 10 embedded validity indicators (EVIs) within executive functioning, attention/working memory, and processing speed measures in 585 adults referred for an attention-deficit/hyperactivity disorder (ADHD) evaluation. Participants were categorized into invalid and valid performance groups as determined by scores from empirical performance validity indicators. Analyses revealed that all of the EVIs could meaningfully discriminate invalid from valid performers (AUCs = .69-.78), with high specificity (≥90%) but low sensitivity (19%-51%). However, none of them explained more than 20% of the variance in validity status. Combining any of these 10 EVIs into a multivariate model significantly improved classification accuracy, explaining up to 36% of the variance in validity status. Integrating six EVIs from the Stroop Color and Word Test, Trail Making Test, Verbal Fluency Test, and Wechsler Adult Intelligence Scale-Fourth Edition was as efficacious (AUC = .86) as using all 10 EVIs together. Failing any two of these six EVIs or any three of the 10 EVIs yielded clinically acceptable specificity (≥90%) with moderate sensitivity (60%). Findings support the use of multivariate models to improve the identification of performance invalidity in ADHD evaluations, but chaining multiple EVIs may only be helpful to an extent.

Omega-3 Fatty Acids, Cognition, and Brain Volume in Older Adults.

The elderly population is growing at increased rates and is expected to double in size by 2050 in the United States and worldwide. The consumption of healthy foods and enriched diets have been associated with improved cognition and brain health. The key nutrients common to many healthy foods and diets are the omega-3 polyunsaturated fatty acids (omega-3 FAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We explored whether omega-3 FA levels are associated with brain volume and cognition. Forty healthy, cognitively normal, Seventh-day Adventist older adults (mean age 76.3 years at MRI scan, 22 females) completed neurocognitive testing, a blood draw, and structural neuroimaging from 2016 to 2018. EPA and an overall omega-3 index were associated with individual measures of delayed recall (RAVLT-DR) and processing speed (Stroop Color) as well as entorhinal cortex thickness. EPA, DHA, and the omega-3 index were significantly correlated with the total white matter volume. The entorhinal cortex, frontal pole, and total white matter were associated with higher scores on delayed memory recall. This exploratory study found that among healthy, cognitively older adults, increased levels of omega-3 FAs are associated with better memory, processing speed, and structural brain measures.

Exploring synchrony effects in performance on tasks involving cognitive inhibition: An online study of young adults

ABSTRACT Inhibition is one of the core components of cognitive control. In experimental tasks which measure cognitive inhibition, performance may vary according to an interplay of individuals’ chronotype and the time of day of testing (“synchrony effect”, or the beneficial impact on cognitive performance of aligning testing with the time of day preferred by an individual’s chronotype). Some prior studies have reported a synchrony effect specifically emerging in activities which require cognitive inhibition, but not in general processing speed, but existing findings are inconsistent. If genuine, synchrony effects should be taken into account when comparing groups of participants. Here we explored whether synchrony effects emerge in a sample of young adults. In a multi-part online study, we captured various components of inhibition (response suppression; inhibitory control; switching) plus a general measure of processing speed across various times of the day. Individuals’ chronotype was included as a predictor of performance. Critically, we found no evidence of a synchrony effect (an association between chronotype and component of interest where the directionality is dependent on time of testing) in our study.

SARS-CoV-2-Specific Immune Responses in Patients With Postviral Syndrome After Suspected COVID-19.

Millions of Americans were exposed to SARS-CoV-2 early in the pandemic but could not get diagnosed with COVID-19 due to testing limitations. Many have developed a postviral syndrome (PVS) including neurologic manifestations similar to those with postacute sequelae of SARS-CoV-2 infection (Neuro-PASC). Owing to those circumstances, proof of SARS-CoV-2 infection was not required for evaluation at Northwestern Medicine's Neuro COVID-19 clinic. We sought to investigate clinical and immunologic findings suggestive of SARS-CoV-2 exposure in patients with PVS. We measured SARS-CoV-2-specific humoral and cell-mediated immune responses against Nucleocapsid and Spike proteins in 29 patients with PVS after suspected COVID-19, 32 confirmed age-matched/sex-matched Neuro-PASC (NP) patients, and 18 unexposed healthy controls. Neurologic symptoms and signs, comorbidities, quality of life, and cognitive testing data collected during clinic visits were studied retrospectively. Of 29 patients with PVS, 12 (41%) had detectable humoral or cellular immune responses consistent with prior exposure to SARS-CoV-2. Of 12 PVS responders (PVS+), 75% harbored anti-Nucleocapsid and 50% harbored anti-Spike responses. Patients with PVS+ had similar neurologic symptoms as patients with NP, but clinic evaluation occurred 5.3 months later from the time of symptom onset (10.7 vs 5.4 months; p = 0.0006). Patients with PVS+ and NP had similar subjective impairments in quality of life measures including cognitive function and fatigue. Patients with PVS+ had similar results in objective cognitive measures of processing speed, attention, and executive function and better results in working memory than patients with NP. Antibody and T-cell assays showed evidence of prior SARS-CoV-2 exposure in approximately 40% of the PVS group. Three-quarters of patients with PVS+ had detectable anti-Nucleocapsid and one-half anti-Spike responses, highlighting the importance of multitargeted COVID-19 immunologic evaluation and the limitations of commercially available diagnostic tests. Despite their persistent symptoms, lack of COVID-19 diagnosis likely delayed clinical care in patients with PVS. Our data suggest that millions of Americans presenting with PVS resembling Neuro-PASC were indeed exposed to SARS-CoV-2 at the beginning of the pandemic, and they deserve the same access to care and inclusion in research studies as patients with NP with confirmed COVID-19 diagnosis.

Mental fatigue, cognitive performance and autonomic response following sustained mental activity in clinical burnout

ObjectiveTo investigate the effects of sustained mental activity on perceptions of mental fatigue, cognitive performance, and autonomic response in patients with clinical burnout as compared to a healthy control group. MethodsPatients with clinical burnout (n = 30) and healthy control participants (n = 30) completed a 3-hour test session, in which they were administered a set of cognitive tests before and after an effortful cognitive task with concurrent sound exposure. Perceptions of mental fatigue and task demands (mental effort and concentration difficulties) were assessed repeatedly over the course of the test session. Heart rate variability was recorded to index autonomic response. ResultsIn comparison with controls, perceived mental fatigue increased earlier in the session for the clinical burnout group and did not recover following a short rest period. Throughout the session, patients rated the tasks as more demanding and showed less improvement on measures of attention and processing speed, inhibition and working memory. While autonomic responses were initially comparable, there was a unique decrease in high-frequency heart rate variability in the clinical burnout group after extended testing and exposure. ConclusionPatients with clinical burnout are affected differently than healthy controls by sustained mental activity, as reflected by ratings of perceived mental fatigue, aspects of cognitive performance and autonomic response. Further investigation into the role of autonomic regulation in relation to cognitive symptoms in clinical burnout is warranted.

Longitudinal neurocognitive effects of nonmyeloablative hematopoietic stem cell transplant among older adolescents and adults with sickle cell disease: A description and comparison with sibling donors

ABSTRACT Sickle cell disease (SCD) is associated with increased risk of neurocognitive deficits. However, whether functioning changes following nonmyeloablative hematopoietic stem cell transplant (HSCT) remains unclear. This study aimed to examine changes in neuropsychological functioning pre- to post-transplant among patients with SCD and compare patients and siblings. Adults with SCD (n = 47; M age = 31.8 ± 8.9) and their sibling stem cell donors (n = 22; M age = 30.5± 9.2) enrolled on a nonmyeloablative HCST protocol completed cognitive and patient-reported outcome assessments at baseline and 12 months post-transplant. Path analyses were used to assess associations between pre-transplant variables and sibling/patient group status and post-transplant function. Mean patient cognitive scores were average at both timepoints. Patient processing speed and somatic complaints improved from baseline to follow-up. Baseline performance predicted follow-up performance across cognitive variables; patient/sibling status predicted follow-up performance on some processing speed measures. Results suggest that patients with SCD demonstrate slower processing speed than siblings. Processing speed increased pre- to post-HSCT among patients and siblings, and on some measures patients demonstrated greater improvement. Thus, HSCT may improve processing speed in patients, although further confirmation is needed. Findings provide promising evidence that neurocognitive functioning remains stable without detrimental effects from pre- to 12-months post nonmyeloablative HSCT in individuals with SCD.

Reproductive period duration and cognitive function in postmenopausal Latina women in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

A shorter reproductive period, a marker of estrogen exposure, has been related to cognitive impairment among older (>65years) non-Hispanic White women. We explored whether reproductive period duration, age at menarche, and age at menopause are related to cognitive function among postmenopausal Hispanic/Latina women. This cross-sectional analysis used baseline (Visit 1: 2008-2011) data from 3630 postmenopausal women in the Hispanic Community Health Study/Study of Latinos. Reproductive period duration, age at menarche, and age at menopause were assessed by self-report. Cognitive function variables included global cognition, verbal learning, memory, verbal fluency, and processing speed. Associations between each reproductive event and cognitive function were examined using multivariable linear and logistic regression analyses accounting for the complex survey design of the study and adjusting for socio-demographics, parity, and cardiovascular risk factors. We assessed whether associations differed by type of menopause (natural versus surgical) and hormone therapy use. The study population was on average aged 59years, with a mean reproductive period duration of 35years. Older age at menopause and a longer reproductive period were related to higher verbal learning (β=0.04, SE=0.02; p<0.05) and processing speed (ß=0.16, SE=0.04; p<0.001); associations were more pronounced for women with natural menopause. Older age at menarche was associated with lower scores on the digit symbol substitution test (ß=-0.62, SE=0.15; p<0.0001). There were no associations with global cognition. Among postmenopausal Hispanic/Latinas, a longer reproductive period was related to more favorable cognitive measures of verbal learning and processing speed. Our findings support the hypothesis that greater lifetime exposure to estrogens may be associated with higher cognitive performance.

Neurophysiological correlates of non-motor symptoms in late premanifest and early-stage manifest huntington's disease

ObjectiveTo find sensitive neurophysiological correlates of non-motor symptoms in Huntington’s disease (HD), which are essential for the development and assessment of novel treatments. MethodsWe used resting state EEG to examine differences in oscillatory activity (analysing the isolated periodic as well as the complete EEG signal) and functional connectivity in 22 late premanifest and early stage people with HD and 20 neurotypical controls. We then assessed the correlations between these neurophysiological markers and clinical measures of apathy and processing speed. ResultsSignificantly lower theta and greater delta resting state power was seen in the HD group, as well as significantly greater delta connectivity. There was a significant positive correlation between theta power and processing speed, however there were no associations between the neurophysiological and apathy measures. ConclusionsWe speculate that these changes in oscillatory power and connectivity reflect ongoing, frontally concentrated degenerative and compensatory processes associated with HD. SignificanceOur findings support the potential utility of quantitative EEG as a proximate marker of processing speed, but not apathy in HD.

UD Interference Test: creation and validation of a new instrument of resistance to interference. Normalisation and standardisation for Spanish population

IntroductionThe UD Interference Test measures processing speed and attention, and is based on the concept of interference of the Stroop Color and Word Test. The main purpose of the study is to provide an alternative version of the Stroop Color and Word Test that overcomes some of the limitations of previous versions in assessing individuals with daltonism or age-related reading difficulties, and to obtain normative and standardised data for the Spanish population. MethodsThis study is part of the Normacog project. We evaluated 905 individuals (age range, 18–93 years) to analyse the test’s reliability and concurrent and construct validity. We evaluated the effect of age, sex, and level of education on UD Interference Test performance and calculated percentiles and age- and education-adjusted scaled scores. ResultsThe test has good reliability (α = 0.875) and concurrent (r = 0.443−0.725; P < .001) and construct validity (r = 0.472–0.737; P < .001). We observed age and educational level to have a significant effect on UD Interference Test scores, explaining 12% to 40% of variance. Sex only had a significant effect on the resistance to interference index. ConclusionsWe present an alternative version of the Stroop Color and Word Test with some advantages over previous versions. We provide standardised and normalised data for the Spanish population to correct the test according to the subject’s age and level of education.

Individual Differences in Holistic and Compositional Language Processing.

Individual differences in cognitive abilities are ubiquitous across the spectrum of proficient language users. Although speakers differ with regard to their memory capacity, ability for inhibiting distraction, and ability to shift between different processing levels, comprehension is generally successful. However, this does not mean it is identical across individuals; listeners and readers may rely on different processing strategies to exploit distributional information in the service of efficient understanding. In the following psycholinguistic reading experiment, we investigate potential sources of individual differences in the processing of co-occurring words. Participants read modifier-noun bigrams like absolute silence in a self-paced reading task. Backward transition probability (BTP) between the two lexemes was used to quantify the prominence of the bigram as a whole in comparison to the frequency of its parts. Of five individual difference measures (processing speed, verbal working memory, cognitive inhibition, global-local scope shifting, and personality), two proved to be significantly associated with the effect of BTP on reading times. Participants who could inhibit a distracting global environment in order to more efficiently retrieve a single part and those that preferred the local level in the shifting task showed greater effects of the co-occurrence probability of the parts. We conclude that some participants are more likely to retrieve bigrams via their parts and their co-occurrence statistics whereas others more readily retrieve the two words together as a single chunked unit.

What lies beneath: White matter microstructure in pediatric myalgic encephalomyelitis/chronic fatigue syndrome using diffusion MRI.

Recent studies in adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) suggest that changes in brain white matter microstructural organization may correlate with core ME/CFS symptoms, and represent a potential biomarker of disease. However, this has yet to be investigated in the pediatric ME/CFS population. We examined group differences in macrostructural and microstructural white matter properties, and their relationship with clinical measures, between adolescents recently diagnosed with ME/CFS and healthy controls. Forty-eight adolescents (25 ME/CFS, 23 controls, mean age 16 years) underwent brain diffusion MRI, and a robust multi-analytic approach was used to evaluate white and gray matter volume, regional brain volume, cortical thickness, fractional anisotropy, mean/axial/radial diffusivity, neurite dispersion and density, fiber density, and fiber cross section. From a clinical perspective, adolescents with ME/CFS showed greater fatigue and pain, poorer sleep quality, and poorer performance on cognitive measures of processing speed and sustained attention compared with controls. However, no significant group differences in white matter properties were observed, with the exception of greater white matter fiber cross section of the left inferior longitudinal fasciculus in the ME/CFS group compared with controls, which did not survive correction for intracranial volume. Overall, our findings suggest that white matter abnormalities may not be predominant in pediatric ME/CFS in the early stages following diagnosis. The discrepancy between our null findings and white matter abnormalities identified in the adult ME/CFS literature could suggest that older age and/or longer illness duration influence changes in brain structure and brain-behavior relationships that are not yet established in adolescence.