Demographically Adjusted Normative Standards for New Indices of Performance on the Paced Auditory Serial Addition Task (PASAT)

Normative Data Estimation in Neuropsychological Tests: A Systematic Review

OBJECTIVE

To quantify the evolution, impact, and importance of normative data (ND) calculation by identifying trends in the research literature and what approaches need improvement.

METHODS

A PRISMA-guideline systematic review was performed on literature from 2000 to 2022 in PubMed, Pub-Psych, and Web of Science. Inclusion criteria included scientific articles about ND in neuropsychological tests with clear data analysis, published in any country, and written in English or Spanish. Cross-sectional and longitudinal studies were included. Bibliometric analysis was used to examine the growth, productivity, journal dispersion, and impact of the topic. VOSViewer compared keyword co-occurrence networks between 1952-1999 and 2000-2022.

RESULTS

Four hundred twelve articles met inclusion and exclusion criteria. The most studied predictors were age, education, and sex. There were a greater number of studies/projects focusing on adults than children. The Verbal Fluency Test (12.7%) was the most studied test, and the most frequently used variable selection strategy was linear regression (49.5%). Regression-based approaches were widely used, whereas the traditional approach was still used. ND were presented mostly in percentiles (44.2%). Bibliometrics showed exponential growth in publications. Three journals (2.41%) were in the Core Zone. VOSViewer results showed small nodes, long distances, and four ND-related topics from 1952 to 1999, and there were larger nodes with short connections from 2000 to 2022, indicating topic spread.

CONCLUSIONS

Future studies should be conducted on children's ND, and alternative statistical methods should be used over the widely used regression approaches to address limitations and support growth of the field.

Changes in psychological and cognitive variables as well as cortisol levels in recovered Covid-19 patients: a longitudinal study

BACKGROUND

Decreased psychological and cognitive functioning is one of the complications of Covid-19 disease. We aimed to evaluate mental health, cognitive functioning, and salivary cortisol levels in Covid-19 patients with different disease severities in three 45-day intervals after recovery.

METHODS

258 Covid-19 patients were assigned into three groups based on their disease severity: 112 patients in mild group, 67 patients in moderate group and 79 patients in severe group. The participants underwent psychological evaluations (including Depression, Anxiety and Stress Scale questionnaire, Beck Depression Inventory, SpeilBerger State-Trait Anxiety Inventory, Pittsburgh Sleep Quality Inventory), cognitive assessments (The Paced Auditory Serial Addition Test) and salivary cortisol level evaluation in three 45-day periods. Non-parametric statistical methods were applied for psychological and cognitive indicators, while two-way mixed model ANOVA was used to evaluate the cortisol concentration in three replications.

RESULTS

The group of mild patients became more anxious and the group of moderate patients became more anxious and depressed. But all three groups of patients developed severe sleep disorders over time. For cognitive functioning, although the results showed a decrease in the correct response rate, a significant increase in the correct response rate was observed in all three groups in all three measurements. However, the response speed not only did not increase, but also decreased in severe group. Cortisol level had a markedly increasing trend in all three groups.

CONCLUSION

Improvement of cognitive functioning was in line with the increase in cortisol. Besides, the decrease in mental health had no effect on the cognitive functioning.

The Frontal Assessment Battery 20 years later: normative data for a shortened version (FAB15)

OBJECTIVE

The Frontal Assessment Battery (FAB) is a neuropsychological tool largely used to assess executive functions. Prior studies found a marked ceiling effect for the prehension behavior subtest (PBT) in healthy and clinical populations. Aims of the present study were (i) to examine the psychometric properties of the FAB without the contribution of PBT and (ii) to provide normative data for a revised version of the FAB after exclusion of PBT (FAB15).

METHODS

The normative sample included 1,187 healthy participants. PBT had near-zero variance, poor content validity, and no discrimination power. Internal consistency increased when PBT was excluded. We assessed the FAB15 factorial structure, interrater, and test-retest reliabilities. Normative data  for the FAB15 were extracted through a regression-based procedure according to sex, age, and education.

RESULTS

The principal component analysis revealed a single "executive factor" or alternatively a bifactorial solution reflecting the different degree of discriminative capability vs. difficulty of the subtests. The FAB15 demonstrated excellent interrater and test-retest reliabilities. Regression analysis showed that sex (lowly educated women < lowly educated men), higher age, and lower education affected FAB15 score. Accordingly, three grids for adjustment of raw scores (men, women, and both) were constructed. The cut-off was fixed at the non-parametric outer tolerance limit on the fifth centile (9.36, 95% CI).

CONCLUSION

The observation of a ceiling effect in healthy subjects makes PBT not suitable for inclusion in a neuropsychological battery. The FAB15 may successfully replace the conventional FAB as a more severe and valid short screening tool to assess executive functioning.

Increasing the Clinical Utility of the Paced Auditory Serial Addition Test: Normative Data for Standard, Dyad, and Cognitive Fatigability Scoring

BACKGROUND

No normative data currently exist that would allow clinicians to decide whether the degree of cognitive fatigability (CF) experienced in individuals with neurologic disease is greater than expected when compared with a healthy population.

OBJECTIVE

To establish discrete and regression-based normative data for CF as defined by an objective decrement in performance over the course of a cognitive task; namely, the Paced Auditory Serial Addition Test (PASAT). In addition, to develop discrete and regression-based normative data for PASAT performance scores-dyad and percent dyad-for which data do not currently exist.

METHOD

One hundred and seventy-eight healthy individuals completed the PASAT as part of a larger neuropsychological battery. PASAT performance scores including total correct responses, total dyads, and percent dyad were calculated. CF scores were calculated by comparing the individuals' performance on the first half (or third) of the test to their performance on the last half (or third) in order to capture any within-task performance decrements over time.

RESULTS

Both age- and education-based discrete normative data and demographically adjusted (sex, age, and education) regression-based formulas were established for the PASAT performance scores and the CF scores.

CONCLUSION

The development of these normative data will allow for greater interpretation of an individual's performance on the PASAT, beyond just the total correct score, through the use of dyad and percent dyad scores. With respect to CF, these data will allow clinicians to objectively quantify decrements in cognitive performance over time better in individuals with neurologic diseases.

Anticipated, experienced, and remembered subjective effort and discomfort on sustained attention versus working memory tasks

This study examined individuals' ability to accurately anticipate how cognitively effortful and uncomfortable a task will feel based on a short sample of the task. Participants completed a sustained attention or working memory task. Post-practice, participants rated the effort and discomfort that they anticipated their task would require and engender, respectively. Participants also rated their effort and discomfort during task-administration and the effort and discomfort they recalled feeling after task-administration. Sustained attention task participants anticipated significantly less effort than working memory task participants. Sustained attention task participants felt significantly more effort during the task and remembered feeling more effort than they had anticipated. Working memory task participants felt significantly less effort during the task than they had anticipated. Sustained attention task participants anticipated, experienced, and recalled feeling more discomfort than working memory task participants. Individuals' anticipation of effort required depends on the task and is different from the effort they actually feel during the task and later recall feeling.

The Dyad-Adaptive Paced Auditory Serial Addition Test (DA-PASAT): Normative data and the effects of repeated testing, simulated malingering, and traumatic brain injury

The Paced Auditory Serial Addition Test (PASAT) is widely used to evaluate processing speed and executive function in patients with multiple sclerosis, traumatic brain injury, and other neurological disorders. In the PASAT, subjects listen to sequences of digits while continuously reporting the sum of the last two digits presented. Four different stimulus onset asynchronies (SOAs) are usually tested, with difficulty increasing as SOAs are reduced. Ceiling effects are common at long SOAs, while the digit delivery rate often exceeds the subject’s processing capacity at short SOAs, causing some subjects to stop performing altogether. In addition, subjects may adopt an “alternate answer” strategy at short SOAs, which reduces the test’s demands on working-memory and processing speed. Consequently, studies have shown that the number of dyads (consecutive correct answers) is a more sensitive measure of PASAT performance than the overall number of correct sums. Here, we describe a 2.5-minute computerized test, the Dyad-Adaptive PASAT (DA-PASAT), where SOAs are adjusted with a 2:1 staircase, decreasing after each pair of correct responses and increasing after misses. Processing capacity is reflected in the minimum SOA (minSOA) achieved in 54 trials. Experiment 1 gathered normative data in two large populations: 1617 subjects in New Zealand ranging in age from 18 to 65 years, and 214 Californians ranging in age from 18 to 82 years. Minimum SOAs were influenced by age, education, and daily hours of computer-use. Minimum SOA z-scores, calculated after factoring out the influence of these factors, were virtually identical in the two control groups, as were response times (RTs) and dyad ratios (the proportion of hits occurring in dyads). Experiment 2 measured the test-retest reliability of the DA-PASAT in 44 young subjects who underwent three test sessions at weekly intervals. High intraclass correlation coefficients (ICCs) were found for minSOAs (0.87), response times (0.76), and dyad ratios (0.87). Performance improved across test sessions for all measures. Experiment 3 investigated the effects of simulated malingering in 50 subjects: 42% of simulated malingerers produced abnormal (p< 0.05) minSOA z-scores. Simulated malingerers with abnormal scores were distinguished with 87% sensitivity and 69% specificity from control subjects with abnormal scores by excessive differences between training performance and the actual test. Experiment 4 investigated patients with traumatic brain injury (TBI): patients with mild TBI performed within the normal range while patients with severe TBI showed deficits. The DA-PASAT reduces the time and stress of PASAT assessment while gathering sensitive measures of dyad processing that reveal the effects of aging, malingering, and traumatic brain injury on performance.

The paced auditory serial addition test for working memory assessment: Psychometric properties

Background: The paced auditory serial addition test (PASAT) was primarily developed to assess the effects of traumatic brain injury on cognitive functioning. Working memory (WM) is one of the most important aspects of cognitive function, and WM impairment is one of the clinically remarkable signs of aphasia. To develop the Persian version of PASAT, an initial version was used in individuals with aphasia (IWA).

Methods: In this study, 25 individuals with aphasia (29-60 years) and 85 controls (18-60 years) were included. PASAT was presented in the form of recorded 61 single-digit numbers (1 to 9). The participants repeatedly added the 2 recent digits. The psychometric properties of PASAT including convergent validity (using the digit memory span tasks), divergent validity (using results in the control group and IWA group), and face validity were investigated. Test-retest reliability was considered as well.

Results: The relationship between the PASAT and digit memory span tests was moderate to strong in the control group (forward digit memory span test: r= 0.52, p< 0.0001; backward digit memory span test: r = 0.48, p< 0.0001). A strong relationship was found in IWA (forward digit memory span test: r= 0.72, p< 0.0001; backward digit memory span test: r= 0.53, p= 0.006). Also, strong testretest reliability (intraclass correlation= 0.95, p< 0.0001) was observed.

Conclusion: According to our results, the PASAT is a valid and reliable test to assess working memory, particularly in IWA. It could be used as a feasible tool for clinical and research applications.

Canadian Normative Data for Minimal Assessment of Cognitive Function in Multiple Sclerosis

OBJECTIVE

The Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) is a consensus-based collection of neuropsychological tests that evaluate cognitive functioning in individuals with multiple sclerosis (MS). The tests are typically scored using each respective published test manual, leaving the examiner to make interpretations from norms derived from different American populations. Given demographic differences, this may lead to misinterpretation of findings in Canadians. Our goal was to establish both discrete and regression-based normative data for the MACFIMS based on a largely co-normed Canadian population to allow for improved psychometric interpretation.

METHODS

MACFIMS data sets were aggregated from across three different Canadian cities (Ottawa, Toronto, and London), yielding a total of 330 healthy control participants from four different studies evaluating cognition in individuals with MS. Given the variety of contributing studies, there was variability in terms of the number of participants completing each measure.

RESULTS

Both age-based discrete normative data and demographically adjusted (sex, age, and education) regression-based formulae were established. The demographic variables varied in their contribution to each MACFIMS test in the regression models, predicting 0 to 18% of the variance.

CONCLUSIONS

Provision of these regression-based formulae will allow for more accurate interpretation of Canadian-derived MACFIMS scores by allowing clinicians to correct for all relevant demographic variables simultaneously, leading to improved clinical decision making for individuals with multiple sclerosis.

The NIH Toolbox Pattern Comparison Processing Speed Test: Normative Data

The NIH Toolbox Pattern Comparison Processing Speed Test was developed to assess processing speed. While initial validation work provides preliminary support for this test in both children and adults, more work is needed to ensure dependability and generalizability. Thus, this replication study examines descriptive data (including age effects), test-retest reliability, and construct validity in n = 4,859 participants ages 3-85 years (matched to 2010 census data). Although the Pattern Comparison was not appropriate for all 3 and 4 years old, by ages 5 and 6, more meaningful scores were apparent. There was evidence for convergent and discriminant validity. There was also a moderate practice effect (i.e., increase of 5.5 points) over a 1-week time frame. Pattern Comparison exhibits a number of strengths: it is appropriate for use across the lifespan (ages 5-85), it is short and easy to administer, and there is support for construct validity.

Cognitive control therapy and transcranial direct current stimulation for depression: a randomized, double-blinded, controlled trial

BACKGROUND

Based on findings that major depressive disorder (MDD) is associated to decreased dorsolateral prefrontal cortical (DLPFC) activity; interventions that increase DLPFC activity might theoretically present antidepressant effects. Two of them are cognitive control therapy (CCT), a neurocognitive intervention that uses computer-based working memory exercises, and transcranial direct current stimulation (tDCS), which delivers weak, electric direct currents over the scalp.

METHODS

We investigated whether tDCS enhanced the effects of CCT in a double-blind trial, in which participants were randomized to sham tDCS and CCT (n=17) vs. active tDCS and CCT (n=20). CCT and tDCS were applied for 10 consecutive workdays. Clinicaltrials.gov identifier: NCT01434836.

RESULTS

Both CCT alone and combined with tDCS ameliorated depressive symptoms after the acute treatment period and at follow-up, with a response rate of approximately 25%. Older patients and those who presented better performance in the task throughout the trial (possibly indicating greater engagement and activation of the DLPFC) had greater depression improvement in the combined treatment group.

LIMITATIONS

Our exploratory findings should be further confirmed in prospective controlled trials.

DISCUSSION

CCT and tDCS combined might be beneficial for older depressed patients, particularly for those who have cognitive resources to adequately learn and improve task performance over time. This combined therapy might be specifically relevant in this subgroup that is more prone to present cognitive decline and prefrontal cortical atrophy.

The Cognitive Reflection Test as a predictor of performance on heuristics-and-biases tasks

The Cognitive Reflection Test (CRT; Frederick, 2005) is designed to measure the tendency to override a prepotent response alternative that is incorrect and to engage in further reflection that leads to the correct response. In this study, we showed that the CRT is a more potent predictor of performance on a wide sample of tasks from the heuristics-and-biases literature than measures of cognitive ability, thinking dispositions, and executive functioning. Although the CRT has a substantial correlation with cognitive ability, a series of regression analyses indicated that the CRT was a unique predictor of performance on heuristics-and-biases tasks. It accounted for substantial additional variance after the other measures of individual differences had been statistically controlled. We conjecture that this is because neither intelligence tests nor measures of executive functioning assess the tendency toward miserly processing in the way that the CRT does. We argue that the CRT is a particularly potent measure of the tendency toward miserly processing because it is a performance measure rather than a self-report measure.

Use of a novel technology for presenting screening measures to detect mild cognitive impairment in elderly patients

BACKGROUND

Available screening tools for mild cognitive impairment (MCI), often a precursor to Alzheimer's disease, are insensitive or not feasible for administration in a busy primary care setting. Display Enhanced TEsting for Cognitive impairment and Traumatic brain injury (DETECT) addresses these issues by creating an immersive environment for the brief administration of neuropsychological (NP) measures.

OBJECTIVE

The aim of this study was to determine if the DETECT cognitive subtests can identify MCI patients as accurately as standard pen and paper NP tests.

METHODS

Twenty patients with MCI recruited from a memory disorders clinic and 20 age-matched controls were given both a full battery of NP tests (standard NP) and the DETECT screen. Logistic regression models were used to determine whether individual tests were predictive of group membership (MCI or control). Demographic variables including age, race, education and gender were adjusted as covariates. Selection methods were used to identify subset models that exhibited maximum discrimination between MCI patients and controls for both testing methods.

RESULTS

Both the standard NP model (C-index = 0.836) and the DETECT model (C-index = 0.865) showed very good discrimination and were not significantly different (p = 0.7323).

CONCLUSION

The DETECT system shows good agreement with standard NP tests and is capable of identifying elderly patients with cognitive impairment.

Race-norming of neuropsychological tests

Recent studies in the United States indicate that some neurologically intact minority groupings perform well below White Americans on neuropsychological tests. This has sparked the production of race-norms, especially for African Americans, that seek to reduce false positive rates (i.e., neurologically intact individuals misdiagnosed with cognitive impairment) in neuropsychological assessments. There are problems with this enterprise including: possible justification for inferior/superior treatment of different racial groupings; unknown effects on false negative rates (i.e., cognitive deficit misdiagnosed as normal); the overlooking of factors possibly responsible for group racial differences (e.g., acculturation); non-scientific and non-operational definitions of race/ethnic groupings; and an impossibly large number of potential race/ethnic groupings for which to generate race-norms. An alternative approach is to use a single set of combined race/ethnic norms and estimate preexisting neuropsychological skill levels by using individual comparison standards. This alternative has been poorly researched, a situation that needs correcting.