Kia Timata Pai (Best Start): a study protocol for a cluster randomised trial with early childhood teachers to support children's oral language and self-regulation development.

INTRODUCTION: Oral language skills are associated with children's later self-regulation and academic skills; in turn, self-regulation in early childhood predicts successful functioning later in life. The primary objective of this study is to evaluate the separate and combined effectiveness of an oral language intervention (Enhancing Rich Conversations, ENRICH) and a self-regulation intervention (Enhancing Neurocognitive Growth with the Aid of Games and Exercise, ENGAGE) with early childhood teachers and parents for children's oral language, self-regulation and academic functioning. METHODS AND ANALYSIS: The Kia Timata Pai (Best Start) study is a cluster randomised controlled trial with teachers and children in approximately 140 early childhood centres in New Zealand. Centres are randomly assigned to receive either oral language intervention only (ENRICH), self-regulation intervention only (ENGAGE), both interventions (ENRICH+ENGAGE) or an active control condition. Teachers' and parents' practices and children's oral language and self-regulation development are assessed at baseline at age 1.5 years and approximately every 9 months to age 5, and academic performance at age 6. Teacher-child interactions will also be videotaped each year in a subset of the centres. Children's brain and behaviour development and parent-child interactions will be assessed every 6 months to age 6 years in a subgroup of volunteers. ETHICS AND DISSEMINATION: The Kia Timata Pai trial and the two substudies (Video Project; Brain and Behaviour Development) have been approved by the University of Otago Human Ethics Committee (Health; H20/116), and reviewed for cultural responsiveness by: the Ngai Tahu Research Committee (University of Otago), the Maori Advisory Group (University of Auckland, Liggins Institute) and an internal cultural advisory group. Results will be disseminated in international and national peer-reviewed academic journals and communicated to local, national and international organisations serving early childhood teachers, parents and young children. Data will be available via communication with the corresponding author. TRIAL REGISTRATION NUMBER: ACTRN12621000845831.

Fear of COVID-19 is associated with trust, subjective numeracy, and differentially with loneliness in older versus younger adults.

Introduction: The emotional impacts of the COVID-19 pandemic and resulting public health emergency are only beginning to be understood. Methods: We assessed the contributions of emotional and cognitive factors and age-related comorbidities to greater COVID-19 fear in a community dwelling sample of 142 younger (Mage = 19.63, SDage = 2.59) and 157 older (Mage = 72.01, SDage = 7.06) adults, between July 2020 and July 2021. We hypothesized that individuals with increased loneliness, depression, and/or decreased subjective numeracy (SN) and interpersonal trust would experience more COVID-19 fear. We also predicted that females and older adults would experience more COVID-19 fear given that age-related comorbidities are associated with increased illness severity. Results: Results showed that the extent of loneliness in older adults was more strongly related to fear of COVID-19 than it was in younger adults (ß = 0.197, p = 0.016), and poorer SN was associated with increased COVID-19 fear in both age groups (ß = -0.138, p = 0.016). Further, higher interpersonal mistrust was associated with increased COVID-19 fear (ß = 0.136, p = 0.039), as was identifying as female (ß = 0.137, p = 0.013). Discussion: Given that self-described poor numeracy was a marker for greater COVID-19 fear, investigators and policy makers might consider mitigation opportunities addressing data literacy requirements imposed by the media. Further, outreach to mitigate loneliness, particularly of the elderly, might effectively lessen the negative psychological impact of this ongoing public health crisis.

The benefits of simultaneous tDCS and working memory training on transfer outcomes: A systematic review and meta-analysis.

BACKGROUND: Transcranial direct current stimulation (tDCS) has shown potential as an effective aid to facilitate learning. A popular application of this technology has been in combination with working memory training (WMT) in order to enhance transfer effects to other cognitive measures after training. OBJECTIVE: This meta-analytic review aims to synthesize the existing literature on tDCS-enhanced WMT to quantify the extent to which tDCS can improve performance on transfer tasks after training. Furthermore, we were interested to evaluate the moderating effects of assessment time point (immediate post-test vs. follow-up) and transfer distance, i.e., the degree of similarity between transfer and training tasks. METHODS: Using robust variance estimation, we performed a systematic meta-analysis of all studies to date that compared WMT with tDCS to WMT with sham in healthy adults. All procedures conformed to PRISMA guidelines. RESULTS: Across 265 transfer measures in 18 studies, we found a small positive net effect of tDCS on improving overall performance on transfer measures after WMT. These effects were sustained at follow-up, which ranged from 1 week to one year after training, with a median of 1 month. Additionally, although there were no significant differences as a function of transfer distance, effects were most pronounced for non-trained working memory tasks. CONCLUSIONS: This review provides evidence that tDCS can be effective in promoting learning over and above WMT alone, and can durably improve performance on trained and untrained measures for weeks to months after the initial training and stimulation period. In particular, boosting performance on dissimilar working memory tasks may present the most promising target for tDCS-augmented WMT.

Functional Field of View Determined by Crowding, Aging, or Glaucoma Under Divided Attention.

Purpose: Parafoveal or peripheral vision is important for various everyday activities. This is particularly relevant to those who suffer from visual field defects. Here we quantified the effect of visual crowding, normal aging, and glaucoma on the spatial extent of the functional field of view (FFV) under divided attention. Methods: Unlike visual acuity measured by single-letter recognition or visual perimetry measured by light spot detection, we measured the FFV using a target letter presented either alone or in letter triplets appearing across the visual field. A subject's task was to report whether the target letter was the same as the letter displayed concurrently at the central fixation region (i.e., divided attention task). Over the trials, a plot of the proportion correct for letter recognition versus target location was constructed, resulting in a visual field map. Results: The results obtained from three subject groups-normal young adults, normal older adults, and patients with glaucoma-showed that on average the central 20° visual field was relatively robust to uncrowded target recognition under divided attention. However, the FFV shrunk down to the central 10° visual field when the target appeared in clutter, suggesting a strong crowding effect on FFV. An additional shrinkage of the FFV occurred in the presence of aging and glaucoma. Conclusions: Using a quantitative method, we demonstrate that crowding, aging, and glaucoma independently decrease the spatial extent of FFV under divided attention and that crowding seems to be the major contributor limiting FFV. Translational Relevance: Our FFV test may complement standard clinical measurements by providing functionally relevant visual field information.

The Effect of Mental Fatigue and Gender on Working Memory Performance during Repeated Practice by Young and Older Adults.

Working memory (WM) is one of the most investigated cognitive functions albeit the extent to which individual characteristics impact on performance is still unclear, especially when older adults are involved. The present study considers repeated practice of a visual N-Back task with three difficulty levels (1-, 2-, and 3-Back) in healthy young and older individuals. Our results reveal that, for both age groups, the expected mental fatigue was countered by a learning effect, in terms of accuracies and reaction times, which turned out to benefit females more than males, for all three N-Back levels. We conclude that future WM studies, in particular when relying on repeated N-Back sessions, should account for learning effects in relation to mental fatigue and gender, in both young and older adults.

N-Back Related ERPs Depend on Stimulus Type, Task Structure, Pre-processing, and Lab Factors.

The N-Back, a common working memory (WM) updating task, is increasingly used in basic and applied psychological research. As such, an increasing number of electroencephalogram (EEG) studies have sought to identify the electrophysiological signatures of N-Back task performance. However, stimulus type, task structure, pre-processing methods, and differences in the laboratory environment, including the EEG recording setup employed, greatly vary across studies, which in turn may introduce inconsistencies in the obtained results. Here we address this issue by conducting nine different variations of an N-Back task manipulating stimulus type and task structure. Furthermore, we explored the effect of the pre-processing method used and differences in the laboratory environment. Results reveal significant differences in behavioral and electrophysiological signatures in response to N-Back stimulus type, task structure, pre-processing method, and laboratory environment. In conclusion, we suggest that experimental factors, analysis pipeline, and laboratory differences, which are often ignored in the literature, need to be accounted for when interpreting findings and making comparisons across studies.

Differential Impact of Cognitive Impairment in MCI Patients: A Case-Based Report.

Mild cognitive impairment (MCI) traditionally refers to an intermediate stage between healthy individuals and early Alzheimer disease. Evidence shows grey and white matter volume changes and decrease in several executive functions, albeit the relation between cognitive performance and brain volume remains unclear. Here, we discuss 3 individual cases of MCI by investigating their MRI scans and cognitive test performance. We also recruited age-matched healthy older adults serving as gold standard for both grey and white matter volume and cognitive test outcomes. Our results show the impact of cognitive impairment on cognitive test performance and grey and white matter volumes, and the role played by cognitive and brain reserve on mitigating cognitive decline. Furthermore, we add evidence to previous studies by showing an increase in white matter volume compared to healthy controls, in all 3 patients. This pattern of increased white matter volume might help us to better understand the pathological mechanisms underlying MCI which in turn could contribute to future investigations.

Single-Trial EEG Responses Classified Using Latency Features.

Covert attention has been repeatedly shown to impact on EEG responses after single and repeated practice sessions. Machine learning techniques are increasingly adopted to classify single-trial EEG responses thereby primarily relying on amplitude-based features instead of latency-based features. In this study, we investigated changes in EEG response signatures of nine healthy older subjects when performing 10 sessions of covert attention training. We show that, when we trained classifiers to distinguish recorded EEG patterns between the two experimental conditions (a target stimulus is "present" or "not present"), latency-based classifiers outperform the amplitude-based ones and that classification accuracy improved along with behavioral accuracy, providing supportive evidence of brain plasticity.

Divergent Research Methods Limit Understanding of Working Memory Training.

Working memory training has been a hot topic over the last decade. Although studies show benefits in trained and untrained tasks as a function of training, there is an ongoing debate on the efficacy of working memory training. There have been numerous meta-analyses put forth to the field, some finding overall broad transfer effects while others do not. However, discussion of this research typically overlooks specific qualities of the training and transfer tasks. As such, there has been next to no discussion in the literature on what training and transfer tasks features are likely to mediate training outcomes. To address this gap, here, we characterized the broad diversity of features employed in N-back training tasks and outcome measures in published working memory training studies. Extant meta-analyses have not taken into account the diversity of methodology at this level, primarily because there are too few studies using common methods to allow for a robust meta-analysis. We suggest that these limitations preclude strong conclusions from published data. In order to advance research on working memory training, and in particular, N-back training, more studies are needed that systematically compare training features and use common outcome measures to assess transfer effects.

Mental workload of young and older adults gauged with ERPs and spectral power during N-Back task performance.

Mental workload has been shown to correlate with alpha and theta band power but only few EEG studies focused on the relation between these bands and Event Related Potentials (ERPs), more specifically the P300 component. We report on an EEG study on mental workload where not only young but also older adults performed an N-Back task. Participants watched a sequence of visual pictures and indicated whether the current picture was the same as the one shown N pictures before. We considered N = 4 difficulty levels and analyzed the relation between these and P300 amplitude and theta and alpha band power, and also examined the effect of age, level of education, work activities, and task accuracy. Our results revealed a decrease in P300 amplitude and alpha band activity for higher difficulty levels for young adults in the parietal region. However, for older adults, fatigue played a more important role than we could anticipate as the alpha band power increased for the highest task difficulty level, and since performance accuracy also decreased, it could even be a sign of task disengagement. Beside alpha band, theta band activity showed a positive correlation with task difficulty level for both young and older adults. Additionally, we found higher P300 amplitudes for young adults compared to older adults, in line with their higher performance accuracies and lower reaction times. In conclusion, we showed that P300 amplitude and alpha and theta bands power provide complementary information for judging mental workload during N-Back performance for young and older subjects and for detecting mental fatigue and task disengagement.

P300, Gray Matter Volume and Individual Characteristics Correlates in Healthy Elderly.

We investigated whether P300-ERP and cognitive test performance differ for age, sex, and education in two groups of healthy elderly, and verified whether any correlations exist between P300 amplitude and latency and gray matter volume using whole brain voxel-by-voxel-based mapping, controlling for age, education, sex and Total Intracranial Volume (TIV). We used 32 channel electroencephalograms (EEG) to record the P300 responses and 3T Magnetic Resonance Imaging (MRI) to determine gray matter volume. We recruited 36 native-Dutch speaking healthy older subjects, equally divided in two sub-groups of 52-64 and 65-76 years old, administered a battery of cognitive tests and recorded their demographics, EEGs and task performance; additionally, 16 adults from the second sub-group underwent an MRI scan. We found significant differences between age groups in their cognitive tests performance, P300 amplitudes for the frontal and parietal electrodes for the most difficult task, and P300 latencies for frontal, central and parietal electrodes for all three tasks difficulty levels. Interesting, sex and education affected cognitive and P300 results. Higher education was related to higher accuracy, and P300 amplitudes and shorter latencies. Moreover, females exhibited higher P300 amplitudes and shorter latencies, and better cognitive tasks performance compared to males. Additionally, for the 16 adults underwent to MRI scan, we found positive correlations between P300 characteristics in frontal, central and parietal areas and gray matter volume, controlling for demographic variables and TIV, but also showing that age, sex, and education correlate with gray matter volume. These findings provide support that age, sex, and education affect an individual's cognitive, neurophysiological and structural characteristics, and therefore motivate the need to further investigate these in relation to P300 responses and gray matter volume in healthy elderly.

Identifying brain changes related to cognitive aging using VBM and visual rating scales.

Aging is often associated with changes in brain structures as well as in cognitive functions. Structural changes can be visualized with Magnetic Resonance Imaging (MRI) using voxel-based grey matter morphometry (VBM) and visual rating scales to assess atrophy level. Several MRI studies have shown that possible neural correlates of cognitive changes can be seen in normal aging. It is still not fully understood how cognitive function as measured by tests and demographic factors are related to brain changes in the MRI. We recruited 55 healthy elderly subjects aged 50-79 years. A battery of cognitive tests was administered to all subjects prior to MRI scanning. Our aim was to assess correlations between age, sex, education, cognitive test performance, and the said two MRI-based measures. Our results show significant differences in VBM grey matter volume for education level (≤ 12 vs. > 12 years), with a smaller amount of grey matter volume in subjects with lower educational levels, and for age in interaction with education, indicating larger grey matter volume for young, higher educated adults. Also, grey matter volume was found to be correlated with working memory function (Digit Span Backward). Furthermore, significant positive correlations were found between visual ratings and both age and education, showing larger atrophy levels with increasing age and decreasing level of education. These findings provide supportive evidence that MRI-VBM detects structural differences for education level, and correlates with educational level and age, and working memory task performance.

N-back training and transfer effects revealed by behavioral responses and EEG.

INTRODUCTION: Cognitive function performance decreases in older individuals compared to young adults. To curb this decline, cognitive training is applied, but it is not clear whether it improves only the trained task or also other cognitive functions. To investigate this, we considered an N-back working memory (WM) training task and verified whether it improves both trained WM and untrained cognitive functions. METHODS: As EEG studies have noted task difficulty and age-related changes in time-locked EEG responses, called event-related potentials (ERPs), we focused on the relation between the P300 ERP component, task difficulty level, and behavior response accuracy and reaction time (RT) in young and older healthy adults. We used two groups of young and older healthy participants to assess the effect of N-back training: cognitive training group (CTG) and passive control group (PCG). Before and after training, cognitive tests were administered to both groups to evaluate transfer effects. RESULTS: Despite the observed age-related differences in the P300 ERP component and in terms of RT and accuracy, our findings demonstrate a stronger improvement in the trained task for older CTGs compared to younger CTGs, larger near- and far-transfer effect to WM and fluid intelligence for both younger and older CTGs, and a far-transfer effect to attention but only for older adults. Significant differences in response accuracy were shown between young and older subjects in spatial memory and attention tests. CONCLUSION: The application of a WM training is a promising tool for both healthy adults, and in particular for older subjects, as it showed physiological and behavioral differences in cognitive plasticity across life span and evidence of benefits in the trained task and near-/far-transfer effects to other cognitive functions.