Erratum: A Comparison Between the Performances of Verbal and Nonverbal Fluency Tests in Discriminating Between Mild Cognitive Impairments and Alzheimer's Disease Patients and Their Brain Morphological Correlates.

[This corrects the article on p. 17 in vol. 21, PMID: 35154337.].

COVID-19 Vaccination Is Not Associated with Psychiatric Adverse Events: A Meta-Analysis.

Coronavirus disease 2019 (COVID-19) has been a global health problem since December 2019. Vaccination has been widely considered the best way to prevent COVID-19 pandemic, but public concerns about the safety of vaccines remain. There have been many studies reporting adverse events in the vaccinated. However, to date, no meta-analysis of the association of COVID-19 vaccination with psychiatric adverse events has been conducted yet. In this meta-analysis, studies on depression, anxiety and distress after COVID-19 vaccination were searched in the PubMed, Cochrane and Embase from January 2020 to April 2022. The OR of depression in four studies with a total sample size of 462,406 is obtained as 0.88 (95% CI; 0.75, 1.03), and the OR of anxiety as 0.86 (95% CI; 0.71, 1.05). However, there were no statistically significant differences between the groups. The mean difference of distress in two studies was −0.04 (95%CI; −0.05, −0.02; p < 0.0001). As a result of the moderator analysis, married people experienced less depression and anxiety after vaccination, and in White people, depression after vaccination was lower than others. We also found that people with a history of COVID-19 infection were more depressed and anxious after vaccination. We suggest that COVID-19 vaccination was not associated with a worsening of depression and anxiety.

A Comparison Between the Performances of Verbal and Nonverbal Fluency Tests in Discriminating Between Mild Cognitive Impairments and Alzheimer's Disease Patients and Their Brain Morphological Correlates.

BACKGROUND AND PURPOSE: Verbal and nonverbal fluency tests are the conventional methods for examining executive function in the elderly population. However, differences in impairments result in fluency tests in patients with mild cognitive impairments (MCIs) and Alzheimer's disease (AD) and in neural correlates underlying the tests still necessitate concrete evidence. METHODS: We compared the test performances in 27 normal controls, 28 patients with MCI, and 20 with AD, and investigated morphological changes in association with the test performances using structural magnetic imaging. RESULTS: Patients with AD performed poorly across all the fluency tests, and a receiver operating characteristics curve analysis revealed that only category fluency test discriminated all the 3 groups. Association, category, and design fluency tests involved temporal and frontal regions, while letter fluency involved the cerebellum and caudate. CONCLUSIONS: Category fluency is a reliable measure for screening patients with AD and MCI, and this efficacy might be related to morphological correlates that underlie semantic and executive processing.

Effect of Cognitive Training in Fully Immersive Virtual Reality on Visuospatial Function and Frontal-Occipital Functional Connectivity in Predementia: Randomized Controlled Trial.

BACKGROUND: Cognitive training can potentially prevent cognitive decline. However, the results of recent studies using semi-immersive virtual reality (VR)-assisted cognitive training are inconsistent. OBJECTIVE: We aimed to examine the hypothesis that cognitive training using fully immersive VR, which may facilitate visuospatial processes, could improve visuospatial functioning, comprehensive neuropsychological functioning, psychiatric symptoms, and functional connectivity in the visual brain network in predementia. METHODS: Participants over 60 years old with subjective cognitive decline or mild cognitive impairment from a memory clinic were randomly allocated to the VR (n=23) or the control (n=18) group. The VR group participants received multidomain and neuropsychologist-assisted cognitive training in a fully immersive VR environment twice a week for 1 month. The control group participants did not undergo any additional intervention except for their usual therapy such as pharmacotherapy. Participants of both groups were evaluated for cognitive function using face-to-face comprehensive neuropsychological tests, including the Rey-Osterrieth Complex Figure Test (RCFT) copy task; for psychiatric symptoms such as depression, apathy, affect, and quality of life; as well as resting-state functional magnetic resonance imaging (rsfMRI) at baseline and after training. Repeated-measures analysis of variance was used to compare the effect of cognitive training between groups. Seed-to-voxel-based analyses were used to identify the cognitive improvement-related functional connectivity in the visual network of the brain. RESULTS: After VR cognitive training, significant improvement was found in the total score (F1,39=14.69, P=.001) and basic components score of the RCFT copy task (F1,39=9.27, P=.005) compared with those of the control group. The VR group also showed improvements, albeit not significant, in naming ability (F1,39=3.55, P=.07), verbal memory delayed recall (F1,39=3.03, P=.09), and phonemic fluency (F1,39=3.08, P=.09). Improvements in psychiatric symptoms such as apathy (F1,39=7.02, P=.01), affect (F1,39=14.40, P=.001 for positive affect; F1,39=4.23, P=.047 for negative affect), and quality of life (F1,39=4.49, P=.04) were found in the VR group compared to the control group. Improvement in the RCFT copy task was associated with a frontal-occipital functional connectivity increase revealed by rsfMRI in the VR group compared to the control group. CONCLUSIONS: Fully immersive VR cognitive training had positive effects on the visuospatial function, apathy, affect, quality of life, and increased frontal-occipital functional connectivity in older people in a predementia state. Future trials using VR cognitive training with larger sample sizes and more sophisticated designs over a longer duration may reveal greater improvements in cognition, psychiatric symptoms, and brain functional connectivity. TRIAL REGISTRATION: Clinical Research Information Service KCT0005243; https://tinyurl.com/2a4kfasa.

Efficacy of Smart Speaker-Based Metamemory Training in Older Adults: Case-Control Cohort Study.

BACKGROUND: Metamemory training (MMT) is a useful training strategy for improving cognitive functioning in the older adult population. Despite the advantages, there are limitations imposed by location and time constraints. OBJECTIVE: This study aimed to develop a smart speaker-based MMT program and evaluate the efficacy of the program in older adults without cognitive impairment. METHODS: This study used a case-control cohort design. The smart speaker-based MMT program comprised 3 training sessions per day, 5 days a week, for 8 weeks. Each training session took approximately 15 minutes. This program was implemented using smart speakers, not human trainers. All participants completed the Mini-Mental State Examination, Subjective Memory Complaints Questionnaire, Verbal Learning Test, Digit Span Test, fluency tests, and a short-form version of the Geriatric Depression Scale before and after training. RESULTS: A total of 60 subjects (29 in the MMT group and 31 in the control group) participated in the study. The training group showed significant increases in the delayed free recall, digit span forward, digit span backward, and fluency test scores compared with the control group. CONCLUSIONS: This study confirmed the efficacy of smart speaker-based MMT in older adults. Home-based smart speaker-based MMT is not limited with respect to location or constrained by space and may help older adults with subjective cognitive decline without requiring intervention by human professionals.

Cognitive Improvement in Older Adults with Mild Cognitive Impairment: Evidence from a Multi-Strategic Metamemory Training.

Intervention programs to relieve memory impairment and memory-related complaints in older adults with mild cognitive impairment are needed. Objective: The purpose of the current study was to assess the efficacy of a novel cognitive training approach-named multi-strategic metamemory training-in older adults with amnestic mild cognitive impairment. Among a total of 113 older adults with mild cognitive impairment, 66 participated in the memory training program (training group) and 47 did not (control group). Repeated measures of analysis of variance revealed that compared with the control group, the training group experienced: i) a significantly greater increase in cognitive test scores of long-term delayed free recall (Finteraction = 6.04, p = .016) and fluency (Finteraction = 4.11, p = .045) and ii) significantly greater decrease in their subjective memory complaints for everyday memory (Finteraction = 7.35, p = .009). These results suggest that the training program can improve verbal memory (i.e., delayed free recall), language processing (i.e., categorical fluency) and limit complaints in everyday instrumental memory activities of mildly impaired older adults.

Interactions between subjective memory complaint and objective cognitive deficit on memory performances.

BACKGROUND: Subjective memory complaint (SMCs) is a common trait amongst older population. The subjective cognition about their memory could depend on objective cognition. The aim of the current study was to examine the interaction between subjective memory cognition (i.e., SMC) and objective cognition on cognitive functions in participants from older generation. METHODS: A total of 219 patients, 181 normal control (NC) patients and 38 patients with mild cognitive impairment (MCI), were examined through standardized and comprehensive clinical evaluation and neuropsychological assessment. The Subjective Memory Complaints Questionnaire was used to assess SMCs along with five cognitive tasks were used to evaluate cognitive decline over following areas: verbal memory, visuospatial memory, attention, fluency, and language. RESULTS: The results of 2 × 2 two-way analysis of variance (ANOVA) showed that there were significant interactions between SMCs and cognitive status (NC, MCI) on memory performances. NC with SMCs showed significantly lower performance in verbal memory and visuospatial memory compared to NCs without SMCs. Conversely, no effect was observed in the MCI group. CONCLUSION: There are interactions between subjective cognition (i.e., SMC) and objective cognition (i.e., cognitive status) on memory performances in older adults. The roles of SMCs on memory performances should be interpreted with older adults' objective cognitive status.

Corrigendum: Behavioral and Neuroimaging Evidence for Facial Emotion Recognition in Elderly Korean Adults with Mild Cognitive Impairment, Alzheimer's Disease, and Frontotemporal Dementia.

[This corrects the article DOI: 10.3389/fnagi.2017.00389.].

Brain structural changes after multi-strategic metamemory training in older adults with subjective memory complaints: A randomized controlled trial.

BACKGROUND: Metamemory is the process of monitoring and controlling one's memory. Improving metamemory may reduce the memory problem in old age. We hypothesized that metamemory training (MMT) would improve cognition in older adults with subjective memory complaints and change the brain region related to metacognition. METHOD: We recruited and randomized older adults to the multi-strategic memory training of 10 weekly 90-min sessions, based on the metamemory concept or usual care. Cognitive tests including the Elderly Verbal Learning Test, Simple Rey Figure Test, Digit Span, Spatial Span, Categorical Fluency, and the Boston Naming Test were done in 201 participants, together with magnetic resonance imaging (MRI) in 49 participants before and after training. RESULTS: A total of 112 in the training group and 89 in the control group participated. The training group had a significant increase in long-term delayed free recall, categorical fluency, and the Boston Naming test. In MRI, the mean diffusivity of the bundles of axon tracts passing from the frontal lobe to the posterior end of the lateral sulcus decreased in the training group. CONCLUSION: These results indicate that the MMT program has a positive impact on enhancing older people' cognitive performance. Improved white matter integrity in the anterior and posterior cerebrum and increased cortical thickness of prefrontal regions, which related to metacognition, possibly suggest that the effects of the MMT would be induced via the enhancement of cognitive control.

A quick test of cognitive speed in older adults with Alzheimer's disease and mild cognitive impairment: A preliminary behavioral and brain imaging study.

The purpose of this study was to assess scores and processing speed distributions of the instrument, A Quick Test of Cognitive Speed (AQT), in Korean older adults through behavioral and brain imaging approaches. Participants were instructed to say the color names, stimuli's form, and both the color and form. Test scores and processing speeds were measured in these three subtests of color, form, and color-form. A total of 67 patients (22 healthy controls (HC), 22 with mild cognitive impairment (MCI), and 23 with Alzheimer's disease (AD)) participated. Only color-form score and processing speed of the three subtests could be used to differentiate AD from MCI and HC. Color-form score showed the largest effects size (partial η2 = 0.268) for distinguishing AD, MCI from HC and ROC curve analysis confirmed a high level of sensitivity (0.857) and specificity (0.826) for discrimination between AD and HC. None of the subtests could differentiate HC from MCI. Voxel-based morphometry analysis of brain structure in 27 participants (9 in each group) revealed that gray matter volume of the middle occipital gyrus and inferior parietal cortex were associated with color-form score. This study suggests preliminary evidence in the clinical utility of the AQT for screening AD in older Korean adults. The color-form score could be implemented for clinical utilization in a very brief time. Furthermore, strong positive correlations between color-form scores and the brain areas responsible for visuospatial working memory corroborate the validity of AQT.

The Mental Health Status and Intellectual Ability of Unwed Mothers Dwelling in Korean Shelter Homes.

Although many unwed mothers have issues concerning mental health and intellectual ability, little research has focused on their mental and cognitive status. Due to the public stigma attached to unwed mothers in South Korea, they tend to conceal their status and are less likely to seek psychiatric and psychological help. In this context, this study aims to assess the current status of their mental health and intellectual characteristics. A total of 48 unwed mothers from two shelter homes in South Korea agreed to participate in the study. We compared the mental health status of these unwed mothers with that of the general female population. Unwed mothers were more likely than those of the general female population to have mood disorders, post traumatic stress disorder (PTSD), alcohol and nicotine use disorders, and attention-deficit hyperactivity disorder (ADHD). Among the 48 unwed mothers, 20 (41.7%) had an IQ of less than 70, and the mean IQ (78.31) was significantly lower than the normalized mean IQ of the general female population. This study confirmed that unwed mothers dwelling in Korean shelter homes are more likely than the general female population to have mental disorders.

Neural predictors of cognitive improvement by multi-strategic memory training based on metamemory in older adults with subjective memory complaints.

Previous studies have indicated that memory training may help older people improve cognition. However, evidence regarding who will benefit from such memory trainings has not been fully discovered yet. Understanding the clinical and neural inter-individual differences for predicting cognitive improvement is important for maximizing the training efficacy of memory-training programs. The purpose of this study was to find the individual characteristics and brain morphological characteristics that predict cognitive improvement after a multi-strategic memory training based on metamemory concept. Among a total of 49 older adults, 39 participated in the memory-training program and 10 did not. All of them underwent brain MRIs at the entry of the training and received the neuropsychological tests twice, before and after the training. Stepwise regression analysis showed that lower years of education predicted cognitive improvement in the training group. In MRI, thinner cortices of precuneus, cuneus and posterior cingulate gyrus and higher white matter anisotropy of the splenium of corpus callosum predicted cognitive improvement in the training group. Old age, lower education level and individual differences in cortical thickness and white matter microstructure of the episodic memory network may predict outcomes following multi-strategic training.

Behavioral and Neuroimaging Evidence for Facial Emotion Recognition in Elderly Korean Adults with Mild Cognitive Impairment, Alzheimer's Disease, and Frontotemporal Dementia.

Background: Facial emotion recognition (FER) is impaired in individuals with frontotemporal dementia (FTD) and Alzheimer's disease (AD) when compared to healthy older adults. Since deficits in emotion recognition are closely related to caregiver burden or social interactions, researchers have fundamental interest in FER performance in patients with dementia. Purpose: The purpose of this study was to identify the performance profiles of six facial emotions (i.e., fear, anger, disgust, sadness, surprise, and happiness) and neutral faces measured among Korean healthy control (HCs), and those with mild cognitive impairment (MCI), AD, and FTD. Additionally, the neuroanatomical correlates of facial emotions were investigated. Methods: A total of 110 (33 HC, 32 MCI, 32 AD, 13 FTD) older adult participants were recruited from two different medical centers in metropolitan areas of South Korea. These individuals underwent an FER test that was used to assess the recognition of emotions or absence of emotion (neutral) in 35 facial stimuli. Repeated measures two-way analyses of variance were used to examine the distinct profiles of emotional recognition among the four groups. We also performed brain imaging and voxel-based morphometry (VBM) on the participants to examine the associations between FER scores and gray matter volume. Results: The mean score of negative emotion recognition (i.e., fear, anger, disgust, and sadness) clearly discriminated FTD participants from individuals with MCI and AD and HC [F(3,106) = 10.829, p < 0.001, η2 = 0.235], whereas the mean score of positive emotion recognition (i.e., surprise and happiness) did not. A VBM analysis showed negative emotions were correlated with gray matter volume of anterior temporal regions, whereas positive emotions were related to gray matter volume of fronto-parietal regions. Conclusion: Impairment of negative FER in patients with FTD is cross-cultural. The discrete neural correlates of FER indicate that emotional recognition processing is a multi-modal system in the brain. Focusing on the negative emotion recognition is a more effective way to discriminate healthy aging, MCI, and AD from FTD in older Korean adults.

Development and Validation of the Rappel Indicé-24: Behavioral and Brain Morphological Evidence.

The primary goals of the present study were to develop and validate the Rappel Indicé 24 (RI-24), a shorter version of the original Rappel Indicé, which includes 48 items (RI-48), and to identify the specific brain regions that were correlated with scores on the RI-24. Using these clinical scales, the present study evaluated 91 elderly Korean participants who were classified into 3 groups: normal control (NC; n = 34), patients with mild cognitive impairment (MCI; n = 29), and patients with Alzheimer disease (AD; n = 28). Of the 91 participants, 77 also underwent magnetic resonance imaging scans. The RI-24 delayed cued recall (DCR) scores significantly differed among the NC, MCI, and AD groups. A receiver-operating characteristic curve analysis revealed that the RI-24 was very sensitive (89%) and specific (91%) for the detection of AD. Furthermore, although the time needed to administer the RI-24 was half that needed for the RI-48, the 24-item version showed a high correlation (r= .85 for the DCR score) with the 48-item version. In terms of brain morphological characteristics, voxel-based morphometry analyses revealed a significant positive correlation between DCR score and gray matter volume in the parahippocampal gyrus (r= .468), which plays a role in cued recall. Taken together, the present findings indicate that the RI-24 is a sensitive and reliable test for the detection of memory impairments in patients with MCI and AD despite its brief administration time.

The Korean Size/Weight Attribute Test: A Semantic Knowledge Test for Korean Older Adults and Brain-Imaging Evidence.

BACKGROUND: A standardized tool for evaluating semantic knowledge of the Korean population is needed. OBJECTIVE: The purpose of this study was to develop a neuropsychological test for the evaluation of semantic knowledge in the Korean elderly population. METHODS: The Korean version of the Size/Weight Attribute Test (SWAT-K) was developed in reference to the original version. The diagnostic validity of SWAT-K was evaluated with 95 elderly outpatients [67 normal controls; 18 with Alzheimer's disease (AD); 10 with semantic-variant progressive aphasia (SV-PPA)]. Voxel-based morphometry (VBM) was employed to examine associations between SWAT-K scores and morphological changes of the brain. RESULTS: SWAT-K could discriminate the three subject groups (normal >AD, p <  0.001; AD >SV-PPA, p = 0.040), whereas Boston Naming Test could not distinguish SV-PPA from AD. ROC curve analysis confirmed high levels of sensitivity (0.90) and specificity (0.93) for SWAT-K. The test's inter-rater reliability (ICC = 0.827) and test-retest reliability (ICC = 0.666) were assessed as well. VBM found a significant positive correlation (uncorrected p <  0.005, k >  100) between SWAT-K scores and gray matter volume in right inferior frontal cortex (T = 4.08, k = 191) and bilateral temporal cortices (left, T = 4.42, k = 135; right, T = 3.55, k = 253), the areas the most affected in SV-PPA. CONCLUSIONS: SWAT-K is a sensitive and reliable test for evaluating semantic knowledge in the Korean elderly population. Strong positive correlations between SWAT-K scores and the brain areas responsible for semantic processing further corroborate the validity of SWAT-K.

Differentiating illiteracy from Alzheimer's disease by using neuropsychological assessments.

BACKGROUND: In Asia, where illiteracy rates are high, determining the degree to which neuropsychological measures can be used to identify cognitive impairment in illiterate elders is important. The aim of this study was to evaluate the effectiveness of using formal neuropsychological assessments to distinguish healthy illiterate elders from dementia patients. METHODS: We compared the cognitive performance of healthy elders who were illiterate (illiterate NC, n = 25) with those who were literate (literate NC, n = 25), literate patients with mild Alzheimer's disease (literate AD, n = 25), and illiterate patients with mild AD (illiterate AD, n = 25). Neuropsychological measures included the Mini-Mental State Examination (MMSE), the verbal fluency test, the Boston naming test, the Rosen drawing test, and the verbal learning test. RESULTS: In the between-group analyses, the scores on all tests, except verbal fluency and recognition memory, were lower for illiterate NC compared to the literate NC. The scores on the MMSE, Boston naming test, Rosen drawing test, and immediate free recall could not distinguish the illiterate NC from literate AD. However, the scores on all tests, except the Rosen drawing test, could distinguish illiterate NC from illiterate AD. ROC analyses showed the same pattern of results. In addition, age-, sex-, and education-matched cut-off scores of all tests, except immediate recall and delayed recall trials of the verbal learning test, showed good specificities in participants who were illiterate compared to those in participants who were literate. CONCLUSION: These findings suggest that the impact of literacy on neuropsychological test performance is an important aspect of cognitive evaluations for elders who are illiterate.

Multistrategic memory training with the metamemory concept in healthy older adults.

OBJECTIVE: According to the increase of older people, the need for effective methods to maintain or improve cognitive functions in the elderly has increased. These cognitive enhancing methods may contribute to the prevention of elderly cognitive decline by aging and dementing illness as well. This study aimed to examine the effectiveness of multistrategic memory training with the metamemory concept on cognitive functions in the normal health elderly in Korea. METHODS: The program used in this study was developed by psychiatrists and psychologists in accordance with Korean situations. We applied the training program to the community-dwelling elderly with subjective memory complaints. Twenty participants were randomly received the intervention with 20 non-treatment controls. This program consisted of 10 sessions and was administered once a week. We examined the effects of this memory training for verbal memory, visuospatial memory, working memory, and verbal fluency ability by repeated ANOVA. RESULTS: There were significant improvements in Word List Short-term Delayed Free and Cued Recall, Word list Long-term Delayed Free and Cued Recall and visuospatial recognition memory. Performance improvements in visuospatial span forwards and the Categorical Fluency Test were also significant. These improvements were still significant after adjusting for depression improvement exact categorical fluency. CONCLUSION: This study shows that multistrategic memory training with the metamemory concept may improve memory ability and other cognitive functions which are not trained and that these improvements may be achieved by pure cognitive training effects.

Brief screening for mild cognitive impairment in elderly outpatient clinic: validation of the Korean version of the Montreal Cognitive Assessment.

The Montreal Cognitive Assessment (MoCA) is a brief cognitive screening tool with high sensitivity for screening patients with mild cognitive impairment (MCI). The authors examined the validity and reliability of the Korean version of the MoCA (MoCA-K) in elderly outpatients. The MoCA-K, a Korean version of the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR) scale, and neuropsychological batteries were administered to 196 elderly persons (mild Alzheimer's disease [AD] = 44, MCI = 37, normal controls [NC] = 115). MoCA-K scores were highly correlated with those of MMSE and CDR. Using a cutoff score of 22/23, the MoCA-K had an excellent sensitivity of 89% and a good specificity of 84% for screening MCI. Internal consistency and test-retest reliability were good. The results obtained show that the MoCA-K is brief, reliable, and suitable for use as a screening tool to screen MCI patients in elderly outpatient clinic settings.