Visual determinants of reduced performance on the Stroop color-word test in normal aging individuals

Elderly Individuals Residing in Nursing Homes in Western Romania Who Have Been Diagnosed with Hearing Loss are at a Higher Risk of Experiencing Cognitive Impairment

Purpose

The objective of this research was to determine if there is any correlation between the severity of neurocognitive disorder and hearing impairment in the elderly.

Patients and Methods

This is a population-based observational study that included subjects aged ≥ 65 years. They were evaluated for the existence of cardiovascular risk factors, diabetes, stroke, alcohol abuse, and smoking. Hearing impairment was diagnosed by an audiologist, using behavioral audiometric examination. These evaluations might have been performed in response to concerns about hearing loss, or they could have been a routine component of yearly comprehensive health screenings that included a Mini-Mental State Examination 2nd Edition (MMSE-2) test. According to the results of the MMSE-2 scale, we divided the individuals into two groups, Group I for those who had cognitive impairment and severe neurocognitive disorder, and Group II for those who did not have cognitive impairment.

Results

The study enrolled 203 patients with a mean age of 77 ± 7.5 years (range 65-98), 99 (48%) were males. When comparing the two groups, group I patients presented more often cardiovascular risk factors, stroke, diabetes, and impaired hearing. The univariable logistic regression found that cognitive impairment was significantly more frequent in the elderly with cardiovascular disease, diabetes, and stroke (p<0.0001). The multivariate regression analysis found that stroke (p<0.0001) diabetes (p=0.0008), cardiovascular disease (p=0.0004), and impaired hearing (p=0.0011) were significantly linked to cognitive impairment. The occurrence of hearing impairment in the elderly was related to having an MMSE-2 score of 14 or below.

Conclusion

According to the findings of this research, the elderly who have trouble hearing in addition to other conditions might have an increased risk for severe neurocognitive disorder.

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

INTRODUCTION

The 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.

METHODS

This 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.

RESULTS

The 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.

CONCLUSIONS

We 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.

Longitudinal Changes in Hearing and Visual Impairments and Risk of Dementia in Older Adults in the United States

IMPORTANCE

Hearing and vision problems are individually associated with increased dementia risk, but the impact of having concurrent hearing and vision deficits, ie, dual sensory impairment (DSI), on risk of dementia, including its major subtypes Alzheimer disease (AD) and vascular dementia (VaD), is not well known.

OBJECTIVE

To evaluate whether DSI is associated with incident dementia in older adults.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study from the Cardiovascular Health Study (CHS) was conducted between 1992 and 1999, with as many as 8 years of follow-up. The multicenter, population-based sample was recruited from Medicare eligibility files in 4 US communities with academic medical centers. Of 5888 participants aged 65 years and older in CHS, 3602 underwent cranial magnetic resonance imaging and completed the modified Mini-Mental State Examination in 1992 to 1994 as part of the CHS Cognition Study. A total of 227 participants were excluded due to prevalent dementia, leaving a total of 3375 participants without dementia at study baseline. The study hypothesis was that DSI would be associated with increased risk of dementia compared with no sensory impairment. The association between the duration of DSI with risk of dementia was also evaluated. Data analysis was conducted from November 2019 to February 2020.

EXPOSURES

Hearing and vision impairments were collected via self-report at baseline and as many as 5 follow-up visits.

MAIN OUTCOMES AND MEASURES

All-cause dementia, AD, and VaD, classified by a multidisciplinary committee using standardized criteria.

RESULTS

A total of 2927 participants with information on hearing and vision at all available study visits were included in the analysis (mean [SD] age, 74.6 [4.8] years; 1704 [58.2%] women; 455 [15.5%] African American or Black; 2472 [85.5%] White). Compared with no sensory impairment, DSI was associated with increased risk of all-cause dementia (hazard ratio [HR], 2.60; 95% CI, 1.66-2.06; P < .001), AD (HR, 3.67; 95% CI, 2.04-6.60; P < .001) but not VaD (HR, 2.03; 95% CI, 1.00-4.09; P = .05).

CONCLUSIONS AND RELEVANCE

In this cohort study, DSI was associated with increased risk of dementia, particularly AD. Evaluation of hearing and vision in older adults may help to identify those at high risk of developing dementia.

An Auditory Stroop Test to Implement in Cognitive Hearing Sciences: Development and Normative Data

Objective:

This study developed and gained insight in an auditory Stroop test, implementable in cognitive hearing sciences.

Methods:

An auditory Stroop test was developed and performed in 178 participants, aged between 18 and 69 years. This Auditory Stroop test consisted of two tests: Stroop-tones and Stroop-words whereby the pitch of pure-tones and spoken words (i.e., the words high and low) had to be identified by high or low, respectively. An interference score was calculated as a measure of verbal executive functioning. Regression models were conducted to examine the effect of age, sex, education, awakeness, hearing, as well as visual and verbal working memory, and processing speed on the auditory Stroop scores. Normative data were obtained per age decade.

Results:

Compared to the visual counterparts, the auditory Stroop outcomes were better predicted by verbal working memory and processing speed. A trend was observed showing a decrease in performances with increasing age. No other participant-related variables had a significant relationship with the auditory Stroop test.

Conclusion:

This auditory Stroop test was considered a good test for measuring executive functioning using auditory stimuli. Implementing this auditory Stroop test within cognitive hearing sciences will contribute to unravel the auditory-cognitive perspective of speech understanding.

UD Interference Test: Creation and validation of a new instrument of resistance to interference. Normalization and standardization for Spanish population

INTRODUCTION

The UD Interference Test measures processing speed and attention, and is based on the concept of interference of the Stroop Test. The main purpose of the study is to provide an alternative version of the Stroop 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.

METHODS

This 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.

RESULTS

The 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 12-40% of variance. Sex only had a significant effect on the resistance to interference index.

CONCLUSIONS

We 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.

Age-Related Deficits in Binocular Vision Are Associated With Poorer Inhibitory Control in Healthy Older Adults

A robust association between reduced visual acuity and cognitive function in older adults has been revealed in large population studies. The aim of this work was to assess the relation between stereoacuity, a key aspect of binocular vision, and inhibitory control, an important component of executive functions. Inhibition was tested using the antisaccade task in older adults with normal or reduced stereopsis (study 1), and in young adults with transiently reduced stereopsis (study 2). Older adults with reduced stereopsis made significantly more errors on the antisaccade task in comparison to those with normal stereopsis. Specifically, there was a significant correlation between stereoacuity and antisaccade errors (r = 0.27, p = 0.019). In contrast, there were no significant differences in antisaccade errors between the normal and reduced stereopsis conditions in the young group. Altogether, results suggest that the association between poorer stereopsis and lower inhibitory control in older adults might arise due to central nervous system impairment that affects the processing of binocular disparity and antisaccades. These results add to a growing body of literature, which highlights the interdependence of sensory and cognitive decline in older adults.

Beta Neurofeedback Training Improves Attentional Control in the Elderly

One of the well-documented behavioral changes that occur with advancing age is a decline in executive functioning, for example, attentional control. Age-related executive deficits are said to be associated with a deterioration of the frontal lobes. Neurofeedback is a training method which aims at acquiring self-control over certain brain activity patterns. It is considered as an effective approach to help improve attentional and self-management capabilities. However, studies evaluating the efficacy of neurofeedback training to boost executive functioning in an elderly population are still relatively rare and controversial. The aim of our study was to contribute to the assessment of the efficacy of neurofeedback as a method for enhancing executive functioning in the elderly. We provided a group of seniors with beta up-training (12-22 Hz), consisting of 20 sessions (30 minutes each), on the Cz site and tested its possible beneficiary influence on attentional control assessed by means of the Stroop and Simon tasks. The analysis of the subjects' mean reaction times during consecutive tasks in the test and the retest, after implementation of neurofeedback training, showed a significant improvement. In contrast, the difference in reaction times between the test and the retest in the control group who had not been submitted to neurofeedback training was not significant.

The effect of cognitive training on the brain's local connectivity organization in healthy older adults

Cognitive training has been shown effective in improving the cognitive function of older adults. While training related plasticity of the brain has been observed at different levels, it is still open to exploration whether local functional connectivity (FC) may be affected by training. Here, we examined the neuroimaging data from a previous randomized-controlled double-blinded behavioural study, in which healthy older adults participated in a 3-month cognitive training program. Resting-state fMRI was acquired at baseline and one year after training. The local FC in the brain was estimated using the regional homogeneity (ReHo), and the high ReHo clusters (HRCs) were extracted to quantify the level of local FC integration. Results showed that: (i) HRCs exhibited a power-law size distribution; (ii) local FC were less integrated in older participants than in younger participants; (iii) local FC in older participants of the training group became more integrated after training than the control group; (iv) the baseline local FC integration was positively correlated with educational level. These results indicated a training-related alteration in local FC.

Effects of Different Cognitive Trainings on Amnestic Mild Cognitive Impairment in the Elderly: A One-Year Longitudinal Functional Magnetic Resonance Imaging (MRI) Study

BACKGROUND Cognitive training has been focused on the interventions of amnestic mild cognitive impairment (aMCI) in recent years, with poor understanding. MATERIAL AND METHODS The study participants with aMCI were screened in a previous intervention trial. Functional magnetic resonance imaging (fMRI) was adopted to investigate effects of single-domain cognitive training (SDCT) and multi-domain cognitive training (MDCT) on aMCI and to explore potential mechanisms. RESULTS There were significant differences in the grey matter volume of the middle frontal gyrus, superior parietal lobule, inferior temporal gyrus, fusiform gyrus, and ventral V3 between the MDCT/SDCT group and the control group (P<0.05). Regional homogeneity (ReHo) increased significantly in the right and left inferior frontal gyrus as well as in the left and right precentral gyrus after intervention in the MDCT group and the SDCT group. ReHo increased significantly in the right and left lingual gyrus of the MDCT group and the control group. ReHo reduced significantly in the right middle temporal gyrus of the MDCT group but increased significantly in the left middle temporal gyrus in the SDCT group and the control group. The voxel of grey matter in the precuneus was positively related to the language scores on RBANS (Repeatable Battery for the Assessment of Neuropsychological Status), and amygdala, fusiform gyrus, and hippocampus also had a positive relationship with delayed memory scores in RBANS of the MDCT group. In the MDCT group, the attention and reasoning scores were also positively related to the ReHo of middle temporal gyrus. CONCLUSIONS Both MDCT and SDCT may improve the aMCI at brain functional and structural levels; however, the MDCT group exhibited higher ReHo values in middle temporal gyrus and superior occipital gyrus. Also, it was confirmed that MDCT leads to better results than SDCT, showing a significant correlation of cognitive functions such as attention, memory, reasoning, and visual-spatial ability.

Protective Role of Recent and Past Long-Term Physical Activity on Age-Related Cognitive Decline: The Moderating Effect of Sex

This study aimed to investigate if the impact of both recent and long-term physical activity on age-related cognitive decline would be modified by sex. One-hundred thirty-five men (N = 67) and women (N = 68) aged 18 to 80 years completed the Modifiable Activity Questionnaire and the Historical Leisure Activity Questionnaire. A composite score of cognitive functions was computed from five experimental tasks. Hierarchical regression analyses performed to test the moderating effect of recent physical activity on age-cognition relationship had not revealed significant result regardless of sex. Conversely, past long-term physical activity was found to slow down the age-related cognitive decline among women (β = 0.22,p = .03), but not men. The findings support a lifecourse approach in identifying determinants of cognitive aging and the importance of taking into account the moderating role of sex. This article presented potential explanations for these moderators and future avenues to explore.

The Victoria Stroop Test: Normative Data in Quebec-French Adults and Elderly

OBJECTIVE

Despite the widespread use of the Victoria Stroop Test (VST; Regard, 1981) in clinical and research settings, information regarding the impact of sociodemographic variables on test performance in Quebec-French adults and elderly people is still nonexistent. Thus, this study aimed to establish normative data for error scores and completion time on all test trials (Dot, Word, and Interference) taking into account the impact of age, education, and sex on test performance.

METHOD

The sample consisted of 646 community-dwelling and healthy Quebec-French individuals aged between 47 and 87 years.

RESULTS

Regression analyses indicated that age was associated with completion time and error scores on all trials. The association was also positive for low and high interference conditions. Education was associated with completion time on Word and Interference trials, and with both interference scores. Finally, sex was associated with completion time on all trials, with women being consistently faster than men. Equations to calculate Z scores and percentiles are presented.

CONCLUSIONS

Norms for the VST will ease interpretation of executive functioning in Quebec-French adults and elderly and favor accurate discrimination between normal and pathological cognitive states.

Effects of Cognitive Training on Resting-State Functional Connectivity of Default Mode, Salience, and Central Executive Networks

Neuroimaging studies have documented that aging can disrupt certain higher cognitive systems such as the default mode network (DMN), the salience network and the central executive network (CEN). The effect of cognitive training on higher cognitive systems remains unclear. This study used a 1-year longitudinal design to explore the cognitive training effect on three higher cognitive networks in healthy older adults. The community-living healthy older adults were divided into two groups: the multi-domain cognitive training group (24 sessions of cognitive training over a 3-months period) and the wait-list control group. All subjects underwent cognitive measurements and resting-state functional magnetic resonance imaging scanning at baseline and at 1 year after the training ended. We examined training-related changes in functional connectivity (FC) within and between three networks. Compared with the baseline, we observed maintained or increased FC within all three networks after training. The scans after training also showed maintained anti-correlation of FC between the DMN and CEN compared to the baseline. These findings demonstrated that cognitive training maintained or improved the functional integration within networks and the coupling between the DMN and CEN in older adults. Our findings suggested that multi-domain cognitive training can mitigate the aging-related dysfunction of higher cognitive networks.

The Lateralization of Intrinsic Networks in the Aging Brain Implicates the Effects of Cognitive Training

Lateralization of function is an important organization of the human brain. The distribution of intrinsic networks in the resting brain is strongly related to cognitive function, gender and age. In this study, a longitudinal design with 1 year’s duration was used to evaluate the cognitive training effects on the lateralization of intrinsic networks among healthy older adults. The subjects were divided into two groups randomly: one with multi-domain cognitive training over 3 months and the other as a wait-list control group. Resting state fMRI data were acquired before training and 1 year after training. We analyzed the functional lateralization in 10 common resting state fMRI networks. We observed statically significant training effects on the lateralization of two important RSNs related to high-level cognition: right- and left- frontoparietal networks (FPNs). The lateralization of the left-FPN was retained especially well in the training group but decreased in the control group. The increased lateralization with aging was observed in the cerebellum network (CereN), in which the lateralization was significantly increased in the control group, although the same change tendency was observed in the training group. These findings indicate that the lateralization of the high-level cognitive intrinsic networks is sensitive to multi-domain cognitive training. This study provides neuroimaging evidence to support the hypothesis that cognitive training should have an advantage in preventing cognitive decline in healthy older adults.

Cognitive training can reduce the rate of cognitive aging: a neuroimaging cohort study

BACKGROUND

The neural mechanisms underlying the restorative effects of cognitive training on aging brains remain unclear. To address this issue, we examined the relationship between changes in spontaneous brain activity and cognitive performance that occur after cognitive training.

METHODS

Participants were older adults who were part of a randomized control trial within a larger longitudinal cognitive training study. We conducted single-domain and multi-domain cognitive training in two respective intervention groups. Participants were trained for 1 h, twice a week, for 12 weeks. Cognition was assessed in all participants and magnetic resonance images were obtained at baseline and 1 year after training. To assess spontaneous fluctuations in brain activity, we acquired resting-state fMRI data. Two indices-functional entropy and time-domain entropy-were used to measure the effects of training. Functional entropy increases with aging, and indicates disruptions in functional conectivity. Time-domain entropy decreases with aging, and indicates structural alterations in the brain and blood-flow reduction.

RESULTS

Seventy participants completed the study: 26 in the multi-domain cognitive training group (70.38 ± 3.30 yrs), 27 in single-domain group (70.48 ± 3.93 yrs), and 17 in a control group (68.59 ± 3.24 yrs). Functional entropy increased significantly less in the multi-domain (p = 0.047) and single-domain groups (p = 9.51 × 10(-4)) compared with the control group. In the multi-domain group, this was true in the paracentral lobule (p = 0.004, Bonferroni corrected p < 0.05). Time-domain entropy also improved with training. Compared with controls, time-domain entropy in the multi-domain group decreased less in the inferior frontal gyrus pars opercularis (p = 3.59 × 10(-4)), the medial part of superior frontal gyrus (p = 1.17 × 10(-5)), and the thalamus (p = 4.72 × 10(-5)), while that in the single-domain group decreased less in the cuneus (p = 2.58 × 10(-4), Bonferroni corrected p < 0.05). Additionally, changes in regional entropy for some regions such as hippocampus significantly correlated with improvements in cognitive performance.

CONCLUSIONS

Cognitive training can induce plastic changes in neural functional connectivity of healthy older people, and these changes may underlie the positive effect of cognitive training.

TRIAL REGISTRATION

ChiCTR-TRC-08000732 (Date of registration: 5th November, 2008).

Five-year follow-up study of multi-domain cognitive training for healthy elderly community members

BACKGROUND

Cognitive training, a safe non-pharmacological intervention, may help mitigate cognitive decline and prevent the development of dementia in elderly individuals.

OBJECTIVE

Evaluate the long-term effects of cognitive training among healthy elderly community members.

METHODS

Healthy individuals 70 years of age or older from one urban community in Shanghai were screened and the 151 individuals who met inclusion criteria were assigned either to an intervention group (n=90) or a control group (n=61). The intervention involved twice-weekly training in reasoning, memory, and strategy that continued for 12 weeks (a total of 24 sessions). Participants were assessed at baseline and at 12 weeks, and 5 years after enrollment using the Chinese versions of the Neuropsychological Test Battery for Elderly persons (NTBE), the Stroop Color-Word Test, and a general health questionnaire.

RESULTS

Forty-nine (54%) intervention group subjects and 33 (54%) control group subjects completed the 5-year follow-up. There were few differences in the baseline neurocognitive measures of those who did and did not complete the 5-year follow-up, and there were few differences between those who dropped out of the intervention group compared to those who dropped out of the control group. At the 5-year follow-up, individuals in the intervention group performed better than those in the control group on only 5 measures (in the Trails Making A Test and the Cancellation Test 3) of the 61 measures assessed by NTBE and the Stroop tests, but none of these differences met the pre-determined required level of statistical significance (p=0.0008).

CONCLUSION

We do not confirm the results of previous studies that report long-term benefits of brief cognitive training courses for elderly community residents. Our failure to identify differences in cognitive functioning five years after cognitive training is not likely due to differential dropout between the intervention and control groups but may be related to the relatively small sample and the large number of measures being assessed. Future intervention studies for cognitive training in the elderly should be hypothesis driven (i.e., focused on a single outcome measure of interest), use much larger samples, and include regular booster sessions as part of the cognitive training package.

Prevention of vision loss protects against age-related impairment in learning and memory performance in DBA/2J mice

The DBA/2J mouse is a model of pigmentary glaucoma in humans as it shows age-related increases in intraocular pressure (IOP), retinal ganglion cell death and visual impairment. Previously, we showed that visual ability declines from 9 to 12 months of age and visual impairment is correlated with poor learning and memory performance in visuo-spatial tasks but not in tasks that do not depend on visual cues. To test the “sensory impairment” hypothesis of aging, which postulates that sensory impaired individuals are disadvantaged in their performance on psychometric tests as a direct result of difficulties in sensory perception, we treated DBA/2J mice with a conventional glaucoma medication used in humans (Timoptic-XE, 0.00, 0.25, or 0.50%) daily from 9 weeks to 12 months of age to determine whether prevention of vision loss prevented the decline in visuo-spatial learning and memory performance. At all ages tested (3, 6, 9, and 12 months of age), mice treated with Timoptic-XE (0.25 and 0.50%) maintained a high level of performance, while 12 month old control mice (0.00%) exhibited impaired performance in visually-dependent, but not non-visual tasks. These results demonstrate that when sensory function is preserved, cognitive performance is normalized. Thus, as in many aging humans, DBA/2J mice show age-related decrements in performance on visually presented cognitive tests, not because of cognitive impairment but as a direct consequence of poor visual ability. Our results demonstrate that age-related impairment in performance in visuo-spatial tasks in DBA/2J mice can be prevented by the preservation of visual ability.

Demographically adjusted norms for Catalan older adults on the Stroop Color and Word Test

The Stroop Color and Word Test (SCWT) is a short test that is widely used in neuropsychological assessment to evaluate the executive aspects of attention control, information processing speed, selective attention, cognitive flexibility, and executive function in terms of the ability to inhibit a usual response in favor of an unusual response. The aim of this study was to create normative data from the SCWT adjusted for age, sex, and educational level for its clinical use in a population of 55 years of age and above. The SCWT was administered to a population-based sample of 2,151 participants aged 55 or older, and the effect of sex, age, and educational level was determined in the SCWT by means of linear regression models. Normative tables were created following the traditional method based on the stratification by relevant variables and on regression models.

Age-related visual impairments and perceiving linguistic stimuli: the rarity of assessing the visual abilities of older participants in written language research

BACKGROUND/STUDY CONTEXT: It is well established that declining visual abilities are widespread amongst older adults (aged 65 years and over) and are known to have profound effects on processing a range of visual stimuli. However, the incidence of assessing the visual abilities of older adults participating in written language research using visually presented linguistic stimuli (text, words, letters) is unknown.

METHODS

All 240 articles investigating perception of visually presented linguistic stimuli (text, words, letters) by older participants, published 2000-2010 in the three foremost journals in aging research, Experimental Aging Research, The Journals of Gerontology, Series B, and Psychology and Aging, were examined.

RESULTS

The majority of articles (68.0%) made no mention at all of participants' visual abilities (59.2%) or relied merely on participants' self-report (8.8%). Other articles (17.9%) reported participants' visual abilities without mentioning any assessment, and only 14.2% reported participants' visual abilities following appropriate assessment.

CONCLUSION

The indications are that appropriate assessments of visual abilities are used rarely in language research investigating perception of visually presented linguistic stimuli by older participants. Much greater use and reporting of these assessments is needed to help reveal the processes underlying perception of written language in older populations.

The effects of multi-domain versus single-domain cognitive training in non-demented older people: a randomized controlled trial

BACKGROUND

Whether healthy older people can benefit from cognitive training (CogTr) remains controversial. This study explored the benefits of CogTr in community dwelling, healthy, older adults and compared the effects of single-domain with multi-domain CogTr interventions.

METHODS

A randomized, controlled, 3-month trial of CogTr with double-blind assessments at baseline and immediate, 6-month and 12-month follow-up after training completion was conducted. A total of 270 healthy Chinese older people, 65 to 75 years old, were recruited from the Ganquan-area community in Shanghai. Participants were randomly assigned to three groups: multi-domain CogTr, single-domain CogTr, and a wait-list control group. Twenty-four sessions of CogTr were administrated to the intervention groups over a three-month period. Six months later, three booster training sessions were offered to 60% of the initial training participants. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS, Form A), the Color Word Stroop test (CWST), the Visual Reasoning test and the Trail Making test (TMT) were used to assess cognitive function.

RESULTS

Multi-domain CogTr produced statistically significant training effects on RBANS, visual reasoning, and immediate and delayed memory, while single-domain CogTr showed training effects on RBANS, visual reasoning, word interference, and visuospatial/constructional score (all P < 0.05). At the 12-month posttest, the multi-domain CogTr showed training effects on RBANS, delayed memory and visual reasoning, while single-domain CogTr only showed effects on word interference. Booster training resulted in effects on RBANS, visual reasoning, time of trail making test, and visuospatial/constructional index score.

CONCLUSIONS

Cognitive training can improve memory, visual reasoning, visuospatial construction, attention and neuropsychological status in community-living older people and can help maintain their functioning over time. Multi-domain CogTr enhanced memory proficiency, while single-domain CogTr augmented visuospatial/constructional and attention abilities. Multi-domain CogTr had more advantages in training effect maintenance.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry.

REGISTRATION NUMBER

ChiCTR-TRC-09000732.

Age-related reorganization of functional networks for successful conflict resolution: a combined functional and structural MRI study

Aging has readily observable effects on the ability to resolve conflict between competing stimulus attributes that are likely related to selective structural and functional brain changes. To identify age-related differences in neural circuits subserving conflict processing, we combined structural and functional MRI and a Stroop Match-to-Sample task involving perceptual cueing and repetition to modulate resources in healthy young and older adults. In our Stroop Match-to-Sample task, older adults handled conflict by activating a frontoparietal attention system more than young adults and engaged a visuomotor network more than young adults when processing repetitive conflict and when processing conflict following valid perceptual cueing. By contrast, young adults activated frontal regions more than older adults when processing conflict with perceptual cueing. These differential activation patterns were not correlated with regional gray matter volume despite smaller volumes in older than young adults. Given comparable performance in speed and accuracy of responding between both groups, these data suggest that successful aging is associated with functional reorganization of neural systems to accommodate functionally increasing task demands on perceptual and attentional operations.

The influence of sex-linked genetic mechanisms on attention and impulsivity

It is now generally agreed that there are inherent sex differences in healthy individuals across a number of neurobiological domains (including brain structure, neurochemistry, and cognition). Moreover, there is a burgeoning body of evidence highlighting sex differences within neuropsychiatric populations (in terms of the rates of incidence, clinical features/progression, neurobiology and pathology). Here, we consider the extent to which attention and impulsivity are sexually dimorphic in healthy populations and the extent to which sex might modulate the expression of disorders characterised by abnormalities in attention and/or impulsivity such as attention deficit hyperactivity disorder (ADHD), autism and addiction. We then discuss general genetic mechanisms that might underlie sex differences in attention and impulsivity before focussing on specific positional and functional candidate sex-linked genes that are likely to influence these cognitive processes. Identifying novel sex-modulated molecular targets should ultimately enable us to develop more effective therapies in disorders associated with attentional/impulsive dysfunction.

The relationship between age-related hearing loss and synaptic changes in the hippocampus of C57BL/6J mice

To explore the relationship between age-related hearing loss (presbycusis) and synaptic degeneration in the hippocampal CA3 region of C57BL/6J mice, we investigated both cognitive performance and synaptic changes within the hippocampus of C57BL/6J mice from three age groups of 6-8, 24-26, and 42-44 weeks; CBA/CaJ mice served as controls. The auditory brainstem response was used as a measure of hearing threshold, and cognitive behavior was evaluated using the Morris water maze. The ultrastructure of synapses was observed with transmission electron microscopy, and the quantity and distribution of the synaptic markers synaptophysin and PSD-95 were observed with immunohistochemistry. The hearing threshold of C57BL/6J mice was significantly higher at 24-26 weeks than at 6-8 weeks, and hearing loss was profound at 42-44 weeks. This was accompanied by progressive degeneration of synapses within the auditory cortex. In contrast, the hearing threshold of CBA/CaJ mice was relatively unchanged at 24-26 weeks of age, and these mice developed only mild hearing loss at 42-44 weeks of age. Interestingly, C57BL/6J, but not CBA/CaJ mice clearly exhibited both decreased performance in the Morris water maze and degeneration of synapses within the hippocampus. We therefore conclude that age-related hearing loss is accompanied by the degeneration of synapses in the hippocampal CA3 region of C57BL/6J mice.

Impact of sensory acuity on auditory working memory span in young and older adults

The impact of sensory acuity, processing speed, and working memory capacity on auditory working memory span (L-span) performance at 5 presentation levels was examined in 80 young adults (18-30 years of age) and 26 older adults (60-82 years of age). Lowering the presentation level of the L-span task had a greater detrimental effect on the older adults than on the younger ones. Furthermore, the relationship between sensory acuity and L-span performance varied as a function of age and presentation level. These results suggest that declining acuity plays an important explanatory role in age-related declines in cognitive abilities.

Sex differences in cognitive control are associated with midcingulate and callosal morphology

Sex differences in the processing of cognitively demanding tasks have attracted much attention in recent years. While there seems to be some agreement on differences between males and females concerning spatial abilities and language skills, a consensus regarding executive functions or cognitive control has not been reached yet. In the present study, male and female subjects participated in a lateralized, tactile Stop-Signal task. Although the behavioral data did not show any differences between sexes, event-related potentials pointed to varieties in neurocognitive processing. As inferred from N200 amplitudes, differences between left- and right-hand stimulation suggested a strong degree of functional lateralization in males in accordance with a left-hemispheric dominance. Females, on the other hand, rather seemed to exhibit a functionally symmetric organization of relevant processes. The P300 did also show evidence of sex-related differences, reflecting disparities in the degree or quality of interhemispheric interaction. In addition, behavioral and electrophysiological parameters were correlated with individual metrics concerning the degree of midcingulate folding asymmetry and the morphology of the corpus callosum. Differential associations of these morphological characteristics with the N200 and P300, respectively, underscore the notion of relevant structure-function associations of the midcingulate cortex and the N200 on the one hand, and the corpus callosum and the P300 on the other hand. Obviously, these variations in neuroanatomy contribute to the observed behavioral and electrophysiological differences between women and men.

DEVELOPMENT OF THE INHIBITORY COMPONENT OF THE EXECUTIVE FUNCTIONS IN CHILDREN AND ADOLESCENTS

The development of inhibitory control, one component of the executive functions, during childhood and adolescence was the focus of the present study. A group of 99 participants between 6 and 17 years of age were studied using the Stroop test. Results suggest the existence of age-related differences both in response times and errors that follow a nonlinear relationship. Interference increased in the first age groups, declining from around 10 years till 17 years. Data also suggest that word reading plays an important role in the performance of the task. When reading is blocked, linear relationships between age and interference measures emerge, showing an increase in inhibitory functions during childhood and adolescence.

The stroop effect in Greek healthy population: normative data for the Stroop Neuropsychological Screening Test

The Stroop Test is a quick and frequently used measure in screening for brain damage, dysfunction of selective attention, and cognitive flexibility. The purpose of the present study is to provide normative data for Trenerry's Stroop Neuropsychological Screening Test (SNST) in a sample of 605 healthy Greek participants (age range: 18-84 years, education range: 6-18 years). Results revealed that age and education significantly contributed to SNST scores, accounting for a significant proportion of variance in time needed to complete the color task and in the interference Color-Word score. Performance on most of the measures decreases with increasing age and lower levels of education. Normative data stratified by age and education for the Greek adult population are provided as a useful set of norms for clinical practice.

The impact of blurred vision on cognitive assessment

The purpose of this study was to systematically assess the effect of blurred vision on several nonverbal neuropsychological measures commonly used as part of test batteries to assess the cognitive status of different patient populations. A total of 30 highly educated and healthy participants aged between 21 and 33 years were placed in one of three blurred vision groups, defined by their maximal visual acuity (20/20 or control group, 20/40, and 20/60). Blurred vision was simulated using positive diopters at a distance of 40 cm, the same distance as that at which tests were administered. Each participant was then assessed on a predetermined battery of nonverbal and verbal neuropsychological tests demanding different levels of acuity for optimal performance (i.e., tests whose items varied in terms of size and spatial frequency characteristics). In general, blurred vision significantly affected performance on nonverbal tests defined by small-sized/high-spatial-frequency items to a greater extent than on tests defined by larger sized/lower spatial-frequency items. As expected, blurred vision did not affect verbal test performance (Similarities, Information, and Arithmetic WAIS subtests). Our results are a clear indication of how even a "minimal" loss of visual acuity (20/40) can have a significant effect on the performance for certain nonverbal tests. In conclusion, such inferior performance is hypothetically interpretable as reflecting impaired cognitive functioning (i.e., attentional) targeted by a specific task (i.e., visual search) and suggests that the precision of the cognitive assessment and subsequent diagnosis are significantly biased when visuo-sensory abilities are not optimal, particularly for older patient populations where blurred vision resulting from correctable visual impairment is quite common.

The Relationship Between Visual Contrast Sensitivity and Neuropsychological Performance in a Healthy Elderly Sample

Visual acuity and contrast sensitivity are two visual domains affected by normal aging; however, the potential impact of well-documented changes in these abilities on neuropsychological assessment is relatively unstudied. The current study examined the relationship between these abilities and neuropsychological performance in a healthy, community-based elderly sample. Fifty-one individuals (Age: M = 79.6) were assessed for visual acuity and visual contrast sensitivity, and received a brief neuropsychological battery. Results indicated contrast sensitivity was significantly related to neuropsychological performance on visually based measures, but not auditory measures. Visual acuity was only weakly related to neuropsychological performance. Clinical implications for assessment of elderly individuals are discussed.

Age-related changes in visual acuity, learning and memory in C57BL/6J and DBA/2J mice

The DBA/2J mouse is a model of age-related pigmentary glaucoma in humans. Visual detection, pattern discrimination and visual acuity were evaluated in DBA/2J, C57BL/6J, B6.mpc1d (a C57 congenic strain) and D2.mpc1b (a D2 congenic strain) mice at 6, 12, 18 and 24 months of age. Mice were also tested in the Morris Water Maze and olfactory discrimination learning task. At 6 months, DBA/2J and D2.mpc1b mice outperformed C57BL/6J and B6.mpc1d mice in the visual detection task and there were no strain differences in performance on the water maze. At 12, 18 and 24 months, C57BL/6J and B6.mpc1d mice outperformed DBA/2J and D2.mpc1b mice in the vision tasks and in the water maze. Strains did not differ in the olfactory learning task. Therefore, loss of visual function occurs between 6 and 12 months of age in DBA/2J mice. Strain differences in visual task performance accounted for a significant proportion of the variance in measures of learning and memory in the water maze at 12, 18 and 24 months of age.

The effect of cataract surgery on neuropsychological test performance: a randomized controlled trial

Recent cross-sectional studies have reported strong associations between visual and cognitive function, and longitudinal studies have shown relationships between visual and cognitive decline in late life. Improvement in cognitive performance after cataract surgery has been reported in patients with Mild Cognitive Impairment. We investigated whether improving visual function with cataract surgery would improve neuropsychological performance in healthy older adults. A randomized clinical trial of cataract surgery performed at acute hospitals was conducted on 56 patients (mean age 73) with bilateral cataract, after excluding a total of 54 patients at the screening stage, of whom 53 did not meet visual acuity criteria and one did not have cataract. In-home assessments included visual and neuropsychological function, computerized cognitive testing and health questionnaires. Results showed no cognitive benefits of cataract surgery in cognitively normal adults. We conclude that visual improvement following cataract surgery is not strongly associated with an improvement in neuropsychological test performance in otherwise healthy adults. Joint associations between visual and cognitive function in late life are likely to be due to central factors, and unlikely to be strongly related to eye disease. Short-term increased neural stimulation from improved visual function does not appear to affect cognitive performance.

The Stroop color-word test: influence of age, sex, and education; and normative data for a large sample across the adult age range

The Stroop Color-Word Test was administered to 1,856 cognitively screened, healthy Dutch speaking participants aged 24 to 81 years. The effects of age, gender, and education on Stroop test performance were investigated to adequately stratify the normative data. The results showed that especially the speed-dependent Stroop scores (time to complete a subtest), rather than the accuracy measures (the errors made per Stroop sub-task), were profoundly affected by the demographic variables. In addition to the main effects of the demographic variables, an Age Low Level of Education interaction was found for the Error III and the Stroop Interference scores. This suggests that executive function, as measured by the Stroop test, declines with age and that the decline is more pronounced in people with a low level of education. This is consistent with the reserve hypothesis of brain aging (i.e., that education generates reserve capacity against the damaging effects of aging on brain functions). Normative Stroop data were established using both a regression-based and traditional approach, and the appropriateness of both methods for generating normative data is discussed.

Colour perception in ADHD

Attention-deficit/hyperactivity disorder (ADHD) is associated with unexplained impairments on speeded naming of coloured stimuli. These deficits may reflect hypofunctioning retinal dopaminergic mechanisms impairing particularly blue-yellow colour discrimination. Colour perception and rapid colour naming ability were investigated in 14 children with ADHD and 13 healthy peers matched for age, gender, and IQ, using the Farnsworth-Munsell 100 Hue Test (FMT) and the Stroop-Colour-Word test. Children with ADHD committed more errors on the FMT, particularly on discrimination of colours along the blue-yellow axis, and were slower on Stroop subtests involving colour naming. However, the latter deficit was accounted for similarly by blue-yellow and red-green discrimination abilities. Blue-yellow colour perception problems in ADHD contribute to but do not fully explain the observed slowed colour naming.

Color naming deficits and attention-deficit/hyperactivity disorder: a retinal dopaminergic hypothesis

BACKGROUND

Individuals with Attention-Deficit/Hyperactive Disorder (ADHD) have unexplained difficulties on tasks requiring speeded processing of colored stimuli. Color vision mechanisms, particularly short-wavelength (blue-yellow) pathways, are highly sensitive to various diseases, toxins and drugs that alter dopaminergic neurotransmission. Thus, slow color processing might reflect subtle impairments in the perceptual encoding stage of stimulus color, which arise from hypodopaminergic functioning.

PRESENTATION OF HYPOTHESES

1) Color perception of blue-yellow (but not red-green) stimuli is impaired in ADHD as a result of deficient retinal dopamine; 2) Impairments in the blue-yellow color mechanism in ADHD contribute to poor performance on speeded color naming tasks that include a substantial proportion of blue-yellow stimuli; and 3) Methylphenidate increases central dopamine and is also believed to increase retinal dopamine, thereby normalizing blue-yellow color perception, which in turn improves performance on the speeded color naming tasks.

TESTING THE HYPOTHESIS

Requires three approaches, including:1) direct assessment of color perception in individuals with ADHD to determine whether blue-yellow color perception is selectively impaired; 2) determination of relationship between performance on neuropsychological tasks requiring speeded color processing and color perception; and 3) randomized, controlled pharmacological intervention with stimulant medication to examine the effects of enhancing central dopamine on color perception and task performance

IMPLICATIONS OF HYPOTHESIS

If substantiated, the findings of color perception problems would necessitate a re-consideration of current neuropsychological models of attention-deficit/hyperactivity disorder, guide psycho-education, academic instruction, and require consideration of stimulus color in many of the widely used neuropsychological tests.

Change in Sensory Functioning Predicts Change in Cognitive Functioning: Results from a 6-Year Follow-Up in the Maastricht Aging Study

OBJECTIVES

To examine the longitudinal relationship between sensory functioning and a broad range of cognitive functions after 6 years follow-up and whether cataract surgery or first-time hearing aid use affected cognition.

DESIGN

Hierarchical regression procedures were employed to determine whether sensory functioning was predictive of cognitive performance.

SETTING

Maastricht University and the University Hospital Maastricht, the Netherlands.

PARTICIPANTS

Older Dutch adults (>/=55) enrolled in the Maastricht Aging Study (N=418).

MEASUREMENTS

Visual and auditory acuity, the Visual Verbal Learning Test (VVLT), the Stroop Color Word Test (SCWT), the Concept Shifting Task (CST), the Verbal Fluency Test, and the Letter-Digit Substitution Test (LDST).

RESULTS

A change in visual acuity was associated with change in most cognitive measures, including the total and recall scores of the VVLT, the mean score of the first two SCWT cards, the mean score of the first two CST cards and the LDST. In addition, a change in auditory acuity predicted change in memory performance (VVLT total and recall scores), and auditory acuity measured at baseline predicted change in the mean score of the first two SCWT cards and the LDST.

CONCLUSION

The findings support the notion of a strong connection between sensory acuity in auditory and visual domains and cognitive performance measures, both from a cross-sectional and a longitudinal perspective. They also suggest that it is essential to screen older individuals in a clinical context for sensory functioning so that changes in visual or auditory acuity are not interpreted as changes in cognitive performance.

Reduced Stroop Interference for Opponent Colors May Be Due to Input Factors: Evidence From Individual Differences and a Neural Network Simulation

Sensory or input factors can influence the strength of interference in the classic Stroop color-word task. Specifically, in a single-trial computerized version of the Stroop task, when color-word pairs were incongruent, opponent color pairs (e.g., the word BLUE in yellow) showed reduced Stroop interference compared with nonopponent color pairs (e.g., BLUE in red). In addition, participants' color discrimination ability was measured by standard color vision tests (i.e., Farnsworth-Munsell 100-Hue Test and Ishihara plates). Error rates in the Farnsworth-Munsell test correlated positively with the amount of Stroop interference. Neural network simulations (variants of J. D. Cohen, K. Dunbar, & J. L. McClelland's, 1990, model) showed that only a distributed trichromatic input layer was able to simulate these findings. Thus, sensory input from the color system needs to be incorporated into current accounts of the Stroop effect.

Executive function and ADHD: a comparison of children's performance during neuropsychological testing and real-world activities

OBJECTIVE

Current understanding of executive function deficits in Attention-Deficit/Hyperactivity Disorder (ADHD) is derived almost exclusively from neuropsychological testing conducted in laboratory settings. This study compared children's performance on both neuropsychological and real-life measures of executive function and processing speed.

METHOD

The Stroop and Wisconsin Card Sorting Task (WCST) were selected as neuropsychological measures, whereas route tasks in a videogame and at the zoo were used to index real-life measures. Participants comprised a community sample of 22 unmedicated boys with ADHD individually matched on age and IQ with 22 normally developing control boys.

RESULTS

There were no group differences in executive function on the Stroop or zoo tasks, but the ADHD group exhibited deficits in set-shifting as assessed by the WCST (perseverative errors and responses) and videogame play (fewer challenges completed). Also, the ADHD group showed slowed processing speed on the Stroop (slower color naming) and zoo activity (longer time to complete task), as well as a slower rate of acquisition of the sorting rule on the WCST (more trials to complete first category). Efficient and flexible videogame play (number of challenges completed) was related positively to efficacy on the Stroop (number of items named correctly in the interference and two control conditions) and inversely related to set-shifting problems on the WCST (perseverative responses and errors). Also, problems in goal-directed behavior at the zoo (number of deviations from designated route) were related to problems in set-shifting on the WCST (perseverative responding).

CONCLUSIONS

Children with ADHD exhibit impairments in executive function and processing speed in real-world activities as well as in neuropsychological testing. Cognitive deficits detected by standardized neuropsychological testing are related to performance difficulties in real-world activities.

Attentional Bias and Drinking to Cope With Social Anxiety

This study investigated the sensitivity of the emotional Stroop test for identifying individuals who reported drinking to cope with social fears. Community volunteers completed a modified Stroop task during which social threat, alcohol-related, and control words were presented. High scores on drinking-to-cope measures were hypothesized to be associated with longer response latencies to both social threat and alcohol-related words. Consistent with previous studies, alcohol dependence was correlated with latencies for alcohol-related words, and level of social anxiety was correlated with response latency to social threat words. As expected, drinking-to-cope measures predicted response latency to alcohol-related and social threat words. These results suggest that the emotional Stroop test is useful in studying the relationship between social anxiety and alcohol consumption.