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Introduction
Skills and Expertise
Publications
Publications (87)
Background: Cognitive assessment of older adults typically includes symptom reports and objective evaluations. However, there is often poor agreement between these measures. Cultural norms, stress, and anxiety may also influence cognitive self-appraisal and performance. Little research describes how other factors affect the self-report/objective te...
Background:
Early discrimination and prediction of cognitive decline are crucial for the study of neurodegenerative mechanisms and interventions to promote cognitive resiliency.
Methods:
Our research is based on resting-state electroencephalography (EEG) and the current dataset includes 137 consensus-diagnosed, community-dwelling Black Americans...
Objective:
Valid estimates of premorbid cognitive functioning (PMIQ) are crucial for the assessment of older adults at risk for Alzheimer's disease. We investigated the relationship between the NIH Toolbox-Cognition Battery's (NIHTB-CB) Oral Reading Recognition (ORR) subtest and Wechsler Test of Adult Reading scores (WTAR, convergent validity). We...
Background:
Identification of older individuals with increased risk for cognitive decline can contribute not only to personal benefits (e.g., early treatment, evaluation of treatment), but could also benefit clinical trials (e.g., patient selection). We propose that baseline resting-state electroencephalography (rsEEG) could provide markers for ea...
The COVID-19 pandemic created stress and trauma for many individuals. Traumatic experiences often trigger reflection on meaning in life, with subsequent growth or despair. This study evaluates the role of meaning in life in buffering stressors in the early stages of the COVID-19 pandemic. The purpose of this study was to determine the extent to whi...
The utilization of a non-invasive electroencephalogram (EEG) as an input sensor is a common approach in the field of the brain–computer interfaces (BCI). However, the collected EEG data pose many challenges, one of which may be the age-related variability of event-related potentials (ERPs), which are often used as primary EEG BCI signal features. T...
The view of the human brain as a complex network has led to considerable advances in understanding the brain’s network organization during rest and task, in both health and disease. Here, we propose that examining brain networks within the task aftereffect model, in which we compare resting-state networks immediately before and after a cognitive en...
Previous research has demonstrated a link between affect and cognitive functioning, particularly showing that negative affect is related to lower cognitive performance across several cognitive domains. However, the relationship between positive affect (PA) and cognitive functioning is not as thoroughly characterized, though some previous work sugge...
NIH Toolbox‐Cognition Battery (NIHTB‐CB) is a computerized cognitive assessment battery frequently used in clinical research. However, the utility of the tablet adaptation has not been well established for clinical characterization, nor have possible racial differences been examined. We aim to identify which of the NIHTB‐CB subtests best differenti...
Older adults in the earliest stages of cognitive decline often present with subjective cognitive complaints which may not be fully reflected in objective measures of cognition. Previous research suggests that a relationship exists between negative emotions, stress and metacognition, but these relationships have not yet been examined in the context...
There is a critical need to identify older adults in the earliest stages of cognitive decline for targeted dementia reduction interventions. Subjective memory concerns often drive older adults to seek objective memory assessments. However, there is often poor agreement between subjective complaints and objective measures. Previous research suggests...
The search for psychophysiological markers that distinguish normal from abnormal aging has produced many candidate EEG dynamics, but relatively little research has been done (or at least reported) on the theta/beta ratio or brain wave asymmetries. We previously reported frontal asymmetries (frontal alpha and frontal beta asymmetry) originally inves...
The COVID-19 pandemic created disruptions in daily life and trauma for many individuals. Traumatic experiences often trigger reflection on meaning in life (MIL), which may result in either resilience or despair. The purpose of this study was to evaluate the role of MIL in mediating the relationship between COVID-related stressors and well-being out...
Recently, we have shown a significant decrease in resting‐state EEG (rsEEG) spectral power at post‐task as compared to pre‐task cognitive engagement in older adults. Further, older adults with mild cognitive impairment (MCI) showed greater decreases in rsEEG in temporal and central cortical regions at post‐task than healthy controls (HC). Here, we...
Estimation of premorbid IQ (PMIQ) among older adults is crucial to characterize cognitive decline properly, particularly among older adults at risk for Alzheimer’s disease. Three scores from the NIH Toolbox‐Cognition Battery (NIHTB‐C) ostensibly may estimate premorbid functioning: Crystallized Cognition (CC) and its component subtests, Picture Voca...
With advanced age, there is a loss of reaction speed that may contribute to an increased risk of tripping and falling. Avoiding falls and injuries requires awareness of the threat, followed by selection and execution of the appropriate motor response. Using event-related potentials (ERPs) and a simple visual reaction task (RT), the goal of our stud...
Cognitive testing data are essential to the diagnosis of mild cognitive impairment (MCI), and computerized cognitive testing, such as the Cogstate Brief Battery, has proven helpful in efficiently identifying harbingers of dementia. This study provides a side-by-side comparison of traditional Cogstate outcomes and diffusion modeling of these outcome...
The COVID-19 pandemic is an unprecedented health emergency that has forced a change in the daily life of all individuals across the nation for over a year. As vaccinations have begun in Detroit, we examined their effect on older African Americans’ emotional experiences and intent to get vaccinated during the pandemic to help understand how persons...
The COVID-19 pandemic, an unprecedented health emergency, has devastated the nation, and disproportionately affected persons of color, especially Black Americans. It has forced health officials to rapidly develop and distribute COVID-19 vaccines, resulting in the importance of understanding Black Americans’ attitudes and beliefs about COVID-19. We...
Background
The Covid‐19 pandemic, with its diverse effects (e.g., on quality of life, health and illness, physical and psychological well‐being, social and economic life), has also been suggested to effect cognitive functioning. To better understand the possible effect of the COVID‐19 pandemic, we examined cognitive functioning of older African Ame...
Background
The COVID‐19 pandemic has devastated multiple Countries targeting vulnerable populations. In Michigan there have been over 550,000 confirmed cases and over 14,000 deaths that forced health officials to rapidly develop and distribute COVID‐19 vaccines (MDHHS, 2021). As researchers study the COVID‐19 virus and vaccines, it is important to...
Background
The COVID‐19 pandemic is a health emergency that has forced a change in the daily life of individuals across all nations, races and socioeconomic groups for over a year. Such a crisis has required social isolation, the closing of businesses, schools and many recreational activities. This abrupt change has had negative effects on mental h...
Computerized cognitive training (CCT) paradigms for children with attention deficit hyperactivity disorder (ADHD) are designed to overcome specific deficits and reduce symptoms of the disorder. Such training is increasingly being researched, but it is not entirely clear how it affects generalised functional deficits, such as attention deficit, impu...
Ageing of population and related cognitive decline have contributed to an increased interest in cognitive computer training as one of options for maintaining cognitive abilities. Our research was aimed at verifying how cognitive computer training affected cognitive abilities as well as how it was connected with initial cognitive abilities and life...
Objective
Black adults are approximately twice as likely to develop Alzheimer’s disease (AD) than non-Hispanic Whites and access diagnostic services later in their illness. This dictates the need to develop assessments that are cost-effective, easily administered, and sensitive to preclinical stages of AD, such as mild cognitive impairment (MCI). T...
Background: Early identification of cognitive decline is critical for identifying individuals for inclusion in clinical trials and for eventual care planning.
Methods: A sample (ages 60–90 years) of consensus‐diagnosed, community‐dwelling Blacks (61 cognitively typical [HC], 28 amnestic mild cognitive impairment [aMCI], and 14 nonamnestic MCI [naMC...
The COVID-19 pandemic has created worldwide uncertainty and heightened fear and worry, elevating the potential for anxiety. We examined environmental, sociodemographic, and behavioral risk factors predicting generalized anxiety among older African Americans in a large metropolitan area during the COVID-19 outbreak. Sixty African American participan...
Background
Mild cognitive impairment (MCI) is characterized by deficits across functional domains, with pronounced memory impairment among amnestic (aMCI) patients. The mixture of cognitive complaints is a challenge in diagnosis and is further complicated by interactions between cognitive domains that are typical for neuropsychological performance....
Community-dwelling African American elders are twice as likely to develop mild cognitive impairment (MCI) or Alzheimer’s disease and related dementias than older white Americans and therefore represent a significant at-risk group in need of early monitoring. More extensive imaging or cerebrospinal fluid studies represent significant barriers due to...
Background
Age and disease related cognitive declines have important socioeconomic implications. Identifying those who are at risk and the underlying mechanisms for accelerated cognitive decline are vital for guiding interventions and improving early prediction of dementia. We propose a novel approach for risk prediction using repeated electrophysi...
https://deepblue.lib.umich.edu/bitstream/2027.42/152558/1/alzjjalz2019063490.pdf
https://deepblue.lib.umich.edu/bitstream/2027.42/153097/1/alzjjalz201908117.pdf
https://deepblue.lib.umich.edu/bitstream/2027.42/152934/1/alzjjalz2019064654.pdf
Prolonged periods of physical inactivity or bed rest can lead to a significant decline of functional and cognitive functions. Different kinds of countermeasures (e.g., centrifugation, nutritional, and aerobic interventions) have been developed to attempt to mitigate negative effects related to bed rest confinement. The aim of this report is to prov...
https://deepblue.lib.umich.edu/bitstream/2027.42/153204/1/alzjjalz201806338.pdf
There is growing interest in use of cognitive training and investigation of its effectiveness for variety of populations. However, there is lack of research into the effectiveness of computerized cognitive training on children with special needs. Our research project involved primary school students with special educational needs, divided into an i...
https://deepblue.lib.umich.edu/bitstream/2027.42/153243/1/alzjjalz201706485.pdf
Cognitive deficits are a potential part of the clinical picture of depression, especially when it comes to late-life depression. The present study was carried out to establish whether distinctive cognitive deficiencies can be linked with depression in the late-life period, especially in executive functioning, working memory, and visuospatial memory...
Acute stress, as bed rest, was shown to increase plasma level of the neurotrophin brain-derived neurotrophic factor (BDNF) in older, but not in young adults. This increase might represent a protective mechanism towards acute insults in aging subjects. Since computerized cognitive training (CCT) is known to protect brain, herein we evaluated the eff...
The hippocampus is closely tied to spatial navigation, a central component in cognitive functioning, and critically involved in age-associated cognitive decline and dementia. This study evaluated a novel, cognitive computerized spatial navigation training (CSNT) program targeting the hippocampus, with expectation of mitigating possible cognitive de...
The finding that some older individuals report declines in aspects of cognitive functioning is becoming a frequently used criteria to identify elderly at risk for mild cognitive impairment (MCI) and dementia. Once concerns are identified in a community setting, however, effective means are necessary to pinpoint those individuals who should go on to...
https://deepblue.lib.umich.edu/bitstream/2027.42/152916/1/alzjjalz201606521.pdf
https://deepblue.lib.umich.edu/bitstream/2027.42/152743/1/alzjjalz2016061716.pdf
Prolonged physical inactivity or bed rest (BR) due to illness or other factors can result in significant declines in physical health and even cognitive functions. Based on random selection, 7 healthy older adult men received computerized spatial navigation training, while 8 served as active controls during 14-day BR. Greater post-BR declines were s...
The slowing of information processing, a hallmark of cognitive aging, has several origins. Previously we reported that in a motion direction discrimination task, older as compared to younger participants showed prolonged non-decision time, an index of an early perceptual stage, while in motion onset visual evoked potentials (MO-VEPs) the P1 compone...
We investigated the effects of bed rest (BR) immobilization, with and without computerized cognitive training with virtual spatial navigation task (CCT), on vascular endothelium on older subjects. The effects of 14-day BR immobilization in healthy older males (n=16) of ages 53-65 years on endothelial function were studied using EndoPAT(®), a noninv...
Partial cortical blindness is a visual deficit caused by unilateral damage to the primary visual cortex, a condition previously considered beyond hopes of rehabilitation. However, recent data demonstrate that patients may recover both simple and global motion discrimination following intensive training in their blind field. The present experiments...
Abstract Understanding the effects of increased and decreased gravity on central nervous system is essential for developing proper physical and cognitive countermeasures to assure safe and effective space missions and human survival in space. This short review covers the available literature on the brain electrocortical activity effects of decrease...
Increasing evidence from clinical practice, epidemiological studies, and clinical trials
shows that gait and cognition are interrelated in older adults. Walking is a rhythmic
motor task that is mostly controlled by sub-cortical brain regions and generally
performed automatically by healthy adults. However, in the elderly, more attention is
required...
Age-related declines in motion perception have been well documented. We investigated the impact of age on electrophysiological correlates of motion perception, namely the P1 and N2 components of motion onset visual evoked potentials (MO-VEPs). Additionally, we used a model of response times based on the diffusion model to pinpoint the cognitive pro...
The attentional blink (AB), characterized as a failure to detect a second target following correct identification of a previous target in a rapid serial visual presentation (RSVP), has become a useful measure for investigation of the temporal dynamics of attention. In our previous work, we proposed a two-stage concurrent inhibition model that attri...
Aging and Alzheimer's disease (AD) are associated with declines in the visual perception of self-movement that undermine navigation and independent living. We studied 214 subjects' heading direction and speed discrimination using the radial patterns of visual motion in optic flow. Young (YA), middle-aged (MA), and older normal (ON) subjects, and AD...
The relationship between cognitive processing stages and event-related potential components has been extensively researched for single components, but even the simplest task comprises multiple electrophysiological and cognitive components. Here we examined the relationship between behavioral measures and several visual evoked potentials (VEPs) rela...
Alzheimer's disease (AD) is associated with changes in cerebral white matter (WM), but the functional significance of such findings is not yet established. We hypothesized that diffusion tensor imaging (DTI) might reveal links between regional WM changes and specific neuropsychologically and psychophysically defined impairments in early AD.
Older a...
The goal of the current investigation was to detect clinically important axonal damage in cerebral white matter after mild traumatic brain injury (TBI) using diffusion tensor imaging (DTI). To this end, we evaluated a prospective, pilot study of six subjects with isolated mild TBI and six matched orthopedic controls. All subjects underwent DTI scan...
We developed visual motion evoked potential (EP) measures related to navigational impairment in Alzheimer disease (AD) and have now applied these methods to explore the role of elementary perceptual and attentional mechanisms mediating these effects.
Older adult (OA) control subjects and AD patients underwent visual motion perceptual testing, atten...
The effects of a number of diffusion-encoding gradient directions (NDGD) on diffusion tensor imaging (DTI) indices have been studied previously with theoretic analysis and numeric simulations. In this study, we made in vivo measurements in the human brain to compare different clinical scan protocols and to evaluate their effects on the calculated D...
We assessed visual processing related to navigational impairment in Alzheimer's disease hypothesizing that visual motion evoked responses to optic flow simulating observer self-movement would be linked to navigational performance. Mild Alzheimer's disease and older adult control subjects underwent open-field navigational testing, visual motion perc...
PURPOSE
In order to reliably measure WM alterations in AD, precision of the DTI techniques needs to be determined. Conflicting reports exist in literature as to whether it is more beneficial to use a higher number (e.g., 30 vs 6) of motion probing gradient (MPG) orientations when the total numbers of images are the same. Computer simulations (Jones...
We have used MR DTI to identify relevant brain structures involved in visuospatial processing, in an attempt to link perceptual and attentional impairments to WM changes in Alzheimer's disease (AD) patients. Correlation of DTI measured parameters with results of several neuropsychological tests will be reported here. Several issues related to quant...
Patients with Alzheimer's disease (AD) and many older adults become lost even in familiar surroundings. This is commonly attributed to memory impairment, but it may reflect impaired spatial cognition.
The authors examined the role of memory, perceptual, and cognitive mechanisms in spatial disorientation by comparing the performance of normal young...
Visuospatial disorientation forces Alzheimer's disease patients to abandon independent activities. We found previously that limitations of ambulatory and vehicular navigation are linked to impaired visual motion processing in Alzheimer's disease. We now hypothesize that these perceptual impairments reflect temporal constraints on visual attention....
The cerebral hemispheres differ in their capabilities and response to verbal versus nonverbal visual material. A priori, it might thus be expected that the right hemisphere would be best activated during a mnemonic task with fMRI when using nonverbalizable images, and the left hemisphere with verbal material. However, previous psychological tests h...
How well will one cerebral hemisphere recognize items viewed initially via the other? Nonverbalizable images or words were presented to one visual field and memory for them tested in the same or the other visual field. The initially viewing hemisphere subsequently had no secure advantage in accuracy, and only for images was there a 30-ms (ca 3%) pe...
A Stroop-analog task with faces and words was developed to investigate intrahemispheric and interhemispheric Stroop effects (SEs). Lateralized faces and words were used in an attempt to invoke right- and left-hemispheric specialization, respectively. A prototypical male face, female face, and baby face and the corresponding words man, woman, and ba...
These experiments explored the interactions remaining between the cerebral hemispheres in two split-brain macaques. The 'split' was earlier confirmed by showing that one hemisphere was incapable of identifying visual images seen by the other. The critical tests for residual interactions were intermingled with control trials in a continuous recognit...
These experiments measured the extra time required to respond when the type of stimulus was changed from one trial to the next. Heretofore, switching costs have been measured for a change in task, but we wished to isolate the cost of changing the sensorial component per se and its necessary analytical processing, as distinct from changing the quest...
This study examined congruence levels between client and counselor beliefs about psychological problems and its impact on counseling outcomes. Clients and counselors endorsed differing views for causation and treatment of psychological problems. Counseling outcomes were unaffected by congruence levels. Practical implications for college counseling...
Accuracy of response and pattern of ocular fixations in three split-brain macaques were used to evaluate performance of each hemisphere in a continuous visual recognition task. The animal indicated by ocular fixation upon response points whether a displayed image or face was 'NEW' or 'OLD'. An inadvertent lesion of cingulate gyrus severely reduced...
