scholarly journals The Disengagement of Visual Attention: An Eye-Tracking Study of Cognitive Impairment, Ethnicity and Age

2020 ◽  
Vol 10 (7) ◽  
pp. 461
Author(s):  
Megan Polden ◽  
Thomas D. W. Wilcockson ◽  
Trevor J. Crawford
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Inhibitory Control ◽  
Reaction Times ◽  
Gap Effect ◽  
Cognitively Impaired ◽  
The Mean ◽  
Disengagement Of Attention ◽  
Effect Of Age

Various studies have shown that Alzheimer’s disease (AD) is associated with an impairment of inhibitory control, although we do not have a comprehensive understanding of the associated cognitive processes. The ability to engage and disengage attention is a crucial cognitive operation of inhibitory control and can be readily investigated using the “gap effect” in a saccadic eye movement paradigm. In previous work, various demographic factors were confounded; therefore, here, we examine separately the effects of cognitive impairment in Alzheimer’s disease, ethnicity/culture and age. This study included young (N = 44) and old (N = 96) European participants, AD (N = 32), mildly cognitively impaired participants (MCI: N = 47) and South Asian older adults (N = 94). A clear reduction in the mean reaction times was detected in all the participant groups in the gap condition compared to the overlap condition, confirming the effect. Importantly, this effect was also preserved in participants with MCI and AD. A strong effect of age was also evident, revealing a slowing in the disengagement of attention during the natural process of ageing.

scholarly journals Heterogeneity of Amyloid Binding in Cognitively Impaired Patients Consecutively Recruited from a Memory Clinic: Evaluating the Utility of Quantitative 18F-Flutemetamol PET-CT in Discrimination of Mild Cognitive Impairment from Alzheimer’s Disease and Other Dementias

2020 ◽  
pp. 1-14
Author(s):  
Yi-Wen Bao ◽  
Anson C.M. Chau ◽  
Patrick Ka-Chun Chiu ◽  
Yat Fung Shea ◽  
Joseph S.K. Kwan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Amyloid Β ◽  
Standardized Uptake Value ◽  
Subjective Cognitive Decline ◽  
Cognitively Impaired ◽  
Memory Clinic ◽  
Pet Ct

Background: With the more widespread use of 18F-radioligand-based amyloid-β (Aβ) PET-CT imaging, we evaluated Aβ binding and the utility of neocortical 18F-Flutemetamol standardized uptake value ratio (SUVR) as a biomarker. Objective: 18F-Flutemetamol SUVR was used to differentiate 1) mild cognitive impairment (MCI) from Alzheimer’s disease (AD), and 2) MCI from other non-AD dementias (OD). Methods: 109 patients consecutively recruited from a University memory clinic underwent clinical evaluation, neuropsychological test, MRI and 18F-Flutemetamol PET-CT. The diagnosis was made by consensus of a panel consisting of 1 neuroradiologist and 2 geriatricians. The final cohort included 13 subjective cognitive decline (SCD), 22 AD, 39 MCI, and 35 OD. Quantitative analysis of 16 region-of-interests made by Cortex ID software (GE Healthcare). Results: The global mean 18F-Flutemetamol SUVR in SCD, MCI, AD, and OD were 0.50 (SD-0.08), 0.53 (SD-0.16), 0.76 (SD-0.10), and 0.56 (SD-0.16), respectively, with SUVR in SCD and MCI and OD being significantly lower than AD. Aβ binding in SCD, MCI, and OD was heterogeneous, being 23%, 38.5%, and 42.9% respectively, as compared to 100% amyloid positivity in AD. Using global SUVR, ROC analysis showed AUC of 0.868 and 0.588 in differentiating MCI from AD and MCI from OD respectively. Conclusion: 18F-Flutemetamol SUVR differentiated MCI from AD with high efficacy (high negative predictive value), but much lower efficacy from OD. The major benefit of the test was to differentiate cognitively impaired patients (either SCD, MCI, or OD) without AD-related-amyloid-pathology from AD in the clinical setting, which was under-emphasized in the current guidelines proposed by Amyloid Imaging Task Force.

scholarly journals Attention and inhibition in Mild Cognitive Impairment and Alzheimer's Disease

2013 ◽  
Vol 6 (3) ◽  
pp. 43-50
Author(s):  
Clara Zancada-Menéndez ◽  
Patricia Sampedro-Piquero ◽  
Azucena Begega ◽  
Laudino López ◽  
Jorge Luis Arias
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Reaction Time ◽  
Alzheimer Disease ◽  
Neuropsychological Test ◽  
Reaction Times ◽  
Stop Signal Task ◽  
Healthy Controls

Mild cognitive impairment is understood as a cognitive deficit of insufficient severity to fulfil the criteria for Alzheimer’s disease. Many studies have attempted to identify which cognitive functions are most affected by this type of impairment and which is the most sensitive neuropsychological test for early detection. This study investigated sustained and selective attention, processing speed, and the inhibition process using a sample of people divided into three groups mild cognitive impairment, Alzheimer disease and cognitively healthy controls selected and grouped based on their scores in the Mini Mental State Examination and Cambridge Cognitive Examination-revised. Three tests from the Cambridge Neuropsychological Test Automated Battery (Motor Screening Task, Stop Signal Task and Reaction time) were used as well as the d2 attention test. The results show that that participants with mild cognitive impairment and Alzheimer disease showed lower levels of concentration compared with the cognitively healthy controls group in the d2 test and longer reaction times in the Cambridge Neuropsychological Test Automated Battery, although the differences were not marked in the latter test. The impairments in basic cognitive processes, such as reaction time and sustained attention, indicate the need to take these functions into account in the test protocols when discriminating between normal aging and early and preclinical dementia processes.

scholarly journals Determining Filipino Normative Data for a Battery of Neuropsychological Tests: The Filipino Norming Project (FNP)

2019 ◽  
Vol 9 (2) ◽  
pp. 260-270
Author(s):  
Jacqueline Cotoong Dominguez ◽  
Thien Kieu Thi Phung ◽  
Ma. Fe Payno de Guzman ◽  
Krizelle Cleo Fowler ◽  
Macario Reandelar Jr ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neuropsychological Tests ◽  
Normative Data ◽  
Neuropsychological Test ◽  
Test Battery ◽  
Cognitive Domains ◽  
Neuropsychological Test Battery ◽  
The Mean ◽  
Effect Of Age

Background: Filipino normative data for neuropsychological tests are lacking. Objectives: This study aimed to determine the Filipino normative data for the Filipino Norming Project (FNP) Neuropsychological Battery, combining the Alzheimer’s Disease Assessment Scale – Cognitive (ADAS-Cog) and the Neuropsychological Test Battery from the Uniform Dataset of Alzheimer’s Disease Center (UDS-ADC). Methods: We recruited participants 60 years and older with normal cognition (MMSE score of 25 and above and did not fulfill criteria for dementia according to DSM-IV criteria). Psychologists administered the tests to the study participants. We conducted multivariate analyses to study the effect of age, gender, and education on test performance. Results: A total of 191 participants underwent the FNP Neuropsychological Test Battery. The mean age was 68.8 years (SD 5.4). The majority were female (84.1%). The mean score of ADAS-Cog was 9.98 (SD 4.74). The effect of education was prominent throughout the cognitive domains tested while the effect of age was limited to a few cognitive domains. The mean ADAS-Cog scores were 11.80 ± 4.40 for primary education, 9.93 ± 5.08 for secondary, and 8.15 ± 3.95 for tertiary. On average, women scored 2.75 points lower than men and performed better on the verbal components. Men performed better on the constructional praxis component. The same effect of education and gender was observed for the UDS-ADC. Conclusion: For the first time, normative data are available for the ADAS-Cog and UDS-ADC for a Filipino older population. This study stresses the importance of establishing population-specific normative data, taking into account the specific sociocultural and linguistic context of that population.

scholarly journals Signal and Texture Features from T2 Maps for the Prediction of Mild Cognitive Impairment to Alzheimer’s Disease Progression

Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 941
Author(s):  
Alejandro I. Trejo-Castro ◽  
Ricardo A. Caballero-Luna ◽  
José A. Garnica-López ◽  
Fernando Vega-Lara ◽  
Antonio Martinez-Torteya
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Texture Features ◽  
Mean Value ◽  
Absolute Difference ◽  
Imaging Features ◽  
Machine Learning Methods ◽  
The Mean

Early detection of Alzheimer’s disease (AD) is crucial to preserve cognitive functions and provide the opportunity for patients to enter clinical trials. In recent years, some studies have reported that features related to the signal and texture of MRI images can be an effective biomarker of AD. To test these claims, a study was conducted using T2 maps, a sequence not previously studied, of 40 patients with mild cognitive impairment (MCI) from the Alzheimer’s Disease Neuroimaging Initiative database, who either progressed to AD (18) or remained stable (22). From these maps, the mean value and absolute difference of 37 signal and texture imaging features for 40 contralateral pairs of regions were measured. We used seven machine learning methods to analyze whether, by adding these imaging features to the neuropsychological studies currently used for diagnosis, we could more accurately identify patients who will progress to AD. The predictive models improved with the addition of signal and texture features. Additionally, features related to the signal and texture of the images were much more relevant than volumetric ones. Our results suggest that contralateral signal and texture features should be further investigated as potential biomarkers for the prediction of AD.

Implications for technological reserve development in advancing age, cognitive impairment, and dementia

2020 ◽  
Vol 43 ◽  
Author(s):  
Jared F. Benge ◽  
Michael K. Scullin
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Assistive Technology ◽  
Cognitive Ability ◽  
Cognitively Impaired ◽  
Technological Culture ◽  
Recent Trends ◽  
Technical Reasoning

Abstract This commentary draws connections between technological culture emergence and recent trends in using assistive technology to reduce the burden of Alzheimer's disease. By the technical-reasoning hypothesis, cognitively-impaired individuals will lack the cognitive ability to employ technologies. By the technological reserve hypothesis, social-motivational and cultural transmissibility factors can provide foundations for using technology as cognitive prosthetics even during neurodegenerative illnesses.

P1-145: Effect of age on ventricular enlargement when comparing cognitively normal elderly, mild cognitive impairment and Alzheimer's disease subjects

2009 ◽  
Vol 5 (4S_Part_7) ◽  
pp. P219-P220
Author(s):  
Liana G. Apostolova ◽  
Amity E. Green ◽  
Sona Babakchanian ◽  
Kristy S. Hwang ◽  
Yi-Yu Chou ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Ventricular Enlargement ◽  
Cognitively Normal ◽  
Effect Of Age

scholarly journals Progression of Cognitive Impairment to Alzheimer’s Disease: Through the Lens of Salivary Extracellular Vesicles

2021 ◽  
Vol 16 ◽  
pp. 263310552110586
Author(s):  
Simran Rastogi ◽  
Komal Rani ◽  
Saroj Kumar
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Screening Method ◽  
Extracellular Vesicle ◽  
Cognitively Impaired ◽  
Non Invasive ◽  
Novel Approach ◽  
Place Of Origin

The elusiveness encircling around the domain of cognition, its impairment, and the poor prognosis of Alzheimer’s disease has made early diagnosis a necessity. The noticeable symptoms in these conditions appear years later after the neuropathological changes occur in the brain. Exosomes, a small-sized extracellular vesicle facilitate intercellular communication of disease pathologies and their cargo can provide molecular information about its place of origin. The study titled “A novel approach to correlate the salivary exosomes and their protein cargo in the progression of cognitive impairment into Alzheimer’s disease” was an attempt toward understanding the role of salivary small-sized extracellular vesicular (EV’s) cargo in monitoring the progression. Outcomes of the study represent, that the salivary small-sized EV’s (ssEV’s) levels were higher in the cognitively impaired and Alzheimer’s diseased as well the differential expression of the protein in the cargo correlates well with the disease severity staging. Thus, it can help in the development of an early non-invasive screening method.

scholarly journals The Effects of Previous Error and Success in Alzheimer’s Disease and Mild Cognitive Impairment

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
T. J. Crawford ◽  
S. Taylor ◽  
D. Mardanbegi ◽  
M. Polden ◽  
T. W. Wilcockson ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Reaction Times ◽  
Control Group ◽  
Future Performance ◽  
Negative Effect ◽  
Saccadic Reaction Times ◽  
Previous Error

AbstractThis work investigated in Alzheimer’s disease dementia (AD), whether the probability of making an error on a task (or a correct response) was influenced by the outcome of the previous trials. We used the antisaccade task (AST) as a model task given the emerging consensus that it provides a promising sensitive and early biological test of cognitive impairment in AD. It can be employed equally well in healthy young and old adults, and in clinical populations. This study examined eye-movements in a sample of 202 participants (42 with dementia due to AD; 65 with mild cognitive impairment (MCI); 95 control participants). The findings revealed an overall increase in the frequency of AST errors in AD and MCI compared to the control group, as predicted. The errors on the current trial increased in proportion to the number of consecutive errors on the previous trials. Interestingly, the probability of errors was reduced on the trials that followed a previously corrected error, compared to the trials where the error remained uncorrected, revealing a level of adaptive control in participants with MCI or AD dementia. There was an earlier peak in the AST distribution of the saccadic reaction times for the inhibitory errors in comparison to the correct saccades. These findings revealed that the inhibitory errors of the past have a negative effect on the future performance of healthy adults as well as people with a neurodegenerative cognitive impairment.

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