Detection of Cognitive Dysfunction in Elderly with a Low Educational Level Using a Reaction-Time Attention Task

2020 ◽  
Vol 78 (3) ◽  
pp. 1197-1205
Author(s):  
Guilherme J. Schmidt ◽  
Yolanda Eliza Moreira Boechat ◽  
Eelco van Duinkerken ◽  
Juliana J. Schmidt ◽  
Tayssa B. Moreira ◽  
...  

Background: Scales for cognitive deterioration usually depend on education level. Objective: We aimed to study the clinical utility of a culture-free Go/No-Go task in a multi-ethnic cohort with low education level. Methods: Sixty-four participants with less than 4 years of formal education were included and divided on the basis of their Clinical-Dementia-Rate scores (CDR) into cognitively unimpaired (CDR = 0), mild cognitive impairment (MCI; CDR = 0.5), and early Alzheimer’s disease (AD, CDR = 1). All underwent a 90-s Continuous Visual Attention Test. This test consisted of a 90-s Go/No-go task with 72 (80%) targets and 18 (20%) non-targets. For each participant, reaction times and intraindividual variability of reaction times of all correct target responses, as well as the number of omission and commission errors were evaluated. Coefficient of variability was calculated for each participant by dividing the standard deviation of the reaction times by the mean reaction time. A MANCOVA was performed to examine between-group differences using age and sex as covariates. Discriminate analysis was performed to find the most reliable test-variable to discriminate the three groups. Results: Commission error, intraindividual variability of reaction time, and coefficient of variability progressively worsened with increasing CDR level. Discriminant analysis demonstrated that coefficient of variability was the best discriminant factor, followed by intraindividual variability of reaction time and commission error. Conclusion: The Go/No-Go task was able to discriminate people with MCI or early AD from controls in the setting of illiteracy.

2021 ◽  
pp. 1-7
Author(s):  
Sergio L. Schmidt ◽  
Yolanda Eliza Moreira Boechat ◽  
Guilherme J. Schmidt ◽  
Denise Nicaretta ◽  
Eelco van Duinkerken ◽  
...  

Background: The Clinical Dementia Rating (CDR) scale is commonly used to stage cognitive impairment, despite having educational limitations. In elderly with low education, a previous study has shown that intraindividual variability of reaction time (CV) and commission errors (CE), measured using a culture-free Go/No-Go task, can reliably distinguish early Alzheimer’s disease (AD) from mild cognitive impairment (MCI) and healthy controls. Objective: We aimed to extend the clinical utility of this culture-free Go/No-Go task in a sample with high educational disparity. Methods: One hundred and ten participants with a wide range of years of formal education (0–14 years) were randomly selected from a geriatric unit and divided based on their CDR scores into cognitively unimpaired (CDR = 0), MCI (CDR = 0.5), and early AD (CDR = 1). All underwent a 90-s reaction-time test that measured the variables previously found to predict CDR in low educated elderly. Here we added years of formal education (educational level) to the model. Multivariate analyses compared differences in group means using educational level as confounding factor. A confirmatory discriminant analyses was performed, to assess if CDR scores could be predicted by the two Go/No-Go variables in a sample with high educational disparity. Results: Over all three groups, differences in both CE and CV reached statistical significance (p <  0.05). The discriminant analysis demonstrated that CV and CE discriminated cognitively impaired from cognitively normal elderly. These results remained similar when discriminating MCI from cognitively unimpaired elderly. Conclusion: The Go/No-Go task reliably discriminates elderly with MCI from elderly without cognitive impairment independent of educational disparity.


2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Zohreh Mohebian ◽  
Somayeh Farhang Dehghan ◽  
Habiballah Dehghan

Heat exposure and unsuitable lighting are two physical hazardous agents in many workplaces for which there are some evidences regarding their mental effects. The purpose of this study was to assess the combined effect of heat exposure and different lighting levels on the attention rate and reaction time in a climatic chamber. This study was conducted on 33 healthy students (17 M/16 F) with a mean (±SD) age of22.1±2.3years. The attention and reaction time test were done by continuous performance test and the RT meter, respectively, in different exposure conditions including the dry temperatures (22°C and 37°C) and lighting levels (200, 500, and 1500 lux). Findings demonstrated that increase in heat and lighting level caused a decrease in average attention percentage and correct responses and increase in commission error, omission error, and response time (P<0.05). The average of simple, diagnostic, two-color selective, and two-sound selective reaction times increased after combined exposure to heat and lighting (P<0.05). The results of this study indicated that, in job task which requires using cognitive functions like attention, vigilance, concentration, cautiousness, and reaction time, the work environment must be optimized in terms of heat and lighting level.


2019 ◽  
Vol 3 ◽  
pp. 205970021983958 ◽  
Author(s):  
Stephanie L Green ◽  
Michelle L Keightley ◽  
Nancy J Lobaugh ◽  
Deirdre R Dawson ◽  
Alex Mihailidis

Background Concussion represents a growing concern in sports participation for adults and youth alike. Studies exploring the neurocognitive sequelae of concussion, such as speed of processing typically compare mean reaction time scores to a control group. Intraindividual variability measures the consistency of reaction times between trials and has been previously explored in adults post-concussion. Some adult studies show increased variability following injury. Developmentally youth show higher intraindividual variability than adults, which may put them at higher risk of increased intraindividual variability change post-concussion. Exploring intraindividual variability may provide additional insight into fluctuating performance reported following injury. Despite preliminary findings of slowed reaction time in youth, a pre-/post-concussion comparison of intraindividual variability of reaction time has not been explored. Objective To describe and compare pre- and post-concussion measures of processing speed and intraindividual variability in youth. Methods A pre-/post-concussion design was used to compare mean reaction time and the coefficient of variation before and after sports-related concussion in 18 youth athletes aged 10–14 years using verbal and nonverbal working memory tasks. Pre-/post-concussion reaction time and coefficient of variation were compared using t-tests. Results The coefficient of variation for nonverbal working memory was significantly higher following concussion, but no changes in average reaction time were found. Conclusions Preliminary findings suggest that average response times are unchanged following concussion, but the fluctuation across response times is more variable during a nonverbal working memory task in youth. Increased variability in speed of reaction times could have implications for safe return to sports and reduced academic performance.


Concussion ◽  
2020 ◽  
pp. CNC
Author(s):  
Allyssa K Memmini ◽  
Xin Sun ◽  
Xiaosu Hu ◽  
Jessica Kim ◽  
Noelle K Herzog ◽  
...  

Aim: The underlying neurophysiological effects of concussion often result in attenuated cognitive and cortical function. To understand the relation between cognition and brain injury, we investigated the effects of concussion on attentional networks using functional near-infrared spectroscopy (fNIRS). Materials & methods: Healthy controls and concussed patients, tested within 72 h from injury (T1) and after symptoms resolved (T2) completed a computerized attention task during fNIRS imaging. Results: T1 patients exhibited slower reaction times and reduced brain activation pattern relative to healthy controls. Interestingly, the cortical oxygenation hemoglobin response at T2 was greater relative to T1 and healthy controls, while reaction time was normative. Conclusion: The exploratory findings of this study suggest once asymptomatic, a compensatory hemodynamic response may support the restoration of reaction time despite ongoing physiological recovery.


GeroPsych ◽  
2011 ◽  
Vol 24 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Philippe Rast ◽  
Daniel Zimprich

In order to model within-person (WP) variance in a reaction time task, we applied a mixed location scale model using 335 participants from the second wave of the Zurich Longitudinal Study on Cognitive Aging. The age of the respondents and the performance in another reaction time task were used to explain individual differences in the WP variance. To account for larger variances due to slower reaction times, we also used the average of the predicted individual reaction time (RT) as a predictor for the WP variability. Here, the WP variability was a function of the mean. At the same time, older participants were more variable and those with better performance in another RT task were more consistent in their responses.


2006 ◽  
Vol 20 (3) ◽  
pp. 186-194 ◽  
Author(s):  
Susanne Mayr ◽  
Michael Niedeggen ◽  
Axel Buchner ◽  
Guido Orgs

Responding to a stimulus that had to be ignored previously is usually slowed-down (negative priming effect). This study investigates the reaction time and ERP effects of the negative priming phenomenon in the auditory domain. Thirty participants had to categorize sounds as musical instruments or animal voices. Reaction times were slowed-down in the negative priming condition relative to two control conditions. This effect was stronger for slow reactions (above intraindividual median) than for fast reactions (below intraindividual median). ERP analysis revealed a parietally located negativity of the negative priming condition compared to the control conditions between 550-730 ms poststimulus. This replicates the findings of Mayr, Niedeggen, Buchner, and Pietrowsky (2003) . The ERP correlate was more pronounced for slow trials (above intraindividual median) than for fast trials (below intraindividual median). The dependency of the negative priming effect size on the reaction time level found in the reaction time analysis as well as in the ERP analysis is consistent with both the inhibition as well as the episodic retrieval account of negative priming. A methodological artifact explanation of this effect-size dependency is discussed and discarded.


2004 ◽  
Vol 9 (1) ◽  
pp. 24-31 ◽  
Author(s):  
Sybille Rockstroh ◽  
Karl Schweizer

Effects of four retest-practice sessions separated by 2 h intervals on the relationship between general intelligence and four reaction time tasks (two memory tests: Sternberg's memory scanning, Posner's letter comparison; and two attention tests: continuous attention, attention switching) were examined in a sample of 83 male participants. Reaction times on all tasks were shortened significantly. The effects were most pronounced with respect to the Posner paradigm and smallest with respect to the Sternberg paradigm. The relationship to general intelligence changed after practice for two reaction time tasks. It increased to significance for continuous attention and decreased for the Posner paradigm. These results indicate that the relationship between psychometric intelligence and elementary cognitive tasks depends on the ability of skill acquisition. In the search for the cognitive roots of intelligence the concept of learning seems to be of importance.


2007 ◽  
Vol 23 (3) ◽  
pp. 157-165 ◽  
Author(s):  
Carmen Hagemeister

Abstract. When concentration tests are completed repeatedly, reaction time and error rate decrease considerably, but the underlying ability does not improve. In order to overcome this validity problem this study aimed to test if the practice effect between tests and within tests can be useful in determining whether persons have already completed this test. The power law of practice postulates that practice effects are greater in unpracticed than in practiced persons. Two experiments were carried out in which the participants completed the same tests at the beginning and at the end of two test sessions set about 3 days apart. In both experiments, the logistic regression could indeed classify persons according to previous practice through the practice effect between the tests at the beginning and at the end of the session, and, less well but still significantly, through the practice effect within the first test of the session. Further analyses showed that the practice effects correlated more highly with the initial performance than was to be expected for mathematical reasons; typically persons with long reaction times have larger practice effects. Thus, small practice effects alone do not allow one to conclude that a person has worked on the test before.


2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.


2021 ◽  
Vol 11 (5) ◽  
pp. 669
Author(s):  
Paweł Krukow ◽  
Małgorzata Plechawska-Wójcik ◽  
Arkadiusz Podkowiński

Aggrandized fluctuations in the series of reaction times (RTs) are a very sensitive marker of neurocognitive disorders present in neuropsychiatric populations, pathological ageing and in patients with acquired brain injury. Even though it was documented that processing inconsistency founds a background of higher-order cognitive functions disturbances, there is a vast heterogeneity regarding types of task used to compute RT-related variability, which impedes determining the relationship between elementary and more complex cognitive processes. Considering the above, our goal was to develop a relatively new assessment method based on a simple reaction time paradigm, conducive to eliciting a controlled range of intra-individual variability. It was hypothesized that performance variability might be induced by manipulation of response-stimulus interval’s length and regularity. In order to verify this hypothesis, a group of 107 healthy students was tested using a series of digitalized tasks and their results were analyzed using parametric and ex-Gaussian statistics of RTs distributional markers. In general, these analyses proved that intra-individual variability might be evoked by a given type of response-stimulus interval manipulation even when it is applied to the simple reaction time task. Collected outcomes were discussed with reference to neuroscientific concepts of attentional resources and functional neural networks.


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