scholarly journals Generalization of Context-Specific Training in Individuals with Mild Cognitive Impairment: An Event-Related Potential Study

2016 ◽  
Vol 6 (3) ◽  
pp. 568-579 ◽  
Author(s):  
Sam C.C. Chan ◽  
Tommy L.H. Lam ◽  
Kenneth N.K. Fong ◽  
Marco Y.C. Pang ◽  
Chetwyn C.H. Chan

Background: This study examined the neural processes associated with the generalization of the effect of context-specific (CS) training to noncontextual situations among individuals with mild cognitive impairment (MCI). Methods: Fourteen and 16 participants with MCI were randomly allocated to a Chinese calligraphy writing (CW) training or a control group, respectively. The CW participants learned how to write Chinese strokes in a semicursive style to construct characters, tapping on working memory functions. The control group, on the other hand, learned how to use a tablet computer without emphasis on working memory functions. They then performed two 2-back tasks with CS semicursive strokes and non-context-specific (NCS) digits. Event-related electroencephalogram signals were concurrently recorded. Results: The CW participants had a significantly shorter reaction time in the CS than in the NCS task (p < 0.05). They showed significantly longer latency in working memory updating (N200; t<Sub>11</Sub> = 4.70, p = 0.05) and shorter latency in the evaluation of visual representation (P300; t<Sub>12</Sub> = 4.67; p = 0.05) than the control group when performing the 2-back CS task. Shorter P300 latency was also revealed in the 2-back NCS task (t<Sub>12</Sub> = 5.15, p = 0.041), suggesting a possible generalization of the training effect among the CW participants. Conclusion: The results suggest that CS working memory is likely to be generalized to NCS domains among individuals with MCI. Future research should extend the scope of the generalization and apply it beyond experimental conditions.

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Anna-Mariya Kirova ◽  
Rebecca B. Bays ◽  
Sarita Lagalwar

Alzheimer’s disease (AD) is a progressive neurodegenerative disease marked by deficits in episodic memory, working memory (WM), and executive function. Examples of executive dysfunction in AD include poor selective and divided attention, failed inhibition of interfering stimuli, and poor manipulation skills. Although episodic deficits during disease progression have been widely studied and are the benchmark of a probable AD diagnosis, more recent research has investigated WM and executive function decline during mild cognitive impairment (MCI), also referred to as the preclinical stage of AD. MCI is a critical period during which cognitive restructuring and neuroplasticity such as compensation still occur; therefore, cognitive therapies could have a beneficial effect on decreasing the likelihood of AD progression during MCI. Monitoring performance on working memory and executive function tasks to track cognitive function may signal progression from normal cognition to MCI to AD. The present review tracks WM decline through normal aging, MCI, and AD to highlight the behavioral and neurological differences that distinguish these three stages in an effort to guide future research on MCI diagnosis, cognitive therapy, and AD prevention.


2012 ◽  
Vol 25 (4) ◽  
pp. 617-626 ◽  
Author(s):  
Barbara Carretti ◽  
Erika Borella ◽  
Silvia Fostinelli ◽  
Michela Zavagnin

ABSTRACTBackground:A growing number of studies are attempting to understand how effective cognitive interventions may be for patients with amnestic mild cognitive impairment (aMCI), particularly in relation to their memory problems.Methods:The present study aimed to explore the benefits of a working memory (WM) training program in aMCI patients. Patients (N= 20) were randomly assigned to two training programs: the experimental group practiced with a verbal WM task, while the active control group conducted educational activities on memory.Results:Results showed that the aMCI patients completing the WM training obtained specific gains in the task trained with some transfer effects on other WM measures (visuospatial WM) and on processes involved in or related to WM, e.g. fluid intelligence (the Cattell test) and long-term memory. This was not the case for the aMCI control group, who experienced only a very limited improvement.Conclusion:This pilot study suggests that WM training could be a valuable method for improving cognitive performance in aMCI patients, possibly delaying the onset of Alzheimer's disease.


Author(s):  
Gorana Pobric ◽  
Jason R. Taylor ◽  
Hemavathy M. Ramalingam ◽  
Emily Pye ◽  
Louise Robinson ◽  
...  

AbstractNeurofibromatosis 1 (NF1) is a single gene disorder associated with working Memory (WM) impairments. The aim of this study was to investigate P300 event-related potential (ERP) associated with WM in NF1. Sixteen adolescents with NF1 were compared with controls on measures of WM and EEG was recorded during a WM nback task. The NF1 group showed poorer performance on measures of WM as compared to the control group. No group differences were observed in P300 amplitude at Pz, but P300 latency was shorter in the NF1 group. Topographic analyses of P300 amplitude showed group differences indicating neural processing differences in the NF1 group relative to controls, which possibly contribute to the cognitive deficits seen in this population.


2021 ◽  
Vol 18 ◽  
Author(s):  
Mabel Ngai Kiu Wong ◽  
Daniel Wing Leung Lai ◽  
Henry Ho-Lung Chan ◽  
Bess Yin-Hung Lam

Objective: This study investigated the relationship between neural activities and retinal structures associated with working memory (WM) in older adults with mild cognitive impairment (MCI). Methods: Eleven older adults with MCI and 29 healthy controls (60 to 73 years old) were tested. All participants underwent an event-related potential (ERP) recording while performing the two-back memory task. The Optical coherence tomography angiography (OCT-A) was administered to examine the perfusion and vessel density in the retina. Results: Results showed that WM performance in the MCI group was negatively associated with ERP latencies in central parietal regions (CP6 and CP8) (ps< 0.05). The left nasal vessel and perfusion den- sities were negatively correlated with the latencies in these two central parietal regions and positively related to WM performance only in the MCI group (ps< 0.05). Conclusion: The findings on WM, central parietal brain activity, and left nasal vessel and perfusion densities in the retina help us gain a better understanding of the neural and retinal underpinnings of WM in relation to MCI.


2020 ◽  
Vol 17 (8) ◽  
pp. 751-761
Author(s):  
Minyoung Shin ◽  
Ahee Lee ◽  
A Young Cho ◽  
Minam Son ◽  
Yun-Hee Kim

Objective This study investigated the effects of process-based cognitive training that targets working memory and cognitive control on memory improvement in healthy elderly individuals and patients with mild cognitive impairment (MCI).Methods Forty healthy subjects and 40 patients with MCI were randomly assigned to either the intervention or control group. The intervention group received 12 sessions of designated cognitive training. The control group did not receive cognitive training. A memory test was administered pre-intervention, post-intervention, and 4 weeks after the intervention. Additional comprehensive neuropsychological tests were also administered including a depression scale questionnaire.Results Performance in attention and working memory, which are directly related to the training domains, and global cognitive function were improved in the intervention group after training. In memory tests, interference by irrelevant stimuli was reduced and recognition memory was improved after the intervention. Furthermore, cognitive training ameliorated depressive symptoms. These training effects were not dependent on MCI status.Conclusion Process-based cognitive training that targets working memory and cognitive control effectively improves memory processes including retrograde interference and recognition, as well as depressive symptoms associated with aging in healthy elderly individuals and patients with MCI.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kyoungwon Baik ◽  
Seon Myeong Kim ◽  
Jin Ho Jung ◽  
Yang Hyun Lee ◽  
Seok Jong Chung ◽  
...  

AbstractWe investigated the efficacy of donepezil for mild cognitive impairment in Parkinson’s disease (PD-MCI). This was a prospective, non-randomized, open-label, two-arm study. Eighty PD-MCI patients were assigned to either a treatment or control group. The treatment group received donepezil for 48 weeks. The primary outcome measures were the Korean version of Mini-Mental State Exam and Montreal Cognitive Assessment scores. Secondary outcome measures were the Clinical Dementia Rating, Unified Parkinson’s Disease Rating Scale part III, Clinical Global Impression scores. Progression of dementia was assessed at 48-week. Comprehensive neuropsychological tests and electroencephalography (EEG) were performed at baseline and after 48 weeks. The spectral power ratio of the theta to beta2 band (TB2R) in the electroencephalogram was analyzed. There was no significant difference in the primary and secondary outcome measures between the two groups. However, the treatment group showed a significant decrease in TB2R at bilateral frontotemporoparietal channels compared to the control group. Although we could not demonstrate improvements in the cognitive functions, donepezil treatment had a modulatory effect on the EEG in PD-MCI patients. EEG might be a sensitive biomarker for detecting changes in PD-MCI after donepezil treatment.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Jiangyi Xia ◽  
Ali Mazaheri ◽  
Katrien Segaert ◽  
David P Salmon ◽  
Danielle Harvey ◽  
...  

Abstract Reliable biomarkers of memory decline are critical for the early detection of Alzheimer’s disease. Previous work has found three EEG measures, namely the event-related brain potential P600, suppression of oscillatory activity in the alpha frequency range (∼10 Hz) and cross-frequency coupling between low theta/high delta and alpha/beta activity, each of which correlates strongly with verbal learning and memory abilities in healthy elderly and patients with mild cognitive impairment or prodromal Alzheimer’s disease. In the present study, we address the question of whether event-related or oscillatory measures, or a combination thereof, best predict the decline of verbal memory in mild cognitive impairment and Alzheimer’s disease. Single-trial correlation analyses show that despite a similarity in their time courses and sensitivities to word repetition, the P600 and the alpha suppression components are minimally correlated with each other on a trial-by-trial basis (generally |rs| &lt; 0.10). This suggests that they are unlikely to stem from the same neural mechanism. Furthermore, event-related brain potentials constructed from bandpass filtered (delta, theta, alpha, beta or gamma bands) single-trial data indicate that only delta band activity (1–4 Hz) is strongly correlated (r = 0.94, P &lt; 0.001) with the canonical P600 repetition effect; event-related potentials in higher frequency bands are not. Importantly, stepwise multiple regression analyses reveal that the three event-related brain potential/oscillatory measures are complementary in predicting California Verbal Learning Test scores (overall R2’s in 0.45–0.63 range). The present study highlights the importance of combining EEG event-related potential and oscillatory measures to better characterize the multiple mechanisms of memory failure in individuals with mild cognitive impairment or prodromal Alzheimer’s disease.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiangfei Hong ◽  
You Chen ◽  
Jijun Wang ◽  
Yuan Shen ◽  
Qingwei Li ◽  
...  

AbstractWorking memory (WM) is a fundamental cognitive function that typically declines with age. Previous studies have shown that targeted WM training has the potential to improve WM performance in older adults. In the present study, we investigated whether a multi-domain cognitive training program that was not designed to specifically target WM could improve the behavioral performance and affect the neural activity during WM retrieval in healthy older adults. We assigned healthy older participants (70–78 years old) from a local community into a training group who completed a 3-month multi-domain cognitive training and a control group who only attended health education lectures during the same period. Behavioral and electroencephalography (EEG) data were recorded from participants while performing an untrained delayed match or non-match to category task and a control task at a pre-training baseline session and a post-training follow-up session. Behaviorally, we found that participants in the training group showed a trend toward greater WM performance gains than participants in the control group. Event-related potential (ERP) results suggest that the task-related modulation of P3 during WM retrieval was significantly enhanced at the follow-up session compared with the baseline session, and importantly, this enhancement of P3 modulation was only significant in the training group. Furthermore, no training-related effects were observed for the P2 or N2 component during WM retrieval. These results suggest that the multi-domain cognitive training program that was not designed to specifically target WM is a promising approach to improve WM performance in older adults, and that training-related gains in performance are likely mediated by an enhanced modulation of P3 which might reflect the process of WM updating.


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