Compensatory Brain Activity in Older Adults. The Search for the Electrophysiological Indicators of Cognitive Processes Involved in This Activity, and Its Possible Changes Induced by Working Memory Training
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 117
- 试验地点
- 1
- 主要终点
- Change in EEG power in theta, alpha and gamma bands (Stroop task)
研究概览
简要总结
There are two important aspects in which the present project will allow to enrich our understanding of compensatory brain activity in older adults. First, in the studies that have been conducted so far the compensatory brain activity in older adults was investigated primarily with the use of the functional magnetic resonance (fMRI) or positon emission tomography (PET). In order to identify compensatory activity in our study we will use electroencephalographic markers (observable in EEG). It will allow to confirm the assumptions about compensatory brain activity relying on new data, as in EEG research the brain markers of the same cognitive processes are different from those used in fMRI and PET research. What is more, in the studies conducted so far brain activity in older adults was only registered and interpreted, whereas the present study additionally adds the training component. The aim of our study is to see if it is possible to influence the compensatory brain activity through cognitive functions training, relying on working memory training. Theoretically, such a training should optimize brain activity in older adults, namely evoke compensatory brain activity during difficult tasks in order to make them easier, whereas in the case of easy tasks it should lead to the disappearance of the need to trigger compensatory activity. This assumption will be verified in an experimental setting.
The participants will be divided into six groups: two experimental (the groups of young and old adults), and by analogy two active control groups and two passive (no-contact) control groups. The experiment was designed in the following way: (1) All groups will be subjected to pre-test measurements that will be EEG registration during a cognitive task execution at different difficulty levels; (2) Experimental groups will undergo working memory training. Over the period of 4 weeks participants in the experimental groups will take part in 12 training sessions. In the active control groups instead of the n-back training the practice of tasks which do not involve working memory will be introduced. Participants of the passive control groups will be awaiting post-test (no-contact control); (3) In all groups post-test measurements will be administered analogically to the pre-test measurements in order to assess changes in cognitive tasks performance and related brain activity.
详细描述
Compensatory brain activity in older adults is an important research area concerned with cognitive aging and the possibilities of cognitive enhancement in late adulthood. Most comprehensively these issues are addressed by the STAC model - Scaffolding Theory of Aging and Cognition. The present study will be concerned with empirical investigations into some of its theoretical assumptions. The innovative character of the research solutions included in the present project is based, on the one hand, on new approaches to the verification of the STAC assumptions and, on the other hand, on the verification of the assumptions that have not been subjected to systematic investigations so far. Such a research agenda has been motivated by gaps in existing knowledge regarding some of the phenomena described in the STAC model. Filling these gaps will be the contribution of the project to the development of research on cognitive aging.
In this context, the aims of the study are the following:
- The verification of the STAC model assumptions about the cognitive processes triggered during compensatory brain activity in older adults based on EEG time-frequency analyses.
- The verification of the STAC model assumption about the possible influence of cognitive training on the emergence and disappearance of compensatory brain activity in older adults, has not been investigated so far.
Research problems justifying the aims:
Re. 1. The cognitive interpretation of compensatory brain activity in older adults, both in the STAC model and in light of research findings collected until now, is based on incomplete premises. Compensatory brain engagement is the overactivation observed in certain brain regions in older adults which is linked to a better performance on cognitive tasks. Better performance on cognitive tasks is regarded here as evidence for ongoing compensation. Compensatory brain activity in older adults has been confirmed by numerous studies utilizing fMRI and PET scans, which are the two most dominant neuroimaging methods in this area. Models of compensatory brain activity in older adults, such as the STAC model, are based on these neuroimaging data. Theoretical interpretations in terms of cognitive processes are imposed on these observations only subsequently. Thus, the verification of the compensatory mechanisms described in these models is limited as the development and the verification of the model are based on the same methodology. Subsequent studies that found a positive relationship between the overactivation of specific brain regions and better performance on cognitive tasks confirmed the empirical relationship that led to the development of the theoretical model. However, the confirmation of the relationship alone does not suffice to verify the theoretical interpretation encapsulated in the model. The need to deepen the understanding of cognitive processes engaged in compensation was indicated by the very authors of the STAC model.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 20 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age: belonging to one of the age groups - older adults (60-75 years old) or young adults (20-35 years old). The 60-75 age group limits the influence of the advance of various age-related changes, and at the same time, this group is classified as early late-adulthood. The 20-35 group, on the other hand, falls within early adulthood (Sugarman, 2001);
- •No history of mental illness;
- •No history of neurological disorders, including neurodegenerative diseases, or severe head injuries.
- •Normal or corrected-to-normal vision;
- •Intellectual norm;
- •No dementia symptoms (in old adults);
- •No visible abnormal brain activity in EEG (verifiable only in the pre-test);
- •Signing an informed consent to participate in the study (after familiarizing oneself with the aim of the study and the conditions of participation, as well as having received satisfactory answers to all questions).
排除标准
- 未提供
研究组 & 干预措施
Working memory adaptive cognitive training
In the intervention, the n-back task involving working memory in terms of its content updating was applied. This task is based on the continuous presentation of items (letters in this study) that appear and disappear one by one. During each presentation, the participant must judge whether the currently displayed item matches the item presented 'n' trials earlier. The n-back task used in the current study was computerized and was programmed in PsychoPy software. All participants started their training from the 1-back level. The training was adaptive, meaning that, according to the performance accuracy achieved, participants progressed to higher (or dropped to lower) levels of difficulty. The increasing/decreasing difficulty was based on a rise/fall in the 'n' parameter. Participants were involved in 12 sessions, three in each of the four weeks. Each session lasted approximately 45 minutes.
干预措施: working memory adaptive training (Behavioral)
Multi-domain non-adaptive cognitive training
Non-adaptive multi-domain computerized training included tasks involving: visual-spatial functions, visual and verbal memory, reasoning on visual and verbal material, and calculia. Participants were involved in 12 sessions, three in each of the four weeks. Each session lasted approximately 45 minutes.
干预措施: multi-domain non-adaptive control training (Behavioral)
No contact
The passive control group was the no-contact group. Participants had no contact with the researcher for 4 weeks, corresponding to the duration of the intervention (training) in the experimental group.
结局指标
主要结局
Change in EEG power in theta, alpha and gamma bands (Stroop task)
时间窗: change from baseline at 4 weeks
The neural brain activity accompanying cognitive engagement during the Stroop task execution. EEG data will be obtained from 32 Ag/AgCl electrodes (left: Fp1, AF3, F3, F7, FC1, FC5, C3, CP1, CP5, F7, P3, P7, PO3, O1; right: Fp2, AF4, F4, F8, FC2, FC6, C4, CP2, CP6, F8, P4, P8, PO4, O2; midline: Fz, Cz, Pz, Oz) placed in accordance with the 10-20 international system and referenced to the right and left earlobes.
Change EEG power in theta, alpha and gamma bands (n-back task)
时间窗: change from baseline at 4 weeks
The neural brain activity accompanying cognitive engagement during the n-back task execution. EEG data will be obtained from 32 Ag/AgCl electrodes (left: Fp1, AF3, F3, F7, FC1, FC5, C3, CP1, CP5, F7, P3, P7, PO3, O1; right: Fp2, AF4, F4, F8, FC2, FC6, C4, CP2, CP6, F8, P4, P8, PO4, O2; midline: Fz, Cz, Pz, Oz) placed in accordance with the 10-20 international system and referenced to the right and left earlobes.
Change n-back task
时间窗: change from baseline at 4 weeks
Accuracy and reaction times in the n-back task indicated by the senstitivity index
Change in EEG power in theta, alpha and gamma bands (GoNoGo task)
时间窗: change from baseline at 4 weeks
The neural brain activity accompanying cognitive engagement during the GoNoGo task execution. EEG data will be obtained from 32 Ag/AgCl electrodes (left: Fp1, AF3, F3, F7, FC1, FC5, C3, CP1, CP5, F7, P3, P7, PO3, O1; right: Fp2, AF4, F4, F8, FC2, FC6, C4, CP2, CP6, F8, P4, P8, PO4, O2; midline: Fz, Cz, Pz, Oz) placed in accordance with the 10-20 international system and referenced to the right and left earlobes.
Change in OSpan task
时间窗: change from baseline at 4 weeks
Accuracy in the OSpan task
Change in GoNoGo task
时间窗: change from baseline at 4 weeks
Accuracy and reaction times in the GoNoGo task.
Change in Stroop task
时间窗: change from baseline at 4 weeks
Accuracy and reaction times in the Stroop task
次要结局
- Change in Digit-Symbol(change from baseline at 4 weeks)
- Change in Raven's SPM(change from baseline at 4 weeks)
- Change in Digit Span(change from baseline at 4 weeks)
研究者
Ludmiła Zając-Lamparska
Professor
Kazimierz Wielki University