Cognitive Dysfunction, Cognitive Training, Mild Cognitive Impairment, tACS
Conditions
Keywords
MCI, tACS, Cognitive training
Brief summary
The current proposal aims to assess if the combination of Speed of Processing (SoP) training with alpha tACS (α-tACS) is able to increase brain speed of processing as assessed by the Useful Field of View (UFOV) when comparing to SoP training plus sham α-tACS. Moreover, a second aim is to assess if those changes in speed of processing transfer to other cognitive domains, such as memory, language and executive functioning. Furthermore, the mechanisms underlying these interventions will be tested, namely to assess brain connectivity and coherence as assessed by EEG. To that purpose, the aim of the current proposal is to conduct a double-blind, parallel randomized trial assessing the effects of combining SoP with alpha endogenous tACS (either active or sham) in participants with Mild Cognitive impairment (MCI).
Detailed description
Dementia is thought to affect 6.3 million people across Europe and is especially prevalent in people over 85 years old (23.7%). In this sense, several cognitive training programs, alone or in combination with non-invasive brain stimulation have been used in order to ameliorate age-related cognitive impairments, and even to act in a prophylactic manner in order to prevent more extreme deficits, such as the ones presented in mild cognitive impairment, or even dementia. Despite all these efforts, the effects of CT - combined or not - with several forms of non-invasive brain stimulation have been modest at most. The current proposal aims to assess if Speed of Processing (SoP) training combined with alpha tACS (α-tACS) increases speed of processing as assessed by the Useful Field of View (UFOV) when comparing to SoP training and sham α-tACS. Furthermore, association betweens changes in speed of processing and changes in other cognitive domains, such as memory, language and executive functioning will be assessed. Finnaly, the current proposal aims at probing the mechanisms underlying these interventions, namely to test brain connectivity and coherence as assessed by EEG.
Interventions
DEVICEalpha tACS
2mA α-tACS (based on the IAF) over the prefrontal cortex (PFC)
BEHAVIORALSpeed of Processing Training
SoP training will have a total of four conditions. In condition 1, participants will be asked to identity objects at increasingly brief exposures. For condition 2, identification of stimulus on the center of the screen will be requested from participants, while a second stimulus will appear somewhere in peripheral vision - stimulus duration, difficulty of the central localization task or the area in which targets may be located are used to change the level of difficulty. Condition 3 is similar to condition 2, but visual distractors are added. Finally, for condition 4, an auditory identification component is superimposed over the visual task (Jobe et al., 2001)
Sponsors
Aveiro University
University of Coimbra
Portucalense University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Masking description
Sham tACS and cognitive training
Intervention model description
double-blinded, parallel randomized trial
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Community-dwelling adults aged 65 years and older, with cognitive complains in memory or other functions, which have declined over time
Exclusion criteria
* Score in the mini mental examination less than 23 (or over 28); * Diagnosis of Alzheimer´s Disease, any other medical condition that may predispose participants for a forthcoming decline in function, or that may increase their risk of mortality during the duration of the study. * Any contra-indication to tACS, severe sensory losses or communication difficulties that will prevent them from successfully complete the training. * Had any cognitive training in the past.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Useful Field of View Test (UFOV) | Change from baseline to week 3 | UFOV is a measure of the speed of visual processing for rapid detection and localization of targets under conditions of divided visual attention and in the presence and absence of visual clutter at an above chance level (i.e. 75%). |
| Useful Field of View (UFOV) | Change from baseline to week 6 | UFOV is a measure of the speed of visual processing for rapid detection and localization of targets under conditions of divided visual attention and in the presence and absence of visual clutter at an above chance level (i.e. 75%). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| EEG power in the alpha band | Change from baseline to week 3 | Total Power |
| P300 Event related potential - L | Change from baseline to week 3 | Latency of the P300 potential |
| P300 Event related potential - A | Change from baseline to week 3 | Amplitude of the P300 potential |
| Executive Composite Score from the Executive Abilities: Measures and Instruments for Neurobehavioral Evaluation and Research (NIH EXAMINER) | Change from baseline to week 3 | The NIH examiner executive composite comprises cognitive control, verbal fluency, and working memory assessments. Scores are based on the Item Response theory (IRT), which allows for the contribution of each item score is weighted by how effective that item measures that ability in any part of the continuum. Instead of a maximum or a minimum, higher scores, mean better performance. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Useful Field of View (UFOV) | Change from baseline to 1 month follow-up (after intervention ended) | Measure of the speed of visual processing for rapid detection and localization of targets under conditions of divided visual attention and in the presence and absence of visual clutter at an above chance level (i.e. 75%). |
| Executive Composite Score from NIH EXAMINER | Change from baseline to 1 month follow-up (after intervention ended) | The NIH examiner comprises cognitive control, verbal fluency, and working memory assessments |
Countries
Portugal
Outcome results
None listed