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Decrease of evoked delta, theta and alpha coherences in Alzheimer patients during a visual oddball paradigm
Güntekin B, Saatçi E, Yener G.. Brain research, 2008-06-19
Topic: Amyloid, tau and blood-test diagnosis
In this study event related coherence of patients with Alzheimer type of dementia (AD) was analyzed by using a visual oddball paradigm as stimuli. A total of 21 mild probable AD subjects (10 untreated, 11 treated) were compared with a group of 19 healthy controls. The members of the groups had their EEG recorded from 12 electrodes by means of a visual oddball paradigm. The evoked coherence was analyzed for delta (1-3.5 Hz), theta (4-7 Hz) and alpha (8-13 Hz) frequency ranges for inter-hemispheric (F3-F4, C3-C4, T3-T4, T5-T6, P3-P4, O1-O2) and long range intra-hemispheric (F3-P3, F4-P4, F3-T5, F4-T6, F3-O1, F4-O2) electrode pairs. The control group showed higher values of evoked coherence in "delta", "theta" and "alpha" bands in the left fronto-parietal electrode pairs in comparison with the untreated AD group (p<0.01 for all frequency bands). Furthermore, the control group showed higher values of evoked coherence in the left fronto-parietal electrode pair in theta frequency band (p<0.01) and higher values of evoked coherence in the right fronto-parietal electrode pair in delta band (p<0.01) when compared to treated AD group. The only significant difference between the treated and untreated AD groups was in the alpha band. The treated AD group showed higher values of evoked coherence at the left fronto-parietal pair in alpha band in comparison to the untreated AD group (p<0.01). During a working memory process the coherence in the left fronto-parietal electrode pair (F3-P3) of AD patients is significantly decreased, thus indicating reduced connectivity between frontal and parietal sites.
Key findings
- A total of 21 mild probable AD subjects (10 untreated, 11 treated) were compared with a group of 19 healthy controls.
- Furthermore, the control group showed higher values of evoked coherence in the left fronto-parietal electrode pair in theta frequency band (p<0.01) and higher values of evoked coherence in the right fronto-parietal electrode pair in delta band (p<0.01) when compared to treated AD group.
- The only significant difference between the treated and untreated AD groups was in the alpha band.
- During a working memory process the coherence in the left fronto-parietal electrode pair (F3-P3) of AD patients is significantly decreased, thus indicating reduced connectivity between frontal and parietal sites.
Why it matters
This small EEG study found reduced event-related brain wave coherence in people with mild Alzheimer's disease compared with healthy controls, with some differences between treated and untreated patients. It describes a brain activity measurement and does not test whether any treatment improves symptoms or changes the disease course.
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Study details
- Participants21
- Evidence strengthLow
How this study scored 43/100
Published in a peer-reviewed journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Brain research) |
| Journal's citation record | 3 / 4 | Brain Research: journal h-index 399 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2008 — within 20 year(s) of the newest study here |
| Sample size | 1 / 4 | 21 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 124 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 6.2 citations a year over 20 year(s) since 2008 |
| Impact for its field and year | 3 / 6 | Cited 4.2× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 1 / 4 | Cited 10 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Görsev Yener: h-index 43 (OpenAlex, whole career) |
| Institution's track record | 0 / 3 | Dokuz Eylül University: institution h-index 271 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 18598686) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 43 / 100 | — |
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Read the original
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Güntekin, B., Saatçi, E., & Yener, G. (2008). Decrease of evoked delta, theta and alpha coherences in Alzheimer patients during a visual oddball paradigm. Brain research. https://doi.org/10.1016/j.brainres.2008.06.028
Vancouver
Güntekin B, Saatçi E, Yener G. Decrease of evoked delta, theta and alpha coherences in Alzheimer patients during a visual oddball paradigm. Brain research. 2008. doi:10.1016/j.brainres.2008.06.028. PMID: 18598686.
BibTeX
@article{guntekin2008-18598686,
author = {Güntekin, B. and Saatçi, E. and Yener, G.},
title = {{Decrease of evoked delta, theta and alpha coherences in Alzheimer patients during a visual oddball paradigm}},
journal = {Brain research},
year = {2008},
doi = {10.1016/j.brainres.2008.06.028},
pmid = {18598686},
url = {https://doi.org/10.1016/j.brainres.2008.06.028}
}
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