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Default-mode network activity distinguishes Alzheimer's disease from healthy aging: Evidence from functional MRI
Michael D. Greicius, Gaurav Srivastava, Allan L. Reiss, Vinod Menon. Proceedings of the National Academy of Sciences, 2004-03-15
Topic: Amyloid, tau and blood-test diagnosis
Recent functional imaging studies have revealed coactivation in a distributed network of cortical regions that characterizes the resting state, or default mode, of the human brain. Among the brain regions implicated in this network, several, including the posterior cingulate cortex and inferior parietal lobes, have also shown decreased metabolism early in the course of Alzheimer's disease (AD). We reasoned that default-mode network activity might therefore be abnormal in AD. To test this hypothesis, we used independent component analysis to isolate the network in a group of 13 subjects with mild AD and in a group of 13 age-matched elderly controls as they performed a simple sensory-motor processing task. Three important findings are reported. Prominent coactivation of the hippocampus, detected in all groups, suggests that the default-mode network is closely involved with episodic memory processing. The AD group showed decreased resting-state activity in the posterior cingulate and hippocampus, suggesting that disrupted connectivity between these two regions accounts for the posterior cingulate hypometabolism commonly detected in positron emission tomography studies of early AD. Finally, a goodness-of-fit analysis applied at the individual subject level suggests that activity in the default-mode network may ultimately prove a sensitive and specific biomarker for incipient AD.
Why it matters
Compared functional MRI scans of 13 people with mild Alzheimer's and 13 age-matched older controls. The Alzheimer's group showed lower resting activity in the posterior cingulate and hippocampus, and the authors suggest activity in this brain network may prove a biomarker for early Alzheimer's.
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How this study scored 58/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it. We have no data on strength of evidence, so that was left out: it earned 55 of the 95 points we could judge it on, which is 58 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Proceedings of the National Academy of Sciences) |
| Journal's citation record | 4 / 4 | Proceedings of the National Academy of Sciences: journal h-index 1,167 (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 | — / 5 | No evidence rating recorded — left out of this score |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2004 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 7 / 7 | Cited 3,696 times (OpenAlex, 2026-10-10) |
| Citations per year | 5 / 5 | 154.0 citations a year over 24 year(s) since 2004 |
| Impact for its field and year | 5 / 6 | Cited 25.1× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 4 / 4 | Cited 344 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Vinod Menon: h-index 119 (OpenAlex, whole career) |
| Institution's track record | 3 / 3 | Stanford University: institution h-index 2,684 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 15070770) |
| Free to read | 2 / 2 | Free to read |
| Points | 55 / 95 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 55 of the 95 points we could judge it on is 58 out of 100. |
| Total | 58 / 100 | — |
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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
Greicius, M. D., Srivastava, G., Reiss, A. L., & Menon, V. (2004). Default-mode network activity distinguishes Alzheimer's disease from healthy aging: Evidence from functional MRI. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.0308627101
Vancouver
Greicius MD, Srivastava G, Reiss AL, Menon V. Default-mode network activity distinguishes Alzheimer's disease from healthy aging: Evidence from functional MRI. Proceedings of the National Academy of Sciences. 2004. doi:10.1073/pnas.0308627101. PMID: 15070770.
BibTeX
@article{greicius2004-15070770,
author = {Greicius, Michael D. and Srivastava, Gaurav and Reiss, Allan L. and Menon, Vinod},
title = {{Default-mode network activity distinguishes Alzheimer's disease from healthy aging: Evidence from functional MRI}},
journal = {Proceedings of the National Academy of Sciences},
year = {2004},
doi = {10.1073/pnas.0308627101},
pmid = {15070770},
url = {https://doi.org/10.1073/pnas.0308627101}
}
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