Are there any open fMRI datasets available on the internet? Experimental design doesn't matter much, since I would be working towards a new data analysis method. If the distributed data has been preprocessed (in a standard manner), that would be a big plus.
The fMRI Data Center (www.fmridc.org) was one such repository. About ten years ago it was a requirement for publication in the Journal of Cognitive Neuroscience that you submit your full fMRI dataset to the fMRIDC. This requirement was only around for a few years, but they ended up having 120+ datasets before the grant funding ran out. The archive is currently being moved to UCLA, so at the moment you can't request any data.
An easy way to grab some data might be to get one of the SPM tutorial datasets. They have the advantage that they are either already preprocessed or there are instructions on how to preprocess the data online. They also tend to be fairly high quality, so you will have fewer issues with noise as you work on your new analysis. You can find the tutorial data here: http://www.fil.ion.ucl.ac.uk/spm/data/
Finally, I think that most imaging researchers would be open to collaboration and data sharing. I worked with a grad student in the stats department for a few years on a new autocorrelation analysis that he was interested in. Just drop the researcher an email with a short proposal and see if they are receptive to the idea.
Other potential data sources:
- nitrc.org: Data has been preprocessed, but there is no complete list of what has been done, and how the data has been collected. Maybe the information is hidden in the previous publications. Anyway, I would not use it for research in the current state.
- birncommunity.org: Datasets come in the DICOM format, i.e. straight out of the MR scanner.
- oasis-brain.org: Seems to host only structural MR images (not functional as was requested)?
- humanconnectome.org: Data is offered in multiple versions, but again one would need to do much preprocessing him/herself.
- openfmri.org: Like with the others, the given amount of information is very minimal.
This might be better suited as a comment, but I'm not allowed to post such.
I went through the nice list collected by Craig Bennett:
nitrc.org: Data has been preprocessed, but there is no complete list of what has been done, and how the data has been collected. Maybe the information is hidden in the previous publications. Anyway, I would not use it for research in the current state.
birncommunity.org: Datasets come in the DICOM format, i.e. straight out of the MR scanner.
oasis-brains.org: Seems to host only structural MR images (not functional as was requested)?
humanconnectome.org: Data is offered in multiple versions, but again one would need to do much preprocessing him/herself.
One more option to the list is www.openfmri.org, but like with the others, the given amount of information is very minimal.
Really, isn't there any public dataset that would be ready-to-use for single-subject and group analyses? Like the OP, I would be interested in such datasets. Such that would come with the necessary details....
There was recently an issue about repositories for neuroimaging data. I just copied the table listing all of them from this paper. (Feel free to add links, I will do so when I have more time.)
- The NITRC image repository,Kennedy D.N. et al.
- The Function Biomedical Informatics Research Network data repository,Keator D.B. et al.
- The image and data archive at the Laboratory of Neuro Imaging,Crawford K. et al.
- COINS Data Exchange: an open platform for compiling curating and disseminating neuroimaging data,Landis D. et al.
- Neuroimaging data sharing on the neuroinformatics database platform,Book G.A. et al.
- XNAT central: open sourcing imaging research data,Herrick R. et al.
- Vanderbilt University Institute of Imaging Science Center for Computational Imaging XNAT: a multimodal data archive and processing environment,Harrigan L. et al.
- ConnectomeDB—sharing human brain connectivity data,Hodge R. et al.
- MGH—USC human connectome project datasets with ultra-high b-value diffusion MRI,Fan Q. et al.
- The Philadelphia Neurodevelopmental Cohort: a publicly available resource for the study of normal and abnormal brain development in youth,Satterthwaite D. et al.
- Parkinson's disease biomarkers program brain imaging repository,Vaillancourt D. et al.
- The diffusion tensor imaging (DTI) component of the NIH MRI study of normal brain development (PedsDTI),Pierpaoli C. et al.
- The Northwestern University Neuroimaging Data Archive (NUNDA),Alpert K. et al.
- The Age-ility Project (Phase 1): structural and functional imaging and electrophysiological data repository,Karayanidis F. et al.
- The Open Science CBS Neuroimaging Repository: sharing ultra-high-field magnetic resonance images of the brain,Tardif L. et al.
- The Pediatric Imaging Neurocognition and Genetics (PING) data repository,Jernigan L. et al.
- SchizConnect: mediating neuroimaging databases on schizophrenia and related disorders for large-scale integration,Wang L. et al.
- Sharing data in the global Alzheimer's association interactive network,Neu S.C. et al.
- Data integration: combined imaging and electrophysiology data in the cloud,Kini G. et al.
- OMEGA: the open MEG archive,Baillet S. et al.
- The MNI data-sharing and processing ecosystem,Das S. et al.
- Northwestern University Schizophrenia Data Sharing for SchizConnect: a longitudinal dataset for large-scale integration,Kogan A. et al.
- The Cerebral Blood Flow Biomedical Informatics Research Network (CBFBIRN) data repository,Shin D. et al.
- The PLORAS Database: a data repository for predicting language outcome and recovery after stroke,Seghier M. et al.
- The Center for Integrated Molecular Brain Imaging (Cimbi) database,Knudsen M. et al.
- Database integration of protocol-specific neurological imaging datasets,Pacurar E. et al.
- BIL&GIN: a neuroimaging cognitive behavioral and genetic database for the study of human brain lateralization,Mazoyer B. et al.
- Pain and Interoception Imaging Network (PAIN): a multimodal multisite brain-imaging repository for chronic somatic and visceral pain disorders,Labus J. et al.
- Connected brains and minds — the UMCD repository for brain connectivity matrices,Brown A. et al.
- NeuroVault.org: a repository for sharing unthresholded statistical maps parcellations and atlases of the human brain,Gorgolewski J. et al.
- ANIMA: a data-sharing initiative for neuroimaging meta-analyses,Reid T. et al.
- A database of age-appropriate average MRI templates,Richards J.E. et al.
- The Cambridge MRI database for animal models of Huntington disease,Sawiak J. et al.
I would go for data in OpenfMRI https://openfmri.org/. It has, as of 2016, a growing collection of data and attempts to present data in a standardized form, so it will be easy to work across datasets.
As @craig-bennett noted there are problems with the fMRI Data Center: I am afraid that the fMRI Data Center is still (as of 2016) no longer well-supported. When I now try http://www.fmridc.org I see nothing.