|We present a general method for automatic meta-analyses in neuroscience and apply it on text data from published functional imaging studies to extract main functions associated with a brain area --- the posterior cingulate cortex. Abstracts from PubMed are downloaded, words extracted and converted to a bag-of-words matrix representation. The combined data is analyzed with hierarchical non-negative matrix factorization. We find that the prominent themes in the PCC corpus are episodic memory retrieval and pain. We further characterize the distribution in PCC of the Talairach coordinates available in some of the articles. This shows a tendency to functional segregation between memory and pain components where memory activations are predominantly in the caudal part and pain in the rostral part of PCC.|
Some part of the work uses the Hotelling's T2-test to set for difference between set of Talairach coordinates. Another test that is suitable for non-Gaussian distributions is described in another work: Testing for difference between two groups of functional neuroimaging experiments.
Data comes from the PubMed and Brede databases, and functions from the Brede Neuroinformatics Toolbox are used to analyze the data. Of interest might also be the Brede database page dedicated to the posterior cingulate gyrus: WOROI: 5 - Posterior cingulate gyrus.
|Finn Årup Nielsen was at that time a Post Doc at the Neurobiology Research Unit, Copenhagen University Hospital on a grant for postdoctoral studies from the Villum Kann Rasmussen Foundation. He is also attached to Informatics and Mathematical Modelling at the Technical University of Denmark.|
|Daniela Balslev was at that time a PhD student at Neurobiology Research Unit, Copenhagen University Hospital and Danish Research Centre for Magnetic Resonance, Hvidovre Hospital.|
|Lars Kai Hansen is Professor at Informatics and Mathematical Modelling, Technical University of Denmark|