title: The dorsal posterior insula is not an island in pain but subserves a fundamental role - Response to: "Evidence against pain specificity in the dorsal posterior insula" by Davis et al.
abstract: An interesting and valuable discussion has arisen from our recent article (Segerdahl, Mezue et al., 2015) and we are pleased here to have the opportunity to expand on the various points we made. Equally important, we wish to correct several important misunderstandings that were made by Davis and colleagues that possibly contributed to their concerns about power when assessing our paper (e.g. actual subject numbers used in control experiment and the reality of the signal-to-noise and sampling of the multi-TI technique we employed). Here, we clarify the methods and analysis plus discuss how we interpret the data in the Brief Communication noting that the extrapolation and inferences made by Davis and colleagues are not consistent with our report or necessarily, in our opinion, what the data supports. We trust this reassures the F1000Research readership regarding the robustness of our results and what we actually concluded in the paper regarding their possible meaning. We are pleased, though, that Davis and colleagues have used our article to raise an important discussion around pain perception, and here offer some further insights towards that broader discussion.
authors.affiliation: Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 4BH, UK; Nuffield Division of Anesthetics, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 4BH, UK.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Segerdahl
authors.affiliation: Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 4BH, UK; Nuffield Division of Anesthetics, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 4BH, UK.
authors.forename: Melvin
authors.initials: M
authors.lastname: Mezue
authors.affiliation: Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 4BH, UK.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Okell
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104-6291, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Farrar
authors.affiliation: Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 4BH, UK; Nuffield Division of Anesthetics, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 4BH, UK.
authors.forename: Irene
authors.initials: I
authors.lastname: Tracey
keywords: Pain, insula, brain imaging, ASL
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