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SummaryData analysis workflows in many scientific domains have become increasingly complex and flexible. To assess the impact of this flexibility on functional magnetic resonance imaging (fMRI) results, the same dataset was independently analyzed by 70 teams, testing nine ex-ante hypotheses. The flexibility of analytic approaches is exemplified by the fact that no two teams chose identical workflows to analyze the data. This flexibility resulted in sizeable variation in hypothesis test results, even for teams whose statistical maps were highly correlated at intermediate stages of their analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Importantly, meta-analytic approaches that aggregated information across teams yielded significant consensus in activated regions across teams. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset. Our findings show that analytic flexibility can have substantial effects on scientific conclusions, and demonstrate factors related to variability in fMRI. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for multiple analyses of the same data. Potential approaches to mitigate issues related to analytical variability are discussed.

Neuroimaging studies of the medial prefrontal cortex (mPFC) suggest that the dorsal anterior cingulate cortex (dACC) region is responsive to a wide variety of stimuli and psychological states, such as pain, cognitive control, and prediction error (PE). In contrast, a recent meta-analysis argues that the dACC is selective for pain, whereas the supplementary motor area (SMA) and pre-SMA are specifically associated with higher-level cognitive processes (Lieberman and Eisenberger, 2015). To empirically test this claim, we manipulated effects of pain, conflict, and PE in a single experiment using human subjects. We observed a robust dorsal-ventral dissociation within the mPFC with cognitive effects of PE and conflict overlapping dorsally and pain localized more ventrally. Classification of subjects based on the presence or absence of a paracingulate sulcus showed that PE effects extended across the dorsal area of the dACC and into the pre-SMA. These results begin to resolve recent controversies by showing the following: (1) the mPFC includes dissociable regions for pain and cognitive processing; and (2) meta-analyses are correct in localizing cognitive effects to the dACC, although these effects extend to the pre-SMA as well. These results both provide evidence distinguishing between different theories of mPFC function and highlight the importance of taking individual anatomical variability into account when conducting empirical studies of the mPFC.

analyse change with age. This series may form the basis for assessment of contrast sensitivity in children. Materials and methodsCaucasian children aged 3 to 15 years and adults 18 to 29 years were subjects in this study. In each age group approximately equal numbers of males and females were tested. All subjects were volunteers. 86% of them were given an ophthalmological examination. Those over 6 years were required to have an uncorrected Snellen acuity of 6/6 or better for distance and those under 6 years an uncorrected acuity of 6/9 by the E test. The 14% not given an ophthalmological test were distributed over all age groups.Vertical sinusoidal gratings were generated in the conventional way2 on a display monitor (Tektronix 604 P31 fast-decay phosphor). The average luminance was 9 cd/M2 and varied from peak to trough between 14 cd/m and 4 cd/M2 giving a maximum contrast value of 0 5, contrast being defined as (Lmax -Lmin/Lmax + Lmin) whtr8-Lmax and Lmin are the maximum and minimum luminances respectively of the gratings display. Observers sat 1 metre from the display, which was viewed binocularly with natural pupils through a circular window mounted on the face of the monitor such that the display subtended 6 degrees. The surround was approximately matched for luminance and colour. Room luminance was approximately 2 cd/M2. An experimenter sat beside the subject and showed samples of gratings, varying the spatial frequency and contrast. The subject's task was to report when any lines were visible. Special care was taken to ensure the instructions were understood. Subjects were asked to keep their heads straight and at the measured distance; this was checked on a video-863 on 12 May 2018 by guest. Protected by copyright.

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