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Statistical parametric maps in functional imaging: A general linear approach
Statistical parametric maps are spatially extended statistical processes that are used to test hypotheses about regionally specific effects in neuroimaging data. The most established sorts ofExpand
Voxel-Based Morphometry—The Methods
At its simplest, voxel-based morphometry (VBM) involves a voxel-wise comparison of the local concentration of gray matter between two groups of subjects. The procedure is relatively straightforwardExpand
A unified statistical approach for determining significant signals in images of cerebral activation
A unified statistical theory for assessing the significance of apparent signal observed in noisy difference images is presented and an estimate of the P‐value for local maxima of Gaussian, t, χ2 and F fields over search regions of any shape or size in any number of dimensions is estimated. Expand
The free-energy principle: a unified brain theory?
  • Karl J. Friston
  • Psychology, Medicine
  • Nature Reviews Neuroscience
  • 1 February 2010
This Review looks at some key brain theories in the biological and physical sciences from the free-energy perspective, suggesting that several global brain theories might be unified within a free- energy framework. Expand
Dynamic causal modelling
As with previous analyses of effective connectivity, the focus is on experimentally induced changes in coupling, but unlike previous approaches in neuroimaging, the causal model ascribes responses to designed deterministic inputs, as opposed to treating inputs as unknown and stochastic. Expand
A theory of cortical responses
  • Karl J. Friston
  • Medicine, Computer Science
  • Philosophical Transactions of the Royal Society B…
  • 29 April 2005
The aims of this article are to encompass many apparently unrelated anatomical, physiological and psychophysical attributes of the brain within a single theoretical perspective and to provide a principled way to understand many aspects of cortical organization and responses. Expand
Psychophysiological and Modulatory Interactions in Neuroimaging
Interactions among extrastriate, inferotemporal, and posterior parietal regions during visual processing, under different attentional and perceptual conditions, are focused on. Expand
Unified segmentation
A probabilistic framework is presented that enables image registration, tissue classification, and bias correction to be combined within the same generative model, based on a mixture of Gaussians. Expand
Assessing the significance of focal activations using their spatial extent
The results mean that detecting significant activations no longer depends on a fixed threshold, but can be effected at any (lower) threshold, in terms of the spatial extent of the activated region. Expand
Spatial registration and normalization of images
A general technique that facilitates nonlinear spatial (stereotactic) normalization and image realignment is presented that minimizes the sum of squares between two images following non linear spatial deformations and transformations of the voxel (intensity) values. Expand