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This paper describes an application of hierarchical or empirical Bayes to the distributed source reconstruction problem in electro- and magnetoencephalography (EEG and MEG). The key contribution is the automatic selection of multiple cortical sources with compact spatial support that are specified in terms of empirical priors. This obviates the need to use(More)
SPM is a free and open source software written in MATLAB (The MathWorks, Inc.). In addition to standard M/EEG preprocessing, we presently offer three main analysis tools: (i) statistical analysis of scalp-maps, time-frequency images, and volumetric 3D source reconstruction images based on the general linear model, with correction for multiple comparisons(More)
Many models of serial recall assume a chaining mechanism whereby each item associatively evokes the next in sequence. Chaining predicts that, when sequences comprise alternating confusable and non-confusable items, confusable items should increase the probability of errors in recall of following non-confusable items. Two experiments using visual(More)
The medial temporal lobe (MTL), a set of heavily interconnected structures including the hippocampus and underlying entorhinal, perirhinal and parahippocampal cortex, is traditionally believed to be part of a unitary system dedicated to declarative memory. Recent studies, however, demonstrated perceptual impairments in amnesic individuals with MTL damage,(More)
We describe an extension of our empirical Bayes approach to magnetoencephalography/electroencephalography (MEG/EEG) source reconstruction that covers both evoked and induced responses. The estimation scheme is based on classical covariance component estimation using restricted maximum likelihood (ReML). We have focused previously on the estimation of(More)
I argue here that functional neuroimaging data--which I restrict to the haemodynamic techniques of fMRI and PET--can inform psychological theorizing, provided one assumes a "systematic" function-structure mapping in the brain. In this case, imaging data simply comprise another dependent variable, along with behavioural data, that can be used to test(More)
Repetition of the same stimulus leads to a reduction in neural activity known as repetition suppression (RS). In functional magnetic resonance imaging (fMRI), RS is found for multiple object categories. One proposal is that RS reflects locally based "within-region" changes, such as neural fatigue. Thus, if a given region shows RS across changes in stimulus(More)
We present an empirical Bayesian scheme for distributed multimodal inversion of electromagnetic forward models of EEG and MEG signals. We used a generative model with common source activity and separate error components for each modality. Under this scheme, the weightings of error for each modality, relative to source components, are estimated automatically(More)
We describe an asymmetric approach to fMRI and MEG/EEG fusion in which fMRI data are treated as empirical priors on electromagnetic sources, such that their influence depends on the MEG/EEG data, by virtue of maximizing the model evidence. This is important if the causes of the MEG/EEG signals differ from those of the fMRI signal. Furthermore, each(More)
Electrophysiological recording in the anterior superior temporal sulcus (STS) of monkeys has demonstrated separate cell populations responsive to direct and averted gaze. Human functional imaging has demonstrated posterior STS activation in gaze processing, particularly in coding the intentions conveyed by gaze, but to date has provided no evidence of(More)