Sidse Marie Arnfred

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In the decomposition of multi-channel EEG signals, principal component analysis (PCA) and independent component analysis (ICA) have widely been used. However, as both methods are based on handling two-way data, i.e. two-dimensional matrices, multi-way methods might improve the interpretation of frequency transformed multi-channel EEG of channel x frequency(More)
The open source toolbox 'ERPWAVELAB' is developed for multi-channel time-frequency analysis of event related activity of EEG and MEG data. The toolbox provides tools for data analysis and visualization of the most commonly used measures of time-frequency transformed event related data as well as data decomposition through non-negative matrix and multi-way(More)
There is a increasing interest in analysis of large-scale multiway data. The concept of multiway data refers to arrays of data with more than two dimensions, that is, taking the form of tensors. To analyze such data, decomposition techniques are widely used. The two most common decompositions for tensors are the Tucker model and the more restricted PARAFAC(More)
We demonstrate how non-negative matrix factorization (NMF) can be used to decompose the inter trial phase coherence (ITPC) of multi-channel EEG to yield a unique decomposition of time-frequency signatures present in various degrees in the recording channels. The NMF optimization is easily generalized to a parallel factor (PARAFAC) model to form a(More)
We present an algorithm for multilinear decomposition that allows for arbitrary shifts along one modality. The method is applied to neural activity arranged in the three modalities space, time, and trial. Thus, the algorithm models neural activity as a linear superposition of components with a fixed time course that may vary across either trials or space in(More)
OBJECTIVE In the International Statistical Classification of Diseases, Tenth Revision(ICD-10) and Diagnostic and Statistical Manual of Mental Disorder, Third and Fourth Edition(DSM-III-IV), the presence of one of Schneider "first-rank symptoms" (FRS) is symptomatically sufficient for the schizophrenia diagnosis. Yet, it has been claimed that FRS may also be(More)
A defect in auditory evoked potential (AEP) P50 gating supports the theory of information-processing deficits in schizophrenia. The relationship between gating of the mid-latency evoked potentials (EP) in the somatosensory and the auditory modalities has not been studied together before. In schizophrenia, we might expect the processing deficits to act on(More)
Originally, the hypothesis of a sensory gating defect in schizophrenia evolved from studies of somatosensory evoked potentials (SEP), although the idea has primarily been pursued in the auditory modality. Gating is the relative attenuation of amplitude following the second stimulus in a stimulus pair. Recently, SEP P50 gating was seen when recording the SEP(More)
The availability of dopamine D(2/3) binding sites in brain of six male and six female Göttingen minipigs was measured in a baseline condition and after challenge with amphetamine sulfate (1mg/kg, i.v.) in PET studies with [(11)C]raclopride. Maps of the binding potential (pB; B(max)/K(d)) of [(11)C]raclopride were spatially normalized and co-registered to a(More)
Behavioral response to novelty in rats has been linked both to dopamine transmission in the ventral striatum, and to propensity to self-administer psychostimulant drugs. In order to probe the relationship between behavioral response to novelty and dopamine systems we have developed a behavioral model for correlation with positron emission tomography (PET)(More)