Package: icaOcularCorrection
Type: Package
Title: Independent Components Analysis (ICA) based artifact correction.
Version: 2.2.4
Date: 2013-06-25
Depends: fastICA, mgcv
Author: Antoine Tremblay, NeuroCognitive Imaging Lab, Dalhousie
University
Maintainer: Antoine Tremblay <trea26@gmail.com>
Description: Removes eye-movement and other types of known (i.e.,
recorded) or unknown (i.e., not recorded) artifacts using the
fastICA package. The correction method proposed in this package
is largely based on the method described in on Flexer, Bauer,
Pripfl, and Dorffner (2005). The process of correcting electro-
and magneto-encephalographic data (EEG/MEG) begins by running
function ``icac'', which first performs independent components
analysis (ICA) to decompose the data frame into independent
components (ICs) using function ``fastICA'' from the package of
the same name. It then calculates for each trial the
correlation between each IC and each one of the noise signals
-- there can be one or more, e.g., vertical and horizontal
electro-oculograms (VEOG and HEOG), electro-myograms (EMG),
electro-cardiograms (ECG), galvanic skin responses (GSR), and
other noise signals. Subsequently, portions of an IC
corresponding to trials at which the correlation between it and
a noise signal was at or above threshold (set to 0.4 by
default; Flexer et al., 2005, p. 1001) are zeroed-out in the
source matrix, ``S''. The user can then identify which ICs
correlate with the noise signals the most by looking at the
summary of the ``icac'' object (using function
``summary.icac''), the scalp topography of the ICs (using
function ``topo_ic''), the time courses of the ICs (using
functions ``plot_tric'' and ``plot_nic''), and other diagnostic
plots. Once these ICs have been identified, they can be
completely zeroed-out using function ``update.icac'' and the
resulting correction checked using functions ``plot_avgba'' and
``plot_trba''. Some worked-out examples with R code are
provided in the package vignette.
Suggests: wavethresh
License: GPL-2
LazyLoad: yes
Packaged: 2013-06-25 16:16:11 UTC; ncil
NeedsCompilation: no
Repository: CRAN
Date/Publication: 2013-06-25 18:35:06