Ongoing EEG artifact correction using blind source separation

Objective: Analysis of the electroencephalogram (EEG) for epileptic spike and seizure detection or brain-computer interfaces can be severely hampered by the presence of artifacts. The aim of this study is to describe and evaluate a fast automatic algorithm for ongoing correction of artifacts in continuous EEG recordings, which can be applied offline and online. Methods: The automatic algorithm for ongoing correction of artifacts is based on fast blind source separation. It uses a sliding window technique with overlapping epochs and features in the spatial, temporal and frequency domain to detect and correct ocular, cardiac, muscle and powerline artifacts. Results: The approach was validated in an independent evaluation study on publicly available continuous EEG data with 2035 marked artifacts. Validation confirmed that 88% of the artifacts could be removed successfully (ocular: 81%, cardiac: 84%, muscle: 98%, powerline: 100%). It outperformed state-of-the-art algorithms both in terms of artifact reduction rates and computation time. Conclusions: Fast ongoing artifact correction successfully removed a good proportion of artifacts, while preserving most of the EEG signals. Significance: The presented algorithm may be useful for ongoing correction of artifacts, e.g., in online systems for epileptic spike and seizure detection or brain-computer interfaces.Comment: 16 pages, 4 figures, 3 table

Enhanced Auditory Brainstem Response and Parental Bonding Style in Children with Gastrointestinal Symptoms

The electrophysiological properties of the brain and influence of parental bonding in childhood irritable bowel syndrome (IBS) are unclear. We hypothesized that children with chronic gastrointestinal (GI) symptoms like IBS may show exaggerated brainstem auditory evoked potential (BAEP) responses and receive more inadequate parental bonding. = 0.024). Multiple regression analysis in females also supported these findings.It is suggested that children with chronic GI symptoms have exaggerated brainstem responses to environmental stimuli and inadequate parental behaviors aggravate these symptoms

Latency of I and V Waves of the Brainstem Auditory Evoked Potential.

<p>Data are expressed with median [interquartile range].</p

Multiple regression analysis for total sample.

<p>GI symptoms as dependent variable and CSI (except GI) score, parental care, over-protection, and latencies of BAEP as independent variables. R² = 0.699, <i>p</i> = 0.0001.</p

The care score and over-protection score of Parental Bonding Instrument in controls and FGID children.

<p><b>A</b>: maternal care, <b>B</b>: maternal overprotection, □open box: controls (n = 64), ▪shaded box: GI group (n = 75). Values (ms) are given as median [interquartile range] (minimum-maximum). Double asterisk (**) indicates significant difference versus controls at <i>p</i> = 0.010 (A). Asterisk (*) indicates significant difference versus controls at <i>p</i> = 0.024 (B).</p

Actual wave forms of the brainstem auditory evoked potential (BAEP) in controls and FGID children.

<p>Upper lines are BAEPs with left ear stimulation, lower lines are BAEPs with right ear stimulation. Gray lines indicate recordings of left side, black lines show those of right side. Note remarkable and positive I, III, and V waves in ipsilateral recordings of stimulated sides, and vague wave forms in contralateral recordings of opposite sides. Note shorter latency of III wave in GI child compared with control.</p

Peak latency of BAEP III wave in females and males.

<p><b>A</b>: female, right ear, □open box: controls (n = 27), ▪shaded box: GI group (n = 35), <b>B</b>: female, left ear, □open box: controls (n = 27), ▪shaded box: GI group (n = 37), <b>C</b>: male, right ear, □open box: controls (n = 36), ▪shaded box: GI group (n = 34), <b>D</b>: male, left ear, □open box: controls (n = 35), ▪shaded box: GI group (n = 36). Values (ms) are given as median [interquartile range] (minimum-maximum). Asterisk (*) indicates significant difference versus controls at <i>p</i> = 0.034. Solid triangle (^▴) indicates tendentially but not significantly different from controls at <i>p</i> = 0.059.</p

Peak latency of BAEP III wave in all children.

<p><b>A</b>: right ear, □open box: controls (n = 63), ▪shaded box: GI group (n = 69). <b>B</b>: left ear, □open box: controls (n = 62), ▪shaded box: GI group (n = 73). Values (msec) are given as median [interquartile range] (minimum-maximum). Asterisk (*) indicates significant difference versus controls at <i>p</i> = 0.032 in the right and <i>p</i> = 0.018 in the left.</p