Objective-The purpose of this study was to evaluate and validate an offline, automated scalp EEGbased seizure detection system and to compare its performance to commercially available seizure detection software.Methods-The test seizure detection system, IdentEvent™, was developed to enhance the efficiency of post-hoc long-term EEG review in epilepsy monitoring units. It translates multi-channel scalp EEG signals into multiple EEG descriptors and recognizes ictal EEG patterns. Detection criteria and thresholds were optimized in 47 long-term scalp EEG recordings selected for training (47 subjects, ~3653 hours with 141 seizures). The detection performance of IdentEvent was evaluated using a separate test dataset consisting of 436 EEG segments obtained from 55 subjects (~1200 hours with 146 seizures). Each of the test EEG segments was reviewed by three independent epileptologists and the presence or absence of seizures in each epoch was determined by majority rule. Seizure detection sensitivity and false detection rate were calculated for IdentEvent as well as for the comparable detection software (Persyst's Reveal ® , version 2008.03.13, with three parameter settings). Bootstrap re-sampling was applied to establish the 95% confidence intervals of the estimates and for the performance comparison between two detection algorithms.Results-The overall detection sensitivity of IdentEvent was 79.5% with a false detection rate (FDR) of 2 per 24 hours, whereas the comparison system had 80.8%, 76%, and 74% sensitivity using its three detection thresholds (perception score) with FDRs of 13, 8, and 6 per 24 hours, respectively. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Bootstrap 95% confidence intervals of the performance difference revealed that the two detection systems had comparable detection sensitivity, but IdentEvent generated a significantly (p < 0.05) smaller FDR. NIH Public AccessConclusions-The study validates the performance of the IdentEvent™ .seizure detection system.Significance-With comparable detection sensitivity, an improved false detection rate makes the automated seizure detection software more useful in clinical practice.

Imaging studies have described hemodynamic activity during fear conditioning protocols with stimulus trains in which a visual conditioned stimulus (CS+) is paired with an aversive unconditioned stimulus (US, painful laser pulse) while another visual stimulus is unpaired (CS−). We now test the hypothesis that CS Event-Related Spectral Perturbations (ERSPs) are related to ratings of CS Expectancy (likelihood of pairing with the US), Valence (unpleasantness) and Salience (ability to capture attention). ERSP windows in EEG were defined by both time after the CS and frequency, and showed increased oscillatory power (Event Related Synchronization, ERS) in the delta/theta Windows (0–8 Hz) and the gamma Window (30–55 Hz). Decreased oscillatory power (Event Related Desynchronization – ERD) was found in alpha (8–14 Hz) and beta Windows (14–30 Hz). The delta/theta ERS showed a differential effect of CS+ versus CS− at Prefrontal, Frontal and Midline Channels, while alpha and beta ERD were greater at Parietal and Occipital Channels early in the stimulus train. The gamma ERS Window increased from Habituation to Acquisition over a broad area from Frontal and occipital electrodes. The CS Valence and Salience were greater for CS+ than CS−, and were correlated with each other and with the ERD at overlapping Channels, particularly in the alpha Window. Expectancy and CS Skin Conductance Response were greater for CS+ than CS− and were correlated with ERSP at fewer Channels than Valence or Salience. These results suggest that alpha ERSP activity during fear conditioning reflects Valence and Salience of the CSs more than conditioning per se. The CS Valence and Salience were correlated with each other and with ERSP in the alpha Window more commonly than in other windows. Delta/theta ERSP differentiates between CS+ and CS− over a Midline Channel at which ERSP is correlated with Expectancy ratings. Although, both Expectancy and CS Skin Conductance Response (SCR) were correlated with ERSP this correlation occurred at fewer and different Channels than those for Valence or Salience. These results suggest that ERSP activity is related to Valence and Salience of the CSs more than to conditioning per se.

Chien JH, Liu CC, Kim JH, Markman TM, Lenz FA. Painful cutaneous laser stimuli induce event-related oscillatory EEG activities that are different from those induced by nonpainful electrical stimuli. J Neurophysiol 112: 824 -833, 2014. First published May 21, 2014 doi:10.1152/jn.00209.2014.-The non-phase-locked EEG response to painful stimuli has usually been characterized as decreased oscillatory activity (event-related desynchronization, ERD) in the alpha band. Increased activity (event-related synchronization, ERS) in the gamma band has been reported more recently. We have now tested the hypothesis that the non-phase-locked responses to nonpainful electric cutaneous stimuli are different from those to painful cutaneous laser stimuli when the baseline salience of the two stimuli is the same and the salience during the protocol is modulated by count laser and count electric tasks. Both of these stimuli were presented in random order in a single train at intensities that produced the same baseline salience in the same somatic location. The response to the laser stimulus was characterized by five windows (designated windows I-V) in the time-frequency domain: early (200 -400 ms) and late (600 -1,400 ms) delta/theta ERS, 500 -900 ms alpha ERD, 1,200 -1,600 ms beta ERS (rebound), and 800 -1,200 ms gamma ERS. Similar ERS/ERD windows of activity were found for the electric stimulus. Individual participants very commonly had activity in windows consistent with the overall analysis. Linear regression of ERS/ERD for parietal channels was most commonly found for sensory (pain or unpleasantness)-or attention (salience)-related measures. Overall, the main effect for modality was found in window I-delta/theta and window V-gamma, and the Modality with Task interaction was found in all five windows. All significant interaction terms included Modality as a factor. Therefore, Modality was the most common factor explaining our results, which is consistent with our hypothesis. attention; cortex; event-related synchronization; EEG; human; pain EVENT-RELATED CHANGES in EEG spectral power can be measured by a decrease in oscillatory activity (event-related desynchronization, ERD) or an increase in oscillatory activity (event-related synchronization, ERS) (Lopes da Silva and Pfurtscheller 1999). These spectral responses (ERS/ERD) are not phase locked to the event but are analyzed by signal averaging in the frequency domain. Different frequency bands exhibit different temporal, spatial, and task-related characteristics, which are consistent with their involvement in different aspects of cerebral processing (Bastiaansen and Brunia 2001;Boiten et al. 1992;Klimesch et al. 1998;Tiihonen et al. 1991). Event-related spectral modulation of scalp EEG has also been applied to studies of the cortical processing of painful stimuli.In response to painful stimuli, ERD has been found most frequently in the alpha band (Babiloni et al. 2006;Ferracuti et al. 1994;Hu et al. 2013;Mouraux et al. 2003;Ploner et al. 2006). ERS has also been reported at long...