A Novel Method for ECG Artifact Removal from EEG without Simultaneous ECG.

The electrocardiogram (ECG) is a common source of electrical artifact in electroencephalogram (EEG). Here, we present a novel method for removing ECG artifact that requires neither simultaneous ECG nor transformation of the EEG signals. The approach relies upon processing a subset of EEG channels that contain ECG artifact to identify the times of each R-wave of the ECG. Within selected brief epochs, data in each EEG channel is signal-averaged ± 60 ms around each R-wave to derive an ECG template specific to each channel. This template is subtracted from each EEG channel which are aligned with the R-waves. The methodology was developed using two cohorts of infants: one with 128-lead EEG including an ECG reference and another with 32-lead EEG without ECG reference. The results for the first cohort validated the methodology the ECG reference and the second demonstrated its feasibility when ECG was not recorded. This method does not require independent, simultaneous recording of ECG, nor does it involve creation of an artifact template based on a mixture of EEG channel data as required by other methods such as Independent Component Analysis (ICA). Spectral analysis confirms that the method compares favorably to results using simultaneous recordings of ECG. The method removes ECG artifact on an epoch by epoch level and does not require stationarity of the artifact. Clinical Relevance - This approach facilitates the removal of ECG noise in frequency bands known to play a central role in brain mechanisms underlying cognitive processes.

The Welch Emotional Connection Screen: validation of a brief mother-infant relational health screen.

AIM: The Welch Emotional Connection Screen (WECS), assesses mother-infant Emotional Connection in clinical settings. It includes: Attraction, Vocal Communication, Facial Communication, Sensitivity/Reciprocity and clinical decision of Emotional Connection (yes/no). We tested concurrent and construct validity of the WECS and associations with behavioural and physiological measures in preterm infants. METHODS: Videos from 76 mothers-infants (gestational age 36 weeks) during an in-NICU caregiving paradigm were coded for maternal caregiving behaviour. Videos of mothers-infants were also obtained at 4 months during 10 minutes of face-to-face play (coded with WECS and for maternal positivity and infant social engagement) and the still-face paradigm (coded for infant behavioural approach towards mother; infant electrocardiogram acquired in vivo). RESULTS: WECS maternal scores were positively associated with maternal sensitivity and quality of vocal contact at 36 weeks (caregiving) and maternal positivity at 4 months (face-to-face). WECS infant scores positively correlated with infant social engagement and maternal positivity during face-to-face interactions at 4 months. Infants from emotionally not connected dyads (vs. emotionally connected dyads) displayed autonomic dysregulation and less approach-seeking behaviour towards mother during interactive/play sessions of the still-face paradigm. CONCLUSION: This preliminary evidence supports the WECS as a valid screen for rating mother-preterm infant emotional connection associated with healthier infant biobehavioural stress responding.