Authors
Laura Jones, Maria Pureza Laudiano-Dray, Kimberley Whitehead, Judith Meek, Maria Fitzgerald, Rebecca Pillai Riddell, Lorenzo Fabrizi

Institution(s)
Department of Neuroscience, Physiology & Pharmacology, University College London
Elizabeth Garrett Anderson Obstetric Wing, University College London Hospitals
Department of Psychology, York University (Toronto)

Introduction
Neonatal mammalian brain activity is dependent upon maternal interaction 1. Maternal presence or absence is associated with brain states supporting attachment or threat learning respectively. The state in which the brain is at the time of a painful intervention is therefore likely to influence the perception of the stimulus. In human adults, cortical processing of a painful stimulus is dependent upon contextual factors 2, and maternal touch/massage and skin-to-skin care can alter neonatal behavioural and physiological reactions 3. However, the effect of maternal contact on neonatal cortical pain processing is not known. We hypothesised that maternal contact during a clinically required painful procedure will alter the neonatal brain activity suggesting different cortical processing of the stimulus.

Methods
EEG, facial expression and heart rate were recorded during a clinically-required heel lance across three age and sex-matched groups of neonates who were either in skin-to-skin, held while clothed, or in the cot. Ethical approval for this study was given by the NHS Health Research Authority. This work was funded by the Medical Research Council UK and an IASP Collaborative Research Grant.

Results
The lance was followed by a sequence of 4-5 event related potentials (ERPs), including a pain-specific ERP (nERP)4, which was smallest for infants held skin-to-skin and largest for infants held while clothed (p=.016). The nERP was followed by additional and divergent long-latency ERPs (>750ms post-lance), not previously described, in each of the conditions. Behavioural (facial expression) and physiological (heart rate) responses to the lance did not differ between groups.