Neurophysiological Markers of Cardiac Interoceptive Processing in First-Time Expectant Mothers: A Study with Heartbeat-Evoked Potentials

Abstract

Pregnancy is associated with functional and structural brain changes. Specifically, the parental caregiving network includes key structures implicated in interoception, that is, the ability to perceive and subjectively experience inner bodily states. Interoceptive processing may be critical for successful caregiving, allowing parents to integrate perceived changes in their own bodily states with information stemming from their child. Thus, it is feasible to hypothesize that pregnancy-related neurobiological changes can modify interoception in expectant mothers. In addition, these changes in interoception might be associated with mental health outcomes, such as anxiety and depression. Therefore, the main goals of the current research project were to compare neural markers of cortical interoceptive processing (heartbeat-evoked potentials; HEP) between first-time expectant mothers and matched non-expectant female subjects and, additionally, to assess whether mental health outcomes are related to interoception (neural correlates and self-report measures). Participants completed a multilevel interoception assessment protocol (self-reported interoceptive attention and accuracy scales, HEP amplitude modulation) and mental health scales (i.e., anxiety and depression). Neural markers of interoception were indexed by HEP, that is, neurophysiological responses to cardiac afferent inputs which are obtained through electroencephalography recordings time-locked to electrocardiography R peaks. HEP were recorded while participants completed the Infant Face Repetition Suppression Task in which sad or neutral infant facial expressions are presented. A condition with adult facial expressions was employed to examine domain-general vs. infant-specific effects. To develop this task, an initial validation study for the infant stimuli was conducted for a Portuguese sample, using stimuli from the Tromso Infant Faces database. Findings from this pioneering study provide further understanding of the parental brain and the role of interoception during pregnancy, contributing to the comprehension of complex processes involved in caregiving, parent-infant bonding, and perinatal mental health.