Unpredictable caregiving is associated with disrupted neurophysiological measures of attention and autonomic function in three-month-old infants

The early caregiving environment exerts a powerful influence over attention and autonomic function in early infancy, which are foundational systems relevant for learning and the development of more complex cognitive and emotional regulation systems. Increasing evidence also implicates the predictability of caregiver sensory signals as a key dimension of the early environment, but few studies have examined impacts on neurophysiological systems relevant to attention and autonomic function in early infancy. The current study examined associations among caregiver sensory predictability, infant autonomic nervous system function (indexed via HRV), and behavioral and neurophysiological measures of sustained attention in a sociodemographically-diverse sample of three-month-old infants (N = 104 infants, 64 males; 51% Hispanic/Latino). The patterning of caregiver sensory signals was assessed by micro-coding for transitions in caregiver visual, auditory, and tactile signals during a semi-structured parent-child interaction and the unpredictability of these sequences was calculated using Shannon's entropy. Results indicated that infants who were exposed to more unpredictable patterns of caregiver sensory signals demonstrated reductions in relative frontal theta EEG power during periods of sustained attention, a neural marker reflecting poorer information processing and attentional control. Moreover, unpredictable caregiver sensory signals also predicted lower baseline HRV in infants, a pattern indicative of dysregulated ANS function. In turn, infant baseline HRV also predicted altered physiological indices of sustained attention. These findings provide preliminary evidence into the importance of the predictability of caregiver sensory signals in shaping developing cortical circuitry and physiological systems relevant to attentional processing from the first months of postnatal life.