A new non-invasive whole body acoustic startle protocol for early infancy

The aim of the present study is to test a new non intrusive and non-invasive whole body acoustic startle protocol suitable for infants. Twelve 5-month-old infants participated in the experiment. Three brief acoustic noise bursts were presented to elicit the startle reflex while infants were seated on an infant-seat, interacting freely with their parents. The protocol foresaw the use of non-invasive startle measurement methodologies. The intensity and latency of whole body motor response were measured by using the AIMMSS (Automated Infant Motor Movement Startle Seat; Dondi, Agnoli, Vacca, Franchin, & Scatturin, 2005; Scatturin & Dondi, in prep.), a new instrument that provides a computerised measurement of infant startles. The strength of the eyeblink to the startle probes was coded using the Eye-Blink Strength Scale (EBS Scale; Essex et al., 2003). The startle facial Action Units onsets were coded using the Facial Action Coding System (FACS; Ekman, Friesen, & Hager, 2002), in particular the readapted version for infant’s face, that is the Baby FACS (Oster, in press). Results showed positive associations between the parameters recorded by the three methodologies. These findings suggest that this protocol can provide a valid non-invasive alternative to the traditional EMG for startle measuring in early infancy.