The Role of Visual Spatial Frequencies in Newborns' Processing of Dynamic Facial Expressions of Emotion

Evidence on newborns' discrimination of emotional facial expressions is scarce, and the question of what is the nature of the visual information that newborns rely on to perform such discrimination remains open. Here, we manipulated the spatial frequency (SF) content of the stimuli by selectively removing low spatial frequency (LSF) and high spatial frequency bands using newborn-appropriate cutoffs to investigate what information newborns use when preferring and discriminating between dynamic displays showing happy and fearful expressions unfolding over time. Using a preferential looking paradigm, in Study 1 (N = 63, 59% females, 92% White), we showed that newborns looked longer to happy over fearful expressions in unfiltered (broad spatial frequency) and high-pass (high spatial frequency >0.6 cycles per degree [cpd]) faces but not in low-pass (LSF < 0.5 cpd) faces. In Study 2 (N = 22, 59% females, 91% White), newborns tested in a visual habituation paradigm showed successful discrimination of the two LSF emotions. Results show that newborns can discriminate between dynamic images of happy and fearful facial expressions containing either extreme low SF (<0.5 cpd) information or higher SF (>0.6 cpd) bandwidth. Their preference for the happy expression was present for intact and high-pass filtered faces but not for low-pass faces. This SF effect is tentatively driven by an enhancement of attentional response to the LSF fearful face, whereas the response to the happy face is unaffected by the SF manipulation. Public Significance Statement<br /> The study extends the limited available evidence on newborns' preference for happy facial expressions to dynamic stimuli and demonstrates, for the first time, that attentional responses to happy and fearful faces at birth rely on different spatial frequency content of the stimuli: low and high frequencies, respectively. The visual information available in the image modulates the perceived salience of facial cues of emotions at birth: Newborns only show a preference for happy expressions when presented with unfiltered images or images with intact high-frequency information and not those with high-frequency information filtered out.