The Influence of Self-Locomotion on Infants’ Sensitivity for Fearful Faces.

• In Event: Poster Session 06
  In Poster Session: PS 06 Topic - Social, Emotional, Personality

Abstract

Our study investigates whether changes in infants’ self-locomotion induces changes in their sensitivity to the boundary between the facial expressions of fear and happiness. Previous studies have shown that walking and crawling produce changes in infants’ emotional development. For instance, Campos and colleagues (2000) showed that crawling infants show more intense expressions of anger compared to non-walking infants. Meanwhile, Walle and Campos (2014) have demonstrated that more walking experience is related to increases in infants’ receptive and productive vocabulary.

Our primary hypothesis is that as infants transition to self-locomotion, they may encounter more situations when parents or caretakers would show fearful expressions in response to unwanted or dangerous activities. Therefore, self-locomotion has the potential to increase infants’ experience with fearful expressions, and thus increase their sensitivity to the distinction between happy and fearful expressions. To test this hypothesis we are conducting a study where we test the ability of infants to discriminate between happy and happy-fearful morphs in a paradigm adapted from Kotsoni and colleagues (2001). We tested 2 groups of infants. In the younger group, infants were between 9 and 10 months of age, while in the older group infants were between 12 and 13 months old. These age ranges were chosen because they capture the typical transition of non-crawling to crawling at approximately 9 months of age, and the typical transition from crawling to walking at approximately 12 months of age. Thus in each age group we were able to test infants of similar ages, but some of whom have already made the transition to crawling or walking, while others have not.

To make the stimuli more naturalistic than still photographs and more interesting for the infants, we opted to used dynamically presented morphs which transition from a neutral expression to one that is either 100% happy, or to one of 10 evenly spaced morphs along a continuum between happiness and fear. The two dynamic stimuli are presented simultaneously on the left and right sides of the screen (the positions were randomized and counter-balanced). In our analyses, we examine the fixation time infants show for the fearful face morph as a percentage of the total fixation time for both stimuli. We then compare these values for the crawlers vs. non-crawlers in the 9-10 month-old group, as well as the crawlers vs. walkers in the 12-13 month-old group.

Preliminary results indicate that among 12-13 month old infants (n=9), walkers and crawlers do not show significant differences in their percentage of fixation time for the fearful morphs versus the happy faces. By contrast, in the group of 9-10 month-olds (n=10) the crawlers (minimum of 6 weeks of crawling experience) show a significantly higher percentage of looking time towards the fearful morph (p = .032) compared to the non-crawlers (fewer than 6 weeks of crawling experience), see Figure 1.

Our preliminary findings therefore suggest that the onset of self-locomotion in the form of crawling has a stronger effect on infants’ sensitivity for fearful faces than the transition from crawling to walking.

Authors

• Michael Vesker, Justus-Liebig-Universität Gießen
  Presenting Author

• Gloria Gehb, Justus-Liebig-Universität Gießen
  Non-Presenting Author

• Daniela Bahn, Philipps-Universität Marburg
  Non-Presenting Author

• Christina Kauschke, Philipps-Universität Marburg
  Non-Presenting Author

• Luise S. Ullrich, University of Giessen
  Non-Presenting Author

• Gudrun Schwarzer, University of Giessen
  Non-Presenting Author