Poster #156 - Piecemeal Development of Motion Preferences in Newborn Organisms

• In Event: 3-206 - Poster Session 13
  In Poster Session: PS 13 Section - Perceptual, Sensory, Motor

Integrative Statement

How does the brain develop a preference for biological motion? Previous studies have reported that both newborn chicks and newborn humans prefer biological motion over non-biological motion during the first few days of life (Simion, Regolin, & Bulf, 2008; Vallortigara & Regolin, 2006; Vallortigara, Regolin, & Marconato, 2005). Due to methodological barriers, however, these studies could only collect data at a single snapshot in time (i.e., a single 5-10 minute testing period). As a result, it has not been possible to determine how motion preferences emerge and change over time in newborn organisms. To overcome this barrier, we used a pre-registered, automated controlled-rearing method that allowed newborn chicks’ behavior to be recorded continuously (24/7) from the onset of vision. This automated method (1) eliminated experimenter bias, (2) produced 2,400 times more data per chick than prior studies, and (3) revealed how chicks’ visual preferences change over the first 10 days of life. As in the studies cited above, we tested subjects with point-light-displays of motion patterns (Fig. 1A). We found that chicks’ preferences emerged in a piecemeal manner. Starting on Day 1, chicks showed a general preference for motion, preferring biological motion over stationary displays (Fig. 1B). On Day 2, chicks began to prefer structured motion over random motion (i.e., preferring biological motion over random motion; Fig. 1C). Finally, on Days 5-6, chicks began to show a preference for more complex motion over less complex motion, preferring biological motion over rigid motion (Fig. 1D). Throughout the 10 test days, the chicks never showed a preference for upright versus inverted biological motion—a critical test of biological motion perception in human adults (Fig. 1E). These results indicate that newborn chicks do not show sensitivity to biological motion per se in the first days of life. Overall, these data suggest that newborns’ motion preferences show a piecemeal developmental trajectory during the earliest stages of visual learning.

Authors

• Samantha Marie Waters Wood, University of Southern California
  Presenting Author

• Justin N Wood, University of Southern California
  Non-Presenting Author