Poster #158 - Increasing the cost of movement: Does infant exploration pay the price?

• In Event: 3-159 - Poster Session 12
  In Poster Session: PS 12 Section - Perceptual, Sensory, Motor

Integrative Statement

Independent locomotion is one of the most significant achievements of infancy. Through spontaneous locomotor exploration, infants accumulate vast amounts of locomotor experience and encounter numerous opportunities for learning. But what incites a stationary infant who can locomote to get up and go? For typically developing infants, locomotion appears to be self-motivating. A growing body of research suggests that many bouts of locomotion (~60%) do not end near discernable destinations such as toys, caregivers, or climbable surfaces (Cole et al., 2016; Hoch et al., 2018). Instead, infants take steps in place, or start and stop walking in the middle of the room. In fact, infants don’t need any destinations at all—they walk just as much in an empty room as in a room full of toys (Hoch et al., 2018). Apparently, much of infants’ locomotor exploration constitutes movement for the sake of movement.

Here, we asked whether locomotor exploration changes when movement is made more costly and effortful. We expect that increasing the cost of locomotion will decrease overall rates of time in motion. However, the critical question concerns the proportion of walking bouts directed toward destinations. One possibility is that increased cost will lead infants to explore more strategically and to direct a larger proportion of locomotor bouts toward new destinations. An alternative possibility is that the added cost of movement will result in even fewer bouts directed toward destinations.
To answer this question, we are experimentally increasing the cost and effort of walking by dressing 14-month-old toddlers in a weighted snowsuit loaded with 15% of infants’ body weight (Figure 1A) and an unweighted fabric snowsuit with the padding removed (Figure 1B). Using a counterbalanced, within-subjects design, we observe infants as they play independently in each condition for 10 minutes. The playroom is equipped with five toys (stroller, broom, popper, large ball, bucket with small balls). Caregivers are seated and in view, but are occupied completing paperwork. Following each play condition, we collect standard measures of walking proficiency using a pressure sensitive carpet.

Preliminary results from 7 infants (expected N by SRCD = 30) show that the weighted snowsuit decreases walking proficiency (Figure 1C). In the weighted condition, infants move slower, and take shorter, wider steps—all markers of less mature gait patterns, ts ≥ 3.89, ps ≤ .008 (Figure 1D-F). Moreover, during free play, 5/7 infants in the weighted condition spent less time in motion and 4/7 fell more frequently (Figure 2A-B). These findings suggest that the weight manipulation successfully increases the cost of walking. Furthermore, 5/7 infants directed a smaller proportion of bouts to destinations while wearing the weighted snowsuit (Figure 2C). Our preliminary data suggest that making movement more costly decreases infants’ interactions with distant people, places, and things. These findings have implications for children with limited mobility who face higher costs for locomotor exploration relative to their typically developing peers.

Authors

• Justine Hoch, New York University
  Presenting Author

• Omar El Fadel, New York University
  Non-Presenting Author

• Paige Selber, New York University
  Non-Presenting Author

• Karen E Adolph, New York University
  Non-Presenting Author