Learning About a Location: Infants Navigate a Deformable Surface Based on Prior Experience

• In Event: Novel Findings and New Methods in Motor Skill Development, Perception, & Learning

Abstract

Navigation of the environment is affected by salient prior experience with specific locations. Drivers slow down at known speed traps, home-owners step around a familiar creaky stair, and primates and rats avoid the side of their chamber where aversive stimuli were encountered previously (Tzschentke, 1998). However, little is known about infants’ ability to learn about locations: Can infants learn to associate environmental cues with salient events and thereby adjust their locomotion when approaching a specific location? Here, we observed infants navigating a deformable “foam pit” because infants could only learn about rigidity through self-involved experience, typical locomotion was impossible, and falling was salient.

Infants were encouraged to locomote over a solid raised walkway. On test trials, the middle of the walkway was replaced with a deformable foam pit (Figure 1A). Twenty infants (10 boys) were observed longitudinally every three weeks from 10.5 months, when all were crawlers, to 15 months, when all had become walkers (Figure 1B). Across sessions, the walkway and the foam pit remained in the same location in the room, and the foam pit was covered by the same visually salient cloth to provide environmental cues for place learning. The deformable surface guaranteed that on their first encounter, infants would fall into the foam pit—or at least experience salient disruptions of ongoing locomotion.

In general, average attempt rates to crawl or walk over the foam pit decreased across sessions, b = -.05, Wald χ^2 = 13.37, p < .001. Attempt rates between the last crawling session and the first walking session did not differ, Wald χ^2 = .25, p = .62, suggesting that knowledge about location did not depend on posture. In addition, many infants deliberately stopped in front of the foam pit and reached out with their hands and feet to touch the surface. Touching was correlated with avoidance, r(1078) = .31, p < .001. No infants displayed signs of enjoying the foam pit (e.g. laughing, speeding up, jumping into the foam pit).

However, infants showed substantial individual differences in learning about the deformable location (Figure 2). Four infants showed instant place avoidance as soon as their hands sank into the foam pit in their first session as crawlers (top panel). They retreated back to the solid side of the walkway and continued to avoid the foam pit in subsequent sessions, even after they began to walk. Twelve infants showed gradual learning and their attempts to cross the foam pit decreased across sessions regardless of whether they were still crawlers or had transitioned to walking (middle panel). They avoided the foam pit or crossed it using an alternative strategy (e.g., backing or sitting). Four infants showed no evidence of behavioral adjustments when approaching the foam pit (bottom panel). They fell repeatedly in almost every session while crawling and walking.

In sum, most infants learned to avoid a location that disrupts ongoing locomotion after repeated experience. Location learning did not depend on motor posture, though it did vary across individual infants.

Authors

• Danyang Han, New York University
  Presenting Author

• Amy Joh, Seton Hall University
  Non-Presenting Author

• Yueqiao Liu, New York University
  Non-Presenting Author

• Whitney G Cole, New York University
  Non-Presenting Author

• Scott R. Robinson, Pacific Ethological Labs
  Non-Presenting Author

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