Mirror Self-Recognition: Ipsilateral and Contralateral Reaching in Toddlers

• In Event: Poster Session 04
  In Poster Session: PS 04 Topic - Perceptual, Sensory, Motor

Abstract

Introduction
The “rouge task” is used to test self-recognition by observing how toddlers react to seeing a “mark” on their face when looking in a mirror. Self-recognition, as indicated by touching the mark on their face, occurs in about half of children by around 18-20 months of age (Amsterdam, 1972; Brownell et al, 2010). Although the “rouge” task has appeared in numerous studies, little is known about children’s reaching strategies during this task. Here, we examine how reaching to the face varies based on the location of the mark on the face, and thus, how sensitivity to body structure is reflected through action. In this study, we applied the mark to either a lateralized (i.e., a cheek) or central (forehead) location on the face. Despite the small distances involved, we expected reaching strategies to vary systematically such that reaching would be primarily ipsilateral for the cheek location, but divided equally across the left/right hands for the central forehead location. An alternative possibility is that toddlers would use their dominant hand to reach to the mark, regardless of its location on the face.

Method
Twenty-four infants (13 female) attempted the mirror self-recognition task during monthly visits beginning at approximately 14 months. We applied a mark with face paint to three different locations: the left cheek, right cheek, or center of the forehead (see Figure 1). Each longitudinal visit included one forehead and one cheek trial (order/cheek laterality counterbalanced). Participants were invited to return until they demonstrated self-recognition on at least two trials or became older than 20 months, whichever occurred first. Self-recognition success was indicated if the infant touched the mark while looking in the mirror or immediately afterwards. The hand used by the infant to reach the mark was recorded as either “right/left” for forehead trials or “contralateral/ipsilateral” for cheek trials. Interobserver reliability for 20% of the trials was 100%.

Results
We analyzed each toddler’s last successful trial (mean age at last success = 18.1 months; mean age at first success = 16.7 months). Thirteen toddlers reached to a mark on their cheek with the ipsilateral hand and one reached with the contralateral hand (Fisher’s exact test p-value <.05; see Figure 2a). In contrast, for midline forehead trials, of the ten toddlers who touched the mark during their last successful trial, nine reached with their right hand. Due to the small number of trials, this right-hand preference was not statistically significant (Fisher’s exact test p-value = .14; see Figure 2b).

Conclusions
Toddlers’ reaching strategies were not random, but varied systematically based on the mark’s location on the face. Toddlers demonstrated an ipsilateral hand preference when reaching to a mark on either cheek, despite these locations being just a few centimeters apart. Although not statistically significant, 9/10 toddlers reached with the right hand to the midline forehead location. Collectively, the results suggest that toddlers show awareness not just of themselves in a mirror, but the structure of their bodies when reaching to a mark on their face.

Authors

• Katarina S. Patton, Tulane University
  Presenting Author

• Lisa K. Chinn, University of Houston
  Non-Presenting Author

• Caroline Mayberry, Tulane University
  Non-Presenting Author

• Claire Noonan, Tulane University
  Non-Presenting Author

• Claire Elise Dame, Tulane University
  Non-Presenting Author

• Jeffrey J Lockman, Tulane University
  Non-Presenting Author