A longitudinal study of seven 2- to 6-month-old infants wearing a rattle on their wrist

• In Event: The Role of Proprioception in the Development of Reaching and Knowledge About the Self

Abstract

As infants become sensitive to the consequences of their actions, they first react to these consequences and then anticipate them. Such detection of sensorimotor contingencies requires the coordination between proprioception and tactile, visual or auditory senses. There is no strong consensus in current literature about the age at which infants start detecting sensorimotor contingencies. Early examples of some anticipation are given in fetuses opening the mouth before the thumb reaches it (Myowa-Yamakoshi et al., 2006), or in newborns elevating the arm higher than spontaneously when it allows them to see it through a beam of light (van der Meer, 1997). However, even 4-month-olds, while moving their connected arm more than the non-connected one, do not give clear cues that they are aware of the contingency between their arm movement and the display on the screen (Jacquey et al., 2019).

The difficulty to establish when infants start being aware that by moving their body in a particular way they can obtain interesting effects either on their own body (self-touch) or in the environment has probably several reasons. An important one is the difficulty to identify good indicators that the infant has associated its movements to the effects of these movements (form of conditioning) and the difficulty to detect the transition from this conditioning to proper awareness. We report the preliminary results of two studies that we conducted to explore cues showing how infants detect the consequences of their movements when they touch their own body (internal effect) and when their movements cause an auditory effect (external effect). We have observed a total of nine infants longitudinally in their homes, between 2 and 4 months of age; six infants participated in a first experiment and were followed to observe their spontaneous self-touch behaviors (weekly recordings); seven infants participated in a second experiment and were followed to investigate their behavior when a sound-producing bracelet is attached to one of their hands (recordings every few days). To track changes in sensitivity to sensorimotor contingencies, we analyzed hand and arm movements in the self-touch observations and arm and leg movements, as well as facial expressions in the bracelet condition.

We have found a rich array of responses that indicate different levels of sensitivity to sensorimotor contingency, such as: shaping the hand before reaching to own body, looking at the limb that caused the effect or at the bracelet where the effect originates, expressing frustration or satisfaction while moving a limb, exploring and repeating the movement leading to the effect and only this one, etc. Our analyses suggest that subtler cues (emotional state, gaze, etc.) than the ones commonly used (movements’ specificity for instance) could show early stages of detection of sensorimotor contingencies.

Authors

• J. Kevin O'Regan, Centre de Recherche Interdisciplinaire and Université de Paris
  Presenting Author

• Claire de Fremond, University of Paris
  Non-Presenting Author

• Judith Vergne
  Non-Presenting Author

• Pramod Murthy, DFKI
  Non-Presenting Author

• Eszter Somogyi, University of Portsmouth
  Non-Presenting Author

• Jacqueline Fagard, Centre National de la Recherche Scientifique (CNRS)
  Non-Presenting Author