Development of body knowledge as measured by arm differentiation in infants: From global to local?

Abstract

The ability to sense and use the body parts in an organized and differentiated manner is a precursor of body knowledge in infancy. To acquire this ability, the infant's brain might explore the perceptual consequences of its bodily actions. Undifferentiated body movements would gradually be replaced by more precise actions. Only a very few studies have tested this ‘global‐to‐local’ hypothesis, and none of them have so far been replicated. In this study, we assessed arm differentiation in 4‐, 6‐, and 8‐month‐old infants using a new contingency detection task in which infants have to detect a contingency between one of their arms’ activity and an audiovisual stimulus on a screen. We found that 4‐ to 8‐month‐old infants seem to be able to use their arms in a differentiated manner. However, surprisingly, we were not able to show a developmental trend in arm differentiation between 4 and 8 months of age. What is already known on this subject? Foetuses and infants possess coarse control of their body and may be sensitive to sensory feedback caused by their own movements. Body knowledge might develop during the first year of life in what can be called a ‘global‐to‐local’ manner. Nevertheless, the precise age at which infants come to possess well‐differentiated local body knowledge requires further investigation. What the present study adds? 4‐ to 8‐month‐old infants seem able to use their arms in a differentiated manner when exposed to an audiovisual stimulation contingent on movements of one of their arms. However, we found no developmental trend in arm differentiation between 4 and 8 months of age. We hypothesize that infants' sensitivity to sensorimotor contingencies and their ability to narrow down contingencies to a specific limb might evolve with age as a function of the infant's current sensorimotor interests.

Making the World Behave: A New Embodied Account on Mobile Paradigm

“…More specifically, 2-month-old infants increased the movement frequency of all limbs during the acquisition phase, and movement increased in the specific arm connected to the mobile only at 4 months. Similarly, limb differentiation was observed in infants aged 4–8 months in a contingency detection task in which the presentation of an audio-visual stimulus was contingent on the movement of a particular arm (Jacquey et al, 2020b ). Despite the failed attempt of Jacquey et al ( 2020b ) to replicate the developmental trend observed in Watanabe and Taga ( 2006 ), both studies showed that the limb differentiation started at 4 months of age.…”

“…Similarly, limb differentiation was observed in infants aged 4–8 months in a contingency detection task in which the presentation of an audio-visual stimulus was contingent on the movement of a particular arm (Jacquey et al, 2020b ). Despite the failed attempt of Jacquey et al ( 2020b ) to replicate the developmental trend observed in Watanabe and Taga ( 2006 ), both studies showed that the limb differentiation started at 4 months of age. Previous results reported by Rovee-Collier et al ( 1978 ) showed that such limb differentiation is evident even at 3 months.…”

“…However, it is also important to note that age-related differences concerning such limb differentiation are inconclusive, and one likely explanation may be that the methodological parameters varied among studies. For example, Watanabe and Taga ( 2006 ) used a motion tracking system to analyze the movement of infants, and Jacquey et al ( 2020b ) measured the arm activity with accelerometers, whereas Rovee-Collier et al ( 1978 ) relied on more traditional methods, such as counting the number of kicks. These findings indicate a need for systematic replications with modern techniques to gain a more nuanced understanding of motor learning across different age groups.…”

“…While arm-based learning is more prominent at the beginning of life (Rochat, 1993 ), caudal body parts (e.g., hips, legs) are integrated into infants’ body representation as infants gain more experience with leg-based learning (Watanabe and Taga, 2011 ; Thomas et al, 2015 ). Recently, studies focusing on the ability to learn contingencies revealed that detecting the contingency between a specific limb movement and mobile is an ability that develops with age (Watanabe and Taga, 2006 ; Jacquey et al, 2020b ). Development involves an ever-changing process of interaction between perception and action.…”

“…For more than 50 years, the mobile paradigm was used to study a wide range of topics, from perceptual abilities to the long-term memory capacity of young infants, challenging contemporary views on the capabilities of and learning opportunities available to young infants. Although a recent article (Jacquey et al, 2020a ) reviewed the literature on contingency learning paradigms, including the mobile paradigm, to examine different determinants affecting learning sensorimotor contingencies, no review has yet attempted to integrate the entire range of studies using the mobile paradigm from Rovee and Rovee ( 1969 ) to today (Jacquey et al, 2020b ; Zaadnoordijk et al, 2020 ). Additionally, the present review discusses a role for a new account on the mobile paradigm by offering a critical perspective on some aspects of this literature.…”