Strength of the perception action coupling in human body discrimination tasks

Perceiving and extracting information from others rely on functional Perception Action Coupling. Because motor experiences influence the strength of the perception action coupling, we explored the duality between vision and proprioceptive information about the self and others in body perception using a sequential same-different visual task from 6 to 7 years old to adults. Using a same-different matching task combined with congruent or incongruent action execution, this study explored in 30 children (M ± SD: 9.2 ± 1.5; 16♀), 33 adolescents (M ± SD: 14.7 ± 1.5; 16♀) and 28 adults (M ± SD: 29.5 ± 6.5; 12♀) how the congruence of the perception action coupling could influence the body representation building in memorizing and discriminating other's postures. The first result revealed better performances to perceive other's body postural changes compared to objects' shapes modifications as early as 6-7 years old. Nevertheless, this ability needs a long time to mature as reflected by the lower performances in children compared to older groups, i.e. adolescents and young adults. In addition, executing a congruent action during the encoding phase increased the RT, reflecting involvement of additional cognitive processes of self-other correspondence, without improving the performance accuracy, due to a slow maturation of multimodal body representations. On the other hand, executing an incongruent action during the encoding phase revealed an interference effect to perceive others' posture, demonstrated by the decrease of performance accuracy. As we initially hypothesized, the strength of perception action coupling appears to be modulated by age. Indeed, the interference effect had a greater impact in adolescents involved in a different judgment of two body postures. Therefore, the assessment of the perception action coupling may predict the body representation maturity in typical development or internal body representation dysfunction in neurodevelopmental disorders.