Holistic Processing of Body Stimuli: Evidence of Body Composite Illusion in Adults and Children

There is inconsistent evidence that human bodies are processed through holistic processing as it has been widely reported for faces. To assess how configural and holistic processes may develop with age, we administered a visual body recognition task assessing the presence of body inversion and composite illusion effects to white adults (114 participants, 77 women, aged between 18 and 35 years) and children (138 participants, 74 girls, aged between 6 and 11 years). Furthermore, to verify the presence of an own-age bias in body processing, we presented either child or adult bodies to both age groups. Adults and children showed reliable and comparable body inversion and composite illusion effects, confirming the use of configural and holistic body processing. Cross-sectional analysis showed that these perceptual strategies were already reliable in children aged 6-7 years and did not encounter significant changes across childhood. Although we found reliable body inversion and composite illusion effects for both own- and different-age bodies, results pointed to greater composite illusion effects for own-age bodies. This may suggest that sharing similar body structures might facilitate the holistic processing of others' bodies. These findings provide new insights into the development of body-specific perceptual processes and may have theoretical and clinical implications for the evaluation and treatment of body perception disorders in childhood.