Biological motion is stored independently from bound representation in working memory

It has been suggested that biological motion has a storage buffer independent of that of basic visual information in working memory. However, as coherent biological motion requires binding information from both the dorsal and ventral pathways, it is possible that biological motion is a type of bound representation, and thus shares the same buffer as binding information. No study has investigated this hypothesis. We closed this gap by requiring participants to memorize a set of biological motion stimuli and colour-shape bindings concurrently. Critically, we fixed the load of one category while manipulating the load of the other. If biological motion and binding share a buffer, then working memory performance on the fixed-load category would be modulated by the memory load of the flexible-load category. In five experiments, we found that performance on the fixed-load category was not affected by the memory load of the other category, suggesting that biological motion and bound representation do not share the same buffer in working memory.