61.5 Saturday, Jan. 5 3D kinematics, motor control and bone strain during feeding in non-human primates IRIARTE-DIAZ, J.*; ROSS, C.F.; University of Chicago; University of Chicago email@example.com
In recent years substantial advances have been made in our understanding of the feeding mechanics of non-human primates. On one hand, researchers have investigated the relationship between the three-dimensional displacement of the mandible and food material properties as well as species-specific differences. Muscle activation patterns have also been recorded in multiple species and patterns of variation have been identified at different hierarchical levels suggesting the importance of intra and inter-individual variability. This variability derives in part from the structural complexity and redundancy of the masticatory muscles. However, little work has been done on evaluating how differences in patterns of muscle activation relate to differences in mandibular movement, and how this interplay affects the forces applied on the mandible. Such interaction, although often ignored due to lack of data, is essential to understand how the masticatory apparatus in primates adapts to changes in food material properties and how this affects feeding behavior. Using a large dataset of 3D mandible kinematics, muscle activation patterns and, in some cases bone strains, recorded simultaneously, we investigate the relationship between all these factors in two species of non-human primates, Macaca mulatta (macaques) and Cebus sp. (capuchins). Our data suggest that differences in loading regimes in the mandible are not driven as much by differences in food material properties as by differences in feeding behavior, and its associated variation in muscle activation patterns and mandibular movement.