Hand to Mouth
HANDTOMOUTH develops a framework for understanding archaeological and fossil evidence for the evolution of speech and manual dexterity. We focus on low-order parameters which can potentially be assessed in fossil and archaeological evidence. The focus will be on motor control in complex, serially ordered, goal-directed movements, with two sub-themes:
Speech production: This will involve physical and digital modelling of vocal tracts of extinct hominins based on anatomical parameters, to recover the range of articulatory manoeuvres and acoustic characteristics. As part of this there will be a comparative anatomical study of the human and nonhuman primate vocal tract and of the primate cranial nerves.
Tool use: This will address the relationship between action understanding and the self-generation of action sequences in human and non-human primates. It will include behavioural analysis of the action recognition system of nonhuman primates in sequentially complex action observation tasks, and kinematic analysis of movement control in stone tool-making and other tool-using tasks in healthy and apraxic human subjects.
Unifying framework: We intend to re-evaluate the possibility that speech may have evolved from an underlying substrate regulating socially-learned tool use, reflecting shared features of neural architecture. We will identify possible areas of convergence and/or homology in behavioural organization and in neural architecture in the two systems. HANDTOMOUTH will enable us to evaluate the extent to which their parallel evolution towards greater complexity in humans was necessary or contingent (and with a better understanding of the evidential controls).