Body Schema - Tool Use

Tool Use

Not only is it necessary for the body schema to be able to integrate and form a three-dimensional representation of the body, but it also plays an important role in tool use. Studies recording neuronal activity in the intraparietal cortex in macaques have shown that, with training, the macaque body schema updates to include tools, such as those used for reaching, into the body schema. In humans, body schema plays an important role in both simple and complex tool use, far beyond that of macaques. Extensive training is also not necessary for this integration.

The mechanisms by which tools are integrated into the body schema are not fully understood. However, studies with long-term training have shown interesting phenomena. When wielding tools in both hands in a crossed posture, behavioral effects reverse in a similar way to when only hands are crossed. Thus, sensory stimuli are delivered the same way be it to the hands directly or indirectly via the tools. These studies suggest the mind incorporates the tools into the same or similar areas as it does the adjacent hands. Recent research into the short term plasticity of the body schema used individuals without any prior training with tools. These results, derived from the relation between afterimages and body schema, show that tools are incorporated into the body schema within seconds, regardless of length of training, though the results do not extend to other species besides humans.