when a part of the body moved through space and approached the remembered location of an object in the dark. The activity of these multisensory neurons therefore signaled the presence of an object near or touching a part of the body, regardless of whether the object was felt, seen, heard, or remembered. Electrical stimulation of these multisensory neurons almost always evoked a complex, coordinated movement that resembled a flinching, blocking, or protecting action. Chemical inhibition of these neurons produced a "nerves of steel" state in which defensive reactions were inhibited. Chemical enhancement of these neurons produced a "super flincher" state in which any mild stimulus, such as an object gently moved toward the face, evoked a full-blown flinching reaction. In Graziano's interpretation, these multisensory neurons form a specialized brain-wide network that encodes the space near the body, computes a margin of safety, and helps to coordinate movements in relation to nearby objects with an emphasis on withdrawal or blocking movements. A subtle level of activation might bias ongoing behavior to avoid collision, whereas a strong level of activation evidently causes an overt defensive action. The neurons that encode peripersonal space may also provide a neuronal basis for the psychological phenomenon of personal space. Personal space, described by Hall, is the flexible bubble of space around each person that is protected from intrusion by other people. The peripersonal neurons may also play a central role in the body schema an internally computed model of the body first proposed to exist by Head and Holmes in 1911. An action map in the motor cortex In the 2000s Graziano's lab obtained evidence suggesting that the motor cortex might not contain a simple map of the body's muscles as in classical descriptions such as Penfield's description of a motor homunculus. Instead, the motor cortex may contain a mapping of coordinated, behaviorally useful actions that make up a typical movement repertoire. In their initial experiments, Graziano and colleagues used electrical microstimulation on the motor cortex of monkeys. Most previous protocols in the motor cortex used very brief stimulation, such as for a hundredth of a second. Graziano applied the stimulation for half a second each time, on a behaviorally relevant time scale, in order to match the typical duration of a monkey's reaching and grasping. The longer stimulation train in Graziano's experiments evoked complex movements that included many joints and that resembled movements from the