Biological Cybernetics
Active Tactile Exploration and Goal-Directed Movement
Stick insects live nocturnally and many species are obligatory walkers (none of the ones we study can jump or fly). As a consequence, many stick insect species use their antennae (or feelers) for tactile near-range orientation. During locomotion, they actively move their antennae as if to search the ambient space for obstacles. Once an antenna touches an object, the animal typically responds to this contact event by directed movements. For example, it may move a front leg to reach for the obstacle touched. In a number of recent and ongoing projects, we study (i) how the animals adapt their tactile exploration behaviour to spontaneous and induced changes in speed and walking direction, (ii) whether and how the tactile contact sequence predicts the forthcoming movements, and (iii) how the coordinate-transfer may work by which the antenna "tells" the leg when and where to grasp an obstacle. Picture: Movement trajectory of a stick insect antenna during walking.