Sensory Feedback During Active Movements of Stick Insects

G. Weiland, U. T. Koch
1987 Journal of Experimental Biology  
In the stick insect Carausius morosus, the role of the chordotonal organ was investigated using a new experimental arrangement which artificially closes the femur-tibia control system. The chordotonal organ was stimulated during voluntary movements by applying trapezoidal ramp stimuli in the closed-loop configuration. The results demonstrate that the feedback loop is used to control the end points of joint movement. In addition, it was found that the control system counteracts experimentally
more » ... lied velocity changes imposed during the middle part of the movements. Acceleration-sensitive units are shown to contribute to the reaction. The results show that during active voluntary movements reflexes measured in the inactive animal are neither simply incorporated in a servo-system nor suppressed. Instead their characteristics are altered so that the voluntary movements are executed as intended by the animal. Thus reflexes cannot be considered as a fixed behavioural unit; rather their changing role must be analysed in the context of the behaviour studied.
doi:10.1242/jeb.133.1.137 fatcat:monjjyalgrgmbhk5x2vueih5hq