The Contemporary Debate in Animal Ethics

This final chapter explores the range of ideas current in the contemporary animal ethics debate. Much of the chapter is devoted to documenting the critique of the animal welfare ethic, which holds that, while animals have moral standing, humans, being persons, have a superior moral status. Three different strands of this critique—based on utilitarian, rights, and contractarian approaches—are identified and explored. The final part of the chapter documents the fragmentation of the animal ethics debate in recent years. This has included a more nuanced position which seeks to decouple animal rights from abolitionism, accounts of animal ethics from virtue ethics and capabilities perspectives, and a relational turn associated with the feminist care ethic tradition and, more recently, the utilization of citizenship theory by Donaldson and Kymlicka.

Postural adjustments for online corrections of arm movements in standing humans

The aim of this study was to investigate how humans correct ongoing arm movements while standing. Specifically, we sought to understand whether the postural adjustments in the legs required for online corrections of arm movements are predictive or rely on feedback from the moving limb. To answer this question we measured online corrections in arm and leg muscles during pointing movements while standing. Nine healthy right-handed subjects reached with their dominant arm to a visual target in front of them and aligned with their midline. In some trials, the position of the target would switch from the central target to one of the other targets located 15°, 30°, or 45° to the right of the central (midline) target. For each target correction, we measured the time at which arm kinematics, ground reaction forces, and arm and leg muscle electromyogram significantly changed in response to the target displacement. Results show that postural adjustments in the left leg preceded kinematic corrections in the limb. The corrective postural muscle activity in the left leg consistently preceded the corrective reaching muscle activity in the right arm. Our results demonstrate that corrections of arm movements in response to target displacement during stance are preceded by postural adjustments in the leg contralateral to the direction of target shift. Furthermore, postural adjustments preceded both the hand trajectory correction and the arm-muscle activity responsible for it, which suggests that the central nervous system does not depend on feedback from the moving arm to modify body posture during voluntary movement. Instead, postural adjustments lead the online correction in the arm the same way they lead the initiation of voluntary arm movements. This suggests that forward models for voluntary movements executed during stance incorporate commands for posture that are produced on the basis of the required task demands.