Reflexes are classically viewed as fast and stereotyped responses to external perturbations. For example, in reaction to a sudden pull on your left arm (left figure) the extensor muscle on the right arm is activated.
Experiments in more complex settings, however, demonstrate the dependence on the context. The activation of the extensor in the right arm depends on whether the right arm is used to stabilised the posture or is used to hold a cup. This demonstrates that the reflex is adaptable to the context. Further experiments demonstrate that it is also learnable and integrated in motor tasks.