[The nature of the sense of effort and its neural substrate]

What are the nature and the neural substrate of voluntary force perception?

Experimental findings demonstrate that efferent signals related to motor command play a dominant role in perceiving voluntary muscular force. This suggests that voluntary force perception is provided through a sense of effort and not through a sense of intramuscular tension. Nevertheless, experimental data show that the contribution of sensory input to effort awareness must not be dismissed. Sensory signals are not involved in generating a signal of effort but rather in calibrating and modulating its magnitude. Neuroimaging and neuropsychological studies revealed that many cortical structures are activated during tasks of voluntary muscular force perception.

In such tasks, the basal ganglia might support the coherence of cortical activity.