Andrew Huberman· PhD
This is something that every first year neuroscience graduate student learns, which is that if you were to step on a sharp object with a bare foot, you would not need to make the decision to retract your foot, you would automatically do that provided you have a healthy nervous system. There are mechanisms in place that cause the retraction of that limb by way of ensuring that the proper muscles contract and other muscles do not contract, in fact, that they fully relax.