In this experiment, you'll press SPACE repeatedly and see a light turn on after each press. Just keep pressing at your own pace.
Use a keyboard (not a touchscreen) for best results.
Based on: Stetson, Cui, Montague & Eagleman (2006). "Motor-Sensory Recalibration Leads to an Illusory Reversal of Action and Sensation." Neuron, 51, 651–659.