 Philosophers have roundly criticized the “no free will” interpretation of these studies offered by Libet and some other neuroscientists (see Mele 2009 for a thorough discussion and Caruso 2012: 189ff, for a dissent from the consensus). Many have emphasized that the “choices” Libet’s subjects are asked to make depart from paradigmatically free cases in important ways. Some note that the ability of subjects to precisely time their own conscious events of any kind (including simple perceptual cues) have been shown to be not fully reliable: their estimates can be manipulated by conscious primes before and after the target event. (They also come in degrees of intensity, such that the onset of an event that might quickly intensify or otherwise evolve might be more difficult to determine than the event itself.) Others observe that the studies do not even purport to identify a determining physical antecedent to conscious choice. Finally, other recent studies (beginning with Schurger et al. 2012) have called into question just what kind of neural activity Libet-style studies are tracking, and in particular whether it is even involved in the production of choice and subsequent behavior. All this remains a subject of continued scientific study and debate. (A large-scale project is currently underway that is developing a wide array of experimental probes of conscious will and its physical determinants: &lt; https://neurophil-freewill.org/&gt; For an overview of philosophical and empirical issues concerning human free will, see  entry on free will.)