Time and consciousness: the studies on antedating by Benjamin Libet

Abstract

The studies of Benjamin Libet et al. in the 1960s-70s regarding temporal antedating are examined. After studying the direct electrical stimulation of the somatosensory cortex, which takes half a second to become conscious, Libet refined the classic thesis of the ‘specious present’, arguing that conscious processes generally take around half a second to form. Next, he explored a masking effect by carrying out experiments involving a sensory stimulus (a prick in the hand) followed by cortical stimulation, concluding that there is an ‘antedating’ of the conscious experience of the pinch (felt half a second later) for an instant of time close to the one when it actually occurred. This result was interpreted by some philosophers and neuroscientists as being a challenge to the mind-brain identity thesis, provoking a reaction by Patricia Churchland of denying the validity of the experiment or the concept of antedating. We argue that such a negative reaction is not justified, and that the experiments are consistent with a physicalist view.