Trevena and Miller provide further evidence that readiness potentials occur in the brain prior to the time that participants claim to have initiated a voluntary movement, a contention originally forwarded by Libet, Gleason, Wright, and Pearl . In their examination of this issue, though, aspects of their data lead them to question whether their measurement of the initiation of a voluntary movement was accurate. The current article addresses this concern by providing a direct analysis of biases in this task. This (...) was done by asking participants to make subjective timing decisions regarding a stimulus that could be measured objectively. Our findings suggest that their timing task was indeed biased such that participants' tend to report events as happening approximately 70 ms later than they actually happened. Implications for the original Libet et al. claims are discussed. (shrink)

This paper focuses on whether static images can depict motion. It is natural to say that pictures depicting objects caught in the middle of a dynamic action—such as Henri Cartier-Bresson’s (1932) Behind the Gare St. Lazare—are pictures of movement, but, given that pictures themselves do not move, can we make sense of such an idea? Drawing on results from experimental psychology and cognitive sciences, I show that we can. Psychological studies on implicit motion and representational momentum indicate that motion is (...) really perceived in some static images: our visual system is built in order to detect motion, even where it is only implied, and to anticipate the probable outcomes of others’ actions—even when the ‘others’ are only the subject matters of pictures’. I argue that, consequently, a range of popular depiction theories—perceptualist theories of depiction—can accommodate depicted motion. (shrink)

We report two experiments in which participants had to judge the time of occurrence of a stimulus relative to a clock. The experiments were based on the control condition used by Libet, Gleason, Wright, and Pearl [Libet, B., Gleason, C. A., Wright, E. W., & Pearl, D. K. . Time of conscious intention to act in relation to onset of cerebral activities : The unconscious initiation of a freely voluntary act. Brain 106, 623–642] to correct for any bias in the (...) estimation of the time at which an endogenous event, the conscious intention to perform a movement, occurred. Participants’ responses were affected systematically by the sensory modality of the stimulus and by the speed of the clock. Such findings demonstrate the variability in judging the time at which an exogenous event occurs and, by extension, suggest that such variability may also apply to the judging the time of occurrence of endogenous events. The reliability of participants’ estimations of when they formed the conscious intention to perform a movement in Libet et al.’s study is therefore questionable. (shrink)