Voluntary actions and their distal effects are intimately related in conscious awareness. When an expected effect follows a voluntary action, the experience of the interval between these events is compressed in time, a phenomenon known as ‘intentional binding’ . Current accounts of IB suggest that it serves to reinforce associations between our goals and our intention to attain these goals via action, and that IB only occurs for self-generated actions. We used a novel approach to study IB in the context (...) of shared intentions and actions. Pairs of participants judged the time of occurrence of actions and events attributed either to oneself or to another agent. We found that IB and subjective agency are not mutually predictive when an action can be attributed to only one of two ‘co-intending’ agents. Our results pose a complication for the prevailing view that IB and subjective agency reflect a common mechanism. (shrink)

We explore experimental methods used to study the phenomena of perceptual organization, first studied by the Gestalt psychologists. We describe an application of traditional psychophysics to perceptual organization and offer alternative methods. Among these, we distinguish two approaches that use multistable stimuli: (1) phenomenological psychophysics, in which the observer's response is assumed to accurately and directly reflect perceptual experience; and (2) the interference paradigm, in which an observer's response is evaluated as correct or incorrect because it pertains to a corrigible (...) task, but does not directly reflect the observer's experience. We show that phenomenological psychophysics can yield valuable information about perceptual organization and lends itself to the development of quantitative theory. We discuss some criticisms of the method and argue that the two approaches that use multistable stimuli are complementary. We also compare each of the approaches with traditional psychophysics. We conclude that the several methods are convergent. (shrink)