These phenomena will clearly suggest that there is a limited temporal time range (on an order of 100вЂ“200 ms) within which the processing of a stimulus presented later can affect the percept of another stimulus presented earlier.

The first part of the paper will introduce a number of classical examples of вЂњbackward perceptual phenomenaвЂќ (section Backward Perceptual Phenomena), as well as the flash-lag effect and its variations as more modern examples (section Flash-lag Effect, its Variations, and Object Updating). This paper will review postdictive phenomena in perception and cognition, mainly from the author's own work with his collaborators but from some classical studies as well, to discuss the implications of these works. This has significant implications in interpreting вЂњfree willвЂќ and вЂњsense of agencyвЂќ in functional, psychophysical and neuroscientific terms. The operational definition of the вЂњpostdictive phenomenonвЂќ can be applicable to such a wide range of sensory/cognitive effects across a wide range of time scale, even though the underlying neural mechanisms may vary across them. By extending the list of postdictive phenomena to memory, sensory-motor and higher-level cognition, one may note that such a postdictive reconstruction may be a general principle of neural computation, ranging from milliseconds to months in a time scale, from local neuronal interactions to long-range connectivity, in the complex brain. In terms of the underlying mechanisms, four prototypical models have been considered: the вЂњcatch up,вЂќ the вЂњreentry,вЂќ the вЂњdifferent pathwayвЂќ and the вЂњmemory revisionвЂќ models. Findings suggest that various visual attributes are reorganized in a postdictive fashion to be consistent with each other, or to be consistent in a causality framework. The TMS-triggered scotoma together with вЂњbackward filling-inвЂќ of it offer a unique neuroscientific case. While backward masking provides a classical example, the flash lag effect stimulates theorists with a variety of intriguing findings. There are a few postdictive perceptual phenomena known, in which a stimulus presented later seems causally to affect the percept of another stimulus presented earlier. Shimojo Psychophysics Laboratory, Division of Biology and Biological Engineering/Computation and Neural Systems, California Institute of Technology, Pasadena, CA, USA.

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