Postdiction: its implications on visual awareness, hindsight, and sense of agency.

Shinsuke Shimojo

doi:10.3389/fpsyg.2014.00196

Abstract

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. While backward masking provides a classical example, the flash lag effect stimulates theorists with a variety of intriguing findings. The TMS-triggered scotoma together with “backward filling-in” of it offer a unique neuroscientific case. 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. In terms of the underlying mechanisms, four prototypical models have been considered: the “catch up,” the “reentry,” the “different pathway” and the “memory revision” models. 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. The operational definition of the “postdictive phenomenon” 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. This has significant implications in interpreting “free will” and “sense of agency” in functional, psychophysical and neuroscientific terms.

Highlights

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
The critical question raised in the section Extending the “postdiction” Concept to the Memory and the Sensory Consequences of Voluntary Movements and the subsequent sections will be whether the postdiction framework, while highly consistent with the object updating, will offer a more inclusive list of phenomena over-arching a much wider range of time scale, from teens of ms to months
We demonstrated that an artificial and temporal scotoma can be created by a combination of a visual stimulus and a singlepulse Transcranial Magnetic Stimulation (TMS) (Kamitani and Shimojo, 1999)

Summary

Introduction

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. With regard to the main theme of this paper, that they consider the postdictive process as a mechanism to yield visual awareness, or a conscious percept (beyond the mere operational definition of the “postdictive phenomena”; section Backward Perceptual Phenomena).

Results

Conclusion