We feel that we perceive events in the environment as they unfold in real-time, but this mode of perception is impossible to implement due to biological constraints such as neural transmission delays; predictive mechanisms compensate these constraints

Perception in real-time: predicting the present, reconstructing the past. Hinze Hogendoorn. Trends in Cognitive Sciences, December 29 2021. https://doi.org/10.1016/j.tics.2021.11.003

Highlights

*  We feel that we perceive our environment in real-time, despite the constraints imposed by neural transmission delays.

*  Due to these constraints, the intuitive view of perception in real-time is impossible to implement.

*  I propose a new way of thinking about real-time perception, in which perceptual mechanisms represent a timeline, rather than a single timepoint.

*  In this proposal, predictive mechanisms predict ahead to compensate for neural delays, and work in tandem with postdictive mechanisms that revise the timeline as additional sensory information becomes available.

*  Building on recent theoretical, computational, psychophysical, and functional neuroimaging evidence, this conceptualisation of real-time perception for the first time provides an integrated explanation for how we can experience the present.

Abstract: We feel that we perceive events in the environment as they unfold in real-time. However, this intuitive view of perception is impossible to implement in the nervous system due to biological constraints such as neural transmission delays. I propose a new way of thinking about real-time perception: at any given moment, instead of representing a single timepoint, perceptual mechanisms represent an entire timeline. On this timeline, predictive mechanisms predict ahead to compensate for delays in incoming sensory input, and reconstruction mechanisms retroactively revise perception when those predictions do not come true. This proposal integrates and extends previous work to address a crucial gap in our understanding of a fundamental aspect of our everyday life: the experience of perceiving the present.

Keywords: perceptiontimepredictionreal-timeneural delays