Modeling temporal perception

We seem to experience a world abounding with events that exhibit dynamic temporal structure; birds flying, children laughing, rain dripping from an eave, melodies unfolding, etc. Seeing objects in motion, hearing and communicating with sound, and feeling oneself move are such common everyday experiences that one is unlikely to question whether humans are capable of perceiving temporal properties and relations. Despite appearing pre-theoretically uncontroversial, there are longstanding and contentious debates concerning the structure of such experience, how temporal perception works, and even whether the perception of change, motion, and succession is possible. The overarching goal of my project is to develop a comprehensive model of temporal perception that does justice to the apparent phenomenology, explains how perception functions to represent temporally structured targets, and generates empirically-informed hypotheses for how such perception is neuro-cognitively realized. I also defend my model against the challenges of anti-realist competitors whom deny the possibility of perceiving temporal relations between non-simultaneous events (e.g., Reid, Chuard, Le Poidevin). In Chapter 1, I begin with the apparent phenomenology of temporal experience, identifying and lending some plausibility to three claims about the nature and content of temporal experience: i) humans perceive dynamic events that instantiate temporal properties and stand in temporal relations (e.g., change, succession, duration, order), ii) humans perceive events as present, and iii) successive events of brief duration can be experienced together as present within some finite interval. This approach enables me to outline what models of present experience are supposed to represent and explain. I proceed to sketch one family of models that posit an extended perceptual present to explain how non-simultaneous events can be experienced together as present, called “Extensionalist Models” (e.g., James, Broad, Russell, Dainton). I examine two distinct branches of extensionalism (Process vs. Content) and proprietary hypotheses linking those models to the real systems they are intended to explain, and challenge the tenability of process extensionalism. Throughout the dissertation, I advocate for Content Extensionalism, the model that holds we perceive the temporal relations between non-simultaneous events in virtue of targeting and representing temporally extended content. I develop the model by pairing it with a theory of mental representation that distinguishes representation from indication, and explains how representations are source-independent isomorphs of their intended targets. In doing so, I demonstrate its comparative advantages over other extensionalist models, provide a straightforward account of claims (i-iii), and equip the model with the resources to defeat an argument that offers two routes to denying the third and most contentious claim—that successive events occurring within a brief interval are experienced together as present. I conclude the chapter by taking a closer look at the “Intentionalist Models” largely based on Edmund Husserl’s seminal work on time consciousness, rehearse some common objections against it, and argue that content extensionalism is a preferable model. In Chapter 2, I turn my attention to motion perception, arguing that perceptual representations of constant motion are not reducible to mere successions of static perceptions representing what happens at a given time. My position directly opposes temporal atomists (e.g., Chuard, Le Poidevin), whom deny that we perceive motion, claiming that we only perceive what happens at a given time and that putative experiences of motion reduce to a series of static perceptual “snapshots” arranged successively. In the first half of the chapter, I examine and challenge some the motivations for atomism, including its connection to the empiricism of Locke and Reid, and its mereological conception of experience, such that purported experiences of motion supervene on and are reducible to the successive atomic perceptions of which they are composed. In the second half of chapter, I argue that both the apparent phenomenology and neurocognitive research shift the burden upon atomism to provide a compelling an error theory to explain away our putative perceptions as of constant motion and make their anti-realism about extended experiences palatable. I proceed to reconstruct and criticize their standard strategy of appealing to cinematic metaphors to motivate their view that motion perception is entirely reducible to series of static perceptions presented successively. Finally, I draw analogies between Zeno’s puzzle of motion and the temporal perception debate, and argue that the atomist explanation of motion experience is analogous to Zeno’s failed solution to the original puzzle and that content extensionalism provides a preferred explanation consonant with the Russell-Salmon solution. In Chapter 3, I continue to combat skepticism about the perception of temporal properties and relations. Le Poidevin (2007) proposes an epistemological puzzle of time perception, from which he derives the claim that the order and duration of events do not causally contribute to our perceptual beliefs about them. Since his view is motivated by a causal truthmaker principle for grounding knowledge, it also holds that perceptual beliefs about temporal features must be caused by the features themselves in order to count as knowledge. Given these theoretical commitments, there is a puzzle concerning how such perceptual beliefs could constitute knowledge of temporal properties. In response to Le Poidevin, I argue for an account according to which order and duration are objects of perception, causally contribute to our perceptual beliefs about them, and such beliefs are capable of counting as knowledge. I conclude by showing that, on my alternative account, the epistemological puzzle dissolves and his own solution to it fails. In Chapter 4, I specify a target range of temporal phenomena salient to understanding perceptual cognition, and motivate the multi-scale sampling (MSS) hypothesis that sensory subsystems sample information at multiple rates, i.e. shorter and longer sampling periods. I argue that both behavioral and neurophysiological data support the hypothesis that nervous systems process temporal information by sampling stimuli signals at shorter and longer durations, favoring the content extensionalist hypothesis that temporal perception is constituted by multi-scale sampling and integration, over a single-sampling rate hypothesis implied by the atomistic “snapshot” model. In the second half of Chapter 4, I defend a form of constructive realism—the view that scientific theories are best understood as (a) families of models and (b) hypotheses that specify the respects and degrees in which a model represents some real physical system. I conclude the dissertation with a section on philosophy of science, because I engage empirical work throughout the project and employ a model-based approach to theorizing. Furthermore, I suggest that philosophical analysis of the experimental findings may generate new hypotheses and predictions, or offer critical arguments to help rule out the plausibility of particular competing models. To illustrate this interdisciplinary upshot, I briefly make a case for possible philosophical contributions to the fertile domain of temporal processing where there remain many contenders and no consensus on the exact mechanisms that realize temporal perception