Introduction to the topical collection "The Structure of Perceptual Objects"—with contributions by Mohan Matthen, EJ Green, Alisa Mandrigin, Blazej Skrzypulec, and Anna Drożdżowicz.

Entities that are, in ordinary perceptual situations, veridically presented as objects can be called ‘perceptual objects’. In the philosophical literature, one can find various approaches to the crucial features that distinguish the class of perceptual objects. While these positions differ in many respects, they share an important general feature: they all characterize perceptual objects as largely subject-independent. More specifically, they do not attribute a significant constitutive role to the perceptual relation connecting a fragment of the environment with a perceiving subject. (...) Fragments of the environment are perceptual objects no matter whether they stand in a perceptual relation to any subject, mainly by virtue of having a certain physical structure. I question this common assumption, relying on Green’s ( 2019 ) definition of perceptual objects, arguing that a proper theory of perceptual objects should accommodate the constitutive role of perceptual relations. This is because there exist fragments of the environment that are perceptual objects only when they stand in a perceptual relation to a subject. (shrink)

Ordinary objects are experienced to endure over space and time, to not be collocated with each other, to be composed of proper parts, and to survive the loss of some of their parts. These qualities are on the one hand difficult to reconcile for theorists of perception and on the other hand pose a variety of problems when considered in isolation. Relying on the theoretical framework of predictive processing, this paper argues that we can use the category of a robust (...) predictive process to conceptualize qualities such as persistence and compositionality in a unified manner. Traditional problems concerning the structural properties of ordinary objects, such as the question of when two objects compose, can then be reformulated using this new category. (shrink)

Common everyday materials such as textiles, foodstuffs, soil or skin can have complex, mutable and varied appearances. Under typical viewing conditions, most observers can visually recognize materials effortlessly, and determine many of their properties without touching them. Visual material perception raises many fascinating questions for vision researchers, neuroscientists and philosophers, yet has received little attention compared to the perception of color or shape. Here we discuss some of the challenges that material perception raises and argue that further philosophical thought should (...) be directed to how we see materials. (shrink)

We think of the world around us as divided into physical objects like toasters and daisies, rather than solely as a smear of properties like yellow and smooth. How do we single out these objects? One theory of object concepts uses part‐of relations and relations of connectedness. According to this proposal, an object is a connected spatial item of maximal extent: Any other connected item that overlaps (i.e., shares a part with) the object must be a part of that object. (...) This article reports four experiments that test this proposal. Participants see descriptions or diagrams of spatial items that vary across trials in their relative positions. In separate experiments, participants decide whether the items are physical objects, whether they are wholes, or how many objects are present. All experiments find support for connectedness as a contributor to object status, but they find little support for maximality. The results suggest that maximality is not a necessary feature of wholes or of objects. (shrink)

Predictive processing has begun to offer new insights into the nature of conscious experience—but the link is not straightforward. A wide variety of systems may be described as predictive machines, raising the question: what differentiates those for which it makes sense to talk about conscious experience? One possible answer lies in the involvement of a higher-order form of prediction error, termed expected free energy. In this paper we explore under what conditions the minimization of this new quantity might underpin conscious (...) experience. Our suggestion is that the minimisation of Expected Free Energy is not in itself sufficient for the occurrence of conscious experience. Instead, it is relevant only insofar as it helps deliver what Ward et al. ( 2011 ) have previously described as a _sense of our own poise over an action space_. Perceptual experience, we will argue, is nothing other than the process that puts current actions in contact with goals and intentions, enabling some creatures to know the space of options that their current situation makes available. This proposal fits with recent work suggesting a deep link between conscious contents and contents computed at an ‘intermediate’ level of processing, apt for controlling action. (shrink)

This paper proposes some guidelines for the undeveloped discussion of auditory epistemology. Auditory epistemology is an approach concerned with the perceptual basis for knowledge and belief, specifically around audition. The article pursues two goals. Firstly, it claims that addressing auditory perception from the viewpoint of epistemology is more fruitful than the discussion on phenomenology which has thus far dominated the debates in the literature on sound. Secondly, it elaborates a concrete proposal pertaining to the cooperation of sense-modalities. In so doing, (...) a model for “Perceptual Coherence” is suggested. The first section of the paper critically reviews the problem of perception as it is usually understood in traditional epistemology. An ensuing section outlines the model of perceptual coherence. (shrink)

Two questions are addressed in this paper. First, what is it to see? I argue that it is veridical experience of things outside the perceiver brought about by looking. Second, what is it to see a material object? I argue that it is experience of an occupant of a spatial region that is a logical subject for other visual features, able to move to another spatial region, to change intrinsically, and to interact with other material objects. I show how this (...) theory is different from the idea that object-seeing is merely the visual segregation of a region of the visual field. Finally, I argue that we do not object-see objects reflected in mirrors, surfaces of back-lit objects, and depictions of objects. (shrink)

Perception is a central means by which we come to represent and be aware of particulars in the world. I argue that an adequate account of perception must distinguish between what one perceives and what one's perceptual experience is of or about. Through capacities for visual completion, one can be visually aware of particular parts of a scene that one nevertheless does not see. Seeing corresponds to a basic, but not exhaustive, way in which one can be visually aware of (...) an item. I discuss how the relation between seeing and visual awareness should be explicated within a representational account of the mind. Visual awareness of an item involves a primitive kind of reference: one is visually aware of an item when one's visual perceptual state succeeds in referring to that particular item and functions to represent it accurately. Seeing, by contrast, requires more than successful visual reference. Seeing depends additionally on meta-semantic facts about how visual reference happens to be fixed. The notions of seeing and of visual reference are both indispensable to an account of perception, but they are to be characterized at different levels of representational explanation. (shrink)

Cognitive scientists have long known that the modalities interact during perceptual processing. Cross-modal illusions like the ventriloquism effect show that the course of processing in one modality can alter the course of processing in another. But how do the modalities interact in the specific domain of object perception? This paper distinguishes and analyzes two kinds of multisensory interaction in object perception. First, the modalities may bind features to a single object or event. Second, the modalities may cooperate when differentiating an (...) object or event from its surroundings. I critically evaluate evidence for various forms of multisensory binding. I then consider the case for multisensory differentiation. I argue that existing evidence for multisensory differentiation is inconclusive. I highlight ways that the issue might be empirically resolved. (shrink)

Debunking arguments aim to undermine common sense beliefs by showing that they are not explanatorily or causally linked to the entities they are purportedly about. Rarely are facts about the aetiology of common sense beliefs invoked for the opposite aim, that is, to support the reality of entities that furnish our manifest image of the world. Here I undertake this sort of un-debunking project. My focus is on the metaphysics of ordinary physical objects. I use the view of perception as (...) approximate Bayesian inference to show how representations of ordinary objects can be extracted from sensory input in a rational and truth-tracking manner. Drawing an analogy between perception construed as Bayesian hypothesis testing and scientific inquiry, I sketch out how some of the intuitions that traditionally inspired arguments for scientific realism also find application with regards to proverbial tables and chairs. (shrink)

A number of philosophers have held that we visually experience objects’ occluded parts, such as the out-of-view exterior of a voluminous, opaque object. That idea is supposed to be what best explains the fact that we see objects as whole or complete despite having only a part of them in view at any given moment. Yet, the claim doesn’t express a phenomenological datum and the reasons for thinking we do experience objects’ occluded parts, I argue, aren’t compelling. Additionally, I anticipate (...) and reply to attempts to salvage the idea by appeal to perceptual expectation and amodal completion. Lastly, I address potential concerns that the only way to capture the phenomenal character of perceiving voluminous objects is to say experience outstrips what’s in view, providing a description of such experience without any implication of that idea. (shrink)

In our target article, we argued that the number sense represents natural and rational numbers. Here, we respond to the 26 commentaries we received, highlighting new directions for empirical and theoretical research. We discuss two background assumptions, arguments against the number sense, whether the approximate number system represents numbers or numerosities, and why the ANS represents rational numbers.

In crossmodal identification, a subject token identifies an item perceived in one sensory modality with an item perceived in another sensory modality. Does crossmodal identification always occur in cognition, or does crossmodal identification sometimes take place in perception? This paper argues that crossmodal identification occurs in cognition, and not in perception. Nevertheless, multisensory perception is not unalive to crossmodal identity. Experimental evidence demonstrates that perception is differentially sensitive to the identity of individuals presented to distinct senses. Such sensitivity enhances recognition (...) and improves action. This approach relies on distinguishing crossmodal identification from perceiving crossmodal identity. Perception registers crossmodal identity, but crossmodal identification as such belongs to thought. (shrink)

It is common to characterize pain with touch-related terms, like ‘cutting’, ‘pressing’, ‘sharp’, and ‘pulsing’, or temperature-related terms, like ‘hot’ or ‘burning’. This suggests that many pains are phenomenally multimodal because they are experienced as having some tactile-like or thermal-like character. The goal of this chapter is to investigate the structure of phenomenally multimodal pain experiences. It is argued that the usual accounts of multimodal structure proposed in investigations regarding exteroceptive experiences cannot be plausibly applied to multimodal experiences of pain. (...) Instead, an alternative framework is proposed which characterizes the structure of tactile-like and thermal-like pains by referring to the notion of crossmodal correspondences. (shrink)

The basis of perception is the processing and categorization of perceptual stimuli from the environment. Much progress has been made in the science of perceptual categorization. Yet there is still no consensus on how the brain generates sensory individuals, from sensory input and perceptual categories in memory. This chapter argues that perceptual categorization is highly variable across perceivers due to their use of different perceptual strategies for solving perceptual problems they encounter, and that the perceptual system structurally adjusts to the (...) strategies that are most successful. Despite this variability, the different sensory individuals that result when different perceivers rely on different strategies nonetheless correspond to actual external world objects/features. This view is called 'perceptual pluralism'. (shrink)

This chapter examines how our sense modalities interact in the perception of persistence. The chapter concentrates on two questions. The first concerns perceptual processing—do perceptual computations of object persistence ever integrate and compute over representations from more than one modality? It argues that this question should be answered affirmatively. The second question concerns perceptual experience—do experiences of object persistence ever exhibit a constitutively multisensory phenomenal character, or is the phenomenology of object persistence always uniquely associated with just one modality? The (...) chapter argues that the available evidence underdetermines the answer to this question, but suggests ways it might be empirically resolved. (shrink)