Science of Perception, Misc

This book has three principle aims: to show that neither vision nor mental imagery involves the creation or inspection of picture-like mental representations; to defend the claim that our visual processes are, in significant part, cognitively impenetrable; and to develop a theory of “visual indexes”. In what follows, I assess Pylyshyn’s success in realising each of these aims in turn. I focus primarily on his arguments against “picture theories” of vision and mental imagery, to which approximately half the book is (...) devoted. I argue that Pylyshyn adopts an unnecessarily restricted interpretation of what it would be for mental representations to be picture-like, and that this leads him prematurely to reject the possibility of explaining the introspective evidence concerning the nature of mental imagery. (shrink)

You can perceive things, in many respects, as they really are. For example, you can correctly see a coin as circular from most angles. Nonetheless, your perception of the world is perspectival. The coin looks different when slanted than when head-on, and there is some respect in which the slanted coin looks similar to a head-on ellipse. Many hold that perception is perspectival because you perceive certain properties that correspond to the “looks” of things. I argue that this view is (...) misguided. I consider the two standard versions of this view. What I call the PLURALIST APPROACH fails to give a unified account of the perspectival character of perception, while what I call the PERSPECTIVAL PROPERTIES APPROACH violates central commitments of contemporary psychology. I propose instead that perception is perspectival because of the way perceptual states are structured from their parts. (shrink)

The sensorimotor theory of vision and visual consciousness is often described as a radical alternative to the computational and connectionist orthodoxy in the study of visual perception. However, it is far from clear whether the theory represents a significant departure from orthodox approaches or whether it is an enrichment of it. In this study, I tackle this issue by focusing on the explanatory structure of the sensorimotor theory. I argue that the standard formulation of the theory subscribes to the same (...) theses of the dynamical hypothesis and that it affords covering-law explanations. This however exposes the theory to the mere description worry and generates a puzzle about the role of representations. I then argue that the sensorimotor theory is compatible with a mechanistic framework, and show how this can overcome the mere description worry and solve the problem of the explanatory role of representations. By doing so, it will be shown that the theory should be understood as an enrichment of the orthodoxy, rather than an alternative. (shrink)

Recently, it has been objected that naïve realism is inconsistent with an empirically well-supported claim that mental states of the same fundamental kind as ordinary conscious seeing can occur unconsciously (SFK). The main aim of this paper is to establish the following conditional claim: if SFK turns out to be true, the naïve realist can and should accommodate it into her theory. Regarding the antecedent of this conditional, I suggest that empirical evidence renders SFK plausible but not obvious. For it (...) is possible that what is currently advocated as unconscious perception of the stimulus is in fact momentaneous perceptual awareness (or residual perceptual awareness) of the stimulus making the subject prone to judge in some way rather than another, or to act in some way rather than another. As to the apodosis, I show that neither the core of naïve realism nor any of its main motivations is undermined if SFK is assumed. On the contrary, certain incentives for endorsing naïve realism become more tempting on this assumption. Since the main motivations for naïve realism retain force under SFK, intentionalism is neither compulsory nor the best available explanation of unconscious perception. (shrink)

The idea of a common currency underlying our choice behaviour has played an important role in sciences of behaviour, from neurobiology to psychology and economics. However, while it has been mainly investigated in terms of values, with a common scale on which goods would be evaluated and compared, the question of a common scale for subjective probabilities and confidence in particular has received only little empirical investigation so far. The present study extends previous work addressing this question, by showing that (...) confidence can be compared across visual and auditory decisions, with the same precision as for the comparison of two trials within the same task. We discuss the possibility that confidence could serve as a common currency when describing our choices to ourselves and to others. others. (shrink)

(This paper will appear in the Australasian Journal of Philosophy. The Accepted Version will be posted when it is published.) -/- Molyneux's Question (MQ) concerns whether a newly sighted man would recognize/distinguish a sphere and a cube by vision, assuming he could previously do this by touch. We argue that (MQ) splits into questions about (a) shared representations of space in different perceptual systems, and about (b) shared ways of constructing higher dimensional spatiotemporal features from information about lower dimensional ones, (...) most of the technical difficulty centring on (b). So understood, MQ resists any monolithic answer: everything depends on the constraints faced by particular perceptual systems in extracting features of higher dimensionality from those of lower. Each individual question of this type is empirical and must be investigated separately. We present several variations on MQ based on different levels of dimensional integration—some of these are familiar, some novel adaptations of problems known elsewhere, and some completely novel. Organizing these cases in this way is useful because it unifies a set of disparate questions about intermodal transfer that have held philosophical and psychological interest, suggests a new range of questions of the same type, sheds light on similarities and differences between members of the family, and allows us to formulate a much-augmented set of principles and questions concerning the intermodal transfer of spatiotemporal organization. (shrink)

In this paper I will argue that ‘colour’ is not in real objects. I will then go beyond that to argue that properties of real objects – if they have properties – cannot be emitted to the perceiver. It becomes necessary, therefore, to hold that all that is ‘known’, via the senses, of the world be inferred from the Representation only.

Expertise is a cognitive achievement that clearly involves experience and learning, and often requires explicit, time-consuming training specific to the relevant domain. It is also intuitive that this kind of achievement is, in a rich sense, genuinely perceptual. Many experts—be they radiologists, bird watchers, or fingerprint examiners—are better perceivers in the domain(s) of their expertise. The goal of this paper is to motivate three related claims, by substantial appeal to recent empirical research on perceptual expertise: Perceptual expertise is genuinely perceptual (...) and genuinely cognitive, and this phenomenon reveals how we can become epistemically better perceivers. These claims are defended against sceptical opponents that deny significant top-down or cognitive effects on perception, and opponents who maintain that any such effects on perception are epistemically pernicious. (shrink)

Teleological accounts of sensory normativity treat normal functioning for a species as a standard: sensory error involves departure from normal functioning for the species, i.e. sensory malfunction. Straightforward reflection on sensory trade-offs reveals that normal functioning for a species can exhibit failures of accuracy. Acknowledging these failures of accuracy is central to understanding the adaptations of a species. To make room for these errors we have to go beyond the teleological framework and invoke the notion of an ideal observer from (...) vision science. The notion of an ideal observer also sheds light on the important distinction between sensory malfunction and sensory limitation. (shrink)

Some investigators of the rubber hand illusion (RHI) have suggested that when standard RHI induction procedures are employed, if the rubber hand is experienced by participants as owned, their corresponding biological hands are experienced as disowned. Others have demurred: drawing upon a variety of experimental data and conceptual considerations, they infer that experience of the RHI might include the experience of a supernumerary limb, but that experienced disownership of biological hands does not occur. Indeed, some investigators even categorically deny that (...) any experimental paradigm has been employed or any evidence can be adduced to support the claim that disownership experiences occur during the RHI. It goes without saying that RHI experiences can be elusive, and that there is some evidence to support claims that supernumerary limb experiences can sometimes occur. Here,however, we test the claim that the conscious experience of disownership can occur during the RHI. In order to test this claim, we developed two new, online, proxies—onset time (OT) for the illusion and illusion duration (ID)—and combined these with established questionnaires that concern the conscious contents of the RHI, in particular ownership/disownership experiences. Both online proxy data and post hoc questionnaire data converge in supporting the claim that disownership experiences do occur, at least when the left hand is the object of investigation. Our findings that OT and ID are reliable measures suggest that investigations of the RHI stand to benefit by devoting more attention to data collected while the RHI is being experienced, in particular data concerning temporal dynamics. (shrink)

This paper is concerned with Maurice Merleau-Ponty’s contribution to the hermeneutical theory of expressive meaning that has been developed on the basis of an ongoing dialogue with traditional phenomenology. The early portion of the paper examines the unstable boundaries between expression and indication as a key to a new approach to expressive meaning. The paper then takes up Merleau-Ponty’s understanding of expressive life as it emerges in ‘Phenomenology of Perception,’ his first attempt to discuss perception, aesthetics, and temporality in comprehensive (...) terms. The third part of the paper examines Merleau-Ponty’s return to the paintings of Paul Cezanne, which not only clarifies his earlier position but also deepens the philosophical meaning of his reflections on language. My final comments are concerned with how phenomenology can be broadened in a way that can become responsive to the hermeneutical theory of expressive meaning. (shrink)

Embodied Cognition is the kind of view that is all trees, no forest. Mounting experimental evidence gives it momentum in fleshing out the theoretical problems inherent in Cognitivists’ separation of mind and body. But the more its proponents compile such evidence, the more the fundamental concepts of Embodied Cognition remain in the dark. This conundrum is nicely exemplified by Pecher and Zwaan’s book, Grounding Cognition, which is a programmatic attempt to rally together an array of empirical results and linguistic data, (...) and its successes in this endeavor nicely epitomize current directions among the various research provinces of Embodied Cognition. The untoward drawback, however, is that such successes are symptomatic of the growing imbalance between experimental progress and theoretical interrogation. In particular, one of the theoretical cornerstones of Embodied Cognition —namely, the very concept of grounding under investigation here—continues to go unilluminated. Hence, the advent of this volume indicates that—now more than ever—the concept of grounding is in dire need of some plain old-fashioned conceptual analysis. In that sense, Embodied Cognition is grounded until further notice. (shrink)

When visual attention is directed away from a stimulus, neural processing is weak and strength and precision of sensory data decreases. From a computational perspective, in such situations observers should give more weight to prior expectations in order to behave optimally during a discrimination task. Here we test a signal detection theoretic model that counter-intuitively predicts subjects will do just the opposite in a discrimination task with two stimuli, one attended and one unattended: when subjects are probed to discriminate the (...) unattended stimulus, they rely less on prior information about the probed stimulus’ identity. The model is in part inspired by recent findings that attention reduces trial-by-trial variability of the neuronal population response and that they use a common criterion for attended and unattended trials. In five different visual discrimination experiments, when attention was directed away from the target stimulus, subjects did not adjust their response bias in reaction to a change in stimulus presentation frequency despite being fully informed and despite the presence of performance feedback and monetary and social incentives. This indicates that subjects did not rely more on the priors under conditions of inattention as would be predicted by a Bayes-optimal observer model. These results inform and constrain future models of Bayesian inference in the human brain. (shrink)

This bookreview discusses Piccolino and Wades' book on Galileo's impact on contemporary perception science.

The chapter deals with the notion of phenomenal realness, which was first systematically explored by Albert Michotte. Phenomenal realness refers to the impression that a perceptual object is perceived to have an autonomous existence in our mind-independent world. Perceptual psychology provides an abundance of phenomena, ranging from amodal completion to picture perception, that indicate that phenomenal realness is an independent perceptual attribute that can be conferred to perceptual objects in different degrees. The chapter outlines a theoretical framework that appears particularly (...) well-suited for dealing with corresponding phenomena. According to this framework, perception can be understood as a triggering of conceptual forms by sensor inputs. It is argued that the attribute of phenomenal realness is based on specific types of internal evaluation functions which deal with the segregation of causes conceived as ‘external’ from those conceived as ‘internal’. These evaluation functions integrate different internal sources of ‘knowledge’ about the potential causes for the activation of conceptual forms and provide markers by which conceptual forms can be tagged as ‘external world objects’. (shrink)

Pictures are 2D surfaces designed to elicit 3D-scene-representing experiences from their viewers. In this essay, I argue that philosophers have tended to underestimate the relevance of research in vision science to understanding the nature of pictorial experience. Both the deeply entrenched methodology of virtual psychophysics as well as empirical studies of pictorial space perception provide compelling support for the view that pictorial experience and seeing face-to-face are experiences of the same psychological, explanatory kind. I also show that an empirically informed (...) account of pictorial experience provides resources to develop a novel, resemblance-based account of depiction. According to what I call the deep resemblance theory, pictures work by presenting virtual models of objects and scenes in phenomenally 3D, pictorial space. (shrink)

Fiona Macpherson (2012) argues that various experimental results provide strong evidence in favor of the cognitive penetration of perceptual color experience. Moreover, she proposes a mechanism for how such cognitive penetration occurs. We argue, first, that the results on which Macpherson relies do not provide strong grounds for her claim of cognitive penetrability; and, second, that, if the results do reflect cognitive penetrability, then time-course considerations raise worries for her proposed mechanism. We base our arguments in part on several of (...) our own experiments, reported herein. (shrink)

Attempts to introduce Gestalt theory into the realm of visual neuroscience are discussed on both theoretical and experimental grounds. To define the framework in which these proposals can be defended, this paper outlines the characteristics of a standard model, which qualifies as a received view in the visual neurosciences, and of the research into natural images statistics. The objections to the standard model and the main questions of the natural images research are presented. On these grounds, this paper defends the (...) view that Gestalt psychology and experimental phenomenology provide a contribution to the research into perception by the construction of phenomenological models for an ecologically meaningful interpretation of the empirical evidence and the hypothetical constructs of the natural image research within the visual neuroscience. A formal framework for the phenomenological models is proposed, wherein Gestalt theoretical principles and empirical evidence are represented in terms of topological properties and relationships, which account for the order and structures that make the environment accessible to observers at a relevant behavioural level. It is finally argued that these models allow us to evaluate the principles and the empirical evidence of various natures which are integrated from different fields into the research into perception, and in particular into visual neurosciences. (shrink)

A central question, if not the central question, of philosophy of perception is whether sensory states have a nature similar to thoughts about the world, whether they are essentially representational. According to the content view, at least some of our sensory states are, at their core, representations with contents that are either accurate or inaccurate. Tyler Burge’s Origins of Objectivity is the most sustained and sophisticated defense of the content view to date. His defense of the view is problematic in (...) several ways. The most significant problem is that his approach does not sit well with mainstream perceptual psychology. (shrink)

Much recent cognitive neuroscientific work on body knowledge is representationalist: “body schema” and “body images”, for example, are cerebral representations of the body (de Vignemont 2009). A framework assumption is that representation of the body plays an important role in cognition. The question is whether this representationalist assumption is compatible with the variety of broadly situated or embodied approaches recently popular in the cognitive neurosciences: approaches in which cognition is taken to have a ‘direct’ relation to the body and to (...) the environment. A “direct” relation is one where the boundaries between the body and the head, or between the environment and the animal are not theoretically important in the understanding of cognition. These boundaries do not play a theoretically privileged role in cognitive explanations of behavior. But representationalism appears to put a representational veil between the locus of cognition and that which is represented, making cognitive relations to the body and to the environment be indirect, with a high associated computational load. For this reason, direct approaches have tried to minimize the use of internal representations (Suchman 1987; Barwise 1987; Agre and Chapman 1987; Brooks 1992; Thelen and Smith 1994; van Gelder 1995; Port and van Gelder 1995; Clark 1997, 1999; Rupert 2009, p. 180). Does a cognitive neuroscience committed to direct relations rule out a representationalist approach to body knowledge? Or is direct representationalism possible? (shrink)

Do spatial features appear the same whether they are perceived through vision or touch? This question is at stake in the puzzle that William Molyneux posed to John Locke, concerning whether a man born blind whose sight was restored would be able immediately to identify the shapes of the things he saw. A recent study purports to answer the question negatively, but I argue here that the subjects of the study likely could not see well enough for the result to (...) have been meaningful. I then propose a way to improve the study, by including cues from object motion. (shrink)

It is a characteristic feature of our mental make-up that the same perceptual input situation can simultaneously elicit conflicting mental perspectives. This ability pervades our perceptual and cognitive domains. Striking examples are the dual character of pictures in picture perception, pretend play, or the ability to employ metaphors and allegories. I argue that traditional approaches, beyond being inadequate on principle grounds, are theoretically ill equipped to deal with these achievements. I then outline a theoretical perspective that has emerged from a (...) theoretical convergence of perceptual psychology, ethology, linguistics, and developmental research. On the basis of this framework, I argue that corresponding achievements are brought forth by a specific type of functional architecture whose core features are as follows: (1) a perceptual system that is biologically furnished with a rich system of conceptual forms, (2) a triggering relation between the sensory input and conceptual forms by which the same sensory input can be exploited by different types or systems of conceptual forms, and (3) computational principles for handling semantically underspecified conceptual forms. Characteristic features of the proposed theoretical framework are pointed out using the Heider–Simmel phenomenon as an example. (shrink)

The chapter outlines an abstract theoretical framework that is currently (re-)emerging in the course of a theoretical convergence of several disciplines. In the first section, the fundamental problem of perception theory is formulated, namely, the generation, by the perceptual system, of meaningful categories from physicogeometric energy patterns. In the second section, it deals with basic intuitions and assumptions underlying what can be regarded as the current Standard Model of Perceptual Psychology and points out why this model is profoundly inadequate for (...) dealing with the fundamental problem of perception theory. In the third section, it discusses a level of analysis that promises to be fruitful for dealing, in conformity with established procedures of the natural sciences, with the problem of perceptual “meaning” and the problem of what constitutes a “perceptual object.” In the fourth section, it outlines a theoretical perspective on basic principles of the perceptual system which centers on the notions of complex data types and conceptual forms, and draws an entirely different theoretical picture of the role of the sensory input than traditional accounts. The final section focusses on the issue of material qualities and discusses, within the general theoretical framework outlined, some observations and results on the perception of certain material properties, namely, lustrous and glassy appearances. (shrink)

It is a characteristic feature of our mental make-up that the same perceptual input situation can simultaneously elicit conflicting mental perspectives. This ability pervades our perceptual and cognitive domains. Striking examples are the dual character of pictures in picture perception, pretend play, or the ability to employ metaphors and allegories. I will argue that traditional approaches, beyond being inadequate on principle grounds, are theoretically ill-equipped to deal with these achievements. I will then outline a theoretical perspective that has been emerging (...) from a theoretical convergence of perceptual psychology, ethology, linguistics, and developmental research. On the basis of this framework, I will argue that corresponding achievements are brought forth by a specific type of functional architecture whose core features are: (i) a perceptual system that is biologically furnished with a rich system of conceptual forms, (ii) a triggering relation between the sensory input and conceptual forms by which the same sensory input can be exploited by different types or systems of conceptual forms, and (iii) computational principles for handling semantically underspecified conceptual forms. Characteristic features of the proposed theoretical framework will be pointed out using the Heider-Simmel phenomenon as an example. (shrink)

The chapter deals with misconceptions in perception theory that are based on the idea of slicing the nature of perception along the joints of physics and on corresponding ill-conceived ʹpurposesʹ and ʹgoalsʹ of the perceptual system. It argues that the conceptual structure underlying the percept cannot be inferentially attained from the sensory input. The output of the perceptual system, namely meaningful categories, is evidently vastly underdetermined by the sensory input, namely physico-geometric energy patterns. Thus, the core task of perception theory (...) is to understand the internal conceptual structure with which our perceptual system is endowed. The conceptual structure underlying the semantic distinctions that characterise the output of the perceptual system can, by conceptual necessity, only be expressed by a logical language that is strictly more powerful than the logical language by which sensory notions can be expressed. Consequently, the internal structure underlying perceptual meaning – including core notions such as ‘Gestalt’ or ‘perceptual object’ – cannot be derived, by whatever kind of general inductive machinery, from the sensory input, or, more generally, from experience. (shrink)