Many of Margaret Cavendish’s criticisms of Thomas Hobbes in the Philosophical Letters (1664) relate to the disorder and damage that she holds would result if Hobbesian pressure were the cause of visual perception. In this paper, I argue that her “two men” thought experiment in Letter IV is aimed at a different goal: to show the explanatory potency of her account. First, I connect Cavendish’s view of visual perception as “patterning” to the “two men” thought experiment (...) in Letter IV. Second, I provide a potential reply on Hobbes’s behalf that appeals to physiological differences between perceivers’ sense organs, drawing upon Hobbes’s optics in De homine. Third, I argue that such a reply would misunderstand Cavendish’s objective of showing the limited explanatory resources available in understanding visual perception as pressing when compared to her view of visual perception as patterning. (shrink)

We present an investigation into the relation between design princi- ples in Japanese gardens, and their associated perceptual effects. This leads to the realization that a set of design principles described in a Japanese gardening text by Shingen (1466), shows many parallels to the visual effects of perceptual grouping, studied by the Gestalt school of psychology. Guidelines for composition of rock clusters closely relate to perception of visual figure. Garden design elements are arranged into patterns that simplify (...) figure-ground segmentation, while seemingly balancing the visual salience of subparts and the global arrangement. Visual ‘ground’ is analyzed via medial axis transformation (MAT), often associated with shape perception in humans. MAT analysis reveals implicit structure in the visual ground of a quintessential rock garden design. The MAT structure enables formal com- parison of structure of figure and ground. They share some aesthetic qualities, with interesting differences. Both contain naturalistic asymmetric, self-similar, branching structures. While the branching pattern of the ground converges towards the viewer, that of the figure converges in the opposite direction. (shrink)

This is a broad summary of my thinking on EM rays and their role in visual perception. It focuses mainly on ambient space and the ramifications of that.

Quilty-Dunn et al.'s wide-ranging defense of the Language of Thought Hypothesis (LoTH) argues that vision traffics in abstract, structured representational formats. We agree: Vision, like language, is compositional – just as words compose into phrases, many visual representations contain discrete constituents that combine in systematic ways. Here, we amass evidence extending this proposal, and explore its implications for how vision interfaces with the rest of the mind.

This paper deals with the mutations in Wittgenstein’s treatment of the notions of “generality” and of “singularity”, from his first philosophy, in the Tractatus Logico-Philosophicus, to his later mature philosophy represented by the Philosophical Investigations. As we shall see, Wittgenstein’s philosophical handling of the notion of “visual perception” plays a key role in those conceptual transformations.

In Remarks on the philosophy of psychology Wittgenstein uses ambiguous illusions to investigate the problematic relation of perception and interpretation. I use this problem as a starting point for developing a conceptual framework capable of expressing problems associated with visual perception in a precise manner. I do this by discerning between subjective and objective meaning of the term “to see” and by specifying the beliefs which are to be ascribed to the observer when we assert that she (...) sees a given object. The framework (detailed in section 2) is then used to analyze the case of the duck/rabbit illusion. It shows that ambiguous illusions present us with a specific skeptical challenge but that the challenge can be overcome by empirical sciences. Along the way I explicate some of the common notions associated with perception (“to look at”, “to have an impression of…”, "to react as if one had an impression of..”, “to convince oneself that what one sees is…”). (shrink)

Recent developments in vision science have resulted in several major changes in our understanding of human visual perception. For example, attention no longer appears necessary for "visual intelligence"--a large amount of sophisticated processing can be done without it. Scene perception no longer appears to involve static, general-purpose descriptions, but instead may involve dynamic representations whose content depends on the individual and the task. And vision itself no longer appears to be limited to the production of a (...) conscious "picture"--it may also guide processes outside the conscious awareness of the observer. (shrink)

Perception is a first-person internal sensation induced within the nervous system at the time of arrival of sensory stimuli from objects in the environment. Lack of access to the first-person properties has limited viewing perception as an emergent property and it is currently being studied using third-person observed findings from various levels. One feasible approach to understand its mechanism is to build a hypothesis for the specific conditions and required circuit features of the nodal points where the mechanistic (...) operation of perception take place for one type of sensation in one species and to verify it for the presence of comparable circuit properties for perceiving a different sensation in a different species. The present work explains visual perception in mammalian nervous system from a first-person frame of reference and provides explanations for the homogeneity of perception of visual stimuli above flicker fusion frequency, the perception of objects at locations different from their actual position, the smooth pursuit and saccadic eye movements, the perception of object borders, and perception of pressure phosphenes. Using results from temporal resolution studies and the known details of visual cortical circuitry, explanations are provided for (a) the perception of rapidly changing visual stimuli, (b) how the perception of objects occurs in the correct orientation even though, according to the third-person view, activity from the visual stimulus reaches the cortices in an inverted manner and (c) the functional significance of well-conserved columnar organization of the visual cortex. A comparable circuitry detected in a different nervous system in a remote species-the olfactory circuitry of the fruit fly Drosophila melanogaster-provides an opportunity to explore circuit functions using genetic manipulations, which, along with high-resolution microscopic techniques and lipid membrane interaction studies, will be able to verify the structure-function details of the presented mechanism of perception. (shrink)

Standard models of visual perception hold that vision is an inferential or interpretative process. Such models are said to be superior to competing, non-inferential views in explanatory power. In particular, they are said to be capable of explaining a number of otherwise mysterious, visual phenomena such as multi-stable perception. Multi-stable perception paradigmatically occurs in the presence of ambiguous figures, single images that can give rise to two or more distinct percepts. Different interpretations are said to (...) produce the different percepts. In this paper, I argue that a non-inferential account of visual perception is just as capable of explaining multi-stable perception. I propose an embedded understanding of vision, and show how the embedded account can, after properly qualifying them, use the explanatory resources of the inferential view to explain just what such a view explains. (shrink)

The question of whether cognition can influence perception has a long history in neuroscience and philosophy. Here, we outline a novel approach to this issue, arguing that it should be viewed within the framework of top-down information-processing. This approach leads to a reversal of the standard explanatory order of the cognitive penetration debate: we suggest studying top-down processing at various levels without preconceptions of perception or cognition. Once a clear picture has emerged about which processes have influences on (...) those at lower levels, we can re-address the extent to which they should be considered perceptual or cognitive. Using top-down processing within the visual system as a model for higher-level influences, we argue that the current evidence indicates clear constraints on top-down influences at all stages of information processing; it does, however, not support the notion of a boundary between specific types of information-processing as proposed by the cognitive impenetrability hypothesis. (shrink)

The distinction between true belief and knowledge is one of the most fundamental in philosophy, and a remarkable effort has been dedicated to formulating the conditions on which true belief constitutes knowledge. For decades, much of this epistemological undertaking has been dominated by a single strategy, referred to here as the modal approach. Shared by many of the most widely influential constraints on knowledge, including the sensitivity, safety, and anti-luck/risk conditions, this approach rests on a key underlying assumption — the (...) modal profiles available to known and unknown beliefs are in some way asymmetrical. The first aim of this paper is to deconstruct this assumption, identifying its plausibility with the way in which epistemologists frequently conceptualize human perceptual systems as excluding certain varieties of close error under conditions conducive to knowledge acquisition. The second aim of this paper is to then argue that a neural phase phenomenon indicates that this conceptualization is quite likely mistaken. This argument builds on the previous introduction of this neural phase to the context of epistemology, expanding the use of neural phase cases beyond relatively narrow questions about epistemic luck to a much more expansive critique of the modal approach as a whole. (shrink)

One of the more compelling beliefs about vision is that it is based on representations that are coherent and complete, with everything in the visual field described in great detail. However, changes made during a visual disturbance are found to be difficult to see, arguing against the idea that our brains contain a detailed, picture-like representation of the scene. Instead, it is argued here that a more dynamic, "just-in-time" representation is involved, one with deep similarities to the way (...) that users interact with external displays. It is further argued that these similarities can provide a basis for the design of intelligent display systems that can interact with humans in highly effective and novel ways. (shrink)

This paper argues that a common form of representationalism has trouble accommodating empirical findings about visual space perception. Vision science tells us that the visual system systematically gives rise to different experiences of the same spatial property. This, combined with a naturalistic account of content, suggests that the same spatial property can have different veridical looks. I use this to argue that a common form of representationalism about spatial experience must be rejected. I conclude by considering alternatives (...) to this view. (shrink)

The analysis method and paradigm of film have become a controversial topic in the data-driven era. Film, is not only an attractive industry that can achieve filmmakers’ imagination but has become a perfect stimulus to understand human being’s mental activity. The core research in this study is to examine the impact of filmmaking experience and the role of narrative denoters from filmmakers’ construction to audiences’ interpretation. Based on previous studies and integrating cognitive approaches, the thesis re-explores the nature and essence (...) of film and proposes an alternative term - narrative denoter - which can be used as the indication of message exchanging between filmmakers and audiences. Using a released film that has a complete story to do the experiment, this study investigates the relationship between major, film interpretations, event segmentation, and audience’s preference. The result showed that filmmaking experience does not impact the interpretation of film; however the identification of the narrative denoter played an important role in film perception and cognition; apart from these, the audience’s preference did not correlate with film interpretation. With respect to this result, the narrative denoter can be indicator to demonstrate the message transitions from filmmaker to audience. Suggestions were made for future cognitive film studies on using the narrative denoters as a new analysis unit. (shrink)

This essay characterizes the perception of the visual hybrid as nonconceptual, introducing the terminology of nonconceptual content theory to aesthetics. The visual hybrid possesses a radical but nonetheless exemplary aesthetic composition and is well established in culture, art, and even design. The essay supplies a philosophical analysis of the results of cross-cultural experiments, showing that while categorization or conceptual hierarchization kicks in when the visual hybrids are juxtaposed with linguistic descriptions, no conceptual scheme takes effect when (...) participants are presented with mere visual hybrids. In isolation, the hybrids do not lend themselves to classification. I draw four conclusions from these experimental outcomes: 1. The perception of visual hybrids follows the structure of a nonconceptual mental content, because the original categories or concepts of the hybrids’ components are not combined into one, and their properties are not applied to one another, therefore none of the components reconstructs the other such that it is introduced to a new category. 2. Language freezes the hybridity of the visual hybrid into conceptuality. 3. Given that language has a freezing effect in the case of an extreme visual phenomenon such as the hybrid, it is all the more restraining in moderate artistic compositions, such as visual metaphors, in which properties of one component (the source) are applied to the other (the target). In those, nonconceptuality emerges from relatively organized compositions, forms, and relations, and from the dependence of objects and their properties on perceptual context. 4. Thus, the nonconceptualist terminology is suitable for the analysis of aesthetic perception in general and aesthetic perception’s relation to language. Keywords aesthetics, perception, nonconceptual content, hybrids, visual metaphors. (shrink)

This commentary critically examines the view of the relationship between perception and memory in Ned Block's *The Border Between Seeing and Thinking*. It argues that visual working memory often stores the outputs of perception without altering their formats, allowing online visual perception to access these memory representations in computations that unfold over longer timescales and across eye movements. Since Block concedes that visual working memory representations are not iconic, we should not think of perceptual (...) representations as exclusively iconic either. (shrink)

I argue that we sometimes visually perceive the intentions of others. Just as we can see something as blue or as moving to the left, so too can we see someone as intending to evade detection or as aiming to traverse a physical obstacle. I consider the typical subject presented with the Heider and Simmel movie, a widely studied ‘animacy’ stimulus, and I argue that this subject mentally attributes proximal intentions to some of the objects in the movie. I further (...) argue that these attributions are unrevisable in a certain sense and that this result can be used to as part of an argument that these attributions are not post-perceptual thoughts. Finally, I suggest that if these attributions are visual experiences, and more particularly visual illusions, their unrevisability can be satisfyingly explained, by appealing to the mechanisms which underlie visual illusions more generally. (shrink)

Research in vision science, developmental psychology, and the foundations of cognitive science has led some theorists to posit referential mechanisms similar to indices. This hypothesis has been framed within a Fodorian conception of the early vision module. The article shows that this conception is mistaken, for it cannot handle the ‘interface problem’—roughly, how indexing mechanisms relate to higher cognition and conceptual thought. As a result, I reject the inaccessibility of early vision to higher cognition and make some constructive remarks on (...) the perception–cognition interface. -/- 1 The Case for Visual Indices 1.1 Preliminary assumptions 1.2 Transcendental arguments 1.3 Evidence from vision science 2 Visual Indices, Object Files, and Fodorian Modularity 3 The Interface Problem 3.1 Top-down attention and modularity 3.2 Selective attention and information 4 Revising the Indexing Hypothesis 4.1 Revising the perception–cognition interface 4.2 Revising the modularity of early vision 5 Concluding Remarks. (shrink)

In the philosophy of perception, direct realism has come into vogue. Philosophical authors assert and assume that what their readers want, and what anyone should want, is some form of direct realism. There are disagreements over precisely what form this direct realism should take. The majority of positions in favor now offer a direct realism in which objects and their material or physical properties constitute the contents of perception, either because we have an immediate or intuitive acquaintance with (...) those objects and properties, or because our perceptual states have informational content that represents the properties of those objects (and which is not itself an object of perception and has no specifically subjective aspect). This paper considers various forms of perceptual realism, including, for purposes of comparison, the largely abandoned indirect or representative realism. After surveying the variety of perceptual realisms and considering their various commitments, I introduce some considerations concerning the phenomenology of visual space that cause trouble for most forms of direct realism. These considerations pertain to the perception of objects in the distance and, secondarily, to the perception of shapes at a slant. I argue that one of the lesser known varieties of perceptual realism, critical direct realism, can meet the challenges offered by the facts of spatial perception. (shrink)

Ordinary human perceivers know that visual objects are perceivable from standpoints other than their own. The aim of this paper is to provide an explanation of how perceptual experience equips perceivers with this knowledge. I approach the task by discussing a variety of action-based theories of perception. Some of these theories maintain that standpoint transcendence is required for shape perception. I argue that this standpoint transcendence must take place in the phenomenal present and that it can be (...) explained in terms of the experience of perceivers who jointly attend to an object. Joint perceivers experience objects as being perceived from standpoints other than their own. They operate in what I call “social space”, in which they single out objects by triangulating targets’ locations relative to their co-perceivers’ standpoints on these targets. It is then possible to explain the public character of the objects of individual experience by appeal to what I call “public space”. This is a spatial framework whose locations are presented as standpoints whence joint attention to the target would ensue, were they occupied by co-perceivers. If shape perception requires standpoint transcendence, then shape perceivers operate in public space and are thus capable of singling out targets by triangulating their locations from standpoints other than their own. If it doesn’t, then the introduction of a public spatial framework is an additional step whose introduction explains how perceivers come to experience objects as perceivable from standpoints other than their own. (shrink)

It has often been assumed that when we use vision to become aware of an object or event in our surroundings, this must be accompanied by a corresponding visual experience (i.e., seeing). The studies reported here show that this assumption is incorrect. When observers view a sequence of displays alternating between an image of a scene and the same image changed in some way, they often feel (or sense) the change even though they have no visual experience of (...) it. The subjective difference between sensing and seeing is mirrored in several behavioral differences, suggesting that these are two distinct modes of conscious visual perception. (shrink)

Kant, Wittgenstein, and Husserl all held that visual awareness of objects requires visual awareness of the space in which the objects are located. There is a lively debate in the literature on spatial perception whether this view is undermined by the results of experiments on a Balint’s syndrome patient, known as RM. I argue that neither of two recent interpretations of these results is able to explain RM’s apparent ability to experience motion. I outline some ways in (...) which each interpretation may respond to this challenge, and suggest which way of meeting the challenge is preferable. I conclude that RM retains some awareness of the larger space surrounding the objects he sees. (shrink)

Perception, Action, and Consciousness: Sensorimotor Dynamics and Two Visual Systems is a state-of-the-art collection whose main goal is to explore, from an interdisciplinary perspective, the relationship between action and perception. A second goal of the volume is to investigate how perception and action interact specifically in the production of phenomenal awareness. In presenting and contrasting the major perspectives on the field, this volume marks a good sign of the progress being made on the nature of phenomenally (...) conscious visual experience. By combining theoretical and empirical approaches it also contributes to the debate in key domains of the cognitive sciences .The book contains a useful editorial introduction written by the Editors and six sections further divided into fifteen chapters. In the first part of this review I briefly summarize the content of each section. Having offered an outline of the volume, I then turn my attention to the main theme of the collection, which is the dichotomy between action-oriented theories of perception and the two visual systems hypothesis and look at the dialectic underlying this debate. (shrink)

We present a rigorous way to evaluate the visual perception of correlation in scatterplots, based on classical psychophysical methods originally developed for simple properties such as brightness. Although scatterplots are graphically complex, the quantity they convey is relatively simple. As such, it may be possible to assess the perception of correlation in a similar way. Scatterplots were each of 5.0 extent, containing 100 points with a bivariate normal distribution. Means were 0.5 of the range of the points, (...) and standard deviations 0.2 of this range. Precision was determined via an adaptive algorithm to find the just noticeable differences (jnds) in correlation, i.e., the difference between two side-by-side scatterplots that could be discriminated 75% of the time. Accuracy was measured by direct estimation, using reference scatterplots with fixed upper and lower values, with a test scatterplot adjusted so that its correlation appeared to be halfway between these. This process was recursively applied to yield several further estimates. Results of the discrimination tests show jnd(r) = k (1/b – r), where r is the Pearson correlation, and parameters 0 < k, b < 1. Integration yields a subjective estimate of correlation g(r) = ln(1 – br) / ln(1– b). The values of b found via discrimination closely match those found via direct estimation. As such, it appears that the perception of correlation in a scatterplot is completely described by two related performance curves, specified by two easily-measured parameters. (shrink)

Our visual experience of the world is one of diverse objects and events, each with particular colors, shapes, and motions. This experience is so coherent, so immediate, and so effortless that it seems to result from a single system that lets us experience everything in our field of view. But however appealing, this belief is mistaken: there are severe limits on what can be visually experienced. -/- For example, in a display for air-traffic control it is important to track (...) all moving items. For a single item, this can be done without problem. Three or four can also be tracked, although some degree of effort may be needed. As the number is increased further, accurate tracking becomes more and more difficult—and eventually, impossible. Performance is evidently affected by a factor within the observer which enables certain kinds of perception to occur, but is limited in some way. This factor is generally referred to as attention. -/- At various times, attention has been associated with clarity of perception, intensity of perception, consciousness, selection, or the allocation of a limited “resource” enabling various operations (see Hatfield, 1998). During the past several decades, considerable progress has been achieved by focusing on the idea of selection (Broadbent, 1982). In particular, attention can be productively viewed as contingently selective processing. This can be embodied in various ways by various processes—there need not be a single quantity identified with all forms of attention, or a single site where it operates (Allport, 1993; Tsotsos, 2011). Although “paying attention” is often considered to be a unitary operation, it may simply refer to the control of one or more selective processes, ideally in a co-ordinated way. While this view has some cost in terms of conceptual simplicity, it can help make sense of a large set of phenomena. -/- This article surveys several of the major issues in our understanding of attention and how it relates to perception. It focuses on vision, since many—if not all—considerations are similar for all sensory modalities, and the level of understanding achieved in this domain is currently the most advanced. (shrink)

Visual perception is widely taken to present properties such as redness, roundness, and so on. This in turn might be thought to give rise to accuracy conditions for experience, and so content, regardless of which metaphysical view of perception one endorses. An influential version of this argument—Susanna Siegel’s ’Argument from Appearing’—aims to establish the existence of content as common ground between representational and relational views of perception. This goes against proponents of ‘austere’ relationalism who deny that (...) content plays a substantive role in philosophical explanations of conscious perceptual experience. Though Siegel’s argument purports to be neutral with respect to the metaphysics of perception, it relies upon an equivocation between the presentation of property-types and property-instances. Consequently, the argument begs the question against the austere relational view, and so fails to establish the desired conclusion. So while relationalists can and should allow that experiences have accuracy conditions, it does not follow from this that they have contents of any philosophically interesting or significant kind. (shrink)

Many philosophers have held that it is not possible to experience a spatial object, property, or relation except against the background of an intact awareness of a space that is somehow ‘absolute’. This paper challenges that claim, by analyzing in detail the case of a brain-damaged subject whose visual experiences seem to have violated this condition: spatial objects and properties were present in his visual experience, but space itself was not. I go on to suggest that phenomenological argumentation (...) can give us a kind of evidence about the nature of the mind even if this evidence is not absolutely incorrigible. (shrink)

Much attention has recently been paid to the idea, which I label ‘External World Acquaintance’ (EWA), that the phenomenal character of perceptual experience is partially constituted by external features. One motivation for EWA which has received relatively little discussion is its alleged ability to help deal with the ‘Explanatory Gap’ (e.g. Fish 2008, 2009, Langsam 2011, Allen 2016). I provide a reformulation of this general line of thought, which makes clearer how and when EWA could help to explain the specific (...) phenomenal nature of visual experience. In particular, I argue that by focusing on the different kinds of perceptual actions that are available in the case of visual spatial vs. colour perception, we get a natural explanation for why we should expect the specific nature of colour phenomenology to remain less readily intelligible than the specific nature of visual spatial phenomenology. (shrink)

Evidence from cognitive science supports the claim that humans and other animals see the world as divided into objects. Although this claim is widely accepted, it remains unclear whether the mechanisms of visual reference have representational content or are directly instantiated in the functional architecture. I put forward a version of the former approach that construes object files as icons for objects. This view is consistent with the evidence that motivates the architectural account, can respond to the key arguments (...) against representational accounts, and has explanatory advantages. I draw general lessons for the philosophy of perception and the naturalization of intentionality. (shrink)

This article discusses several key issues concerning the study of attention and its relation to visual perception, with an emphasis on behavioral and experiential aspects. It begins with an overview of several classical works carried out in the latter half of the 20th century, such as the development of early filter and spotlight models of attention. This is followed by a survey of subsequent research that extended or modified these results in significant ways. It covers current work on (...) various forms of induced blindness and on the capabilities of nonattentional processes. It also includes proposals about how a "just-in-time" allocation of attention can create the impression that we see our surroundings in coherent detail everywhere, as well as how the failure of such allocation can result in various perceptual deficits. The final section examines issues that have received little consideration to date, but may be important for new lines of research in the near future. These include the prospects for a better characterization of attention, the possibility of more systematic explanations, factors that may significantly modulate attentional operation, and the possibility of several kinds of visual attention and visual experience. (shrink)

Experiments are presented showing that visual search for Mueller-Lyer (ML) stimuli is based on complete configurations, rather than component segments. Segments easily detected in isolation were difficult to detect when embedded in a configuration, indicating preemption by low-level groups. This preemption—which caused stimulus components to become inaccessible to rapid search—was an all-or-nothing effect, and so could serve as a powerful test of grouping. It is shown that these effects are unlikely to be due to blurring by simple spatial filters (...) at early visual levels. It is proposed instead that they are due to more sophisticated processes that rapidly bind contour fragments into spatially-extended assemblies. These results support the view that rapid visual search cannot access the primitives formed at the earliest stages of visual processing; rather, it can access only higher-level, more ecologically-relevant structures. (shrink)

Ordinary cases of object seeing involve the visual perception of space and spatial location. But does seeing an object require such spatial perception? An empirical challenge to the idea that it does comes from reflection upon Bálint's syndrome, for some suppose that in Bálint's syndrome subjects can see objects without seeing space or spatial location. In this article, I question whether the empirical evidence available to us adequately supports this understanding of Bálint's syndrome, and explain how the (...) aforementioned empirical challenge can be resisted. (shrink)

East Asians and Westerners differ in various aspects of perception and cognition. For example, visual memory for East Asians is believed to be more influenced by the contextual aspects of a scene than is the case for Westerners (Masuda & Nisbett, 2001). There are also differences in visual search: for Westerners, search for a long line among short is faster than for short among long, whereas this difference does not appear to hold for East Asians (Ueda et (...) al., submitted). However, it is unclear how these group-level differences originate. To investigate the extent to which they depend upon environment, we tested visual search and visual memory in East Asian immigrants who had lived in Canada for different amounts of time. Recent immigrants were found to exhibit no search asymmetry, unlike Westerners who had spent their lives in Canada. However, immigrants who had lived in Canada for more than two years showed performance comparable to that of Westerners. These differences could not be explained by the general analytic/holistic processing distinction believed to differentiate Westerners and East Asians, since all observers showed a strong holistic tendency for visual recognition. Results instead support the suggestion that exposure to a new environment can significantly affect the particular processes used to perceive a given stimulus. (shrink)

Four experiments investigated the extent to which abstract quantitative information can be conveyed by basic visual features. This was done by asking observers to estimate and discriminate Pearson correlation in graphical representations where the first data dimension of each element was encoded by its horizontal position, and the second by the value of one of its visual features; perceiving correlation then requires combining the information in the two encodings via a common abstract representation. Four visual features were (...) examined: luminance, color, orientation, and size. All were able to support the perception of correlation. Indeed, despite the strikingly different appearances of the associated stimuli, all gave rise to performance that was much the same: just noticeable difference was a linear function of distance from complete correlation, and estimated correlation a logarithmic function of this distance. Performance differed only in regards to the level of noise in the feature, with these values compatible with estimates of channel capacity encountered in classic experiments on absolute perceptual magnitudes. These results suggest that quantitative information can be conveyed by visual features that are abstracted at relatively low levels of visual processing, with little representation of the original sensory property. It is proposed that this is achieved via an abstract parameter space in which the values in each perceptual dimension are normalized to have the same means and variances, with perceived correlation based on the shape of the joint probability density function of the resultant elements. (shrink)

Scene Perception is the visual perception of an environment as viewed by an observer at any given time. It includes not only the perception of individual objects, but also such things as their relative locations, and expectations about what other kinds of objects might be encountered. -/- Given that scene perception is so effortless for most observers, it might be thought of as something easy to understand. However, the amount of effort required by a process (...) often bears little relation to its underlying complexity. A closer look shows that scene perception is a highly complex activity, and that any account of it must deal with several difficult issues: What exactly is a scene? What aspects of it do we represent? And what are the processes involved? Finding the answers to these questions has proven to be extraordinarily difficult. (shrink)

Through extensive training, experts acquire specialized knowledge and abilities. In this paper, I argue that experts also acquire specialized visual experiences. Specifically, I articulate and defend the account that experts enjoy visual experiences that represent gestalt properties through perceptual learning. I survey an array of empirical studies on face perception and perceptual expertise that support this account. I also look at studies on perceptual adaptation that some might argue present a problem for my account. I show how (...) the data are subject to an interpretation that is friendly to it. Last, I address two theoretical objections to the claim that visual experiences represent gestalt properties. (shrink)

Is vision merely a state of the beholder’s sensory organ which can be explained as an immediate effect caused by external sensible objects? Or is it rather a successive process in which the observer actively scanning the surrounding environment plays a major part? These two general attitudes towards visual perception were both developed already by ancient thinkers. The former is embraced by natural philosophers (e.g., atomists and Aristotelians) and is often labelled “intromissionist”, based on their assumption that vision (...) is an outcome of the causal influence exerted by an external object upon a sensory organ receiving an entity from the object. The latter attitude to vision as a successive process is rather linked to the “extramissionist” theories of the proponents of geometrical optics (such as Euclid or Ptolemy) who suggest that an entity – a visual ray – is sent forth from the eyes to the object. The present paper focuses on the contributions to this ancient controversy proposed by some 13th-century Latin thinkers. [...]. (shrink)

A modified visual search task demonstrates that humans are very good at resuming a search after it has been momentarily interrupted. This is shown by exceptionally rapid response time to a display that reappears after a brief interruption, even when an entirely different visual display is seen during the interruption and two different visual searches are performed simultaneously. This rapid resumption depends on the stability of the visual scene and is not due to display or response (...) anticipations. These results are consistent with the existence of an iterative hypothesis-testing mechanism that compares information stored in short-term memory (the perceptual hypothesis) with information about the display (the sensory pattern). In this view, rapid resumption occurs because a hypothesis based on a previous glance of the scene can be tested very rapidly in a subsequent glance, given that the initial hypothesis-generation step has already been performed. (shrink)

It has long been known that memory need not be a literal reproduction of the past but may be a constructive process. To say that memory is a constructive process is to say that the encoded content may differ from the retrieved content. At the same time, memory is bound by the authenticity constraint which states that the memory content must be true to the subject's original perception of reality. This paper addresses the question of how the constructive nature (...) of visual memory can be reconciled with the authenticity constraint. In what respect and to what extent may the content of a visual memory differ from the original perceptual state while still adequately reflecting the subject's original perception? (shrink)

This paper examines Helmholtz's attempt to use empirical psychology to refute certain of Kant's epistemological positions. Particularly, Helmholtz believed that his work in the psychology of visual perception showed Kant's doctrine of the a priori character of spatial intuition to be in error. Some of Helmholtz's arguments are effective, but this effectiveness derives from his arguments to show the possibility of obtaining evidence that the structure of physical space is non-Euclidean, and these arguments do not depend on his (...) theory of vision. Helmholtz's general attempt to provide an empirical account of the "inferences" of perception is regarded as a failure. (shrink)

It seems plausible that visual experiences of darkness have perceptual phenomenal content that clearly differentiates them from absences of visual experiences. I argue, relying on psychological results concerning auditory attention, that the analogous claim is true about auditory experiences of silence. More specifically, I propose that experiences of silence present empty spatial directions like ‘right’ or ‘left’, and so have egocentric spatial content. Furthermore, I claim that such content is genuinely auditory and phenomenal in the sense that one (...) can, in principle, recognize that one is experiencing silence. This position is far from obvious, as the majority of theories concerning silence perception do not ascribe perceptual phenomenal content to experiences of silence. (shrink)

What is the biological function of perception? I hold perception, especially visual perception in humans, has the biological function of accurately representing the environment. Tyler Burge argues this cannot be so in Origins of Objectivity (Oxford, 2010), for accuracy is a semantical relationship and not, as such, a practical matter. Burge also provides a supporting example. I rebut the argument and the example. Accuracy is sometimes also a practical matter if accuracy partly explains how perception (...) contributes to survival and reproduction. (shrink)

Some recently popular accounts of perception account for the phenomenal character of perceptual experience in terms of the qualities of objects. My concern in this paper is with naturalistic versions of such a phenomenal externalist view. Focusing on visual spatial perception, I argue that naturalistic phenomenal externalism conflicts with a number of scientific facts about the geometrical characteristics of visual spatial experience.

The paper uses the tools of mereotopology (the theory of parts, wholes and boundaries) to work out the implications of certain analogies between the 'ecological psychology' of J. J Gibson and the phenomenology of Edmund Husserl. It presents an ontological theory of spatial boundaries and of spatially extended entities. By reference to examples from the geographical sphere it is shown that both boundaries and extended entities fall into two broad categories: those which exist independently of our cognitive acts (for example, (...) the planet Earth, its exterior surface); and those which exist only in virtue of such acts (for example: the equator, the North Sea). The visual field, too, can be conceived as an example of an extended entity that is dependent in the sense at issue. The paper suggests extending this analogy by postulating entities which would stand to true judgments as the visual field stands to acts of visual perception. The judgment field is defined more precisely as that complex extended entity which comprehends all entities which are relevant to the truth of a given (true) judgment. The work of cognitive linguists such as Talmy and Langacker, when properly interpreted, can be shown to yield a detailed account of the structures of the judgment fields corresponding to sentences of different sorts. A new sort of correspondence-theoretic definition of truth for sentences of natural language can then be formulated on this basis. (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)

How tight is the conceptual connection between imagination and perception? A number of philosophers, from the early moderns to present-day predictive processing theorists, tie the knot as tightly as they can, claiming that states of the imagination, i.e. mental imagery, are a proper subset of perceptual experience. This paper labels such a view ‘perceptualism’ about the imagination and supplies new arguments against it. The arguments are based on high-level perceptual content and, distinctly, cognitive penetration. The paper also defuses a (...) recent, influential argument for perceptualism based on the ‘discovery’ that visual perception and mental imagery share a significant neural substrate: circuitry in V1, the brain’s primary visual cortex. Current neuropsychology is shown to be equivocal at best on this matter. While experiments conducted on healthy, neurotypical subjects indicate substantial neural overlap, there is extensive clinical evidence of dissociations between imagery and perception in the brain, most notably in the case of aphantasia. (shrink)

A visual experience, as understood here, is a sensory event that is conscious, or like something to undergo. This chapter focuses on three issues concerning such experiences. The first issue is the so-called ‘transparency’ of experiences. The chapter distinguishes a number of different interpretations of the suggestion that visual experiences are ‘transparent’. It then discusses in what sense, if any, visual experiences are ‘transparent’, and what further conclusions one can draw from that. The second issue is which (...) properties we are presented with in visual experiences. It is widely accepted that we sometimes experience red for example. But exactly which properties do we sometimes visually experience, and which properties do we never visually experience? The third issue is which particulars, if any, we are presented with in visual experiences. Do we for example sometimes visually experience mind-independent particulars like trees? Do we sometimes visually experience mind-dependent, particular ‘sense-data’? (shrink)

For scatterplots with gaussian distributions of dots, the perception of Pearson correlation r can be described by two simple laws: a linear one for discrimination, and a logarithmic one for perceived magnitude (Rensink & Baldridge, 2010). The underlying perceptual mechanisms, however, remain poorly understood. To cast light on these, four different distributions of datapoints were examined. The first had 100 points with equal variance in both dimensions. Consistent with earlier results, just noticeable difference (JND) was a linear function of (...) the distance away from r = 1, and the magnitude of perceived correlation a logarithmic function of this quantity. In addition, these laws were linked, with the intercept of the JND line being the inverse of the bias in perceived magnitude. Three other conditions were also examined: a dot cloud with 25 points, a horizontal compression of the cloud, and a cloud with a uniform distribution of dots. Performance was found to be similar in all conditions. The generality and form of these laws suggest that what underlies correlation perception is not a geometric structure such as the shape of the dot cloud, but the shape of the probability distribution of the dots, likely inferred via a form of ensemble coding. It is suggested that this reflects the ability of observers to perceive the information entropy in an image, with this quantity used as a proxy for Pearson correlation. (shrink)