In apparent motion experiments, participants are presented with what is in fact a succession of two brief stationary stimuli at two different locations, but they report an impression of movement. Philosophers have recently debated whether apparent motion provides evidence in favour of a particular account of the nature of temporal experience. I argue that the existing discussion in this area is premised on a mistaken view of the phenomenology of apparent motion and, as a (...) result, the space of possible philosophical positions has not yet been fully explored. In particular, I argue that the existence of apparent motion is compatible with an account of the nature of temporal experience that involves a version of direct realism. In doing so, I also argue against two other claims often made about apparent motion, viz. that apparent motion is the psychological phenomenon that underlies motion experience in the cinema, and that apparent motion is subjectively indistinguishable from real motion. (shrink)

Apparent motion is an illusion in which two sequentially presented and spatially separated stimuli give rise to the experience of one moving stimulus. This phenomenon has been deployed in various philosophical arguments for and against various theories of consciousness, time consciousness and the ontology of time. Nevertheless, philosophers have continued working within a framework that does not reflect the current understanding of apparent motion. The main objectives of this paper are to expose the shortcomings of the (...) explanations provided for apparent motion and to offer an alternative explanation for the phenomenon. (shrink)

Introspectively, it appears that we can have experiences as of temporally extended phenomena such as change, motion, and the passage of time. A central question in the ontology of time is whether we can make sense of these experiences without assuming that the passage of time is real. The antireductionist argument against such a possibility maintains that if there is no passage of time, but only static time slices, then our experiences as of arguably temporally extended phenomena cannot be (...) explained. Consequently, insofar as we can have such experiences, reductionists need to show that these experiences are in fact realized by static means. By drawing from cognitive sciences, this is exactly what Laurie A. Paul recently aimed to show. I will argue that Paul’s argumentation fails on two grounds. First, even if her argument for accounting apparent motion by static means is successful, it does not apply to other experiences of temporal phenomena. Second, there are reasons to doubt that even apparent motion is represented by static means. Accordingly, the antireductionist argument remains to be addressed. (shrink)

Based on concepts of self-organization, we interpret apparent motion as the result of a so-called non-equilibrium phase transition of the perceptual system with the stimulus-onset asynchrony (SOA) acting as a control parameter. Accordingly, we predict a significantly increasing variance of the quality index of apparent motion close to critical SOAs. [Shepard].

A number of studies in the apparent motion literature were examined using the cognitive penetrability criterion to determine the extent to which beliefs affect the perception of apparent motion. It was found that the interaction between the perceptual processes mediating apparent motion and higher order processes appears to be limited. In addition, perceptual and inferential beliefs appear to have different effects on perceived motion optimality and direction. Our findings suggest that the system underlying (...) apparent motion perception has more than one stage and is informationally encapsulated from cognitive factors. (shrink)

Shepard's analysis of how shape, motion, and color are perceptually represented can be generalized. Apparent motion and shape may be associated with a group of spatial transformations, accounting for rigid and plastic motion, and perceived object color may be associated with a group of illuminant transformations, accounting for the discriminability of surface-reflectance changes and illuminant changes beyond daylight. The phenomenological and mathematical parallels between these perceptual domains may indicate common organizational rules, rather than specific ecological adaptations. (...) [Barlow; Hecht; Kubovy & Epstein; Schwartz; Shepard; Todorovic]. (shrink)

We investigated the key anatomical structures mediating interhemispheric integration during the perception of apparent motion across the retinal midline. Previous studies of commissurotomized patients suggest that subcortical structures mediate interhemispheric transmission but the specific regions involved remain unclear. Here, we exploit interindividual variations in the propensity of normal subjects to perceive horizontal motion, in relation to vertical motion. We characterize these differences psychophysically using a Dynamic Dot Quartet (an ambiguous stimulus that induces illusory motion). We (...) then tested for correlations between a tendency to perceive horizontal motion and fractional anisotropy (FA) (from structural diffusion tensor imaging), over subjects. FA is an indirect measure of the orientation and integrity of white matter tracts. Subjects who found it easy to perceive horizontal motion showed significantly higher FA values in the pulvinar. Furthermore, fiber tracking from an independently identified (subject-specific) visual motion area converged on the pulvinar nucleus. These results suggest that the pulvinar is an anatomical hub and may play a central role in interhemispheric integration. (shrink)

Austere relationism rejects the orthodox analysis of hallucinations and illusions as incorrect perceptual representations. In this article, I argue that illusions of optimal motion present a serious challenge for this view. First, I submit that austere-relationist accounts of misleading experiences cannot be adapted to account for IOMs. Second, I show that any attempt at elucidating IOMs within an austere-relationist framework undermines the claim that perceptual experiences fundamentally involve relations to mind-independent objects. Third, I develop a representationalist model of IOMs. (...) The proposed analysis combines two ideas: Evans' dynamic modes of presentation and Fine's relational semantics for identity. (shrink)

Human infants begin very early in life to take advantage of multisensory information by extracting the invariant amodal information that is conveyed redundantly by multiple senses. Here we addressed the question as to whether infants can bind multisensory moving stimuli, and whether this occurs even if the motion produced by the stimuli is only illusory. Three- to four-month-old infants were presented with two bimodal pairings: visuo-tactile and audio-visual. Visuo-tactile pairings consisted of apparently vertically moving bars (the Barber Pole illusion) (...) moving in either the same or opposite direction with a concurrent tactile stimulus consisting of strokes given on the infant’s back. Audio-visual pairings consisted of the Barber Pole illusion in its visual and auditory version, the latter giving the impression of a continuous rising or ascending pitch. We found that infants were able to discriminate congruently (same direction) vs. incongruently moving (opposite direction) pairs irrespective of modality (Experiment 1). Importantly, we also found that congruently moving visuo-tactile and audio-visual stimuli were preferred over incongruently moving bimodal stimuli (Experiment 2). Our findings suggest that very young infants are able to extract motion as amodal component and use it to match stimuli that only apparently move in the same direction. (shrink)

In a now famous thought experiment, Frank jackson asked us t0 imagine an omniscient scientist, Mary, who is coniincd in a black-and-white room and then released into the world 0f color . Assuming that she is omniscicnt in respect of all physical facts—roughiy, all the facts available to physics and all the facts that they in turn Hx or determine-physicalism would suggest that there is no new fact Mary can discover after emancipation; physicalism holds that all facts are physical in (...) the relevant sense . Yet we cannot help but feel that coming out of that room would be an occasion of dramatic enlightenment and, in particular, an occasion for learning facts to do with how red or yellow or blue 100ks or, as it is usually said, with what it is like t0 sec red or yellow or blue. Many in the black-and—whit<—: room knew all the physical facts about the world, where these may be taken to include three sorts of color facts: objcctual facts, as to what surface colors different objects have, assuming as I shall do throughout—that colors are properties of objects; intentional facts, as to which colors different objects 0r apparent objects are represented as having in the subjc-:ct’s experience, rightly or wrongly; and nonintentional facts, about what such color experiences are like in their effects on subiccts—wh<—:ther they are comforting, or arousing, or whatever. But, according to the argument, Mary didn’t know how any color looks or, equivalently, what color experience is like in itself, not just in its effects O1'1 subjects. This particular nonintentional fact about the quality of color c-zxpc-2ri<—:ncc-—this phenomenal fact, as it is often describcd—she did not. (shrink)

The debate about cinematic motion revolves around the question of whether the movement of cinematic images is real. That the movement we perceive in film should be construed as the movement of images is taken for granted. But this is a mistake. There is no reason to suppose that cinematic images of moving objects are themselves perceived to be moving. All that is necessary is to perceive these images as continuously changing images of one and the same object.

The naïve view of temporal experience (Phillips, in: Lloyd D, Arstila V (eds) Subjective time: the philosophy, psychology, and neuroscience of temporality, forthcoming-a) comprises two claims. First, that we are perceptually aware of temporal properties, such as succession and change. Second, that for any temporal property apparently presented in experience, our experience itself possesses that temporal property. In his paper ‘Silencing the experience of change’ (forthcoming), Watzl argues that this second naïve inheritance thesis faces a novel counter-example in the form (...) of the striking motion silencing effects recently demonstrated by Suchow and Alvarez (Curr Biol 21(2):140–143, 2011). Here I clarify the form which any counter-example to naïve inheritance must take. I then explain how, on a plausible, rival ‘crowding’ interpretation of Suchow and Alvarez’s data, motion silencing poses no more of a threat to naïve inheritance than standard cases of change blindness. (shrink)

There are few articles in science that remain relevant over a span of 100 years; Max Wertheimer's pioneering experimental studies on apparent motion and figural organization are notable exceptions. Wertheimer's 1912 account of motion perception started a revolution and established the Gestalt school of psychology. It also paved the way for further investigations of apparent motion perception, including subsequent research by Oliver Braddick, Stuart Anstis, Vilaynur Ramachandran, and others. Wertheimer's 1923 article on figural organization helped (...) define grouping as a principle of figure-ground perception. This book provides contemporary readers and researchers with Wertheimer's two pivotal articles, newly translated into English and each accompanied by a synopsis, and two essays on apparent motion and figural organization that describe the long-term impact of Wertheimer's work. The translation of the original German into readable English prose allows English-language readers for the first time to appreciate Wertheimer's visionary ideas. The accompanying essays tie Wertheimer's phenomenological descriptions to the underlying neuronal mechanisms, bridging the years between the articles' first publication and modern research. (shrink)

It is often claimed (most recently by Michael Friedman) that Kant intended to justify Newton’s most fundamental claims expressed in the Principia, such as his laws of motion and the law of universal gravitation. In this article, I argue that the differences between Newton’s laws of motion and Kant’s laws of mechanics are not superficial or merely apparent. Rather, they reflect fundamental differences in their respective projects. This point can be seen especially clearly by considering the nature (...) of the various projects undertaken in Germany prior to Kant that discuss the laws of motion. Wolff and his followers qua metaphysicians were especially interested in providing nonempirical justifications of their laws of motion as well as an intelligible account of the fundamental properties of bodies in terms of substance, accident, and force. Maupertuis and Euler, despite often being seen as Newtonians, both drew on traditions other than Newton’s. Physics textbooks (by figures such as Erxleben, Karsten, ‘s Gravesande, and Musschenbroek) vary considerably in their aims, but in none of these cases is Newton’s main argument of the Principia presented. In light of the fact that these projects are distinct in significant ways from Newton’s project, the differences between Newton’s laws of motion and Kant’s laws of mechanics are most likely not merely apparent but reflect the fact that Kant, too, was pursuing a project fundamentally distinct from Newton’s. (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)

As I have read the scholium, it divides into three main parts, not including the introductory paragraph. The first consists of paragraphs one to four in which Newton sets out his characterizations of absolute and relative time, space, place, and motion. Although some justificatory material is included here, notably in paragraph three, the second part is reserved for the business of justifying the characterizations he has presented. The main object is to adduce grounds for believing that the absolute quantities (...) are indeed distinct from their relative measures and are not reducible to them. Paragraph five takes this up for the case of time. Paragraphs eight to twelve endeavor to do this for rest and motion by appealing to their properties, causes and effects. In arguing that absolute motion is not reducible to any particular form of the relative motion of bodies with respect to one another, and thus, as is directly argued in the third argument, must be understood in terms of motionless places, Newton thereby constructs an indirect case that absolute space is indeed something distinct from any relative space. Paragraph thirteen functions as conclusion to this line of inquiry and comments on how, in the light of this, the names of these quantities are to be interpreted in the scriptures. The third and final part consists of paragraph fourteen alone, and addresses the question: given that true motion is motion with respect to absolute space, but the parts of the latter are not perceivable, is it possible for us to know the true motions of individual bodies? Newton illustrates how this may be done from the evidence provided by their apparent motions and the forces which are the causes and effects of true motion. This forms a bridge to the body of the work insofar as the purpose of the Principia, according to Newton, is to show how this, and the converse problem, of inferring true and apparent motions from the forces, can be dealt with.Part II of this paper will appear in the next issue of Studies in History and Philosophy of Science. (shrink)

IT IS fairly well known that the problem of motion or, more generally, that of change is one of the oldest philosophical problems which can be traced to the very dawn of Western thought. It was inseparable from the basic problem which the Presocratics faced: that of the primary stuff underlying the phenomenal diversity of our sensory experience. Once the sensory diversity is viewed as merely apparent, one cannot avoid the question how such an appearance is generated by (...) the underlying single principle; in other words, one faces the problem of the origin of things, i.e., the problem of change. Hence the monism which in various forms underlies the majority of the early cosmogonic or protocosmogonic speculations. But already then three different theses are discernible: a) one rather extreme view which upholds rigorously the strict oneness of the underlying substance and from its immutability infers the impossibility of change; this was the view of Parmenides and his disciples; b) the second view which, while retaining the Eleatic principle of the singleness and immutability of the basic stuff, admits its existence in a plural form. This is atomism which reduces change to a change of position. In other words, diversity is retained only in the form of numerical diversity, and change only in the form of spatial displacement. All apparently qualitative changes are thus explainable in terms of combination and recombination of the homogeneous and immutable elements. Such are the basic premises not only of ancient Greek atomism, but very nearly of all forms of atomism in all different periods of history. Its basic inspiration has always remained Eleatic, although a very important concession has been made to sensory perception in the sense that the reality of change has been admitted. But it is admitted in its most innocuous form—in the form of displacement of the unchanging units of Being. (shrink)