A midbrain neural basis for the perceptualoscillations of binocular rivalry is suggestedon the basis of fMRI studies of rivalry andinferences from the properties of rivalry thatcannot be explained from the known propertiesof primary visual cortical (V1) neurons. Therivalry switch is proposed to activatehomologous areas of each cerebral hemispherealternately, by means of a bistable oscillatorcircuit that straddles the midline of theventral tegmentum. This bistable oscillatoroperates at the same slow rate that ischaracteristic of perceptual rivalryalternations. Whilst attempting to (...) divert thepresent preoccupation with cortical mechanismsfor rivalry, the new proposal integrates manycortical areas, in keeping with recent evidencethat binocular rivalry involves widespreadareas of the hemispheres. By linking rivalry tointerhemispheric switching mechanisms in thisway, the new proposal for the switch makes theprediction that binocular rivalry will besubject to high level influences such as moodand motivation. These predictions are beingfulfilled, with rivalry playing an increasingrole in the diagnosis and understanding if mooddisorders, schizophrenia and other psychiatricconditions. (shrink)

In addressing thescientific study of consciousness, Crick and Koch state, It is probable that at any moment some active neuronal processes in your head correlate with consciousness, while others do not: what is the difference between them? (1998, p. 97). Evidence from electrophysiological and brain-imaging studies of binocular rivalry supports the premise of this statement and answers to some extent, the question posed. I discuss these recent developments and outline the rationale and experimental evidence for the interhemispheric switch hypothesis (...) of perceptual rivalry. According to this model, the perceptual alternations of rivalry reflect hemispheric alternations, suggesting that visual consciousness of rivalling stimuli may be unihemispheric at any one time (Miller et al., 2000). However, in this paper, I suggest that interhemispheric switching could involve alternating unihemispheric attentional selection of neuronal processes for access to visual consciousness. On this view, visual consciousness during rivalry could be bi hemispheric because the processes constitutive of attentional selection may be distinct from those constitutive of visual consciousness. This is a special case of the important distinction between the neuronal correlates and constitution of visual consciousness. (shrink)

In addressing the scientific study of consciousness, Crick and Koch state, “It is prob- able that at any moment some active neuronal processes in your head correlate with consciousness, while others do not: what is the difference between them?” (1998, p. 97). Evidence from electro- physiological and brain-imaging studies of binocular rivalry supports the premise of this statement and answers to some extent, the question posed. I discuss these recent developments and outline the rationale and experimental evidence for the (...) interhemispheric switch hypothesis of perceptual rivalry. According to this model, the perceptual alternations of rivalry reflect hemispheric alterna- tions, suggesting that visual consciousness of rivalling stimuli may be unihemispheric at any one time (Miller et al., 2000). However, in this paper, I suggest that interhemispheric switching could involve alternating unihemispheric attentional selection of neuronal processes for access to visual consciousness. On this view, visual consciousness during rivalry could be bihemispheric because the processes constitutive of attentional selection may be distinct from those constitutive of visual consciousness. This is a special case of the important distinction between the neuronal correlates and constitution of visual consciousness. (shrink)

Nikos K. Logothetis University of Manchester, Manchester, UK In binocular rivalry, the visual percept alternates stochastically between two dichoptically presented stimuli. It is established that both processes related to the eye of origin and binocular, stimulus-related processes account for these fluctuations in conscious perception. Here we studied how their relative contributions vary over time. We applied brief disruptions to rivalry displays, concurrent with an optional eye swap, at varying time intervals after one stimulus became visible (dominant). We found (...) that early in a dominance phase the dominant eye determined the percept by stabilizing its own contribution (regardless of the stimulus), with an additional yet weaker stabilizing contribution of the stimulus (regardless of the eye). Their stabilizing contributions declined in parallel with time so that late in a dominance phase the stimulus (and in some cases also the eye-based) contribution turned negative, favoring a perceptual (or ocular) switch. Our findings show that depending on the time, first processes related to the eye of origin and then those related to the stimulus can have a greater net influence on the stability of the conscious percept. Their co-varying change may be due to feedback from image- to eyeof-origin representations. (shrink)

We investigated how the structure of the brain network relates to the stability of perceptual alternation in binocular rivalry. Historically, binocular rivalry has provided important new insights to our understandings in neuroscience. Although various relationships between the local regions of the human brain structure and perceptual switching phenomena have been shown in previous researches, the global organization of the human brain structural network relating to this phenomenon has not yet been addressed. To approach this issue, we (...) reconstructed fiber-tract bundles using diffusion tensor imaging and then evaluated the correlations between the speeds of perceptual alternation and fractional anisotropy (FA) values in each fiber-tract bundle integrating among 84 brain regions. The resulting comparison revealed that the distribution of the global organization of the structural brain network showed positive or negative correlations between the speeds of perceptual alternation and the FA values. First, the connections between the subcortical regions stably were negatively correlated. Second, the connections between the cortical regions mainly showed positive correlations. Third, almost all other cortical connections that showed negative correlations were located in one central cluster of the subcortical connections. This contrast between the contribution of the cortical regions to destabilization and the contribution of the subcortical regions to stabilization of perceptual alternation provides important information as to how the global architecture of the brain structural network supports the phenomenon of binocular rivalry. (shrink)

The relationship between brain activity and conscious visual experience is central to our understanding of the neural mechanisms underlying perception. Binocular rivalry, where monocular stimuli compete for perceptual dominance, has been previously used to dissociate the constant stimulus from the varying percept. We report here fMRI results from humans experiencing binocular rivalry under a dichoptic stimulation paradigm that consisted of two drifting random dot patterns with different motion coherence. Each pattern had also a different color, which both (...) enhanced rivalry and was used for reporting which of the two patterns was visible at each time. As the perception of the subjects alternated between coherent motion and motion noise, we examined the effect that these alternations had on the strength of the MR signal throughout the brain. Our results demonstrate that motion perception is able to modulate the activity of several of the visual areas which are known to be involved in motion processing. More specifically, in addition to area V5 which showed the strongest modulation, a higher activity during the perception of motion than during the perception of noise was also clearly observed in areas V3A and LOC, and less so in area V3. In previous studies, these areas had been selectively activated by motion stimuli but whether their activity reflects motion perception or not remained unclear; here we show that they are involved in motion perception as well. The present findings therefore suggest a lack of a clear distinction between ?processing? versus ?perceptual? areas in the brain, but rather that the areas involved in the processing of a specific visual attribute are also part of the neuronal network that is collectively responsible for its perceptual representation. (shrink)

Traditional explanations of multistable visual phenomena (e.g. ambiguous figures, perceptual rivalry) suggest that the basis for spontaneous reversals in perception lies in antagonistic connectivity within the visual system. In this review, we suggest an alternative, albeit speculative, explanation for visual multistability – that spontaneous alternations reflect responses to active, programmed events initiated by brain areas that integrate sensory and non-sensory information to coordinate a diversity of behaviors. Much evidence suggests that perceptual reversals are themselves more closely (...) related to the expression of a behavior than to passive sensory responses: (1) they are initiated spontaneously, often voluntarily, and are influenced by subjective variables such as attention and mood; (2) the alternation process is greatly facilitated with practice and compromised by lesions in non-visual cortical areas; (3) the alternation process has temporal dynamics similar to those of spontaneously initiated behaviors; (4) functional imaging reveals that brain areas associated with a variety of cognitive behaviors are specifically activated when vision becomes unstable. In this scheme, reorganizations of activity throughout the visual cortex, concurrent with perceptual reversals, are initiated by higher, largely non-sensory brain centers. Such direct intervention in the processing of the sensory input by brain structures associated with planning and motor programming might serve an important role in perceptual organization, particularly in aspects related to selective attention. (shrink)

Traditional explanations of multistable visual phenomena (e.g. ambiguous figures, perceptual rivalry) suggest that the basis for spontaneous reversals in perception lies in antagonistic connectivity within the visual system. In this review, we suggest an alternative, albeit speculative. explanation for visual multistability - that spontaneous alternations reflect responses to active, programmed events initiated by brain areas that integrate sensory and non-sensory information to coordinate a diversity of behaviors. Much evidence suggests that perceptual reversals are themselves more closely (...) related to the expression of a behavior than to passive sensory responses: (1) they are initiated spontaneously, often voluntarily, and are influenced by subjective variables such as attention and mood; (2) the alternation process is greatly facilitated with practice and compromised by lesions in non- visual cortical areas; (3) the alternation process has temporal dynamics similar to those of spontaneously initiated behaviors; (4) functional imaging reveals that brain areas associated with a variety of cognitive behaviors are specifically activated when vision becomes unstable. In this scheme, reorganizations of activity throughout the visual cortex, concurrent with perceptual reversals, are initiated by higher, largely non- sensory brain centers. Such direct intervention In the processing of the sensory input by brain structures associated with planning and motor programming might serve an important role in perceptual organization, particularly in aspects related to selective attention. (shrink)

Slower perceptual alternations, a notable perceptual effect observed in psychiatric disorders, can be alleviated by antidepressant therapies that affect serotonin levels in the brain. While these phenomena have been well documented, the underlying neurocognitive mechanisms remain to be elucidated. Our study bridges this gap by employing a computational cognitive approach within a Bayesian predictive coding framework to explore these mechanisms in depression. We fitted a prediction error (PE) model to behavioral data from a binocular rivalry task, (...) uncovering that significantly higher initial prior precision and lower PE led to a slower switch rate in patients with depression. Furthermore, serotonin‐targeting antidepressant treatments significantly decreased the prior precision and increased PE, both of which were predictive of improvements in the perceptual alternation rate of depression patients. These findings indicated that the substantially slower perception switch rate in patients with depression was caused by the greater reliance on top‐down priors and that serotonin treatment's efficacy was in its recalibration of these priors and enhancement of PE. Our study not only elucidates the cognitive underpinnings of depression, but also suggests computational modeling as a potent tool for integrating cognitive science with clinical psychology, advancing our understanding and treatment of cognitive impairments in depression. (shrink)

Is consciousness based in prefrontal circuits involved in cognitive processes like thought, reasoning, and memory or, alternatively, is it based in sensory areas in the back of the neocortex? The no-report paradigm has been crucial to this debate because it aims to separate the neural basis of the cognitive processes underlying post-perceptual decision and report from the neural basis of conscious perception itself. However, the no-report paradigm is problematic because, even in the absence of report, subjects might engage in (...) post-perceptual cognitive processing. Therefore, to isolate the neural basis of consciousness, a no-cognition paradigm is needed. Here, I describe a no-cognition approach to binocular rivalry and outline how this approach can help resolve debates about the neural basis of consciousness. (shrink)

A very natural view about perceptual knowledge is articulated, one on which perceptual knowledge is closely related to perceptual discrimination, and which fits well with a relevant alternatives account of knowledge. It is shown that this kind of proposal faces a problem, and various options for resolving this difficulty are explored. In light of this discussion, a two-tiered relevant alternatives account of perceptual knowledge is offered which avoids the closure problem. It is further shown how this (...) proposal can: accommodate our intuitions about perceptual knowledge and perceptual discrimination in terms of the notion of primary relevance, give an account of how alternatives can be rationally excluded without appeal to perceptual discrimination in terms of the notion of secondary relevance, and deal with the problem posed by inverted Gettier cases, and hence explain what it means to rationally exclude alternatives which are of secondary relevance. (shrink)

In the cognitive neuroscience of consciousness, participants have commonly been instructed to report their conscious content. This, it was claimed, risks confounding the neural correlates of consciousness (NCC) with their preconditions, i.e., allocation of attention, and consequences, i.e., metacognitive reflection. Recently, the field has therefore been shifting towards no-report paradigms. No-report paradigms draw their validity from a direct comparison with no-report conditions. We analyze several examples of such comparisons and identify alternative interpretations of their results and/or methodological issues in all (...) cases. These go beyond the previous criticism that just removing the report is insufficient, because it does not prevent metacognitive reflection. The conscious mind is fickle. Without having much to do, it will turn inward and switch, or timeshare, between the stimuli on display and daydreaming or mind-wandering. Thus, rather than the NCC, no-report paradigms might be addressing the neural correlates of conscious disengagement. This observation reaffirms the conclusion that no-report paradigms are no less problematic than report paradigms. (shrink)

This paper examines the relationship between perceptual knowledge and discrimination in the light of the so-called ‘relevant alternatives’ intuition. It begins by outlining an intuitive relevant alternatives account of perceptual knowledge which incorporates the insight that there is a close connection between perceptual knowledge and the possession of relevant discriminatory abilities. It is argued, however, that in order to resolve certain problems that face this view, it is essential to recognise an important distinction between favouring and discriminating (...) epistemic support that is often overlooked in the literature. This distinction complicates the story regarding how an alternative becomes relevant, and in doing so weakens the connection between perceptual knowledge and discrimination. The theory that results, however—what I term a ‘two-tiered’ relevant alternatives theory of perceptual knowledge—accommodates many of our intuitions about perceptual knowledge and so avoids the revisionism of some recent proposals in the epistemological literature. (shrink)

This paper examines the model of the emotions put forward by Reinach and Scheler at the beginning of the 20th century and presents it as a plausible alternative to the contemporary “perceptual model.” According to the Reinach-Scheler view, emotions are not perceptions of value, but possible responses to values given to us in value-feelings. The paper is divided into two parts. The first is an historical investigation of the origins of the model in Reinach’s and Scheler’s works within the (...) broader context of early phenomenology. The second part presents systematic arguments for the distinction between value-feeling and emotional response. (shrink)

Against the backdrop of the political intrigue in biomedicine’s ascendancy to orthodoxy, this article examines its contemporary rapprochement with Complementary Alternative Medicine (CAM), in the move toward an integrated medical regime. It also identifies and explores factors underlying the rapprochement, as well as different ethical challenges that face integrated medicine. It argues that a major approach to tackling these challenges hinges on devising just and equitable criteria for evaluating the efficacy of plural therapeutic paradigms inherent in CAM models. This is (...) attainable through a policy that encourages creating public health policy and medical personnel deliberately exposed as part of their curriculum to the philosophical and theoretical features of diverse therapeutic traditions. (shrink)

Religion is presented as a family of religions, identified by a cluster of religion-making features, most but not all of which must be present, involving beliefs and practices which are diverse and often in conflict. Because of differences in scope, application of scientific method, and vocabulary, science can also be regarded as a family—this time a family of sciences. The universality of the physical sciences contrasts with the more restricted scope of the earth sciences and the human sciences. Their relationship (...) can be shown by a three-tiered pyramid, with the physical sciences at the base, the human sciences at the top, and the earth sciences in the middle. Despite three notable differences between science and religion, science and religion are not, as popularly believed, in conflict. The contrary view, espoused by the “new atheists,” is shown to be based on oversimplified views of religion and science. There are nontheistic religions and science is committed, not to metaphysical naturalism (“scientism”), but only to methodological naturalism. Stephen Jay Gould escapes the conflict view by proposing that science and religion are independent “magisteria”, science being occupied with facts and religion with values. In divorcing the realm of facts from the realm of values, he too distorts their complex nature, for science is not devoid of values and religion makes claims about the facts. As Hume long ago suggested, facts and values are interconnected. While a fact is not the same as a value, a fact cannot support a value without presupposing another value in turn. Interaction between facts and values is here to stay. (shrink)

Studies of consciousness have traditionally been based mainly upon the perceptual domains of consciousness. However, there is another side of consciousness, represented by various types of intrinsic conscious experiences. Even though intrinsic experiences can represent up to 50% of our conscious experiences, they are still largely neglected in conscious studies. We assume there are two reasons for this. First, the field of intrinsic conscious experiences is methodologically far more problematic than any other. Second, specific paradigms for capturing the correlates (...) of intrinsic conscious experiences are almost nonexistent. Nevertheless, we expect the intrinsic side of consciousness to soon take its place in conscious studies, but first new experimental paradigms will have to be devised, which would be of a similar design to the paradigms used in studies of perceptual consciousness. In this hypothesis and theory article, we propose such a hypothetical paradigm, presenting the exploratory data of our proof-of-concept study, discussing its use, and addressing its shortcomings and their possible remediation. (shrink)

Among psychologists and vision scientists,binocular rivalry has enjoyed sustainedinterest for decades dating back to the 19thcentury. In recent years, however, rivalry''saudience has expanded to includeneuroscientists who envision rivalry as a tool for exploring the neural concomitants ofconscious visual awareness and perceptualorganization. For rivalry''s potential to berealized, workers using this tool need toknow details of this fascinating phenomenon,and providing those details is the purpose ofthis article. After placing rivalry in ahistorical context, I summarize major findingsconcerning the (...) spatial characteristics and thetemporal dynamics of rivalry, discuss two majortheoretical accounts of rivalry ( eye vs stimulus rivalry) and speculate on possibleneural concomitants of binocular rivalry. (shrink)

People can be taught to manipulate symbols according to formal mathematical and logical rules. Cognitive scientists have traditionally viewed this capacity—the capacity for symbolic reasoning—as grounded in the ability to internally represent numbers, logical relationships, and mathematical rules in an abstract, amodal fashion. We present an alternative view, portraying symbolic reasoning as a special kind of embodied reasoning in which arithmetic and logical formulae, externally represented as notations, serve as targets for powerful perceptual and sensorimotor systems. Although symbolic reasoning (...) often conforms to abstract mathematical principles, it is typically implemented by perceptual and sensorimotor engagement with concrete environmental structures. (shrink)

Rahnev & Denison's (R&D) critique of optimality in perceptual decision making leads either to implicitly retaining optimality as a normative benchmark or disregarding the normative approach altogether. We suggest that “bounded rationality,” and particularly the “satisficing” criterion, would help dispense with optimality while salvaging normativity. We also suggest that satisficing would provide a parsimonious and robust explanation for perceptual behavior.

My interest lies in offering a phenomenological perspective on how noise is experienced, with particular attention to what may be common to different sorts of noise phenomena. As a counterpoint to the notion that noise is an empty or constructed notion, I argue for two desiderata of a phenomenological account of noise; accommodating a plurality of noise experiences, on the one hand, and clarifying their specific phenomenal character, on the other. I then pursue these desiderata by turning to an examination (...) of some contemporary views of perception that have implications for how the phenomenal character of perceptual noise in particular is to be understood; an epistemic misfire view and a sensory misfire view. After clarifying each and its appeal, I convey concerns about the one and the other. I propose a third alternative for further exploration - a perceptual disjoint view - and point to how it ought to explored. On the premise that there is something like a unity of consciousness or experience, I lay out the idea that there may then be many forms of 'disunities' of experience. From an analysis of the latter, I suggest, one may account for many different types of experiences of noise, though with a common ‘phenomenal’ thread running through them. (shrink)

Carter and Pritchard (2016) and Pritchard (2010, 2012, 2016) have tried to reconcile the intuition that perceptual knowledge requires only limited discriminatory abilities with the closure principle. To this end, they have introduced two theoretical innovations: a contrast between two ways of introducing error-possibilities and a distinction between discriminating and favoring evidence. I argue that their solution faces the “sufficiency problem”: it is unclear whether the evidence that is normally available to adult humans is sufficient to retain knowledge of (...) the entailing proposition and come to know the entailed proposition. I submit that, on either infallibilist or fallibilist views of evidence, Carter and Pritchard have set the bar for deductive knowledge too low. At the end, I offer an alternative solution. I suggest that the knowledge-retention condition of the closure principle is not satisfied in zebra-like scenarios. (shrink)

Suppose you have recently gained a disposition for recognizing a high-level kind property, like the property of being a wren. Wrens might look different to you now. According to the Phenomenal Contrast Argument, such cases of perceptual learning show that the contents of perception can include high-level kind properties such as the property of being a wren. I detail an alternative explanation for the different look of the wren: a shift in one’s attentional pattern onto other low-level properties. Philosophers (...) have alluded to this alternative before, but I provide a comprehensive account of the view, show how my account significantly differs from past claims, and offer a novel argument for the view. Finally, I show that my account puts us in a position to provide a new objection to the Phenomenal Contrast Argument. (shrink)

Focus+Context techniques are commonly used in visualization systems to simultaneously provide both the details and the context of a particular dataset. This paper proposes a new methodology to empirically investigate the effect of various Focus+Context transformations on human perception. This methodology is based on the shaker paradigm, which tests performance for a visual task on an image that is rapidly alternated with a transformed version of itself. An important aspect of this technique is that it can determine two different kinds (...) of perceptual cost: (i) the effect on the perception of a static transformed image, and (ii) the effect of the dynamics of the transformation itself. This technique has been successfully applied to determine the extent to which human perception is invariant to scaling and rotation [Rensink 2004]. In this paper, we extend this approach to examine nonlinear fisheye transformations of the type typically used in a Focus+Context system. We show that there exists a no-cost zone where performance is unaffected by an abrupt, noticeable fisheye transformation, and that its extent can be determined. The lack of perceptual cost in regards to these sudden changes contradicts the belief that they are necessarily detrimental to performance, and suggests that smoothly animated transformations between visual states are not always necessary. We show that this technique also can map out low-cost zones where transformations result in only a slight degradation of performance. Finally, we show that rectangular grids have no positive effect on performance, acting only as a form of visual clutter. These results therefore demonstrate that the perceptual costs of nonlinear transformations can be successfully quantified. Interestingly, they show that some kinds of sudden transformation can be experienced with minimal or no perceptual cost. This contradicts the belief that sudden changes are necessarily detrimental to performance, and suggests that smoothly animated transformations between visual states are not always necessary.. (shrink)

There is variation in how people perceive colors and other secondary qualities. The challenge of perceptual variation is to say whose perceptions are accurate. According to Sextus, Protagoras’ response is that all of our perceptions might be accurate. As this response is traditionally developed, it is difficult to explain color illusion and color constancy. This difficulty is due to a widespread assumption called perceptual atomism. This chapter argues that, if we want to develop Protagoras’ response, we need to (...) give up perceptual atomism. It ends with a brief sketch of an alternative called perceptual structuralism. (shrink)

The Belt and Road initiative was announced in 2013 under the administration of China’s President, Xi Jinping. It was designed to fulfill the aim of interconnecting Asia, Europe, and Africa through reliable connectivity networks. In reaction to it, the 47th summit of G7 in June 2021 has given a response to this Chinese Initiative with the idea of Build Back Better World. G7 tried to show that the world can have an alternative to BRI. The main objective of the study (...) is to compare the feasibility of these two massive infrastructural projects. It is a qualitative document analysis of the previously published material on the related theme, that highlighted a competition of economic supremacy between the US and China. The research finds that BRI is gaining enough popularity as compared to B3W in the eyes of the world specifically in connecting different regions. (shrink)

Doxasticism about our awareness of normative (i.e. justifying) reasons – the view that we can recognise reasons for forming attitudes or performing actions only by means of normative judgements or beliefs – is incompatible with the following triad of claims: -/- (1) Being motivated (i.e. forming attitudes or performing actions for a motive) requires responding to and, hence, recognising a relevant reason. -/- (2) Infants are capable of being motivated. -/- (3) Infants are incapable of normative judgement or belief. -/- (...) It should be clear that (3) is true, given that infants lack the required reflective and conceptual capacities. So doxasticists have to reject either (1) or (2) (or both). But this forced choice may be understood as a dilemma for doxasticism. On the hand, doxasticists may adopt a Kantian approach and reject (2), precisely because they think that motivation presupposes the doxastic recognition of reasons, and because infants lack the capacity to doxastically recognise reasons. But this choice seems to wrongly reduce the responses of infants to mere reflexes or instinctive reactions. On the other hand, doxasticists may choose a Humean route and deny (1) by espousing a purely causal or teleological account of motivation. But this would mean detrimentally ignoring the normative nature of (some instances of) motivation. -/- One elegant way of avoiding this dilemma is to give up doxasticism and instead endorse experientialism – the view that we enjoy some experiential access to reasons, which is independent of, and perhaps more fundamental than, our capacity to form normative judgements and beliefs. In this talk, I would like to provide an argument for the existence of such a non-doxastic form of access to reasons. More specifically, I aim to defend the claim that our basic awareness of reasons is phenomenal in nature. What this means is that it forms part of our access from the inside to those of our mental episodes that provide us with access to reasons. In other words, when we introspectively attend to reason-giving mental episodes and what they are about, we have the impression of the presence of a reason for us. My defence of this experientialist alternative to doxasticism will primarily focus on perceptual reasons for first-order beliefs about the external world. (shrink)

Cognitive functions like perception, memory, language, or consciousness are based on highly parallel and distributed information processing by the brain. One of the major unresolved questions is how information can be integrated and how coherent representational states can be established in the distributed neuronal systems subserving these functions. It has been suggested that this so-called ''binding problem'' may be solved in the temporal domain. The hypothesis is that synchronization of neuronal discharges can serve for the integration of distributed neurons into (...) cell assemblies and that this process may underlie the selection of perceptually and behaviorally relevant information. As we intend to show here, this temporal binding hypothesis has implications for the search of the neural correlate of consciousness. We review experimental results, mainly obtained in the visual system, which support the notion of temporal binding. In particular, we discuss recent experiments on the neural mechanisms of binocular rivalry which suggest that appropriate synchronization among cortical neurons may be one of the necessary conditions for the buildup of perceptual states and awareness of sensory stimuli. (shrink)

In recent years, there has been a renewed interest in Perceptual Intuitionism. A significant portion of the literature on the topic has focused on the ethical perception defense, the supposition seeming to be that one must defend Perceptual Intuitionism by showing that one can have ethical experiences which immediately and non-inferentially justify one’s beliefs about the rightness or wrongness of particular actions. This thesis rejects this thought by proposing an alternative defense of Perceptual Intuitionism which employs the (...) Wittgensteinian concept of criteria and an understanding of principles of prima facie duties as “grammatical propositions”. (shrink)

According to capacitism, to perceive is to employ personal-level, perceptual capacities. In a series of publications, Schellenberg (2016, 2018, 2019b, 2020) has argued that capacitism offers unified analyses of perceptual particularity, perceptual content, perceptual consciousness, perceptual evidence, and perceptual knowledge. “Capacities first” (2020: 715); appealing accounts of an impressive array of perceptual and epistemological phenomena will follow. We argue that, given the Schellenbergian way of individuating perceptual capacities which underpins the above analyses, (...) perceiving an object does not require employing a perceptual capacity which picks it out. Although each eye, used on its own, can suffice for perceiving objects in one’s environment, binocular vision allows one to see the same object(s) via both eyes, taking advantage of informational disparities registered by each eye. Yet in certain conditions it is possible to simultaneously see one object via the left eye and a distinct object via the right eye (at least when the inputs are sufficiently similar to prevent the onset of binocular rivalry). We argue that capacitism has trouble making sense of this. After surveying responses, we conclude that not all of the above phenomena can be unified under the capacitist framework. We then present a more nuanced, disjunctivist account of how capacities are individuated. While it may be illuminating to think of perceiving as the employment of perceptual capacities, this picture does not best favour a ‘common factor’ theory of perceptual content in the way existing presentations have envisaged. (shrink)

Perceptual modalities have been traditionally considered the product of dedicated biological systems producing information for higher cognitive processing. Psychological and neuropsychological evidence is offered which undermines this point of view and an alternative account of modality from the enactive approach to understanding cognition is suggested. Under this view, a perceptual modality is a stable form of perception which is structured not just by the biological sensitivities of the agent, but by their goals and the set of skills or (...) expertise which they are deploying at a given time. Such a view suggests that there is no such thing as an experience that is purely visual, auditory, or otherwise modal and that our attempts to understand consciousness and the mind must be conducted within a framework that provides an account of embodied, goal-directed adaptive coping with the world. (shrink)

Commonsense epistemology regards perceptual experience as a distinctive source of knowledge of the world around us, unavailable in ‘blindsight’. This is often interpreted in terms of the idea that perceptual experience, through its representational content, provides us with justifying reasons for beliefs about the world around us. I argue that this analysis distorts the explanatory link between perceptual experience and knowledge, as we ordinarily conceive it. I propose an alternative analysis, on which representational content plays no explanatory (...) role: we make perceptual knowledge intelligible by appeal to experienced objects and features. I also present an account of how the commonsense scheme, thus interpreted, is to be defended: not by tracing the role of experience to its contribution in meeting some general condition on propositional knowledge (such as justification), but by subverting the assumption that it has to be possible to make the role of experience intelligible in terms of some such contribution. (shrink)

According to the Perceptual Symbols Theory of cognition (), modality‐specific simulations underlie the representation of concepts. A strong prediction of this view is that perceptual processing affects conceptual processing. In this study, participants performed a perceptual detection task and a conceptual property‐verification task in alternation. Responses on the property‐verification task were slower for those trials that were preceded by a perceptual trial in a different modality than for those that were preceded by a perceptual trial (...) in the same modality. This finding of a modality‐switch effect across perceptual processing and conceptual processing supports the hypothesis that perceptual and conceptual representations are partially based on the same systems. (shrink)

In the philosophy of perception, representationalism is the view that all phenomenological differences among mental states are representational differences, in other words, differences in content. In this paper I defend an alternative view which I call external sortalism, inspired by traditional adverbialism, and according to which experiences are not essentially representational. The central idea is that the external world serves as a model for sorting, conceptualizing, and reasoning surrogatively about perceptual experience. On external sortalism, contents are construed as a (...) kind of gloss on experiences themselves. We can retain what is attractive about representationalism, namely, that perceptual experiences can be evaluated for accuracy, without problematic commitment to the idea that they bear a substantive, representational relation to external objects and properties and that this relation determines the phenomenal character of experience. (shrink)

1. Sometimes perceptual experience is crystal clear, as when one inspects an object close-up in bright light with corrective lenses. But experience can be less clear. To illustrate how experiences...

In this paper, we propose an account of how perceptual evidence might allow us to draw justified conclusions about the existence of composite objects. We call the thesis at issue PERCEPTUAL ADEQUACY, and argue that a specific, naïve realist picture of the phenomenal character of perception provides us with a straightforward way to defend it. The claim that we have empirical evidence for the existence of macroscopic composites cannot be propped up merely by the plausible claim, granted by (...) many, that our perceptual experiences have composites-presenting phenomenology. Rather, a specific account of the nature of the phenomenology is needed so that it can provide the required evidence. We propose a way to accomplish this: one on which in the good cases it would be constituted by the presentation of the truth-makers of the relevant ontological claims. We argue, further, that this potential defence of a feasible empirically-informed approach to metaphysics is preferable to the best alternative, one based on an object-dependent version of intentionalism about perceptual consciousness. (shrink)

First impressions suggest the following contrast between perception and memory: perception generates new beliefs and reasons, justification, or evidence for those beliefs; memory preserves old beliefs and reasons, justification, or evidence for those beliefs. In this paper, I argue that reflection on perceptual learning gives us reason to adopt an alternative picture on which perception plays both generative and preservative epistemic roles.