Perceptual Content Research Articles

지각 내용의 개념성과 인식적 정당화

지각 내용의 개념성과 인식적 정당화

경험적 접근과 지각 내용

경험적 접근과 지각 내용

What do our impressions say? The Stoic theory of perceptual content and belief formation

Abstract Here I propose an interpretation of the ancient Stoic psychological theory on which (i) the concepts that an adult human possesses affect the content of the perceptual impressions (φαντασίαι αἰσθητικαί) she forms, and (ii) the content of such impressions is exhausted by an ‘assertible’ (ἀξίωμα) of suitable complexity. What leads the Stoics to accept (i) and (ii), I argue, is their theory of assent and belief formation, which requires that the perceptual impression communicate information suitable to serve as the content of belief. In arguing for (i), I reject a rival interpretation on which conceptualization occurs subsequently to the formation of a perceptual impression. In arguing for (ii), I deny that perceptual impressions have two kinds of content: one formulated in an assertible, the other sensory, featuring independently of this assertible. I explore the implications of (i) and (ii) for the Stoic theory of emotions, expertise, and rationality, and argue that they shed new light on the workings of impression, assent, and belief.

Deep image reconstruction from human brain activity.

The mental contents of perception and imagery are thought to be encoded in hierarchical representations in the brain, but previous attempts to visualize perceptual contents have failed to capitalize on multiple levels of the hierarchy, leaving it challenging to reconstruct internal imagery. Recent work showed that visual cortical activity measured by functional magnetic resonance imaging (fMRI) can be decoded (translated) into the hierarchical features of a pre-trained deep neural network (DNN) for the same input image, providing a way to make use of the information from hierarchical visual features. Here, we present a novel image reconstruction method, in which the pixel values of an image are optimized to make its DNN features similar to those decoded from human brain activity at multiple layers. We found that our method was able to reliably produce reconstructions that resembled the viewed natural images. A natural image prior introduced by a deep generator neural network effectively rendered semantically meaningful details to the reconstructions. Human judgment of the reconstructions supported the effectiveness of combining multiple DNN layers to enhance the visual quality of generated images. While our model was solely trained with natural images, it successfully generalized to artificial shapes, indicating that our model was not simply matching to exemplars. The same analysis applied to mental imagery demonstrated rudimentary reconstructions of the subjective content. Our results suggest that our method can effectively combine hierarchical neural representations to reconstruct perceptual and subjective images, providing a new window into the internal contents of the brain.

Of fillings and feelings: locating affect, attention, and vagueness

ABSTRACTThe article discusses the location of affect in human experience by situating the concept in relation to attention and to different degrees of propositional structuring. By bringing together extended mind theories, the affect philosophies of Spinoza and Deleuze, and Whitehead’s theory of intensities, the article seeks to mediate between different strands of affect theory; especially between what has been termed ‘non-representational’ theories of affect and those that couple affective processes with intentional and perceptual contents. The article will end by discussing vagueness as an important empirical interface in both trajectories of theorizing affect.

Perceptual Content, Not Physiological Signals, Determines Perceived Duration When Viewing Dynamic, Natural Scenes

The neural basis of time perception remains unknown. A prominent account is the pacemaker-accumulator model, wherein regular ticks of some physiological or neural pacemaker are read out as time. Putative candidates for the pacemaker have been suggested in physiological processes (heartbeat), or dopaminergic mid-brain neurons, whose activity has been associated with spontaneous blinking. However, such proposals have difficulty accounting for observations that time perception varies systematically with perceptual content. We examined physiological influences on human duration estimates for naturalistic videos between 1–64 seconds using cardiac and eye recordings. Duration estimates were biased by the amount of change in scene content. Contrary to previous claims, heart rate, and blinking were not related to duration estimates. Our results support a recent proposal that tracking change in perceptual classification networks provides a basis for human time perception, and suggest that previous assertions of the importance of physiological factors should be tempered.

Типы содержания представлений у Канта

In this essay, I specify types of representational content that can be attributed to Kant’s account of representation. The more specific aim is to examine which of these types of content can be regarded as possible without the application of concepts. In order to answer the question, I proceed as follows. First, I show how intuition (in Kant’s sense) can be seen as providing indexical content independently of empirical concepts. Second, I show in what sense the generation of spatial content can be regarded as non-categorial. A key distinction is that a perceptual examination of an object can be understood as thoroughly sensible and particular, whereas a conceptual determination always grasps the object via its generalisable features. Third, I propose that the faculties of sensibility and understanding are not only separable in principle, but that their contributions remain in a certain sense separate in actual cognition as well. This is to say that a conceptual determination of an object does not entail that the object ceases to be non-conceptually available to the perceiver, which further suggests the autonomy of sensibility and its perceptual content. Finally, I raise difficulties in attributing non-conceptual representational content to Kant’s judgment-centered stance on representation and experience, only to emphasise how these difficulties easily lead to a misappreciation of Kant’s fundamental distinction between sensibility and understanding and their unique cognitive contributions.

Contraria sunt complementa o los Orbes del sueño de Clara Janés una historia de amor

In Orbes del sueno, Clara Janes offers a sample of the “orbs” that dreaming makes accessible, all of which are somewhat associated with areas in physics (hidden variables, quantum indivisibility and entanglements, multiple universes, relativity, wave function, supersymmetry, chaos theories…). In these formulations, the author finds parallels with subjective and internal experiences. Poems articulate encounters between poles that are traditionally opposed and mutually exclusive (subject/object, body/mind, inside/outside…) exemplifying Niels Bohr’s complementarity princile by which it becomes possible to elucidate the perceptual content of the phenomenon. The more the poetic speaker inserts herself into the cosmic web, the more she experiences a love-like relationship with the creativity of the cosmos and apprehends the life that it sustains.

Hegel’s Phenomenology: On the Logical Structure of Human Experience

Abstract I argue that Hegel’s Phenomenology is an attempt to prove that human experience displays a sui generis logical structure. This is because, as rational animals who instinctively create a universe of meaning to navigate our environment, the perceptual content of our conscious experience of objects, the desires that motivate our self-conscious experience of action, and the beliefs and values that make up our sociohistorical experience all testify to the presence of rationality as their condition of possibility. As such, Hegel’s Phenomenology not only requires of us that we transform the mission of logic into a description of the immanent logic at the basis of human experience, thereby making the task of logic “anthropological.” It also presents us with a novel model of human experience—one that: demonstrates the rationality already instinctively at work in our bodily sensations, perceptions, and desires; gives an account of the origins of human society and history; and also makes human experience irreducible to cognitive processes in the brain, psychological mechanisms, and the biological imperatives of survival and reproduction.

Non-conceptualism, observational concepts, and the given

In “Study of Concepts”, Peacocke puts forward an argument for non-conceptualism derived from the possession conditions of observational concepts. In this paper, I raise two objections to this argument. First, I argue that if non-conceptual perceptual contents are scenario contents, then perceptual experiences cannot present perceivers with the circumstances specified by the application conditions of observational concepts and, therefore, they cannot play the semantic and epistemic roles Peacocke wants them to play in the possession conditions of these concepts. Second, I argue that if non-conceptual perceptual contents are protopropositions, then Peacocke’s account of the possession conditions of observational concepts falls into the Myth of the Given.

Abstract Representation of Prospective Reward in the Hippocampus.

Motivation enhances memory by increasing hippocampal engagement during encoding. However, whether such increased hippocampal activation reflects encoding of the value of highly rewarding events per se is less understood. Here, using a monetary incentive encoding task with a novel manipulation, we tested in humans whether the hippocampus represents abstract reward value, independent of perceptual content. During functional MRI scanning, men and women studied object pairs, each preceded by a monetary reward cue indicating the amount of money they would receive if they successfully remembered the object pair at test. Reward cues varied on both the level of reward (penny, dime, and dollar) and visual form (picture or word) across trials to dissociate hippocampal responses to reward value from those reflecting the perceptual properties of the cues. Behaviorally, participants remembered pairs associated with the high reward (dollar) more often than pairs associated with lower rewards. Neural pattern-similarity analysis revealed that hippocampal and parahippocampal cortex activation patterns discriminated between cues of different value regardless of their visual form, and that hippocampal discrimination of value was most pronounced in participants who showed the greatest behavioral sensitivity to reward. Strikingly, hippocampal patterns were most distinct for reward cues that differed in value but had similar visual appearance, consistent with theoretical proposals of hippocampal-pattern differentiation of competing representations. Our data illustrate how contextual representations within the hippocampus go beyond space and time to include information about the motivational salience of events, with hippocampal reward coding tracking the motivational impact on later memory.SIGNIFICANCE STATEMENT Motivation, such as the promise of future rewards, enhances hippocampal engagement during encoding and promotes successful retention of events associated with valuable rewards. However, whether the hippocampus explicitly encodes reward value, dissociable from sensory information, is unclear. Here, we show that the hippocampus forms abstract representation of valuable rewards, encoding conceptual rather than perceptual information about the motivational context of individual events. Reward representation within the hippocampus is associated with preferential retention of high-value events in memory. Furthermore, we show that hippocampal-pattern differentiation serves to emphasize differences between visually similar events with distinct motivational salience. Collectively, these findings indicate that hippocampal contextual representations enable individuals to distinguish the motivational value of events, leading to prioritized encoding of significant memories.

An epistemic argument for liberalism about perceptual content

ABSTRACTThis paper concerns the question of which properties figure in the contents of perceptual experience. According to conservatives, only low-level properties figure in the contents of perceptual experience. Liberals, on the other hand, claim that high-level properties, such as natural kind properties, artifacts, and even moral properties, can figure in the contents of perceptual experience. I defend a novel argument in favor of liberalism, the Epistemic Argument, which hinges on two crucial claims. The first is that many perceptual experiences of even neurotypical human beings can justify beliefs in high-level properties without providing justification for their low-level constituents. The second claim, roughly, is that any experience that alone provides (defeasible) justification for beliefs about some property p, other things being equal, has p as part of its content. In short, certain perceptual experiences represent high-level but not low-level properties, which entails that liberalism is true.

Inflation versus filling-in: why we feel we see more than we actually do in peripheral vision

Do we perceive fine details in the visual periphery? Here, we propose that phenomenology in the visual periphery can be characterized by an inflated sense of perceptual capacity, as observers overestimate the quality of their perceptual inputs. Distinct from the well-known perceptual phenomenon of 'filling-in' where perceptual content is generated or completed endogenously, inflation can be characterized by incorrect introspection at the subjective level. The perceptual content itself may be absent or weak (i.e. not necessarily filled-in), and yet such content is mistakenly regarded by the system as rich. Behaviourally, this can be reflected by metacognitive deficits in the degree to which confidence judgements track task accuracy, and decisional biases for observers to think particular items are present, even when they are not. In two experiments using paradigms that exploit unique attributes of peripheral vision (crowding and summary statistics), we provide evidence that both types of deficits are present in peripheral vision, as observers' reports are marked by overconfidence in discrimination judgements and high numbers of false alarms in detection judgements. We discuss potential mechanisms that may be the cause of inflation and propose future experiments to further explore this unique sensory phenomenon.This article is part of the theme issue 'Perceptual consciousness and cognitive access'.

Agency, perception, space and subjectivity

The goal of this paper is to illuminate the connections between agency, perception, subjectivity, space and the body. Such connections have been the subject matter of much philosophical work. For example, the importance of the body and bodily action on perception is a growth area in philosophy of mind. Nevertheless, there are some key relations that, as will become clear, have not been adequately explored. We start by examining the relation between embodiment and agency, especially the dependence of agency on perception and the dependence of perception on agency. We also consider the nature of subjectivity itself: In virtue of what do humans and animals but not rocks and pencils have genuine perceptual and agentive intentional contents? We sketch a hylomorphic account of subjects and subjectivity, which highlights connections between the conclusions argued for in the previous sections and some basic principles of teleosemantics.

The Way Things Look: a Defence of Content

How does perceptual experience disclose the world to our view? In the first introductory section, I set up a contrast between the representational and the purely relational conception of perceptual experience. In the second section, I discuss an argument given by Charles Travis (Mind 113: 57–94, 2004) against perceptual content. The third section is devoted to the phenomenon of perceptual constancy: in 3.1 I describe the phenomenon. In 3.2 I argue that the description given suggests a phenomenological distinction that can be deployed for a defence of content. In 3.3 I compare and contrast my view of perceptual content with that of Susanna Schellenberg (The Journal of Philosophy 105(02): 55–84, 2008). Finally (3.4), I support my conception of content by means of an argument that links content to the way in which the mind-independent nature of material objects is manifest in perceptual experience.

DISTRIBUTED VIDEO IDENTIFICATION WITH PERCEPTUAL TAGS IN PEER-TO-PEER NETWORKS

Existing methods in Peer-to-Peer (P2P) networks mainly use file tags or cryptographic hashes of the entire file for video searching and identification. These methods however become insufficient to correctly identify a video when the name and format of the files are changed. In this paper, a distributed solution is proposed for video identification and copy detection in P2P networks, which represents a video file in the network with a set of (64-256) bits, named as perceptual tags. As such information is derived from the perceptual content of the video rather than its bitstream representation as in the case of cryptographic hashes, it provides a robust identification after the alterations in the file names and formats provided that the visual quality of the video is at acceptable levels. The paper first briefly discusses the requirements for a distributed perceptual tagging system considering the low computational power and low bandwidth of internet users. Then, it presents the proposed perceptual tag extraction method using the temporal differences between the video frame averages and the proposed distributed searching scheme for a P2P implementation. The proposed extraction and searching methods provide robustness to the alterations in video formats and small additions and cuttings in the video content as the typical processing in P2P environment and also achieve uniform distribution and storage load between the peers.

A defense of holistic representationalism

Representationalism holds that a perceptual experience's qualitative character is identical with certain of its representational properties. To date, most representationalists endorse atomistic theories of perceptual content, according to which an experience's content, and thus character, does not depend on its relations to other experiences. David Rosenthal, by contrast, proposes a view that is naturally construed as a version of representationalism on which experiences’ relations to one another determine their contents and characters. I offer here a new defense of this holistic representationalism, arguing that some objections to atomistic views are best interpreted as supporting it.

In the interest of saving time: a critique of discrete perception.

A recently proposed model of sensory processing suggests that perceptual experience is updated in discrete steps. We show that the data advanced to support discrete perception are in fact compatible with a continuous account of perception. Physiological and psychophysical constraints, moreover, as well as our awake-primate imaging data, imply that human neuronal networks cannot support discrete updates of perceptual content at the maximal update rates consistent with phenomenology. A more comprehensive approach to understanding the physiology of perception (and experience at large) is therefore called for, and we briefly outline our take on the problem.

Robust Image Fingerprinting via Distortion-Resistant Sparse Coding

Content fingerprinting recently emerges as an effective nonintrusive solution for copyright protection. Fingerprinting algorithm maps the perceptual contents of media file to an invariant digest, so that unauthorized copies can be identified via fingerprint comparison. This letter presents a distortion-resistant sparse coding strategy for image fingerprinting that simulates the hierarchical information processing flow of visual system. Sparse coding, which seeks a small set of atoms that can best represent input signal, helps fingerprinting algorithm detect the intrinsic visual features of image. However, the high freedom of atom selection makes sparse coding sensitive to distortion. In this letter, several measures are applied on sparse coding and dictionary learning to jointly ensure the invariance of fingerprint, such as imposing the neighborhood-priority principle on atom selection, regulating the layout of atoms, and forcing sparse codes to preserve the distance in the image space. Content identification performance of the proposed work was tested on a database of 219 000 images. The error rate of the proposed algorithm is at least ten times lower than state-of-the-arts, and satisfactory performance was observed even under extremely low bit budget.

Should a Few Null Findings Falsify Prefrontal Theories of Conscious Perception?

Is activity in prefrontal cortex (PFC) critical for conscious perception? Major theories of consciousness make distinct predictions about the role of PFC, providing an opportunity to arbitrate between these views empirically. Here we address three common misconceptions: (1) PFC lesions do not affect subjective perception; (2) PFC activity does not reflect specific perceptual content; and (3) PFC involvement in studies of perceptual awareness is solely driven by the need to make reports required by the experimental tasks rather than subjective experience per se. These claims are incompatible with empirical findings, unless one focuses only on studies using methods with limited sensitivity. The literature highlights PFC's essential role in enabling the subjective experience in perception, contra the objective capacity to perform visual tasks; conflating the two can also be a source of confusion.Dual Perspectives Companion Paper: Are the Neural Correlates of Consciousness in the Front or in the Back of the Cerebral Cortex? Clinical and Neuroimaging Evidence, by Melanie Boly, Marcello Massimini, Naotsugu Tsuchiya, Bradley R. Postle, Christof Koch, and Giulio Tononi.