Introspection and Primacy of Perception: A Critical Reflection on Naïve Realism

A fundamental issue in philosophy of perception is to understand the nature of experience and the relation of the experience with objects or states of affairs that is experienced. A prominent philosophical issue here is posed by the possibility of hallucinatory experiences, which are subjectively indistinguishable from veridical perception for the experiencer. The philosophical views in this matter can be grouped into three major positions on the basis of the nature of the subjective experience and relation of the subjective experience with the object. These are the sense-data theories—which consider that the objects of perception are mental entities; the representative theories—according to which perception is a representation of the objects in the external world; and the naïve realist theories—which proclaim that the external objects are constitutive of the very perceptual experience and not a representation of it. Naïve realism claims it is the defence of common-sense notion regarding experience i.e. how experience seems to the experiencer upon introspective reflection on it. This position has a growing number of proponents in philosophy especially in the last two decades. But it also entails radical departure of established philosophical views regarding the nature of experience, the phenomenal character of experience, and the experiencer–object relation. In this paper, we critically examine naïve realism from two crucial aspects pertaining to it—the question of introspection being basis of naïve realist thesis, and the notion of primacy of perception over non-veridical forms of experiences. We find that there are significant problems which weaken the naïve realist thesis.

     

A memory-based, Simon-like, spatial congruence effect: Evidence for persisting spatial codes

The Simon effect refers to the finding that in a task where stimulus location is irrelevant, reaction time is faster when stimulus and response locations are congruent than when they are not. Dominant theories of the Simon effect have generally attributed this spatial congruence effect to a spatial code automatically generated upon stimulus presentation. A common assumption of these theories is that this spatial code decays in less than a few hundred milliseconds following stimulus onset. We report two working-memory experiments suggesting a reexamination of this assumption—a Simon-like spatial congruence effect persisted over a delay of as long as 2400 ms. We propose that, in addition to generating short-lived perceptual codes, spatial information may be coded in working memory as part of the context associated with stimulus events. When reactivated by cues from the original event, such information may influence response selection and produce spatial congruence effects (in this case, positive when participants made a “yes” response and negative when they made a “no” response).     

Alethic Pluralism and the Role of Reference in the Metaphysics of Truth

In this paper, I outline and defend a novel approach to alethic pluralism, the thesis that truth has more than one metaphysical nature: where truth is, in part, explained by reference, it is (relevantly) relational in character and can be regarded as consisting in correspondence; but where instead truth does not depend upon reference it is not (relevantly) relational and involves only coherence. In the process, I articulate a clear sense in which truth may or may not depend upon reference: this involves distinguishing semantic denotation from pragmatic speaker reference and claiming that there may or may not exist a metasemantic connection between these two notions. Finally, I argue that reference is not in general inscrutable—that this metasemantic connection does exist in the case of our ordinary discourse about present macroscopic concrete objects—but that it is in pure mathematics, where reference cannot be secured, and which therefore plays no role in accounting for truth. In this manner, alethic pluralism is upheld.     

Evidence for unusual spatial location coding in Williams syndrome: an explanation for the local bias in visuo-spatial construction tasks?

Individuals with Williams syndrome (WS) display poor visuo-spatial cognition relative to verbal abilities. Furthermore, whilst perceptual abilities are delayed, visuo-spatial construction abilities are comparatively even weaker, and are characterised by a local bias. We investigated whether this differentiation in visuo-spatial abilities can be explained by a deficit in coding spatial location in WS. This can be measured by assessing participants' understanding of the spatial relations between objects within a visual scene. Coordinate and categorical spatial relations were investigated independently in four participant groups: 21 individuals with WS; 21 typically developing (TD) children matched for non-verbal ability; 20 typically developing controls of a lower non-verbal ability; and 21 adults. A third task measured understanding of visual colour relations. Results indicated first, that the comprehension of categorical and coordinate spatial relations is equally poor in WS. Second, that the comprehension of visual relations is also at an equivalent level to spatial relational understanding in this population. These results can explain the difference in performance on visuo-spatial perception and construction tasks in WS. In addition, both the WS and control groups displayed response biases in the spatial tasks. However, the direction of bias differed across the groups. This finding is explored in relation to current theories of spatial location coding.     

Relational Complexes

A theory of relations is presented that provides a detailed account of the logical structure of relational complexes. The theory draws a sharp distinction between relational complexes and relational states. A salient difference is that relational complexes belong to exactly one relation, whereas relational states may be shared by different relations. Relational complexes are conceived as structured perspectives on states ‘out there’ in reality. It is argued that only relational complexes have occurrences of objects, and that different complexes of the same relation may correspond to the same state.     

INTENTIONALITY AND ONE-SIDED RELATIONS

Intentional states appear to relate thinkers to objects and situations even when these latter do not exist. Given the concern to allow that thought is a mode of engagement between subject and world, many writers have presented relational theories of intentionality and introduced odd relata to account for thought of the non-existent. However there are familiar epistemological and ontological objections to such accounts which give reason to look for other ways of accommodating the appearance of relationality. A little explored possibility is to countenance not odd relata but odd relations, ones not requiring existent terms other than those which ground the relation on the side of the subject. Proposals to this effect by Findlay and Grossmann are underdescribed and not obviously different from more familiar odd relata theories. Here a more developed view is explored, which derives from scholastic accounts of intentionality, in particular that presented by John of St Thomas, as this has been elaborated and defended in recent writings by John Deely. While judging it to fail, I suggest that it leads us towards an older tradition according to which the intentionality of thought is constituted by the occurrence of the forms of things in the mind. ‘Formally and principally the whole difference between a mind-independent relation and a mind-dependent one comes down to this, that a physical relation has a mind-independent fundament with a coexistent terminus while a mental relation lacks such a foundation.’(Joannes a Sancto Thoma, Cursus Philosophicus: Ars Logica; Tractatus de Signis)¹     

In Defense of Relational Direct Realism

Abstract: According to proponents of relational direct realism, veridical perceptual experiences are irreducibly relational mental states that include as constituents perceived physical objects or intrinsic aspects of them. One consequence of the theory is the rejection of the causal theory of perception. This paper defends the relational theory against several objections recently developed by Paul Coates. He argues that the required experiential relation is incoherent and unmotivated. The argument that it is incoherent commits a fallacy. In reply to the argument that it is unmotivated, I suggest that the relational theorist's appeal to transparency provides sufficient motive and, when properly clarified, defeasibly justifies the theory as well. Coates also argues that rejection of the causal theory leaves relational theorists without any way of determining which object is perceived or of accommodating our scientific understanding of perceptual experiences as causally dependent on physical objects. I reply that relational theorists are able to provide the required explanations and discuss how the relational theory is consistent with this scientific understanding of perceptual experience.     

Perceptions of proportionality in young children: matching spatial ratios

Three experiments examined the ability of young children (4- and 5-year-olds) and adults to identify correspondences in spatial ratios. In all three experiments, children as young as 4 and 5 years of age made accurate spatial proportionality judgments. Moreover, their judgments were no less accurate when both response alternatives differed in spatial configuration from the sample than when all the configurations were alike, indicating that those judgments were based on relational information and not on the exact form of the stimuli. The findings, which suggest that the concept of ratio may have important foundations in the ways young children perceive relations within and between objects, have implications for theories of mathematical development and for methods of mathematics instruction.     

Developmental changes in children's understanding of the similarity between photographs and their referents

In a series of three experiments, we investigated the development of children's understanding of the similarities between photographs and their referents. Based on prior work on the development of analogical understanding (e.g. Gentner & Rattermann, 1991), we suggest that the appreciation of this relation involves multiple levels. Photographs are similar to their referents both in terms of the constituent objects and in terms of the relations among these objects. We predicted that children would appreciate object similarity (whether photographs depict the same objects as in the referent scene) before they would appreciate relational similarity (whether photographs depict the objects in the same spatial positions as in the referent scene). To test this hypothesis, we presented 3-, 4-, 5-, 6-, and 7-year-old children and adults with several candidate photographs of an arrangement of objects. Participants were asked to choose which of the photographs was 'the same' as the arrangement. We manipulated the types of information the photographs preserved about the referent objects. One set of photographs did not preserve the object properties of the scene. Another set of photographs preserved the object properties of the scene, but not the relational similarity, such that the original objects were depicted but occupied different spatial positions in the arrangement. As predicted, younger children based their choices of the photographs largely on object similarity, whereas older children and adults also took relational similarity into account. Results are discussed in terms of the development of children's appreciation of different levels of similarity.     

Confirmation and reduction: a Bayesian account

Various scientific theories stand in a reductive relation to each other. In a recent article, we have argued that a generalized version of the Nagel-Schaffner model (GNS) is the right account of this relation. In this article, we present a Bayesian analysis of how GNS impacts on confirmation. We formalize the relation between the reducing and the reduced theory before and after the reduction using Bayesian networks, and thereby show that, post-reduction, the two theories are confirmatory of each other. We then ask when a purported reduction should be accepted on epistemic grounds. To do so, we compare the prior and posterior probabilities of the conjunction of both theories before and after the reduction and ask how well each is confirmed by the available evidence.     

Beyond common features: the role of roles in determining similarity

Historically, accounts of object representation and perceived similarity have focused on intrinsic features. Although more recent accounts have explored how objects, scenes, and situations containing common relational structures come to be perceived as similar, less is known about how the perceived similarity of parts or objects embedded within these relational systems is affected. The current studies test the hypothesis that objects situated in common relational systems come to be perceived as more similar. Similarity increases most for objects playing the same role within a relation (e.g., predator), but also increases for objects playing different roles within the same relation (e.g., the predator or prey role in the hunts relation) regardless of whether the objects participate in the same instance of the relation. This pattern of results can be captured by extending existing models that extract meaning from text corpora so that they are sensitive to the verb-specific thematic roles that objects fill. Alternative explanations based on analogical and inferential processes are also considered, as well as the implications of the current findings to research in language processing, decision making, and category learning.     

Flexible visual processing of spatial relationships

Visual processing breaks the world into parts and objects, allowing us not only to examine the pieces individually, but also to perceive the relationships among them. There is work exploring how we perceive spatial relationships within structures with existing representations, such as faces, common objects, or prototypical scenes. But strikingly, there is little work on the perceptual mechanisms that allow us to flexibly represent arbitrary spatial relationships, e.g., between objects in a novel room, or the elements within a map, graph or diagram. We describe two classes of mechanism that might allow such judgments. In the simultaneous class, both objects are selected concurrently. In contrast, we propose a sequential class, where objects are selected individually over time. We argue that this latter mechanism is more plausible even though it violates our intuitions. We demonstrate that shifts of selection do occur during spatial relationship judgments that feel simultaneous, by tracking selection with an electrophysiological correlate. We speculate that static structure across space may be encoded as a dynamic sequence across time. Flexible visual spatial relationship processing may serve as a case study of more general visual relation processing beyond space, to other dimensions such as size or numerosity.     

Object and spatial representations in the corner enhancement effect

Cole, Gellatly, and Blurton have shown that targets presented adjacent to geometric corners are detected more efficiently than targets presented adjacent to straight edges. In six experiments, we examined how this corner enhancement effect is modulated by corner-of-object representations (i.e., corners that define an object's shape) and local base-level corners that occur as a result of, for instance, overlapping the straight edges of two objects. The results show that the corner phenomenon is greater for corners of object representations than for corners that do not define an object's shape. We also examined whether the corner effect persists within the contour boundaries of an object, as well as on the outside. The results showed that a spatial gradient of attention accompanies the corner effect outside the contour boundaries of an object but that processing within an object is uniform, with no corner effect occurring. We discuss these findings in relation to space-based and object-based theories of attention.     

Predictable and self-initiated visual motion is judged to be slower than computer generated motion

Self-initiated action effects are often perceived as less intense than identical but externally generated stimuli. It is thought that forward models within the sensorimotor system pre-activate cortical representations of predicted action effects, reducing perceptual sensitivity and attenuating neural responses. As self-agency and predictability are seldom manipulated simultaneously in behavioral experiments, it is unclear if self-other differences depend on predictable action effect contingencies, or if both self- and externally generated stimuli are modulated similarly by predictability. We factorially combined variation in (1) predictability of action effects, (2) spatial congruence, and (3) performance by the self or computer to dissociate these influences on a visual discrimination task. Participants performed 2AFC speed judgments. Self-initiated motion was judged to be slower than computer-initiated motion when action effect contingencies were predictable, while spatial congruence influenced speed judgments only when action effect contingencies were unpredictable. Results are discussed in relation to current theories of sensory attenuation.     

Pragmatic antirealism: a new antirealist strategy

In everyday speech we seem to refer to such things as abstract objects, moral properties, or propositional attitudes that have been the target of metaphysical and/or epistemological objections. Many philosophers, while endorsing scepticism about some of these entities, have not wished to charge ordinary speakers with fundamental error, or recommend that the discourse be revised or eliminated. To this end a number of non-revisionary antirealist strategies have been employed, including expressivism, reductionism and hermeneutic fictionalism. But each of these theories faces forceful objections. In particular, we argue, proponents of these strategies face a dilemma: either concedes that their theory is revisionary, or adopt an implausible account of speaker-meaning whereby the content of certain types of utterance is opaque to their speakers. In this paper we introduce a new type of antirealist strategy, which is thoroughly non-revisionary, and leaves speaker-meaning transparent to speakers. We draw on work on pragmatics in the philosophy of language to develop a theory we call ??pragmatic antirealism??. The pragmatic antirealist holds that while the sentences of the discourses in question have metaphysically contentious truth conditions, ordinary utterances of them are pragmatically modified in context in such a way that speakers do not incur commitment to those truth conditions. After setting out the theory, we show how it might be developed for both mathematical and ethical discourse, before responding to some likely objections.     

Assessing the concreteness of relational representation

Research has shown that people's ability to transfer abstract relational knowledge across situations can be heavily influenced by the concrete objects that fill relational roles. This article provides evidence that the concreteness of the relations themselves also affects performance. In 3 experiments, participants viewed simple relational patterns of visual objects and then identified these same patterns under a variety of physical transformations. Results show that people have difficulty generalizing to novel concrete forms of abstract relations, even when objects are unchanged. This suggests that stimuli are initially represented as concrete relations by default. In the 2nd and 3rd experiments, the number of distinct concrete relations in the training set was increased to promote more abstract representation. Transfer improved for novel concrete relations but not for other transformations such as object substitution. Results indicate that instead of automatically learning abstract relations, people's relational representations preserve all properties that appear consistently in the learning environment, including concrete objects and concrete relations.     

Projective invariance and visual shape constancy

As one moves about a table, the projection of its shape on the retina varies enormously, yet the table's shape appears constant. The various retinal images of a single object are nearly congruent in projective geometry. To explain apparent constancy, standard theories of vision assume that the visual system has access to this projective congruence. We present four experiments that undermine this assumption (i.e., the projective thesis). The basic result is that observers' estimates of shape in a simple production task represent gross departures from correct projection, even when observers are given aids to fixation. We manipulate both observer sample and experimental procedure in an attempt to find a source of these persistent errors. Our present hypothesis is that observers lack the sensitivity or implicit knowledge of projective geometry that has been attributed to them.