Delusional thinking and cognitive disorder

A hypothesis is presented regarding the genesis of paranoid delusion that attempts to take into account certain data. The data of interest are (a) the failure to find evidence of cognitive impairment in diagnosed paranoid patients, (b) the evidence of perceptual disorder as a primary and prior condition in the natural history of the clinical development of delusions and the empirical relationship of the perceptual disorder to presence of “thought disorder,” (c) the failure to find evidence supporting universal psychodynamic patterns of etiology, (d) appearance of “delusional” phenomena in normal subjects in situations of deviant sensory experience, and (e) the reports of articulate patients writing of their experiences.     

Phenomenology and delusions: Who put the ‘alien’ in alien control?

Although current models of delusion converge in proposing that delusions are based on unusual experiences, they differ in the role that they accord experience in the formation of delusions. On some accounts, the experience comprises the very content of the delusion, whereas on other accounts the delusion is adopted in an attempt to explain an unusual experience. We call these the endorsement and explanationist models, respectively. We examine the debate between endorsement and explanationist models with respect to the 'alien control' delusion. People with delusions of alien control believe that their actions and/or thoughts are being controlled by an external agent. Some accounts of alien control (e.g., ) are best thought of in explanationist terms; other accounts (e.g., ) seem more suited to an endorsement approach. We argue that recent cognitive and neurophysiological evidence favours an endorsement model of the delusion of alien control.     

Dream experience and a revisionist account of delusions of misidentification

Standard accounts of delusion explain them as responses to experience. Cognitive models of feature binding in the face recognition systems explain how experiences of mismatch between feelings of "familiarity" and faces can arise. Similar mismatches arise in phenomena such as déjà and jamais vu in which places and scenes are mismatched to feelings of familiarity. These cognitive models also explain similarities between the phenomenology of these delusions and some dream states which involve mismatch between faces, feelings of familiarity and identities. Given these similarities it makes sense to retain that aspect of the standard account in the face of revisionist arguments that feature binding anomalies which lead to delusions of misidentification are not consciously experienced.     

Low-Level Properties in Perceptual Experience

Whether perceptual experience represents high-level properties like causation and natural-kind in virtue of its phenomenology is an open question in philosophy of mind. While the question of high-level properties has sparked disagreement, there is widespread agreement that the sensory phenomenology of perceptual experience presents us with low-level properties like shape and color. This paper argues that the relationship between the sensory character of experience and the low-level properties represented therein is more complex than most assume. Careful consideration of mundane examples, like looking at a coin from an oblique angle, show that the low-level properties represented in experience do not necessarily figure in the sensory character of the experience. Furthermore, the sensible properties invoked when characterizing the sensory character of a perceptual experience are not necessarily included in the sensible properties represented in a perceptual experience. On this basis it is argued that perceptual experience has a disunified metaphysics, consisting in distinct sensory and cognitive components. The account is developed in relation to existing unified and disunified accounts, and discussed in terms of its implications for cognitive penetration, the reliability of introspection, the transparency of experience, and cognitive phenomenology.     

Unawareness of visual and sensorimotor defects: A hypothesis

A theory is proposed to account for unawareness of blindness, hemianopsia, and hemiplegia, and for phantom limb after amputation. It is assumed that interruption of a sensory pathway at any level--from peripheral nerve to primary sensory cortex--is not associated with any immediate sensory experience that uniquely specifies the defect. Instead the sensory loss must be discovered by a process of self-observation and inference. Discovery is easy for defects that create major functional disability, such as total blindness. Hence unawareness of total blindness occurs only in association with severe intellectual impairment, precluding the required self-observation and inference. In contrast, hemianopsia is difficult to discover because several mechanisms automatically compensate the defect effectively. Thus unawareness of hemianopsia is common, even in intellectually normal individuals. Insensate fields are often the source of suggested (false) percepts, because no information from such a field specifies the absence of a sensory stimulus. The most powerful source of suggestion is sensory activity in uninvolved portions of the affected sensory field. Thus hemianopsics may perceive complete geometric forms when only incomplete forms are shown and the missing portion falls in the hemianopsic fields. Such perceptual completion also occurs in hemianesthetic hemiplegics, creating the illusion that there are normally functioning limbs on the affected side. This perceptual completion increases the difficulty of discovery of hemianesthetic hemiplegia, but the disability is still sufficiently obvious that some additional cognitive impairment is invariably present in patients with lasting unawareness of hemiplegia. Phantom limb after amputation is the product of perceptual completion without associated cognitive impairment. The patient with phantom limb is thus aware of the illusory quality of his phantom. Some insight into the neural basis of perceptual completion and of unawareness of sensory loss may derive from considering sensory systems and associative cortex as parallel-distributed processing mechanisms.     

Perceiving expressions of emotion: What evidence could bear on questions about perceptual experience of mental states?

What evidence could bear on questions about whether humans ever perceptually experience any of another’s mental states, and how might those questions be made precise enough to test experimentally? This paper focusses on emotions and their expression. It is proposed that research on perceptual experiences of physical properties provides one model for thinking about what evidence concerning expressions of emotion might reveal about perceptual experiences of others’ mental states. This proposal motivates consideration of the hypothesis that categorical perception of expressions of emotion occurs, can be facilitated by information about agents’ emotions, and gives rise to phenomenal expectations. It is argued that the truth of this hypothesis would support a modest version of the claim that humans sometimes perceptually experience some of another’s mental states. Much available evidence is consistent with, but insufficient to establish, the truth of the hypothesis. We are probably not yet in a position to know whether humans ever perceptually experience others’ mental states.     

The phenomenological character of color perception

When an object looks red to an observer, the visual experience of the observer has two important features. The experience visually represents the object as having a property—being red. And the experience has a phenomenological character; that is, there is something that it is like to have an experience of seeing an object as red. Let qualia be the properties that give our sensory and perceptual experiences their phenomenological character. This essay takes up two related problem for a nonreductive account of qualia. Some have argued that on such an account there is no room in a physicalist ontology for qualia. Section 1 shows how qualia might fit into a physicalist ontology. The second problem begins with the observation that there is a gap in scientific accounts of color experience; there is no explanation of why the features of the brain that determine our color experiences give those experiences their phenomenological character. Building on the results of Sect. 1, Sect. 2 develops an account of color perception that bridges this gap and shows how qualia give color perception its phenomenological character. To get a grip on the issues involved the paper begins by considering some aspects of a physicalist account of color.     

Restating the role of phenomenal experience in the formation and maintenance of the Capgras delusion

In recent times, explanations of the Capgras delusion have tended to emphasise the cognitive dysfunction that is believed to occur at the second stage of two-stage models. This is generally viewed as a response to the inadequacies of the one-stage account. Whilst accepting that some form of cognitive disruption is a necessary part of the aetiology of the Capgras delusion, I nevertheless argue that the emphasis placed on this second-stage is to the detriment of the important role played by the phenomenology underlying the disorder, both in terms of the formation and maintenance of the delusional belief. This paper therefore proposes an interactionist two-stage model in which the phenomenal experience of the Capgras patient is examined, emphasised, and its relation to top-down processing discussed.

The epistemic force of perceptual experience

What is the metaphysical nature of perceptual experience? What evidence does experience provide us with? These questions are typically addressed in isolation. In order to make progress in answering both questions, perceptual experience needs to be studied in an integrated manner. I develop a unified account of the phenomenological and epistemological role of perceptual experience, by arguing that sensory states provide perceptual evidence due to their metaphysical structure. More specifically, I argue that sensory states are individuated by the perceptual capacities employed and that there is an asymmetric dependence between their employment in perception and their employment in hallucination and illusion. Due to this asymmetric dependence, sensory states provide us with evidence.     

Characterizing observers using external noise and observer models: assessing internal representations with external noise

External noise methods and observer models have been widely used to characterize the intrinsic perceptual limitations of human observers and changes of the perceptual limitations associated with cognitive, developmental, and disease processes by highlighting the variance of internal representations. The authors conducted a comprehensive review of the 5 most prominent observer models through the development of a common formalism. They derived new predictions of the models for a common set of behavioral tests that were compared with the data in the literature and a new experiment. The comparison between the model predictions and the empirical data resulted in very strong constraints on the observer models. The perceptual template model provided the best account of all the empirical data in the visual domain. The choice of the observer model has significant implications for the interpretation of data from other external noise paradigms, as well as studies using external noise to assay changes of perceptual limitations associated with observer states. The empirical and theoretical development suggests possible parallel developments in other sensory modalities and studies of high-level cognitive processes.     

Shame and psychopathology

The origins of the word "shame" recall the concept of the infraction of integrity both as scandal and as individualization. The human experience of shame stretches along a continuum from modesty to disabling interpersonal terror. Unlike other basic affects, its emergence is a fundamental moment in the process of self-awareness and self-object differentiation. Neglected by psychiatry because it was regarded as a moral concept, today it is possible to hypothesize that it has a biologic basis that one can attempt to describe in terms of corticothalamic pathways. In this respect, like other affects, it could be considered as a cognitive shortcut to activate specific and evolutionally useful behavioral patterns, such as concealment or a request for affiliation. It is fairly ubiquitous in psychopathology, but is clinically much more structured in its abnormal expressions in anxiety disorders, particularly social phobia, obsessive-compulsive disorder, eating disorders, body dysmorphic disorder, and even in bipolar mood disorder. In schizophrenia it has been described as being one stage in the construction of delusion. Its presence is connected to interpersonal relationship (altruism) though it seems absent in autism. The assessment of shame experiences in psychiatric patients could be useful for both pharmacological and psychotherapeutic strategies, and could provide a categorization of a new psychopathology based on abnormal affects.     

Varieties of cognitive penetration in visual perception

Is our perceptual experience a veridical representation of the world or is it a product of our beliefs and past experiences? Cognitive penetration describes the influence of higher level cognitive factors on perceptual experience and has been a debated topic in philosophy of mind and cognitive science. Here, we focus on visual perception, particularly early vision, and how it is affected by contextual expectations and memorized cognitive contents. We argue for cognitive penetration based on recent empirical evidence demonstrating contextual and top-down influences on early visual processes. On the basis of a perceptual model, we propose different types of cognitive penetration depending on the processing level on which the penetration happens and depending on where the penetrating influence comes from. Our proposal has two consequences: (1) the traditional controversy on whether cognitive penetration occurs or not is ill posed, and (2) a clear-cut perception–cognition boundary cannot be maintained.     

Psychosis: A Synthesis of Motivational and Defect Perspectives

Based on the evolution of human intelligence and the tremendous cognitive capacities arising from it, we have an innate tendency for the extreme thought content, thought form, and sensory perceptions of psychosis. During the conscious and awake state, cognitive regulatory control processes block these more extreme variants to facilitate reality congruency necessary for adaptive functioning. While asleep there is no need for reality congruency and the cognitive regulatory control processes are deactivated allowing psychotic equivalents to be expressed in dreams. This paper helps synthesize the two dominant perspectives regarding the etiology of psychosis: the neuroscience defect perspective and the psychoanalytic motivational perspective. Regarding the former, defective cognitive regulation arising from certain conditions, such as the deficit state of schizophrenia, allows extreme cognitive distortions, thought form variants, and sensory perceptual experiences to intrude into the conscious and awake state, thereby producing psychosis. Consistent with the psychoanalytic motivational perspective, defensive processes can motivate extreme cognitive distortions, thought form variants and sensory perceptual experiences, and also facilitate their expression by deactivating the relevant cognitive regulatory control processes.     

Observer memories may not be for everyone

ABSTRACT

Six studies explored the preponderance of people who experience third-person perspective observer memories during autobiographical memory retrieval. The concept of first-person field versus observer memories has been extensively used in the areas of cognitive, social, and clinical psychology. An implicit assumption is the idea that most people use both of these perspectives. What varies are the circumstances that bias people to use one perspective over another for a given autobiographical memory. We challenge that assumption across six studies by showing that, while there are some people who report to regularly have observer memories, there are also those that report to rarely or never have them. These reports were found to be related to levels of reported dissociative experiences. We discuss how this difference in the experience of observer memories may also reflect other innate characteristics, and may correspond to predispositions for various pathologies, including depression, social phobia, and post-traumatic stress disorder.     

Developmental dyslexia and animal studies: at the interface between cognition and neurology

Recent findings in autopsy studies, neuroimaging, and neurophysiology indicate that dyslexia is accompanied by fundamental changes in brain anatomy and physiology, involving several anatomical and physiological stages in the processing stream, which can be attributed to anomalous prenatal and immediately postnatal brain development. Epidemiological evidence in dyslexic families led to the discovery of animal models with immune disease, comparable anatomical changes and learning disorders, which have added needed detail about mechanisms of injury and plasticity to indicate that substantial changes in neural networks concerned with perception and cognition are present. It is suggested that the disorder of language, which is the cardinal finding in dyslexic subjects, results from early perceptual anomalies that interfere with the establishment of normal cognitive-linguistic structures, coupled with primarily disordered cognitive processing associated with developmental anomalies of cortical structure and brain asymmetry. This notion is supported by electrophysiological data and by findings of anatomical involvement in subcortical structures close to the input as well as cortical structures involved in language and other cognitive functions. It is not possible at present to determine where the initial insult lies, whether near the input or in high-order cortex, or at both sites simultaneously.     

What the Disjunctivist is Right About

There is a traditional conception of sensory experience on which the experiences one has looking at, say, a cat could be had by someone merely hallucinating a cat. Disjunctivists take issue with this conception on the grounds that it does not enable us to understand how perceptual knowledge is possible. In particular, they think, it does not explain how it can be that experiences gained in perception enable us to be in 'cognitive contact' with objects and facts. I develop this challenge to the traditional conception and then show that it is possible to accommodate an adequate account of cognitive contact in keeping with the traditional conception. One upshot of the discussion is that experiences do not bear the explanatory burden placed upon them by disjunctivists.     

Qualitative character and sensory representation

Perceptual experience seems to involve distinct intentional and qualitative features. Inasmuch as one can visually perceive that there is a Coke can in front of one, perceptual experience must be intentional. But such experiences seem to differ from paradigmatic intentional states in having introspectible qualitative character. argues that a perceptual experience's qualitative character is determined by intrinsic, nonrepresentational properties. But also argues that perceptual experiences have nonconceptual representational content in addition to conceptual content and nonrepresentational sensational properties. He thus distinguishes between conceptual, nonrepresentational, and nonconceptual but representational aspects of perceptual experience. I will argue that Peacocke posits too much. Contrary to his (1983) arguments, the sensational properties Peacocke claims are nonrepresentational are best construed as representational; they are best explained in terms of their relation to the perceptible properties they enable us to perceive. Since sensational properties are arguably nonconceptual, they are best construed as nonconceptual representational properties. I offer the Homomorphism View of sensory qualities, pioneered by, as a unified account of qualitative character and nonconceptual sensory representation. According to this view, a sensory quality represents a perceptible stimulus property in virtue of resembling and differing from other sensory qualities in ways parallel to the ways the stimulus property resembles and differs from other perceptible properties.