The purpose of this paper is to show that understanding AI hallucination requires an interdisciplinary approach that combines insights from epistemology and cognitive science to address the nature of AI-generated knowledge, with a terminological worry that concepts we often use might carry unnecessary presuppositions. Along with terminological issues, it is demonstrated that AI systems, comparable to human cognition, are susceptible to errors in judgement and reasoning, and proposes that epistemological frameworks, such as reliabilism, can be similarly applied to enhance the (...) trustworthiness of AI outputs. This exploration seeks to deepen our understanding of the possibility of AI cognition and its implications for the broader philosophical questions of knowledge and intelligence. (shrink)

In artificial intelligence (AI), responses generated by machine-learning models (most often large language models) may be unfactual information presented as a fact. For example, a chatbot might state that the Mona Lisa was painted in 1815. Such phenomenon is called AI hallucinations, seeking inspiration from human psychology, with a great difference of AI ones being connected to unjustified beliefs (that is, AI “beliefs”) rather than perceptual failures). -/- AI hallucinations may have their source in the data itself, that (...) is, the source content, or in the training procedure, i.e. the way the knowledge was encoded in the model’s parameters, so that errors in encoding and decoding textual and non-textual representations can cause hallucinations. In this paper, we will observe how such errors come to life and how they might be mitigated. For this purpose, we will analyze the usability of justification logics, to behave as a proof checker for validating the correctness of large language models’ (LLM) responses. Justification logic was developed by S. Artemov, and later on mostly by Artemov and M. Fitting, deriving its main idea from the logic of proofs (LP): knowledge and belief modalities are seen as justification terms, i.e. t:X stands for t is a (proper) justification for X. Justification logic originated from attempts to create semantics for intuitionistic logic where proofs were the most proper justifications, but in further development, justification logic could be applied to different kinds of justifications). With the recent attempts to mitigate incorrect LLM responses, we will analyze various guardrails that are currently used for LLM responses, and see how the logic of justification may provide its benefits as an AI safety layer against false data. (shrink)

Generative Artificial Intelligence (AI) tools produce hallucinations exposing developers and users to a myriad of liabilities in courts. Given the absence of strict laws and regulations structuring how Generative AI content interact with potential allegations of defamation, libel, and slander, judges and attorneys are left with the semiotics of the fragmented articles and rules in each system attempting to settle such cases. The endless interpretations of written and non-verbal signs in the law across the world constitutes a new realm (...) for legal semiotics in the area of Generative AI and defamation. The present analysis examines existing civil liability articles in the Jordanian code to shed light on the litigation and defenses afforded in the defamation realm with respect to Generative AI content. The key finding is that like other countries, civil codes in Jordan are outdated concerning Generative AI content opening a plethora of liability scenarios in libel or slander cases. More importantly, the exercise of semiotic interpretation generates several defenses salvaging users and developers under strict sets of conditions. In sum, new amendments and updated legislative frameworks are needed to protect the healthy development of Generative AI while preserving citizens from damaging defamation, libel, and slander. (shrink)

This paper explores the intersection of AI hallucinations and the question of AI consciousness, examining whether the erroneous outputs generated by large language models (LLMs) could be mistaken for signs of emergent intelligence. AI hallucinations, which are false or unverifiable statements produced by LLMs, raise significant philosophical and ethical concerns. While these hallucinations may appear as data anomalies, they challenge our ability to discern whether LLMs are merely sophisticated simulators of intelligence or could develop genuine cognitive processes. (...) By analyzing the causes of AI hallucinations, their impact on the perception of AI cognition, and the potential implications for AI consciousness, this paper contributes to the ongoing discourse on the nature of artificial intelligence and its future evolution. (shrink)

This study explores the potential of contemporary large language models (LLMs) to achieve Gilles Deleuze’s goal of integrating art into daily life. Deleuze’s philosophy, with its focus on creative repetition, finds a parallel in LLMs, which replicate and innovate artistic styles by transforming text prompts into various artistic expressions. Although LLMs can very effectively blend and mimic these styles, they remain mere tools – as suggested by the metaphor of a stochastic parrot; the true creative force remains the human artist. (...) Currently, these models are experimental, and their artistic outputs, while impressive, are still viewed as pastiches rather than genuine art. Nonetheless, we can expect advances that may soon enable artists to use LLMs to create genuine artworks. (shrink)

The prospects of AI-driven chatbots that can replicate the online presence of persons who have died (so-called ‘deathbots’) has given rise to concerns about the potential to replace the dead or disrupt the grieving process of their survivors. These concerns assume, however, that these ‘deathbots’ (hereafter Interactive Personality Constructs of the Dead, or IPCDs) could successfully replicate the experience of being in the (mediated) presence of a dead person. This paper considers recent discussions of the psychological phenomenon known as bereavement (...) hallucination to determine what it is to experience the presence of a dead person, and whether chatbots could replicate this. Phenomenological analysis of bereavement hallucination suggests that the felt presence of the dead turns on an embodied sense of the opening-up of intersubjective possibilities by the characteristic way-of-being of the dead person. Once we understand the experience of the presence of the dead in this way, we can see that there are no apparent impediments to IPCDs producing such a sense of presence with the dead. (shrink)

Recently, there has been considerable interest in large language models: machine learning systems which produce human-like text and dialogue. Applications of these systems have been plagued by persistent inaccuracies in their output; these are often called “AI hallucinations”. We argue that these falsehoods, and the overall activity of large language models, is better understood as bullshit in the sense explored by Frankfurt (On Bullshit, Princeton, 2005): the models are in an important way indifferent to the truth of their outputs. (...) We distinguish two ways in which the models can be said to be bullshitters, and argue that they clearly meet at least one of these definitions. We further argue that describing AI misrepresentations as bullshit is both a more useful and more accurate way of predicting and discussing the behaviour of these systems. (shrink)

The advent of generative artificial intelligence and the widespread adoption of it in society engendered intensive debates about its ethical implications and risks. These risks often differ from those associated with traditional discriminative machine learning. To synthesize the recent discourse and map its normative concepts, we conducted a scoping review on the ethics of generative artificial intelligence, including especially large language models and text-to-image models. Our analysis provides a taxonomy of 378 normative issues in 19 topic areas and ranks them (...) according to their prevalence in the literature. The study offers a comprehensive overview for scholars, practitioners, or policymakers, condensing the ethical debates surrounding fairness, safety, harmful content, hallucinations, privacy, interaction risks, security, alignment, societal impacts, and others. We discuss the results, evaluate imbalances in the literature, and explore unsubstantiated risk scenarios. (shrink)

The field of AI has undergone a series of transformations, each marking a new phase of development. The initial phase emphasized curation of symbolic models which excelled in capturing reasoning but were fragile and not scalable. The next phase was characterized by machine learning models—most recently large language models (LLMs)—which were more robust and easier to scale but struggled with reasoning. Now, we are witnessing a return to symbolic models as complementing machine learning. Successes of LLMs contrast with their inscrutability, (...) inaccuracy, and hallucinations, which underwrite concerns over the reliability and trustworthiness of these systems, motivating investigations into commonsense reasoning, AI explainability, and formal verification techniques. Moreover, proper assessments of hybrid machine learning/symbolic systems require novel strategies to facilitate comparisons of performance and guide future AI progress. The EDGeS AAAI 2023 Spring symposium brought together researchers focusing on novel assessments and benchmarks for evaluating hybrid and artificial general intelligence (AGI) systems. This symposium revealed what was already suspected: research concerning evaluation of machine learning/symbolic hybrids and AGI is, unfortunately, lacking. Even so, the discussion was fruitful. (shrink)

This paper analyses the phenomenology and epistemology of chatbots such as ChatGPT and Bard. The computational architecture underpinning these chatbots are large language models (LLMs), which are generative artificial intelligence (AI) systems trained on a massive dataset of text extracted from the Web. We conceptualise these LLMs as multifunctional computational cognitive artifacts, used for various cognitive tasks such as translating, summarizing, answering questions, information-seeking, and much more. Phenomenologically, LLMs can be experienced as a “quasi-other”; when that happens, users anthropomorphise them. (...) For most users, current LLMs are black boxes, i.e., for the most part, they lack data transparency and algorithmic transparency. They can, however, be phenomenologically and informationally transparent, in which case there is an interactional flow. Anthropomorphising and interactional flow can, in some users, create an attitude of (unwarranted) trust towards the output LLMs generate. We conclude this paper by drawing on the epistemology of trust and testimony to examine the epistemic implications of these dimensions. Whilst LLMs generally generate accurate responses, we observe two epistemic pitfalls. Ideally, users should be able to match the level of trust that they place in LLMs to the degree that LLMs are trustworthy. However, both their data and algorithmic opacity and their phenomenological and informational transparency can make it difficult for users to calibrate their trust correctly. The effects of these limitations are twofold: users may adopt unwarranted attitudes of trust towards the outputs of LLMs (which is particularly problematic when LLMs hallucinate), and the trustworthiness of LLMs may be undermined. (shrink)

Keywords are essential to the searchability and therefore discoverability of museum and archival collections in the modern world. Without them, the collection management systems (CMS) and online collections these cultural organisations rely on to record, organise, and make their collections accessible, do not operate efficiently. However, generating these keywords manually is time consuming for these already resource strapped organisations. Artificial intelligence (AI), particularly generative AI and Large Language Models (LLMs), could hold the key to generating, even automating, this key data (...) and as such be considered a co-creative add-on. This study contributes to the literature by introducing the use of Meta’s open-source LLM, Llama, to generate keywords from curator/archivist written descriptions of museum and archival collection items. Our findings suggest that these technologies add significant value compared to current manual methods for keyword generation. In particular, we find that through using carefully crafted prompts, successful keyword augmentations could be established making museum and archival collections much more accessible to wider and more diverse audiences. However, the results also showed that generative AI has biases (e.g., hallucinations, over generalisations, outdated language), though the frequency of occurrence was not as high as general perception may insist. Hence, we also discuss mitigation strategies to address these and how cultural institutions can recognise the risks and errors while getting the most from the systems. Finally, we discuss options to achieve structured results which allow easier ingestion of data back into CMS. Ultimately, LLMs hold significant potential to enhance accessibility to museum and archival collections, yet they are not without imperfection as we extensively discuss. (shrink)

In artificial intelligence literature, “delusions” are characterized as the generation of unfaithful output from reliable source content. There is an extensive literature on computer-generated delusions, ranging from visual hallucinations, like the production of nonsensical images in Computer Vision, to nonsensical text generated by (natural) language models, but this literature is predominantly taxonomic. In a recent research paper, however, a group of scientists from DeepMind successfully presented a formal treatment of an entire class of delusions in generative AI models (i.e., (...) models based on a transformer architecture, both with and without RLHF—reinforcement learning with human feedback, such as BERT, GPT-3 or the more recent GPT-3.5), referred to as auto-suggestive delusions. Auto-suggestive delusions are not mere unfaithful output, but are self-induced by the transformer models themselves. Typically, these delusions have been subsumed under the concept of exposure bias, but exposure bias alone does not elucidate their nature. In order to address their nature, I will introduce a formal framework that clarifies the probabilistic delusions capable of explaining exposure bias in a broad manner. This will serve as the foundation for exploring auto-suggestive delusions in language models. Next, an examination of self- or auto-suggestive delusions will be undertaken, by drawing an analogy with the rule-following problematic from the philosophy of mind and language. Finally, I will argue that this comprehensive approach leads to the suggestion that transformers, large language models in particular, may develop in a manner that touches upon solipsism and the emergence of a private language, in a weak sense. (shrink)

While there are many public concerns about the impact of AI on truth and knowledge, especially when it comes to the widespread use of LLMs, there is not much systematic philosophical analysis of these problems and their political implications. This paper aims to assist this effort by providing an overview of some truth-related risks in which LLMs may play a role, including risks concerning hallucination and misinformation, epistemic agency and epistemic bubbles, bullshit and relativism, and epistemic anachronism and epistemic incest, (...) and by offering arguments for why these problems are not only epistemic issues but also raise problems for democracy since they undermine its epistemic basis– especially if we assume democracy theories that go beyond minimalist views. I end with a short reflection on what can be done about these political-epistemic risks, pointing to education as one of the sites for change. (shrink)

The article is devoted to the description of the differences in the conceptualization of space observed in informants, large language models and computer vision models capable of generating a text describing what they “saw”. We use the concept of a cognitive agent and substantiate the distinction between “natural vs artificial cognitive agent”: the first is understood as a person, the second is an AI model capable of making decisions and performing tasks adequately in a given situation. The aim of the (...) study is to compare the ways of understanding the location of an object in space in natural cognitive agents and artificial cognitive agents of two types: large language models and models created for Image to Text task. The main methods are the method of linguistic experiment and the method of semantic description based on the theory of topological semantics by L. Talmi. As an incentive material, six paintings from the collection of the State Hermitage Museum were used, divided into three groups: portraits, monofigure paintings on mythological or religious themes, and multifigure compositions. The participants of the experiments were: 63 informants (Mean age = 19.1, 48 females, 15 males), 5 LLMs, 6 Image to Text models based on computer vision technology and capable of generating descriptions of recognized images in English. Using the typology of configurational topological schemes and “figure – background” type schemes, we compared the ways of understanding space that the models rely on. As a result, we have formulated a number of conclusions, the most important of which is that natural cognitive agents differ from artificial cognitive agents in its ability to integrate the process of conceptualization of an object in space into other cognitive processes: entity recognition and categorization, attention mechanisms, awareness of cause-and-effect relationships. Artificial cognitive agents are only learning such integrativity and mutual coordination, for example, when generative models conceptualize those objects in which they are not sure, since these are products of hallucination, as objects with fuzzy boundaries, and Image to Text models combine into a single heterogeneous human object and the most striking original detail of its environment, because they “believe” that this is the most important thing for description tasks. (shrink)

If Large Language Models can make real scientific contributions, then they can genuinely use language, be systematically wrong, and be held responsible for their errors. AI models which can make scientific contributions thereby meet the criteria for scientific authorship.

Felt presence, a sensation that “someone is there”, is an integral part of our everyday experience. It can manifest itself in a variety of forms ranging from most subtle fleeting impressions to intense hallucinations of demonic assault or visions of the divine. Felt presence phenomenon outside of the context of neurological disorders is largely neglected and not well understood by contemporary science. This paper focuses on the experiential and expressive qualities of the phenomenon and attempts to bring forth the (...) complexity and the richness of possibilities for inter- and intrasubjective awareness represented by these experiences. Are these simply misperceptions and hallucinations heightened and enforced by the mystical or superstitious mind? Or are these entities projections of our own “selves”, elements of self-estrangement? How are such experiences shaping our understanding of ourselves and of others? And finally, what is the interplay between intersubjective, private experiences and private or public spaces of dwelling? (shrink)

Scientific and philosophical perspectives on hallucination: essays that draw on empirical evidence from psychology, neuroscience, and cutting-edge philosophical theory.

According to the epistemic theory of hallucination, the fundamental psychological nature of a hallucinatory experience is constituted by its being 'introspectively indiscriminable', in some sense, from a veridical experience of a corresponding type. How is the notion of introspective indiscriminability to which the epistemic theory appeals best construed? Following M. G. F. Martin, the standard assumption is that the notion should be construed in terms of negative epistemics: in particular, it is assumed that the notion should be explained in terms (...) of the impossibility that a hallucinator might possess a certain type of knowledge on a certain basis. I argue that the standard assumption is mistaken. I argue that the relevant notion of introspective indiscriminability is better construed in terms of positive epistemics: in particular, I argue that the notion is better explained by reference to the fact that it would be rational for a hallucinator positively to make a certain type of judgement, were that judgement made on a certain basis. (shrink)

When one visually hallucinates, the object of one’s hallucination is not before one’s eyes. On the standard view, that is because the object of hallucination does not exist, and so is not anywhere. Many different defenses of the standard view are on offer; each have problems. This paper defends the view that there is always an object of hallucination—a physical object, sometimes with spatiotemporally scattered parts.

Hallucination is a big deal in contemporary philosophy of perception. The main reason for this is that the way hallucination is treated marks an important stance in one of the most hotly contested debates in this subdiscipline: the debate between 'relationalists' and 'representationalists'. I argue that if we take hallucinations to be a form of mental imagery, then we have a very straightforward way of arguing against disjunctivism: if hallucination is a form of mental imagery and if mental imagery (...) and perception have some substantive common denominator, then a fortiori, perception and hallucination will also have a substantive common denominator. (shrink)

When you hallucinate an object, you are not in the normal sort of concurrent causal sensory interaction with that object. It's standardly further inferred that the hallucinated object does not actually exist. But the lack of normal concurrent causal sensory interaction does not imply that there does not exist an object that is hallucinated. It might be a past‐perceived object. In this paper, I argue that this claim holds for at least some interesting cases of hallucination. Hallucinations generated by (...) misleading cues (e.g. ‘seeing’ Kanizsa triangles), hallucinations of Charles Bonnet Syndrome patients, and dreams are experiences of past‐perceived objects. (shrink)

A natural starting point for theories of perceptual states is ordinary perception, in which a subject is successfully related to her mind-independent surroundings. Correspondingly, the simplest theory of perceptual states models all such states on perception. Typically, this simple, common-factor relational view of perceptual states has received a perfunctory dismissal on the grounds that hallucinations are nonperceptual. But I argue that the nonperceptual view of hallucinations has been accepted too quickly. I consider three observations thought to support the (...) view, and argue that all three are dealt with equally well by an alternative view, illusionism, on which hallucinations do involve perception. Since this is so, adopting a common-factor relational view of all perceptual states remains a tenable option. (shrink)

In Real Hallucinations, Matthew Ratcliffe offers a philosophical examination of the structure of human experience, its vulnerability to disruption, and how it is shaped by relations with other people. He focuses on the seemingly simple question of how we manage to distinguish among our experiences of perceiving, remembering, imagining, and thinking. To answer this question, he first develops a detailed analysis of auditory verbal hallucinations (usually defined as hearing a voice in the absence of a speaker) and thought (...) insertion (somehow experiencing one's own thoughts as someone else's). He shows how thought insertion and many of those experiences labeled as "hallucinations" consist of disturbances in a person's senseof being in one type of intentional state rather than another. Ratcliffe goes on to argue that such experiences occur against a backdrop of less pronounced but wider-ranging alterations in the structure of intentionality. In so doing, he considers forms of experience associated with trauma, schizophrenia, and profound grief. The overall position arrived at is that experience has an essentially temporal structure, involving patterns of anticipation and fulfillment that are specific to types of intentional states and serve to distinguish them phenomenologically. Disturbances of this structure can lead to various kinds of anomalous experience. Importantly, anticipation-fulfillment patterns are sustained, regulated, and disrupted by interpersonal experience and interaction. It follows that the integrity of human experience, including the most basic sense of self, is inseparable from how we relate to other people and to the social world as a whole. (shrink)

What are hallucinations? A common view in the philosophical literature is that hallucinations are degenerate kinds of perceptual experience. I argue instead that hallucinations are degenerate kinds of sensory imagination. As well as providing a good account of many actual cases of hallucination, the view that hallucination is a kind of imagination represents a promising account of hallucination from the perspective of a disjunctivist theory of perception like naïve realism. This is because it provides a way of (...) giving a positive characterisation of hallucination—rather than characterising hallucinations in negative, relational, terms as mental events that are subjectively indistinguishable from veridical perceptual experiences. (shrink)

How is it that many schizophrenics identify certain instances of verbal imagery as hallucinatory? Most investigators have assumed that alterations in sensory features of imagery explain this. This approach, however, has not yielded a definitive picture of the nature of verbal hallucinations. An alternative perspective suggests itself if one allows the possibility that the nonself quality of hallucinations is inferred on the basis of the experience of unintendedness that accompanies imagery production. Information-processing models of “intentional” cognitive processes call (...) for abstract planning representations that are linked to goals and beliefs. Unintended actions - and imagery - can reflect planning disruptions whereby cognitive products do not cohere with concurrent goals. A model of schizophrenic speech disorganization is presented that postulates a disturbance of discourse planning. Insofar as verbal imagery can be viewed as inwardly directed speech, a consequence of such planning disturbances could be the production of unintended imagery. This link between the outward disorganization of schizophrenic speech and unintended verbal imagery is statistically supported by comparing the speech behavior of hallucinating and nonhallucinating schizophrenics. Studies of “borderline” hallucinations during normal, “goal-less” relaxation and drowsiness suggest that experiential unintendedness leads to a nonpathological variant of hallucinatory otherness that is correctable upon emerging from such passive cognitive states. This contrasts with the schizophrenic case, where nonconcordance with cognitive goals reinforces the unintendedness of verbal images and sustains the conviction of an external source. This model compares favorably with earlier models of verbal hallucinations and provides further evidence for a language production disorder in many schizophrenics.Short Abstract: How is it that many schizophrenics identify certain instances of verbal imagery as hallucinatory? This paper proposes that the critical feature identifying hallucinations is the experience of unintendedness. This experience is nonpathological during passive conscious states but pathological if occurring during goal-directed cognitive processing. A model of schizophrenic speech disorganization is presented that postulates a disturbance of discourse planning that specifies communicative intentions. These alterations could generate unintended verbal imagery as well. Statistical data are offered to support the model, and relevant empirical studies are reviewed. (shrink)

No particular dagger was the object of Macbeth’s hallucination of a dagger. In contrast, when he hallucinated his former comrade Banquo, Banquo himself was the object of the hallucination. Although philosophers have had much to say about the nature and philosophical import of hallucinations (e.g. Macpherson and Platchias, Hallucination, 2013) and object-involving attitudes (e.g. Jeshion, New essays on singular thought, 2010), their intersection has largely been neglected. Yet, object-involving hallucinations raise interesting questions about memory, perception, and the ways (...) in which we have knowledge of the world around us. In this paper, I offer an account of object-involving hallucinations. Specifically, I argue that they are an unusual species of perceptual remembering. (shrink)

Like dreaming, hallucination has been a formative trope for modern philosophy. The vivid, often tragic, breakdown in the mind’s apparent capacity to disclose reality has long served to support a paradoxical philosophical picture of sensory experience. This picture, which of late has shaped the paradigmatic empirical understanding the senses, displays sensory acts as already complete without the external world; complete in that the direct objects even of veridical sensory acts do not transcend what we could anyway hallucinate. Hallucination is thus (...) the mother of Representationalism, which insists that it is mental intermediaries that make other.. (shrink)

In this paper, I examine the so-called disjunctive views on hallucinations. I argue that neither of the options open to the disjunctivist is capable of accommodating basic phenomenological facts about hallucinatory experiences and the explanatory demands behind the classical argument from hallucination. A positive characterization of the hallucinatory case is not attractive to a disjunctivist once she is disposed to accept certain commonalities with veridical experiences. Negative disjunctivism glosses the hallucinatory disjunct in terms of indiscriminability. I will argue that (...) this move either renounces to characterize phenomenally the hallucinatory experience or does not take seriously questions about why indiscriminability is possible in the phenomenal realm. (shrink)

This chapter introduces and motivates the Null View about standard causally matching hallucinations. The Null View holds that these hallucinations fail to present any objects or sensible qualities, despite being dead ringers for perceptions of ordinary objects and their qualities. Motivation for the Null View comes from a neglected observation about perception-based thought, namely that perception can permit perception-based thought about a sensible quality even while misleading a subject about that quality. The chapter's other contribution is defensive. Most (...) reject the Null View on phenomenological or epistemic grounds. These objections to the Null View are sharpened and then undermined. (shrink)

Relationalism is the view that perception is partly constituted by external objects (McDowell 1994; Campbell 2002; Martin 2004). Faced with the hallucination argument, and unsatisfied with the standard disjunctivist reply, some ‘new wave’ relationalists explain away the possibility of hallucinations as mere illusions (Alston 1999; Watzl 2010; Ali 2018; Masrour 2020). In this paper, I argue that some of these illusions (as in Chalmers 2005; Ali 2018) are perceptions of internal objects which appear as external ones. Then, in response (...) to the obvious screening-off objection, I argue for a novel reply called ‘intrameralism’: roughly, external objects are ordinarily perceived because they gain internal parts—they ‘grow into the head’. The preceding hallucinations are thus ultimately explained away as a kind of perceptual synecdoche, in which internal parts appear as their (ordinarily perceived) external wholes. The paper concludes by addressing some objections. (shrink)

Relationalism maintains that mind-independent objects are essential constituents of veridical perceptual experiences. According to the argument from hallucination, relationalism is undermined by perfect hallucinations, experiences that are introspectively indistinguishable from veridical perceptual experiences but lack an object. Recently, a new wave of relationalists have responded by questioning whether perfect hallucinations are possible: what seem to be perfect hallucinations may really be something else, such as illusions, veridical experiences of non-obvious objects, or experiences that are not genuinely possible. (...) This paper argues that however well new wave relationalism may handle brains in vats, drug users “seeing” pink elephants, and other extraordinary hallucinations, it struggles to accommodate mundane hallucinations, such as “hearing” your child cry out from the room down the hall when she is actually sound asleep or “feeling” vibrations on your thigh even when your phone isn't in your pocket. Mundane hallucinations are best explained as byproducts of noise in the perceptual system, and noise-induced hallucinations are resistant to the strategies that new wave relationalists deploy to explain away other hallucinations. Mundane hallucinations can thus underpin an especially powerful version of the argument from hallucination. (shrink)

Hallucinations are among the most impressive of psychopathological symptoms and may appear in all the sensory modalities. They are the most common symptom in schizophrenia, where patients usually experience auditory hallucinations, often hearing voices which speak to them in direct communication or in the form of running commentary. One of the major research strategies in psychopathology during the last years has become the neuropsychological reconstruction of psychopathological symptoms in order to detect basic “core” deficits of the different symptoms. (...) Given the successful identification of such core deficits, they may then serve as heuristic tools to identify candidate brain regions of putative pathology. These brain sites in turn can be explored with respect to their impact for the pathogenesis of schizophrenia. Among these neuropsychological approaches, one of the most prominent concepts reconstructing schizophrenic symptomatology is the concept of a self-monitoring disturbance, based on the conceptual and empirical work of the group around Christopher Frith. Although this conceptualization is evidence-based and appears plausible, it does not fully explain the high degree of certainty or confidence with which schizophrenic patients usually judge the reality status of their hallucinations and the frequency with which the latter might occur. The concept of self-monitoring disturbance thus provides a necessary but not a sufficient theoretical account of how hallucinations are generated. (shrink)

Behrendt & Young (B&Y) suggest that hallucinations occur as a result of decoupling of neuronal populations from sensory control. I propose that such a decoupling is in fact a constant feature of brain activity, even under nonpathological conditions. This position is justified by evidence from recent neurophysiological recording studies. I suggest that hallucinations arise because of a breakdown in segregation of internally and externally generated activity in a neuronal population.

Behrendt & Young's (B&Y's) novel “unifying model” of hallucinations, although comprehensive, fails to incorporate research into the possible role of 5-HT2A receptors in the mode of action of novel “atypical” antipsychotic drugs (which treat hallucinations effectively), and into the role of such receptors, which are located in thalamocortical circuits, in mediating drug-induced hallucinations.

What we perceive is the product of an intrinsic process and not part of external physical reality. This notion is consistent with the philosophical position of transcendental idealism but also agrees with physiological findings on the thalamocortical system. -Frequency rhythms of discharge activity from thalamic and cortical neurons are facilitated by cholinergic arousal and resonate in thalamocortical networks, thereby transiently forming assemblies of coherent oscillations under constraints of sensory input and prefrontal attentional mechanisms. Perception and conscious experience may be based (...) on such assemblies and sensory input to thalamic nuclei plays merely a constraining role in their formation. In schizophrenia, the ability of sensory input to modulate self-organisation of thalamocortical activity may be generally reduced. If during arousal thalamocortical self-organisation is underconstrained by sensory input, then attentional mechanisms alone may determine the content of perception and hallucinations may arise. (shrink)

Synesthesia literally means a “union of the senses” whereby two or more of the five senses that are normally experienced separately are involuntarily and automatically joined together in experience. For example, some synesthetes experience a color when they hear a sound, although many instances of synesthesia also occur entirely within the visual sense. In this paper, I first mainly engage critically with Sollberger’s view that there is reason to think that at least some synesthetic experiences can be viewed as truly (...) veridical perceptions, and not as illusions or hallucinations. Among other things, I explore the possibility that many forms of synesthesia can be understood as experiencing what I will call “second-order secondary properties,” that is, experiences of properties of objects induced by the secondary qualities of those objects. In doing so, I shed some light on why synesthesia is typically one-directional and its relation to some psychopathologies such as autism. (shrink)

In this paper, I argue that the indirect realists’ recourse to mental representations does not allow them to account for the possibility of hallucination, nor for the presentational character of visual experience. To account for the presentational character, I suggest a kind of intentionalism that is based on the interdependency between the perceived object and the embodied perceiver. This approach provides a positive account to the effect that genuine perception and hallucination are different kinds of states. Finally, I offer a (...) tentative suggestion as to how a hallucinatory experience may still be mistaken for a genuine perceptual experience. (shrink)

Perceptual experiences have been construed either as representational mental states—Representationalism—or as direct mental relations to the external world—Disjunctivism. Both conceptions are critical reactions to the so-called ‘Argument from Hallucination’, according to which perceptions cannot be about the external world, since they are subjectively indiscriminable from other, hallucinatory experiences, which are about sense-data ormind-dependent entities. Representationalism agrees that perceptions and hallucinations share their most specific mental kind, but accounts for hallucinations as misrepresentations of the external world. According to Disjunctivism, (...) the phenomenal character of perceptions is exhausted by worldly objects and features, and thus must be different from the phenomenal character of hallucinations. Disjunctivism claims that subjective indiscriminability is not the result of a common experiential ground, but is because of our inability to discriminate, from the inside, hallucinations from perceptions. At first sight, Representationalism is more congenial to the way cognitive science deals with perception. However, empirically oriented revisions of Disjunctivism could be developed and tested by giving a metacognitive account of hallucinations. Two versions of this account can be formulated, depending on whether metacognition is understood as explicit metarepresentation or as implicit monitoring of first-order informational states. The first version faces serious objections, but the second is more promising, as it embodies a more realistic view of perceptual phenomenology as having both sensory and affective aspects. Affectbased phenomenology is constituted by various metacognitive feelings, such as the feeling of being perceptually confronted with the world itself, rather than with pictures or mere representations. (shrink)

Do self‐monitoring accounts, a dominant account of the positive symptoms of schizophrenia, explain auditory verbal hallucination? In this essay, I argue that the account fails to answer crucial questions any explanation of auditory verbal hallucination must address. Where the account provides a plausible answer, I make the case for an alternative explanation: auditory verbal hallucination is not the result of a failed control mechanism, namely failed self‐monitoring, but, rather, of the persistent automaticity of auditory experience of a voice. My argument (...) emphasizes the importance of careful examination of phenomenology as providing substantive constraints on causal models of the positive symptoms in schizophrenia. (shrink)

Based on recent insight into the thalamocortical system and its role in perception and conscious experience, a unified pathophysiological framework for hallucinations in neurological and psychiatric conditions is proposed, which integrates previously unrelated neurobiological and psychological findings. Gamma-frequency rhythms of discharge activity from thalamic and cortical neurons are facilitated by cholinergic arousal and resonate in networks of thalamocortical circuits, thereby transiently forming assemblies of coherent gamma oscillations under constraints of afferent sensory input and prefrontal attentional mechanisms. If perception is (...) based on synchronisation of intrinsic gamma activity in the thalamocortical system, then sensory input to specific thalamic nuclei may merely play a constraining role. Hallucinations can be regarded as underconstrained perceptions that arise when the impact of sensory input on activation of thalamocortical circuits and synchronisation of thalamocortical gamma activity is reduced. In conditions that are accompanied by hallucinations, factors such as cortical hyperexcitability, cortical attentional mechanisms, hyperarousal, increased noise in specific thalamic nuclei, and random sensory input to specific thalamic nuclei may, to a varying degree, contribute to underconstrained activation of thalamocortical circuits. The reticular thalamic nucleus plays an important role in suppressing random activity of relay cells in specific thalamic nuclei, and its dysfunction may be implicated in the biological vulnerability to hallucinations in schizophrenia. Combined with general activation during cholinergic arousal, this leads to excessive disinhibition in specific thalamic nuclei, which may allow cortical attentional mechanisms to recruit thalamic relay cells into resonant assemblies of gamma oscillations, regardless of their actual sensory input, thereby producing an underconstrained perceptual experience. Key Words: Charles Bonnet syndrome; gamma oscillations; hallucinations; late paraphrenia; Lewy body dementia; perception; schizophrenia; thalamocortical system. (shrink)

We suggest that as people move to construe robots as social agents, interact with them, and treat them as capable of social ties, they might develop (close) relationships with them. We then ask what kind of relationships can people form with bots, what functions can bots fulfill, and what are the societal and moral implications of such relationships.

Ordinary language and scientific language enable us to speak about, in a singular way, what we recognize not to exist: fictions, the contents of our hallucinations, abstract objects, and various idealized but nonexistent objects that our scientific theories are often couched in terms of. Indeed, references to such nonexistent items-especially in the case of the application of mathematics to the sciences-are indispensable. We cannot avoid talking about such things. Scientific and ordinary languages thus enable us to say things about (...) Pegasus or about hallucinated objects that are true, such as "Pegasus was believed by the ancient Greeks to be a flying horse," or "That elf I'm now hallucinating over there is wearing blue shoes." Standard contemporary metaphysical views and semantic analyses of singular idioms on offer in contemporary philosophy of language have not successfully accommodated these routine practices of saying true and false things about the nonexistent while simultaneously honoring the insight that such things do not exist in any way at all. That is, philosophers often feel driven to claim that such objects do exist, or they claim that all our talk isn't genuine truth-apt talk, but only pretence. This book reconfigures metaphysics in radical ways that allow the accommodation of our ordinary ways of speaking of what does not exist while retaining the absolutely crucial presupposition that such objects exist in no way at all, have no properties, and so are not the truth-makers for the truths and falsities that are about them. (shrink)

Case Reports Int J Psychoanal -/- . 1989:70 ( Pt 3):461-79. Negative hallucinations, other irretrievable experiences and two functions of consciousness L W Brakel -/- PMID: 2793325 -/- Abstract -/- After providing a psychodynamic exploration of negative hallucinations in four clinical cases, the focus of this paper was broadened in an attempt to understand the mechanism of negative hallucination. To this end, after defining the term 'irretrievable experiences', two other examples--preconscious perceptions and infantile amnesia, both analogues to negative (...) hallucination--were examined. A discussion followed concerning two types of 'consciousness': 'consciousness' as a synonym for 'awareness' and 'consciousness' as a distinct psychological state. Next, the role of different functions of each sort of consciousness in the processes of conferring, fixing and retrieving mental contents within particular categories of experience was taken up. Finally, integrating developmental aspects of these same functions, explanations were offered regarding the mechanisms involved in preconscious perception, infantile amnesia and negative hallucinations. -/- PubMed. (shrink)

Tradition has it that, although we experience darkness, we can neither hear nor hallucinate silence. At most, we hear that it is silent, in virtue of lacking auditory experience. This cognitive view is at odds with our ordinary thought and talk. Yet it is not easy to vouchsafe the perception of silence: Sorensen‘s recent account entails the implausible claim that the permanently and profoundly deaf are perpetually hallucinating silence. To better defend the view that we can genuinely hear and hallucinate (...) silence, we must reject the austere picture of conscious experience which underpins the cognitive theory. According to that picture, conscious experience is a simple relation between subjects and objects. In the absence of an object, there is no relation, and so no experience. By enriching this picture, room can be found for the experience of silence. I explore this idea in two phases. First, I defend the thought that we can hear and hallucinate certain forms of silence, such as pauses, in virtue of experiencing contrastive sounds. Second, I draw on Moore‘s analysis of sensation to suggest that simply experiencing silence is a special form of objectless consciousness. I offer two ways of fleshing out this idea. According to the first, auditory experience possesses a temporal field within which the absence of sounds can be perceived. According to the second, purely Moorean account, it is our capacity to listen in the absence of sounds that underlies the phenomenon of experiencing silence. (shrink)

This paper sets out a novel response to the ‘screening off problem’ for naïve realism. The aim is to resist the claim (which many naïve realists accept) that the kind of experience involved in hallucinating also occurs during perception, by arguing that there are causal constraints that must be met if an hallucinatory experience is to occur that are never met in perceptual cases. Notably, given this response, it turns out that, contra current orthodoxy, naïve realists need not adopt any (...) particular view about the psychological nature of hallucinatory experience to handle the screening off problem. Consequently, room opens up for naïve realists to endorse whatever theory of hallucinatory experience seems to best capture the distinctive nature of such episodes. (shrink)