We present Activity Analysis as a new method for the quantification of subjective reports of altered states of consciousness with regard to the indicated level of simulated motor activity. Empirical linguistic activity analysis was conducted with dream reports conceived immediately after EEG-controlled periods of hypnagogic hallucinations and REM-sleep in the sleep laboratory. Reports of REM-dreams exhibited a significantly higher level of simulated physical dreamer activity, while hypnagogic hallucinations appear to be experienced mostly from the point of (...) passive observer. This study lays the groundwork for clinical research on the level of simulated activity in pathologically altered states of subjective experience, for example in the REM-dreams of clinically depressed patients, or in intrusions and dreams of patients diagnosed with PTSD. (shrink)

Hypnagogic and hypnopompic experiences (HHEs) accompanying sleep paralysis (SP) are often cited as sources of accounts of supernatural nocturnal assaults and paranormal experiences. Descriptions of such experiences are remarkably consistent across time and cultures and consistent also with known mechanisms of REM states. A three-factor structural model of HHEs based on their relations both to cultural narratives and REM neurophysiology is developed and tested with several large samples. One factor, labeled Intruder, consisting of sensed presence, fear, and auditory and (...) visual hallucinations, is conjectured to originate in a hypervigilant state initiated in the midbrain. Another factor, Incubus, comprising pressure on the chest, breathing difficulties, and pain, is attributed to effects of hyperpolarization of motoneurons on perceptions of respiration. These two factors have in common an implied alien ''other'' consistent with occult narratives identified in numerous contemporary and historical cultures. A third factor, labeled Unusual Bodily Experiences, consisting of floating/flying sensations, out-of-body experiences, and feelings of bliss, is related to physically impossible experiences generated by conflicts of endogenous and exogenous activation related to body position, orientation, and movement. Implications of this last factor for understanding of orientational primacy in self-consciousness are considered. Central features of the model developed here are consistent with recent work on hallucinations associated with hypnosis and schizophrenia. (shrink)

The phenomenology of auditory verbal hallucinations occurring in hypnagogic and hypnopompic states has received little attention. In a sample of healthy participants, 108 participants reported H&H AVHs and answered subsequent questions on their phenomenology. AVHs in the H&H state were found to be more likely to only feature the occasional clear word than to be clear, to be more likely to be one-off voices than to be recurrent voices, to be more likely to be voices of people known (...) to the individual than unknown persons, to be more likely to talk directly to the person rather than not, and to only rarely give commands, ask questions, or to result in an interactive conversation. Their phenomenology was similar to normative AVHs in wakefulness in that the voice-hearer was usually the target of the voice, and the voice was more likely to be of a recognized person. However, H&H AVHs differed from AVHs in wakefulness in that commands and questions were rare, and there was typically no dialogical engagement with the voice. We conclude by proposing that two distinct types of H&H AVHs may exist, based on an analysis of the phenomenology of the experience, and suggest avenues for future research. (shrink)

The paper proposes a minimal definition of dreaming in terms of immersive spatiotemporal hallucination (ISTH) occurring in sleep or during sleep–wake transitions and under the assumption of reportability. I take these conditions to be both necessary and sufficient for dreaming to arise. While empirical research results may, in the future, allow for an extension of the concept of dreaming beyond sleep and possibly even independently of reportability, ISTH is part of any possible extension of this definition and thus is a (...) constitutive condition of dreaming. I also argue that the proposed ISTH model of dreaming, in conjunction with considerations on the epistemic relationship between dreaming and dream reports, raises important questions about the extent to which dreams typically involve a detailed body representation—an assumption that plays an important role in philosophical work on dreaming. As a commonly accepted definition of dreaming is lacking in current dream research, the ISTH model, which integrates conceptual analysis and epistemological considerations with results from empirical research, is an important contribution to this field. By linking dreaming to felt presence, full-body illusions, and autoscopic phenomena such as out-of-body experiences in wakefulness and in the hypnagogic state, the ISTH model of dreaming also helps integrate dream research, both theoretically and experimentally, with the study of other altered states of consciousness involving hallucinations. It makes straightforward and investigable predictions by claiming that all of these experiences have amodal spatiotemporal hallucinations as their common denominator. Finally, it is theoretically relevant for the philosophical discussion on minimal phenomenal selfhood. (shrink)

Kafka's writings are frequently interpreted as representing the historical period of modernism in which he was writing. Little attention has been paid, however, to the possibility that his writings may reflect neural mechanisms in the processing of self during hypnagogic (i.e., between waking and sleep) states. Kafka suffered from dream-like, hypnagogic hallucinations during a sleep-deprived state while writing. This paper discusses reasons (phenomenological and neurobiological) why the self projects an imaginary double (autoscopy) in its spontaneous hallucinations (...) and how Kafka's writings help to elucidate the underlying cognitive and neural mechanisms. I further discuss how the proposed mechanisms may be relevant to understanding paranoid delusions in schizophrenia. Literature documents and records cognitive and neural processes of self with an intimacy that may be otherwise unavailable to neuroscience. To elucidate this approach, I contrast it with the apparently popularizing view that the symptoms of schizophrenia result from what has been called an operative (i.e., pre-reflective) hyper-reflexivity. The latter approach claims that pre-reflective self-awareness (diminished in schizophrenia) pervades all conscious experience (however, in a manner that remains unverifiable for both phenomenological and experimental methods). This contribution argues the opposite: the. (shrink)

A 'sensed presence' often accompanies hypnagogic and hypnopompic hallucinations associated with sleep paralysis. Qualitative descriptions of the sensed presence during sleep paralysis are consistent with the experience of a monitoring, stalking predator. It is argued that the sensed presence during sleep paralysis arises because of REM-related endogenous activation of a hypervigilant and biased attentive state, the normal function of which is to resolve ambiguities inherent in biologically relevant threat cues. Given the lack of disambiguating environmental cues, however, the (...) feeling of presence persists as a protracted experience that is both numinous and ominous. This experience, in turn, shapes the elaboration and integration of the concurrent hallucinations that often take on supernatural and daemonic qualities. The sense of presence considered here is an 'other' that is radically different from, and hence more than a mere projection of, the self. Such a numinous sense of otherness may constitute a primordial core consciousness of the animate and sentient in the world around us. (shrink)

We present one of the first quantitative studies on auditory verbal experiences and auditory verbal agency voices or characters”) in healthy participants across states of consciousness. Tools of quantitative linguistic analysis were used to measure participants’ implicit knowledge of auditory verbal experiences and auditory verbal agencies, displayed in mentation reports from four different states. Analysis was conducted on a total of 569 mentation reports from rapid eye movement sleep, non-REM sleep, sleep onset, and waking. Physiology was controlled with the nightcap (...) sleep–wake mentation monitoring system. Sleep-onset hallucinations, traditionally at the focus of scientific attention on auditory verbal hallucinations, showed the lowest degree of VE and VA, whereas REM sleep showed the highest degrees. Degrees of different linguistic-pragmatic aspects of VE and VA likewise depend on the physiological states. The quantity and pragmatics of VE and VA are a function of the physiologically distinct state of consciousness in which they are conceived. (shrink)

Dissociative symptoms are notorious for their enigmatic, disparate nature encompassing excessive daydreaming, memory problems, absentmindedness, and impairments and discontinuities in perceptions of the self, identity, and the environment. Recent studies (e.g., Koffel & Watson, 2009) have linked dissociative symptoms to vivid dreaming, nightmares, and objective sleep parameters (e.g., lengthening of REM sleep) for discussion, see (Van der Kloet et al., 2013). Germane to this link between dissociative symptomology and sleep, is the idea that in dissociative individuals, the waking state as (...) compared to REM sleep may be marked by an increase in “fluid” and hyperassociative thinking. Against this background, we invited contributions in the following areas: 1) a progressive and enduring de-differentation of wake and dream states of consciousness eventually results in schizophrenia (Llewellyn, 2011); a lesser degree of de-differentiation may have implications for dissociative symptoms; 2) sleep disturbances are not only linked to dissociation but to memory fragmentation also, further fuelling both dissociation and other manifestations of psychopathology; 3) sleep, memory and psychopathologies have complex interlinkages. Our summary below, relates the contributions to our topic to these areas. The contributing articles also give a comprehensive overview on current directions and challenges in these research fields.First, Soffer-Dudek elucidates why heightened sleep experiences (vivid dreams, nightmares, hypnagogic hallucinations) might be particularly associated with psychopathology. She explains how various psychopathologies may represent de-differentiation of the waking and dreaming states through intrusions of wake-like consciousness into sleep and dream-like cognition into wake. With regard to de-differentiation, she discusses theories of transliminality (‘thin boundaries between consciousness states’) and dissociation as potential mechanisms. Lucid dreaming is a hybrid state where wake-like cognition suffuses REM sleep/dreaming (Voss et al. 2009). Mota and colleagues compared the spontaneous occurrence of lucid dreaming in patients with psychotic symptoms (25 with schizophrenia and 20 with bipolar disorder) and 28 non-psychotic subjects. They found lucid dreaming was associated with psychosis- giving some support to the hypothesis of a link between state de-differentiation and psychopathology. In a methodological note, Ribeiro et al, having studied the prevalence of lucid dreaming using two questionnaires, show that the type of methodology used in lucid dreaming studies may have an effect upon their findings. Poerio et al state that both research and theory points to dissociation being engendered by the intrusion of dream-like mentation into waking consciousness. To extend this idea they examine the role of sleep and daydreaming as potentiating states for subsequent dissociation in depersonalization/derealization disorder (DDD). They show the occurrence and content of daydreams may act as potentiating states for heightened, in the moment, dissociation. Sleep paralysis is a dissociated state where a heightened level of wake-like alertness coexists with muscle atonia. Rodrigez de Sa and Mota-Rolim take a broad interdisciplinary perspective on sleep paralysis through reviewing its occurrence in Brazilian folklore by exploring the “Pisadeira” with a sleep science approach and link this with the field of history and art.There is now substantial evidence that active memory processing continues during sleep (see, for example, Rasch and Born (2013)) and dreaming may be involved (Llewellyn, 2013). De-differentiation of the wake, sleep and dream states would disrupt this memory processing fuelling dissociation and other psychopathologies. Horton presents an overview of discontinuity of consciousness in both wake and sleep, focusing on the processes of sleep-dependent memory consolidation and fragmentation. Nakagawa et al focus specifically on working memory and the relation with sleep. With their article, they are the first to investigate differences between verbal working memory (VWM) and visuospatial working memory (VSWM) related to daytime nap duration, nap frequency, and dream content recall frequency (DCRF). They discuss sex-related differences in the effects of sleep habits on VMW and VSWM and ascribe this to differences in underlying neural correlates, and effectiveness of sleep habits in males and females. Rosales-Lagarde and colleagues related to emotional memory by designing an extended International Affective Picture System (IAPS) instrument to measure bizarreness and show some interesting age and gender disparities. Finally, several authors took a developmental approach through focusing on sleep, memory and psychopathology in adolescents. Wang and colleagues show the relation between children and adolescents’ mental health and sleep problems in a 10-year longitudinal trial, and find anxiety, depression, attention problems and aggressive behaviour during childhood to be important predictors for later sleep problems. Importantly, sleep problems are also predictive of behavioural difficulties later in life. Nader, Murkar, and Smith investigated changes in sleep in adolescents between 12 and 19 years old following procedural task training and found that contrary to earlier work, there were no changes in sleep spindle density. Interestingly, participants who successfully learned the task showed no changes in their sleep stage proportions, but participants who were not successful showed a decrease in the proportion of Stage 2 and increases in both SWS and REM sleep, which is in line with the two stage model of sleep and memory by Smith et al. (2004).The self and the world during dreaming differ. The perceived world during waking depends on making sense of external sensory input, which engenders a strong sense of external reality in which the ‘self and its inner-world’ exists. Self-organizing during waking and dreaming enables integration of the self and the world in both states. It is noteworthy, that within this research topic so many novel themes have emerged and new questions and speculations have been posed with regards to relations among unusual sleep experiences – specifically lucid dreaming -, dissociation, psychosis, and memory. It brings together a richness of research by combining fields that originally have worked in isolation from each other. (shrink)

The nature and time course of sleep onset (hypnagogic) mentation was studied in the home environment using the Nightcap, a reliable, cost-effective, and relatively noninvasive sleep monitor. The Nightcap, linked to a personal computer, reliably identified sleep onset according to changes in perceived sleepiness and the appearance of hypnagogic dream features. Awakenings were performed by the computer after 15 s to 5 min of sleep as defined by eyelid quiescence. Awakenings from longer periods of sleep were associated with (...) (1) an increase in reported sleepiness, (2) a decrease in the length of mentation reports, (3) a decrease in the frequency of reports of normal, wake-like thoughts, (4) an increase in the frequency of ''unusual thoughts,'' and (5) increased frequencies of formal dream features, including visual hallucination, self-representation, fictive movement, narrative plot, and bizarreness. While sleep-onset reports can include all features of rapid eye movement (REM) dream reports, the number of such features is markedly reduced at sleep onset, suggesting that this mentation is a greatly diminished version of REM dreaming. (shrink)

This paper discusses the significance for the philosophy of perception and aesthetics of certain productions of the ‘offline brain’. These are experienced in hypnagogic and other trance states, and in disease- or drug-induced hallucination. They bear a similarity to other visual patterns in nature, and reappear in human artistry, especially of the craft type. The reasons behind these resonances are explored, along with the question why we are disposed to find geometrical complexity and ‘supercolouration’ beautiful. The paper concludes with (...) a plea on behalf of neuroaesthetics, but with a caution or two. (shrink)

Threat themes are clearly over-represented in dreams. Threat is, however, not the only theme with potential evolutionary significance. Even for hypnagogic and hypnopompic hallucinations during sleep paralysis, for which threat themes are far commoner than for ordinary dreaming, consistent non-threat themes have been reported. Revonsuo's simulation hypothesis represents an encouraging initiative to develop an evolutionary functional approach to dream-related experiences but it could be broadened to include evolutionarily relevant themes beyond threat. It is also suggested that Revonsuo's evolutionary (...) re-interpretation of dreams might profitably be compared to arguments for, and models of, evolutionary functions of play. [Revonsuo]. (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)

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

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)

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.

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)

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)

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)

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)

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)

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)

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)

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)

This paper examines the standard conceptualizations of the notion of hallucination in light of various non-ordinary phenomenological patterns associated with altered states of consciousness induced by psychoactive agents. It is argued that in general, the conceptualizations encountered in the literature do not do justice to the richness and complexity that the psychological phenomenology actually exhibits. A close inspection of this phenomenology reveals some pertinent distinctions which are usually not made in the scientific literature. On the one hand, the discussion is (...) based on first-hand experiences and, on the other hand, it is grounded in empirical and theoretical cognitive investigations of the phenomenology of human consciousness. Theoretically, the discussion is grounded in an approach highlighting the centrality of experience, meaning and action in cognition. (shrink)

In this commentary, we present two examples where perception is not only influenced by, but also in fact driven by, top-down effects: hallucinations and mental imagery. Crucially, both examples avoid all six of the potential confounds that Firestone & Scholl (F&S) raised as arguments against previous studies claiming to demonstrate the influence of top-down effects on perception.

The standard interpretation of quantum mechanics and a standard interpretation of the awareness of pain have a common feature: Both postulate the existence of an irresolvable duality. Whereas many physicists claim that all particles exhibit particle and wave properties, many philosophers working on pain argue that our awareness of pain is paradoxical, exhibiting both perceptual and introspective characteristics. In this chapter, we offer a pessimistic take on the putative paradox of pain. Specifically, we attempt to resolve the supposed paradox by (...) undermining the reasons offered for accepting the introspective side of the dualism. (shrink)

Waking hallucinations suggest mechanisms of dream initiation and maintenance. Visual association cortex activation, yielding poorly attended-to, visually ambiguous dream environments, suggests conditions favoring hallucinosis. Attentional and visual systems, coactivated during sleep, may generate imagery that is inserted into virtual environments. Internally consistent dreaming may evolve from successive, contextually evoked images. Fluctuating arousal and context-evoked imagery may help explain dream features.

There is currently no consensus about a general account of hallucination and its object. The problem of hallucination has de facto generated contrasting accounts of perception, led to opposing epistemic and metaphysical positions, and, most significantly, exposed a manifold of diverging views concerning the intentionality of experience, in general, and perceptual intentionality, in particular. In this article, I aim to clarify the controversial status, experiential possibility, and intentional structure of hallucination qua distinctive phenomenon. The analysis will first detect a phenomenological, (...) Husserlian-informed concept of hallucination in its irreducibility to other kinds and modes of sensory experience. This will set the theoretical basis to develop an account of hallucination by means of a morphological description of those diversified structures of intentional consciousness that lend themselves to generate hallucinatory appearances. I will then describe both the turning of certain kinds of intentional experience into hallucinatory perceptions and the status of hallucinatory objects. This will support the possibility of hallucination in a strict and rigorous sense, elucidate the enigmatic claim that ‘in hallucination we are conscious of something while nothing truly appears,’ and offer a seminal perspective concerning the alleged problem that hallucinations pose on perceptual intentionality. With the aid of some crucial distinctions, I will then argue that hallucinations do not affect perceptual intentionality as a dyadic, relational structure. (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)

Ordinary people tend to be realists regarding perceptual experience, that is, they take perceiving the environment as a direct, unmediated, straightforward access to a mindindependent reality. Not so for (ordinary) philosophers. The empiricist influence on the philosophy of perception, in analytic philosophy at least, made the problem of perception synonymous with the view that realism is untenable. Admitting the problem (and trying to offer a view on it) is tantamount to rejecting ordinary people’s implicit realist assumptions as naive. So what (...) exactly is the problem? We can approach it via one of the central arguments against realism – the argument from hallucination. The argument is intended as a proof that in ordinary, veridical cases of perception, perceivers do not have an unmediated perceptual access to the world. There are many versions of it; I propose the following1: 1. Hallucinations that are subjectively indistinguishable from veridical perceptions are possible. 2. If two subjective states are indistinguishable, then they have a common nature. 3. The contents of hallucinations are mental images, not concrete external objects. 4. Therefore, the contents of veridical perceptions are mental images rather than concrete external objects. The key move is, I believe, from the fact that hallucinations that are subjectively indistinguishable from cases of veridical perception are possible to an alleged common element, factor, or nature, in the form of a mental state, in the two cases – that is, premise 2. Disjunctivism, at its core, can be taken as simply denying this move, and arguing that all that follows from the premise stating the possibility of hallucinations that are subjectively indistinguishable from cases veridical perception is that there is a broader category, that of “experience as of...”, which encompasses both cases.. (shrink)

There are strong resemblances between the neurobiological characteristics of hallucinations occurring in the particular case of schizophrenia and the hallucinatory activity observed during the rapid-eye-movement (dreaming) sleep stage: the same prefrontal dorsolateral deactivation; forebrain disconnectivity and disinhibition; sensory deprivation; and acetylcholine, monoamine, and glutamate modifications.

Collerton et al. propose that one and the same mechanism (PAD) underlies recurrent complex visual hallucinations (RCVH) in various disorders, including schizophrenia, dementia, and eye disease. The present commentary offers an alternative account of RCVH and other recurrent complex hallucinations specific to schizophrenia and related disorders only. The proposed account is consistent with the bias of schizophrenic RCVH contents toward animate, socially active entities.

Derrida's treatment of Chinese script as essentially non-phonetic in Of Grammatology has been a recurrent leitmotif among several sinologists and scholars of Chinese origin, particularly in Rey Chow's famous 2001 essay ‘How Inscrutable Chinese Led to Globalized Theory’. Despite forceful refutations of this misconception, the accusation of a fantasizing ‘ethnocentrism thinking itself as anti-ethnocentrism’ has endured and could still be found in a recent 2015 article suggestively titled ‘A Sort of European Hallucination: On Derrida's “Chinese Prejudice”’. This essay will probe (...) into the recurrent accusation of a Derridean hallucination of the other as the other's own hallucination in order to analyse the sustained misreading of Derrida's phrase ‘outside of all logocentrism’ used about the Chinese ideogram. (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)

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)

Recent work on the mechanisms underlying auditory verbal hallucination (AVH) has been heavily informed by self-monitoring accounts that postulate defects in an internal monitoring mechanism as the basis of AVH. A more neglected alternative is an account focusing on defects in auditory processing, namely a spontaneous activation account of auditory activity underlying AVH. Science is often aided by putting theories in competition. Accordingly, a discussion that systematically contrasts the two models of AVH can generate sharper questions that will lead to (...) new avenues of investigation. In this paper, we provide such a theoretical discussion of the two models, drawing strong contrasts between them. We identify a set of challenges for the self-monitoring account and argue that the spontaneous activation account has much in favor of it and should be the default account. Our theoretical overview leads to new questions and issues regarding the explanation of AVH as a subjective phenomenon and its neural basis. Accordingly, we suggest a set of experimental strategies to dissect the underlying mechanisms of AVH in light of the two competing models. (shrink)

Chris Frith has argued that a loss of the sense of agency is central to schizophrenia. This suggests a connection between hallucinations and delusions on the one hand, and the misidentification of the subject’s imaginings as perceptions and beliefs on the other. In particular, understanding the mechanisms that underlie imagination may help us to explain the puzzling phenomena of thought insertion and withdrawal. Frith sometimes states his argument in terms of a loss of metarepresentational capacity in schizophrenia. I argue (...) that this formulation is unhelpful. (shrink)

Recently the attempt has been made to demonstrate Heidegger's relevance to the concerns of analytic philosophers. A focus for this effort has been the criticism in his early work of Cartesian ontology. While a number of important works have mapped out this area of Heidegger's thought, a crucial task has not been carried out, namely that of assessing how Heidegger can accommodate those phenomena which motivate the Cartesian to adopt his highly counter-intuitive ontology. As long as we fail to examine (...) how Heidegger's early ontology copes with the possibilities of error and of hallucination, the suspicion will remain that Heidegger is simply insensitive to those phenomena on which the Cartesian focuses. Neither Heidegger nor the Cartesian have been done any favours by commentators showing little inclination to bring the opponents into closer combat. This paper attempts to correct that omission. (shrink)

The problem of Nishida Kitaro's historical philosophy and an introduction to the psychedelic paradigm -- The Zen nexus between Nishida Kitaro and modern psychedelic experience -- Experience and the self: the early phase of Nishida's thought (1911-1931) -- Nishida Kitaro's historical world (1931-1945) -- A psychedelic paradigm of history -- Hallucinating the end of history: reflections on myth, the eschaton and the problem of overcoming modernity.

Hallucination: the perception of an impossible image. That which can never appear suddenly does so anyways - a private world that appears only to the eye of the one imagining it... until now. Ted Serios, psychic photographer, claimed he could project images directly from his mind onto photographic film. Under the sign of the psychic photograph, “Hallucinating Ted Serios” is a theorization of the dominant forms of uncertainty that persist in postmodern evaluations of representation, interpretation and identity. The central thesis (...) of this paper is that the imaginary and the real have collapsed into the spectral hallucination of one another, rendering impossible the rhetorical separation of hallucination from image. With the collapse of the boundary between the fictive and the real, the world of representation becomes intelligible only as an imaginary phenomenon; with the collapse between the object and the observer, interpretation is rendered deceptively magical; and, with the collapse between the self and its anonymous double, identity itself is relegated to a state of impossibility. Consequently, under the persisting signs of the imaginary, the magical and the impossible, “Hallucinating Ted Serios” asserts that in our contemporary world there no longer exists the possibility of failed performativity – psychic, imaginary or otherwise. (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)

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)

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)