This paper considers the way mathematical and computational models are used in network neuroscience to deliver mechanistic explanations. Two case studies are considered: Recent work on klinotaxis by Caenorhabditis elegans, and a longstanding research effort on the network basis of schizophrenia in humans. These case studies illustrate the various ways in which network, simulation and dynamical models contribute to the aim of representing and understanding network mechanisms in the brain, and thus, of delivering mechanistic explanations. After outlining this mechanistic construal (...) of network neuroscience, two concerns are addressed. In response to the concern that functional network models are non-explanatory, it is argued that functional network models are in fact explanatory mechanism sketches. In response to the concern that models which emphasize a network’s organization over its composition do not explain mechanistically, it is argued that this emphasis is both appropriate and consistent with the principles of mechanistic explanation. What emerges is an improved understanding of the ways in which mathematical and computational models are deployed in network neuroscience, as well as an improved conception of mechanistic explanation in general. (shrink)

The target article sketched and explored a mechanism (action-oriented predictive processing) most plausibly associated with core forms of cortical processing. In assessing the attractions and pitfalls of the proposal we should keep that element distinct from larger, though interlocking, issues concerning the nature of adaptive organization in general.

Schizophrenia is a worldwide, prevalent disorder with a multifactorial but highly genetic aetiology. A constant prevalence rate in the face of reduced fecundity has caused some to argue that an evolutionary advantage exists in unaffected relatives. Here, I critique this adaptationist approach, and review – and find wanting – Crow's “speciation” hypothesis. In keeping with available biological and psychological evidence, I propose an alternative theory of the origins of this disorder. Schizophrenia is a disorder of the social brain, and it (...) exists as a costly trade-off in the evolution of complex social cognition. Paleoanthropological and comparative primate research suggests that hominids evolved complex cortical interconnectivity (in particular, frontotemporal and frontoparietal circuits) to regulate social cognition and the intellectual demands of group living. I suggest that the ontogenetic mechanism underlying this cerebral adaptation was sequential hypermorphosis and that it rendered the hominid brain vulnerable to genetic and environmental insults. I argue that changes in genes regulating the timing of neurodevelopment occurred prior to the migration of Homo sapiens out of Africa 100,000–150,000 years ago, giving rise to the schizotypal spectrum. While some individuals within this spectrum may have exhibited unusual creativity and iconoclasm, this phenotype was not necessarily adaptive in reproductive terms. However, because the disorder shared a common genetic basis with the evolving circuitry of the social brain, it persisted. Thus schizophrenia emerged as a costly trade-off in the evolution of complex social cognition. Key Words: cortical connectivity; evolution; heterochrony; metarepresentation; primates; psychiatry; schizophrenia; social brain; social cognition. (shrink)

In this paper, we use a phenomenological approach to compare the unusual ways in which language can be experienced by individuals with schizophrenia or severe mood disorders, specifically mania and melancholia. Our discussion follows a tripartite/dialectical format: first we describe traditionally observed distinctions ; then we consider some apparent similarities in the experience of language in these conditions. Finally, we explore more subtle, qualitative differences. These involve: 1, interpersonal orientation, 2, forms of attention and context-relevance, 3, underlying mutations of experience, (...) and 4, meta-attitudes toward language. Such distinctions appear to reflect significant differences in underlying forms of subjectivity; they are broadly consistent with work in phenomenological psychopathology on other aspects of experience, including body, self, and social world. An understanding of such distinctions may assist with difficult cases of differential diagnosis, while also contributing to a better understanding of suffering persons and of psychological factors underlying their disorders. (shrink)

In this paper I discuss an intriguing and relatively little studied symptomatic expression of schizophrenia known as experiences of activity in which patients form the delusion that they can control some external events by the sole means of their mind. I argue that experiences of activity result from patients being prone to aberrantly infer causal relations between unrelated events in a retrospective way owing to widespread predictive deficits. Moreover, I suggest that such deficits may, in addition, lead to an aberrant (...) intentional binding effect i.e., the subjective compression of the temporal interval between an intentional action and its external effects. In particular, it might be that patient’s thoughts are bound to the external events they aimed to control producing, arguably, a temporal contiguity between these two components. Such temporal contiguity would reinforce or sustain the feeling that the patient mind is directly causally efficient. (shrink)

Life is preserved and enhanced by coordinated selectivity in local neural circuits. Narrow receptive-field selectivity is necessary to avoid the curse-of-dimensionality, but local activities can be made coherent and relevant by guiding learning and processing using broad coordinating contextual gain-controlling interactions. Better understanding of the functions and mechanisms of those interactions is therefore crucial to the issues Clark examines.

This paper offers a comparative investigation of anomalous self-experiences common in schizophrenia instrument) and those of normal individuals in an intensely introspective orientation. The latter represent a relatively pure manifestation of certain forms of exaggerated self-consciousness, one facet of the disturbance of core- or minimal-self postulated as central in schizophrenia. Significant similarities with schizophrenia-like experience were found but important differences also emerged. Affinities included feelings of passivity, fading of self or world, and alienation from thoughts, feelings, or lived-body. Differences involved (...) confusion between self and world and severe dislocation or erosion of first-person perspective, qualities unique to schizophrenia. The purpose is threefold: 1, place the putatively schizophrenic experiences of self-disorder in a broader, comparative context; 2, evaluate hypotheses concerning core processes in schizophrenia; 3, orient investigation of possible pathogenetic pathways as well as psychotherapeutic interventions. (shrink)

Here we consider interpersonal experience in schizophrenia, melancholia, and mania. Our goal is to improve understanding of similarities and differences in how other people can be experienced in these disorders, through a review of first-person accounts and case examples and of contemporary and classic literature on the phenomenology of these disorders. We adopt a tripartite/dialectical structure: first we explore main differences as traditionally described; next we consider how the disorders may resemble each other; finally we discuss more subtle but perhaps (...) foundational ways in which the phenomenology of these disorders may nonetheless be differentiated. These involve disruptions of common sense and conventionality, abnormalities of empathy, distinct forms of paranoia and the sense of personal centrality, and altered perceptions of intentionality, deadness, and artificiality. We end by considering some neurocognitive research relevant to these abnormal forms of subjectivity, including work on theory of mind, experience of human movement, and perception of faces. (shrink)

We argue that thought insertion primarily involves a disruption of the sense of ownership for thoughts and that the lack of a sense of agency is but a consequence of this disruption. We defend the hypothesis that this disruption of the sense of ownership stems from a fail- ure in the online integration of the contextual information related to a thought, in partic- ular contextual information concerning the different causal factors that may be implicated in their production. Loss of unity (...) of consciousness, manifested by incoherent subjective experiences is a general phenomenal characteristic of schizophrenia. This loss of coherence has been hypothesized to reflect a generalized deficit of contextual information integration not conveyed by, but related to, a target event. This deficit is manifested across many cog- nitive domains. We argue that it is also manifested in the process of thinking itself, result- ing in causally decontextualized thoughts that are experienced as inserted thoughts. (shrink)

This paper considers contradictory features of emotional or affective experience and expression in schizophrenia in light of the “Kretschmerian paradox”—the fact that schizophrenia-spectrum patients can simultaneously experience both exaggerated and diminished levels of affective response. An attempt is made to explain the paradox and explore its implications. Recent research on emotion in schizophrenia is reviewed, including subjective reports, psychophysiological measures of arousal or activation, and behavioural measures, focusing on flat-affect and negative-symptom patients. After discussing relevant concepts and vocabulary of emotion (...) (“affect”, “emotion”, “mood”, “feelings”, the “passions”), the need for a phenomenological approach focusing on subjective experience is proposed. Four modes of nonparanoid experience in schizophrenia are discussed: Bodily Alienation, Disengagement, Unworlding, and Subjectivisation. Each mode involves withdrawal from functional contexts—temporal, practical, and interpersonal—normally associated with emotional reactivity and expression; each may be accompanied by forms of non-emotional affectivity no less intense than the emotions they replace. Possible relationships between psychophysiological measures, expressive behaviour, and subjective emotional or affective response are considered. (shrink)

This paper offers a biosemiotic account of the poetic aspects of gesture and speech in schizophrenia. The argument is that speech and gesture are not the mere expression of pre-verbal thoughts. Instead, meaning is enacted by the temporal and semantic coordination of speech and gesture. The bodily basis of language is highlighted by the fact that, failing to create language that is organized around topics, individuals with schizophrenia often rely on poetic associations in directing their utterances. Accordingly, the analysis of (...) schizophrenic speech and gesture based on McNeill’s Growth Point theory is enriched with reference to both Cowley’s (2007b) views on language as distributed social coordination, and Alexander’s (Biosemiotics 2(1):77–100, 2009) description of formal causes in nature. Schizophrenic language can be seen as a hypertrophied manifestation of the discourse-scaffolding function of poetic associations in speech and gesture. The analysis of schizophrenic language shows that language behavior need not be built on pre-verbal thoughts and important aspects of schizophrenic language, such as metalinguistic awareness and semiotic agency, can be clarified by applying concepts from biosemiotics. (shrink)