Exploring rationality in schizophrenia

Self-disorder explained: Yasunaga's "Phantom Space Theory" on schizophrenia

The present article revisits the theoretical model of schizophrenia by Hiroshi YASUNAGA (1929-2011). Yasunaga restated ego disturbance in schizophrenia as the "Pattern Reversal" between selfhood and otherness, based on British philosopher Wauchope's concept of "pattern." This concept is meant as asymmetrical relatedness (A/B) within a pair of concepts, such as life and death, quality and quantity, and self and other, prioritizing the former (A side) over the latter (B side). When applied to the pair of self and other, the pattern is vital for human experiences, and its disruption fundamentally alters every lived experience. Subsequently, Yasunaga extended the theory of pattern and invented his original "Phantom Space Theory," in which he postulated "Phantom Space," an experiential space that constitutes system a (A-side-led and consciously determined distance) and system a' (B-side-dominated and extra-consciously given distance). He then constructed a kind of neural system model composed of systems a and a', and thereby schematically presented a novel viewpoint on experiences of self and the outside world. The theory further illustrated how the hypothesized imbalance (Phantom Space shrinkage or diminished elasticity of system a') causes symptoms of schizophrenia, such as ego disturbances, auditory hallucinations, and other unspecific symptoms. This article then examines the clinical and theoretical implications of Yasunaga's psychiatric works. Phantom Space Theory is a non-stigmatizing account of schizophrenia because it does not presuppose personal or existential causes of psychosis. The relationship between Phantom Space Theory and dual-process theory is also explored.

Deficits in Analytic and Common-Sense Reasoning in Schizophrenia

ABSTRACT

Human rationality has a dual nature including analytic and common-sense thinking. Symptoms of schizophrenia have been suggested to be related to deficits in these aspects of logical reasoning. However, empirical studies investigating logical reasoning errors in schizophrenia and their clinical and neurocognitive correlates are scarce. Formal thought disorder and theory of mind (ToM) might be particularly important for understanding logical reasoning errors in schizophrenia. The current study compared the performances of 80 patients with schizophrenia with those of 49 healthy controls on syllogistic and counterfactual reasoning tasks and investigated clinical, neuropsychological, and social cognitive correlates of logical reasoning in schizophrenia. Patients with schizophrenia were impaired in both analytic and common-sense thinking. ToM impairment was a significant predictor of analytic reasoning abilities in schizophrenia. Executive functions and verbal memory were also significantly associated with analytic reasoning in schizophrenia. Further studies investigating logical reasoning errors in the early phases of the illness are needed.

Delusions beyond beliefs: a critical overview of diagnostic, aetiological, and therapeutic schizophrenia research from a clinical-phenomenological perspective

Delusions are commonly conceived as false beliefs that are held with certainty and which cannot be corrected. This conception of delusion has been influential throughout the history of psychiatry and continues to inform how delusions are approached in clinical practice and in contemporary schizophrenia research. It is reflected in the full psychosis continuum model, guides psychological and neurocognitive accounts of the formation and maintenance of delusions, and it substantially determines how delusions are approached in cognitive-behavioural treatment. In this Review, we draw on a clinical-phenomenological framework to offer an alternative account of delusion that incorporates the experiential dimension of delusion, emphasising how specific alterations to self-consciousness and reality experience underlie delusions that are considered characteristic of schizophrenia. Against that backdrop, we critically reconsider the current research areas, highlighting empirical and conceptual issues in contemporary delusion research, which appear to largely derive from an insufficient consideration of the experiential dimension of delusions. Finally, we suggest how the alternative phenomenological approach towards delusion could offer new ways to advance current research and clinical practice.

Exploring social cognition in schizophrenia

The aim of the study was to compare social cognition between groups of patients diagnosed with schizophrenia and healthy controls and to replicate two previous studies using tests of social cognition that may be particularly sensitive to social cognitive deficits in schizophrenia. Thirty-eight first-admitted patients with schizophrenia and 38 healthy controls solved 11 "imaginary conversation (i.e., theory of mind)" items, 10 "psychological understanding" items, and 10 "practical understanding" items. Statistical tests were made of unadjusted and adjusted group differences in models adjusting for intelligence and neuropsychological test performance. Healthy controls performed better than patients on all types of social cognitive tests, particularly on "psychological understanding." However, after adjusting for intelligence and neuropsychological test performance, all group differences became nonsignificant. When intelligence and global cognitive functioning is taken into account, schizophrenia patients and healthy controls perform similarly on social cognitive tests.