Schizotypy,cognitive performance,and genetic risk for schizophrenia in a non-clinical population

Schizophrenia risk alleles are expected to mediate effects on cognitive task performance, and aspects of personality including schizotypy, in nonclinical populations. We investigated how 32 of the best-validated schizophrenia risk alleles, singly and as summed genetic risk, were related to measures of schizotypal personality and measures of two aspects of cognitive performance, verbal skills (vocabulary) and visual-spatial skills (mental rotation), in healthy individuals. Summed genetic risk score was not associated with levels of total schizotypy or its three main subscales. Similarly, genotypic variation at none of the individual risk loci was related to cognitive performance measures, after correction for multiple tests. Higher overall genetic risk score was, however, associated with lower performance on the mental rotation test in males, with a broad set of loci contributing to this effect. These results imply that there is a lack of linear, genetically-based continuity connecting schizotypal cognition with the expression of schizophrenia itself, and indicate that, for males, higher genetic risk of schizophrenia exerts negative effects on visual-spatial skills, as measured by mental rotation.     

Chapter 4. The Intervention Process

Abstract

The qualitative research methods used by the author to study one parent-child activity group are shared. This qualitative research study documented what the participants of a parent-child activity group on a child psychiatric inpatient unit reported about their experiences with each other and how these participants interacted with each other in the group over the course of eight months. The group was studied through     

Learning from women with psychosis

The article describes psychoanalytic reflections in the work of a consultant psychiatrist responsible for a recently developed female intensive care unit. The manifestations of aggression were observed to be different from that of male patients. The behavioural manifestation of aggression by women was linked to the themes of secrets, and of hidden aggression, which are described in the analytic literature as feminine characteristics. The relationships between women as sibling inpatients and with female staff may explain some of the difficulties in managing aggression. Hidden aggression in the dyad of female-to-female transferences and countertransference may contribute to problems in all female inpatient settings. Bringing together the themes of psychosis and of women from a psychoanalytic perspective, the author suggests that the care pathway leading to transfer to the intensive care unit may exacerbate psychotic symptoms in acute states, due to specific vulnerabilities of women. The provision of specialized inpatient services for women may be more therapeutic if female development and the nature of their relationships were better understood.     

Functional connectivity abnormalities during contextual processing in schizophrenia and in Parkinson’s disease

Functional connectivity was evaluated in patients with schizophrenia (SC) and in patients with Parkinson’s disease (PD) during the performance of a local contextual processing paradigm, to investigate the proposition that functional disconnection is involved with contextual processing deficits in these populations. To this end, we utilized event-related EEG signals, synchronization likelihood and graph theoretical analysis. Local context was defined as the occurrence of a predictive sequence of stimuli before the presentation of a target event. In the SC patients, we observed a decrease in path length (L) in the beta band, for the predictive sequence and for predicted and random targets, compared with controls. These abnormalities were associated with weaker frontal-temporal-parietal connections. In the PD patients we found longer L (theta band) for predicted targets, and higher cluster coefficients for both the predictive sequence (theta band) and predicted targets (alpha and theta bands), compared with controls. Detection of predicted targets was associated with weaker frontal-parietal connections in PD. No group differences were found for randomized standard stimuli in both SC and PD patients. These findings provide evidence of task-specific functional connectivity abnormalities within frontal networks during local contextual processing.     

IntrospectionIntrospection and schizophrenia: A comparative investigation of anomalous self experiences

This paper offers a comparative investigation of anomalous self-experiences common in schizophrenia (defined in Examination of Anomalous Self Experiences (EASE) instrument) and those of normal individuals in an intensely introspective orientation (early 20th-century “introspectionist” psychology). The latter represent a relatively pure manifestation of certain forms of exaggerated self-consciousness (“hyperreflexivity”), one facet of the disturbance of core- or minimal-self (“ipseity” disturbance) 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.     

The intentionality bias and schizotypy

The “intentionality bias” refers to our automatic tendency to judge other people's actions to be intentional. In this experiment we extended research on this effect in two key ways. First, we developed a novel nonlinguistic task for assessing the intentionality bias. This task used video stimuli of ambiguous movements. Second, we investigated the relationship between the strength of this bias and schizotypy (schizophrenia-like symptoms in healthy individuals). Our results showed that the intentionality bias was replicated for the video stimuli and also that this bias is stronger in those individuals scoring higher on the schizotypy rating scales. Overall these findings lend further support for the existence of the intentionality bias. We also discuss the possible relevance of these findings for our understanding of certain symptoms of schizophrenic illness.     

Exploring self-defining memories in schizophrenia

Previous studies have shown that patients with schizophrenia are impaired in recalling specific events from their personal past. However, the relationship between autobiographical memory impairments and disturbance of the sense of identity in schizophrenia has not been investigated in detail. In this study the authors investigated schizophrenic patients’ ability to recall self-defining memories; that is, memories that play an important role in building and maintaining the self-concept. Results showed that patients recalled as many specific self-defining memories as healthy participants. However, patients with schizophrenia exhibited an abnormal reminiscence bump and reported different types of thematic content (i.e., they recalled less memories about past achievements and more memories regarding hospitalisation and stigmatisation of illness). Furthermore, the findings suggest that impairments in extracting meaning from personal memories could represent a core disturbance of autobiographical memory in patients with schizophrenia.     

Poly I:C母体免疫刺激诱导的子代精神分裂症神经发育动物模型研究

精神分裂症是一组病因未明的重性精神障碍,其病理生理学机制极其复杂,建立能够确切模拟精神分裂症的动物模型对于其发病机制的研究及抗精神分裂症药物的研发具有十分重要的意义。本文意在介绍产前母体免疫刺激（聚肌胞苷酸聚肌苷酸-聚胞苷酸,poly-I:C）诱导子代出现精神分裂症样的神经发育动物模型,以及该模型对精神分裂症的病因研究、生物学机制及其治疗和药物研发的重要意义。     

Perceptual hysteresis as a marker of perceptual inflexibility in schizophrenia

People with schizophrenia are known to exhibit difficulties in the updating of their current belief states even in the light of disconfirmatory evidence. In the present study we tested the hypothesis that people with schizophrenia could also manifest perceptual inflexibility, or difficulties in the updating of their current sensory states. The presence of perceptual inflexibility might contribute both to the patients’ altered perception of reality and the formation of some delusions as well as to their social cognition deficits. Here, we addressed this issue with a protocol of auditory hysteresis, a direct measure of sensory persistence, on a population of stabilized antipsychotic-treated schizophrenia patients and a sample of control subjects. Trials consisted of emotional signals (i.e., screams) and neutral signals (i.e., spectrally-rotated versions of the emotional stimuli) progressively emerging from white noise – Ascending Sequences – or progressively fading away in white noise – Descending Sequences. Results showed that patients presented significantly stronger hysteresis effects than control subjects, as evidenced by a higher rate of perceptual reports in Descending Sequences. The present study thus provides direct evidence of perceptual inflexibility in schizophrenia.     

If waking and dreaming consciousness became de-differentiated, would schizophrenia result?

If both waking and dreaming consciousness are functional, their de-differentiation would be doubly detrimental. Differentiation between waking and dreaming is achieved through neuromodulation. During dreaming, without external sensory data and with mesolimbic dopaminergic input, hyper-cholinergic input almost totally suppresses the aminergic system. During waking, with sensory gates open, aminergic modulation inhibits cholinergic and mesocortical dopaminergic suppresses mesolimbic. These neuromodulatory systems are reciprocally interactive and self-organizing. As a consequence of neuromodulatory reciprocity, phenomenologically, the self and the world that appear during dreaming differ from those that emerge during waking. As a result of self-organizing, the self and the world in both states are integrated.Some loss of self-organization would precipitate a degree of de-differentiation between waking and dreaming, resulting in a hybrid state which would be expressed heterogeneously, both neurobiologically and phenomenologically. As a consequence of progressive de-differentiation, certain identifiable psychiatric disorders may emerge. Ultimately, schizophrenia, a disorganized-fragmented self, may result.