Does hallucination affect vigilance performance in schizophrenia? An exploratory study.
01 Sep 2011-Asian Journal of Psychiatry (Asian J Psychiatr)-Vol. 4, Iss: 3, pp 196-202
TL;DR: Results revealed that schizophrenia patients are deficient as compared to their healthy counterparts in the ability to focus on a specific target while inhibiting non-relevant information across all conditions.
Abstract: The present study investigates the role of "auditory verbal hallucination" (AVH) in the attentional processes of individuals diagnosed with schizophrenia compared with healthy participants. The sample consisted of 26 participants diagnosed with schizophrenia divided into - "schizophrenia with hallucination" (N=12) and "schizophrenia without hallucination" (N=14). 13 matched healthy participants were taken. A general health questionnaire was used to screen out psychiatric morbidity in healthy participants. The presence and/or absence of AVH were substantiated through the administration of the Positive and Negative Syndrome Scale (PANSS). Only individuals having higher composite scores in the positive scale were included. Edinburgh Handedness Inventory was administered to all participants. Software designed to measure vigilance was used to assess attentional deficits in the three groups included in the study. The complexity of the "vigilance task" was varied across three parameters: (1) spatial position of the target stimulus and buffer, (2) frequency of the target stimulus and buffer and (3) colour of target stimulus and buffer. The performances of the 3 groups were compared statistically in terms of Hit, Miss and False Alarm scores. Results revealed that schizophrenia patients are deficient as compared to their healthy counterparts in the ability to focus on a specific target while inhibiting non-relevant information across all conditions. Also, schizophrenia patients who have AVH are relatively more deficient as compared to the schizophrenia patients without AVH. It can be concluded that perceptual abnormality in schizophrenia patients with hallucination has an additional negative impact on attentional processes.
01 Jan 2014
TL;DR: There are large similarities in disturbances in selective attention between TBI and schizophrenia, yet, whenever similar, these disturbances are of different degrees and there are some qualitative differences between the two pathologies.
TL;DR: In this paper, the authors compared performance of patients with TBI and schizophrenia in a task of selective attention and found that both groups had different levels of attentional processing speed, reduced target processing efficiency, instant attentional overload, and difficulties in discriminating targets from distractors.
Abstract: There are hypotheses that traumatic brain injury (TBI) and schizophrenia might exhibit similar patterns of cognitive disorders in attention, executive function and memory. Yet, empirical studies comparing directly the two populations are extremely rare. The aim of this exploratory study was to compare performance of patients with TBI and schizophrenia in a task of selective attention. A group of TBI patients ( n = 18), a group of patients with schizophrenia ( n = 21), and a control group with no history of neurologic or psychiatric illness ( n = 31) participated in this study. A paced paper-and-pencil cancellation task was completed by each participant, allowing for discrimination between intact and impaired attention subcomponents. Compared to the controls, both patient groups had (a) slower processing speed, (b) reduced target processing efficiency, (c) instant attentional overload, and (d) difficulties in discriminating targets from distractors. However, these deficits were of different degrees between the groups. Furthermore, (e) a marked selective impairment of processing of distractors was observed in patients with schizophrenia only, as well as (f) a failure to regulate attentional resources over time. Finally, (g) none of the groups showed any shifts in response strategies. These results suggest that there are large similarities in disturbances in selective attention between these two pathologies. Yet, whenever similar, these disturbances are of different degrees. Furthermore, there are some qualitative differences between the two pathologies.
TL;DR: Review of five studies involving the PANSS provided evidence of its criterion-related validity with antecedent, genealogical, and concurrent measures, its predictive validity, its drug sensitivity, and its utility for both typological and dimensional assessment.
Abstract: The variable results of positive-negative research with schizophrenics underscore the importance of well-characterized, standardized measurement techniques. We report on the development and initial standardization of the Positive and Negative Syndrome Scale (PANSS) for typological and dimensional assessment. Based on two established psychiatric rating systems, the 30-item PANSS was conceived as an operationalized, drug-sensitive instrument that provides balanced representation of positive and negative symptoms and gauges their relationship to one another and to global psychopathology. It thus constitutes four scales measuring positive and negative syndromes, their differential, and general severity of illness. Study of 101 schizophrenics found the four scales to be normally distributed and supported their reliability and stability. Positive and negative scores were inversely correlated once their common association with general psychopathology was extracted, suggesting that they represent mutually exclusive constructs. Review of five studies involving the PANSS provided evidence of its criterion-related validity with antecedent, genealogical, and concurrent measures, its predictive validity, its drug sensitivity, and its utility for both typological and dimensional assessment.
01 Jun 1968
TL;DR: It's coming again, the new collection that this site has; the favorite dementia praecox or the group of schizophrenias monograph series on schizophrenia no 1 book is offered today.
Abstract: It's coming again, the new collection that this site has. To complete your curiosity, we offer the favorite dementia praecox or the group of schizophrenias monograph series on schizophrenia no 1 book as the choice today. This is a book that will show you even new to old thing. Forget it; it will be right for you. Well, when you are really dying of dementia praecox or the group of schizophrenias monograph series on schizophrenia no 1, just pick it. You know, this book is always making the fans to be dizzy if not to find.
TL;DR: A new theory of search and visual attention is presented, which accounts for harmful effects of nontargets resembling any possible target, the importance of local nontarget grouping, and many other findings.
Abstract: A new theory of search and visual attention is presented. Results support neither a distinction between serial and parallel search nor between search for features and conjunctions. For all search materials, instead, difficulty increases with increased similarity of targets to nontargets and decreasedsimilarity between nontargets, producing a continuum of search efficiency. A parallel stage of perceptual grouping and description is followed by competitive interaction between inputs, guiding selective access to awareness and action. An input gains weight to the extent that it matches an internal description of that information needed in current behavior (hence the effect of targetnontarget similarity). Perceptual grouping encourages input weights to change together (allowing "spreading suppression" of similar nontargets). The theory accounts for harmful effects of nontargets resembling any possible target, the importance of local nontarget grouping, and many other findings.
TL;DR: The amplitude of the P300 component is controlled multiplicatively by the subjective probability and task relevance of eliciting events, whereas its latency depends on the duration of stimulus evaluation as mentioned in this paper.
Abstract: To understand the endogenous components of the event-related brain potential (ERP), we must use data about the components' antecedent conditions to form hypotheses about the information-processing function of the underlying brain activity These hypotheses, in turn, generate testable predictions about the consequences of the component We review the application of this approach to the analysis of the P300 component The amplitude of the P300 is controlled multiplicatively by the subjective probability and the task relevance of the eliciting events, whereas its latency depends on the duration of stimulus evaluation These and other factors suggest that the P300 is a manifestation of activity occurring whenever one's model of the environment must be revised Tests of three predictions based on this “context updating” model are reviewed Verleger's critique is based on a misconstrual of the model as well as a partial and misleading reading of the relevant literature
01 Jan 2002
TL;DR: "Dementia Praecox and Paraphrenia" (1919) was the book in which Kraepelin first presented his work on schizophrenia to the English-speaking world, and it was probably the most influential psychiatric text of the entire 20th century, and has now become rare.
Abstract: The German psychiatrist Emil Kraepelin (1856 - 1926) is justly called "the father of modern psychiatry". He was the first to identify dementia praecox (schizophrenia) and manic-depression, and he pioneered the use of drugs to treat mental illness. He was also joint discoverer of Alzheimer's disease - which he named after his collaborator, Dr Alois Alzheimer. Kraepelin presented these and other discoveries in successive editions of his "Psychiatrie: Ein Lehrbuch" (definitive 8th edition also now available from Thoemmes Press). Much of this gigantic textbook can only be read in the original German; but parts of it were translated into English, and they had a very profound influence on the development of world psychiatry for the rest of the 20th century. Although Bleuler's name for the disease "schizophrenia" came to replace Kraepelin's term, Kraepelin's general description of the syndrome and division of it into subforms such as hebephrenia and catatonia has persisted. He succeeded in tying together into a single recognizable diagnostic category a disparate array of symptoms that, before Kraepelin, had not been seen as cohering. Despite myriad later refinements, Kraepelin's description of the syndrome is still the classic presentation; it very much lives on in the "Diagnostic and Statistical Manual" used by present-day psychiatrists. "Dementia Praecox and Paraphrenia" (1919) was the book in which Kraepelin first presented his work on schizophrenia to the English-speaking world. It was probably the most influential psychiatric text of the entire 20th century, and has now become rare. Thoemmes Press is pleased to make this facsimile of the first edition available as a single volume.