Neuropsychological impairments in schizophrenia: Integration of performance-based and brain imaging findings.

[Correction Notice: An erratum for this article was reported in Vol 134(3) of Psychological Bulletin (see record 2008-04614-006). In the article "Neuropsychological Impairments in Schizophrenia: Integration of Performance-Based and Brain Imaging Findings," by Abraham Reichenberg and Philip D. Harvey (Psychological Bulletin, 2007, Vol. 133, No. 5, pp. 833-858), on page 837, right column, first paragraph; in Table 1 (p. 835); and in Table 2 (p. 843), the word perseverations was misspelled as preservations. In addition, on page 846, left column, third paragraph, the last word in the sentence was incorrect. The correct word should be hyperactivation.] Until recently, the dominant view was that schizophrenia patients have limited, if any, neuropsychological impairments, and those that are observed are only secondary to the florid symptoms of the disorder. This view has dramatically changed. This review integrates recent evidence demonstrating the severity and profile of neuropsychological impairments in schizophrenia. We present quantitative evaluation of the literature demonstrating that the most severe impairments are apparent in episodic memory and executive control processes, evident on a background of a generalized cognitive deficit. The neuropsychological impairments potentially represent genetic liability to the disorder, as similar, yet milder, impairments are evident in schizophrenia patients even before the onset of psychotic symptoms, as well as in the nonpsychotic relatives of schizophrenia patients. Corresponding cognitive neuroimaging literature on executive functions, episodic memory, and working memory in schizophrenia documenting abnormalities in frontal and medial temporal lobes is summarized, and current models integrating neuropsychological and neuroimaging data are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological disturbance in schizophrenia: A diffusion tensor imaging study.

Patients with schizophrenia and healthy control subjects underwent both neuropsychological evaluation and magnetic resonance diffusion tensor imaging, during which the cingulum bundle (CB) and the uncinate fasciculus (UF) were defined with fiber tractography and their integrity was quantified. On the basis of prior findings, it was hypothesized that neuropsychological disturbance in schizophrenia may be characterized, in part, by 2 dissociable functional neuroanatomical relationships: (a) executive functioning-CB integrity and (b) episodic memory-UF integrity. In support of the hypothesis, hierarchical regression results indicated that reduced white matter of the CB and the UF differentially and specifically predicted deficits in executive functioning and memory, respectively. Neuropsychological correlates of the CB also extended to lower generalized intelligence, as well as to reduced visual memory that may be related to failures of contextual monitoring of to-be-remembered scenes. Reduced white matter of the CB and the UF may each make distinct contributions to neuropsychological disturbance in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological differences among empirically derived clinical subtypes of schizophrenia.

Neuropsychological profile differences between empirically derived clinical subtypes of schizophrenia were examined. Two hundred five patients and 209 demographically matched controls were administered a neuropsychological battery examining 8 domains. Subtypes included negative, disorganized, paranoid, Schneiderian, and mild. All subtypes displayed a neuropsychological profile of generalized impairment with greater deficits in learning, memory, and attention. Results were suggestive of diffuse cognitive dysfunction in schizophrenia with more severe deficits in learning and memory relative to executive skills. This pattern of greater learning and memory impairment was pronounced for disorganized patients. In contrast, paranoid patients outperformed disorganized and negative patients in several domains. These findings reflect bilateral frontal–temporal dysfunction, particularly in disorganized and negative patients. Subtype differences highlight the importance of conceptualizing schizophrenia as a multifocal disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive impairments associated with formal thought disorder in people with schizophrenia.

Formal thought disorder (FTD), or disorganized speech, is one of the central signs of schizophrenia. Despite extensive research, the cognitive processes associated with FTD are still unclear. However, the authors' review of FTD theories and research indicates that considerable progress has been made in identifying possible cognitive impairments associated with FTD. Specifically, FTD is strongly associated with impaired executive functioning and with impaired processing of semantic information. Their review indicates that previous research has not yet supported an association between FTD and either an increase in spreading activation or an impairment within the language production system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological impairment in patients with schizophrenia and evidence of hyponatremia and polydipsia.

Patients with schizophrenia and water imbalance may represent a subset of patients with distinct pathophysiological abnormalities and susceptibility to cognitive impairment. Specifically, patients with polydipsia and hyponatremia have been shown to have smaller anterior hippocampal volumes, which are also associated with various impairments in neuroendocrine function. To determine whether abnormalities in patients with water imbalance extend to the cognitive realm, the present study evaluated neuropsychological functioning in three groups of patients with schizophrenia: polydipsic hyponatremic, polydipsic normonatremic, and nonpolydipsic normonatremic. Participants were administered cognitive tests assessing intelligence, attention, learning/memory (verbal, nonverbal, emotional), and facial discrimination. Hyponatremic patients showed poorer overall neuropsychological functioning relative to all other patients, and polydipsic normonatremic patients performed intermediate to the other two groups. Results indicate that patients with schizophrenia and polydipsia, and particularly those with hyponatremia, show prominent cognitive deficits relative to patients without water imbalance. The clinical, neuroendocrine, and cognitive abnormalities in these patients may arise from pathology within the anterior hippocampus and associated prefrontal/limbic brain regions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive impairments in the STOP null mouse model of schizophrenia.

Cognitive dysfunction is a primary and persisting core deficit of schizophrenia that is marginally improved by antipsychotic treatment. Adult mice that lack the stable tubule-only polypeptide (STOP) have neurochemical and behavioral abnormalities that model some features of schizophrenia. Recognition and long-term memory in the STOP null mouse were tested with the novel object recognition task and an olfactory discrimination task, respectively. Researchers examined the brains from STOP null mice to determine whether differences in task performance were associated with alterations in brain morphology. STOP null mice displayed deficits in both recognition and long-term memory. These behavioral deficits were accompanied by a massive enlargement of the cerebral ventricular system as well as by reductions in volume of cortical and diencephalic structures. In addition to deficits in recognition and long-term memory, STOP null mice displayed exaggerated neuroanatomical deficits somewhat reminiscent of those observed among individuals with schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Neuropsychological Interventions: Clinical Research and Practice.

Reviews the book, Neuropsychological Interventions: Clinical Research and Practice by Paul J. Eslinger (Ed.) (2005). The pessimistic assumption that the mature human brain lacks any physiological mechanism to support recovery of function beyond that attending the dissipation of diathesis is now thankfully relegated to the (recent) past. Advances in neuroimaging have provided striking evidence of the brain's capacity for functional reorganization, and fueled interest in rehabilitation treatments that may facilitate this process. This book addresses an important facet of this rapidly evolving field, the link between clinical research and practice. The basic science underpinning our emerging appreciation of the brain's plasticity is avowedly not the focus of this volume but is tied with varying degrees of success to the treatment strategies covered. The book contains 14 chapters organized into three parts covering Foundations of Neuropsychological Impairments, Models of Interventions for (specific) Neuropsychological Impairments, and Future Directions, respectively. The reviewer suggests that this is a book that should occupy the most accessible part of the bookshelf of those who work with or have an interest in patients with neuropsychological deficits. It is a concise, thoughtful, well researched, and authoritative resource that can be strongly recommended as a core text for graduate-level rehabilitation psychology courses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Workshops in Neuropsychological Assessment.

A past issue of Professional Psychology (February 1982) dealt with peer review and quality assurance. These issues are of particular interest to clinical neuropsychology, as evidenced by several articles in Professional Psychology. Over the past 5 years, clinical neuropsychology has rapidly emerged as an important diagnostic and treatment specialty within psychology. Unfortunately, from the standpoint of peer review and quality assurance, this growth has not been appropriately governed. The intention of writing this letter is to bring attention to this particular problem. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological Correlates of Diffusion Tensor Imaging in Schizophrenia.

Patients with schizophrenia (n = 41) and healthy comparison participants (n = 46) completed neuropsychological measures of intelligence, memory, and executive function. A subset of each group also completed magnetic resonance diffusion tensor imaging (DTI) studies (fractional anisotropy and cross-sectional area) of the uncinate fasciculus (UF) and cingulate bundle (CB). Patients with schizophrenia showed reduced levels of functioning across all neuropsychological measures. In addition, selective neuropsychological-DTI relationships emerged. Among patients but not controls, lower levels of declarative-episodic verbal memory correlated with reduced left UF, whereas executive function errors related to performance monitoring correlated with reduced left CB. The data suggested abnormal DTI patterns linking declarative-episodic verbal memory deficits to the left UF and executive function deficits to the left CB among patients with schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological impairments after spinal cord injury: A comparative study with mild traumatic brain injury.

Objective: To determine if individuals with mild traumatic brain injury (MTBI) perform differently on neuropsychological measures than individuals with spinal cord injury (SCI) having no loss of consciousness. Design and Participants: Data were collected prospectively on 33 matched pairs of individuals with SCI or MTBI. Independent t tests were performed to identify differences between the SCI and MTBI groups. Results: Although those with SCI generally outperformed individuals with MTBI, no meaningful between-groups differences were noted on 5 of the 10 neuropsychological tests administered. Greater than 40% of the SCI patients were identified as having impairments in processing speed, motor speed, and verbal learning. Conclusions: Treatment planning after SCI should include procedures to identify cognitive deficits that may complicate adjustment to disability and delay acquisition of new skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Building up linguistic context in schizophrenia: Evidence from self-paced reading.

An impairment in the build-up and use of context has been proposed as a core feature of schizophrenia. The current study tested the hypothesis that schizophrenia patients show impairments in building up context within sentences because of abnormalities in combining semantic with syntactic information. Schizophrenia patients and healthy controls read and made acceptability judgments about sentences containing verbs that were semantically associated with individual preceding words but that violated either the meaning (animacy/semantic constraints) or the syntactic structure (morphosyntactic constraints) of their preceding contexts. To override these semantic associations and determine that such sentences are unacceptable, participants must integrate semantic with syntactic information. These sentences were compared with congruous and pragmatically/semantically violated sentences that imposed fewer semantic-syntactic integration demands. At sentence-final words and decisions, patients showed smaller reaction time differences than controls to animacy/semantically violated or morphosyntactically violated sentences relative to pragmatically/semantically violated or nonviolated sentences. The relative insensitivity to these violations in patients with schizophrenia may arise from impairments in combining semantic and syntactic information to build up sentence context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual psychodynamic psychotherapy of schizophrenia: Empirical evidence for the practicing clinician.

Practicing psychodynamically oriented clinicians need empirical evidence to support the use of individual psychodynamic psychotherapy for the treatment of individuals with schizophrenia. The purpose of this article is to provide psychodynamically oriented clinicians with that needed empirical evidence. A review of the meta-analytic research on the use of individual psychodynamic psychotherapy was conducted. It is concluded that strong empirical support exists for the use of individual psychodynamic psychotherapy in the treatment of schizophrenia. In addition, several suggestions are made to help clinicians apply the meta-analytic evidence to their daily clinical work. Limitations of the available evidence are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychology and imaging.

Introduces this special of issue of Neuropsychology, the theme of which is Neuropsychology and Imaging. The question for neuropsychology is no longer how to locate the lesions, but, rather, how to consistently relate neuropsychological dysfunctionings with the image of the lesion. Both questions are easier to answer when lesions are better circumscribed. Answers are more difficult in the presence of multiple, diffuse, or subcortical lesions. In order to address the more difficult questions, this issue includes papers by Levin and High, Wilson et al., Wiednann et al., and Jernigan and Butters which are devoted to challenging clinical diseases (head injury, Alzheimer's, and Huntington's) where lesions and dysfunctionings are not consistently defined. Interestingly, some disease-related correlations emerge from these papers, and SPECT data are viewed as well. Correlating neuropsychological and imaging measurements is both unbounded and restrained. Papers in this special issue on Neuropsychology and Imaging highlight this, and the issues and concerns for future investigations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurocognition in first-episode schizophrenia: A meta-analytic review.

Compromised neurocognition is a core feature of schizophrenia. Following Heinrichs and Zakzanis’s (1998) seminal meta-analysis of middle-aged and predominantly chronic schizophrenia samples, the aim of this study is to provide a meta-analysis of neurocognitive findings from 47 studies of first-episode (FE) schizophrenia published through October 2007. The meta-analysis uses 43 separate samples of 2,204 FE patients with a mean age of 25.5 and 2,775 largely age- and gender-matched control participants. FE samples demonstrated medium-to-large impairments across 10 neurocognitive domains (mean effect sizes from ?0.64 to ?1.20). Findings indicate that impairments are reliably and broadly present by the FE, approach or match the degree of deficit shown in well-established illness, and are maximal in immediate verbal memory and processing speed. Larger IQ impairments in the FE compared to the premorbid period, but comparable to later phases of illness suggests deterioration between premorbid and FE phases followed by deficit stability at the group level. Considerable heterogeneity of effect sizes across studies, however, underscores variability in manifestations of the illness and a need for improved reporting of sample characteristics to support moderator variable analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Course of neurocognitive deficits in the prodrome and first episode of schizophrenia.

Understanding the trajectory of cognitive changes in the development of schizophrenia may shed light on the neurodevelopmental processes in the beginning stage of illness. Subjects at risk for psychosis (AR, n = 48), patients in their first episode of schizophrenia (FE, n = 20), and normal comparison subjects (n = 29) were assessed on a neurocognitive battery at baseline and at a 6-month follow-up. There were significant group differences across all cognitive domains as well as a significant group by time interaction in the verbal learning domain. After statistically controlling for practice effects and regression to the mean, a high proportion of FE subjects showed an improvement in verbal learning, and a significant number of AR subjects improved in general intelligence. Moreover, a higher than expected percentage of FE subjects, as well as AR subjects who later converted to psychosis, showed a deterioration in working memory and processing speed. These inconsistent trajectories suggest that some domains may improve with stabilization in the early stages of psychosis, whereas others may decline with progression of the illness, indicating possible targets for cognitive remediation strategies and candidate vulnerability markers for future psychosis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differentiating among prefrontal substrates in psychopathy: Neuropsychological test findings.

Frontal lobe and consequent executive dysfunction have long been related to psychopathy. More recently, there have been suggestions that specific regions of frontal cortex, rather than all of frontal cortex, may be implicated in psychopathy. To examine this issue, the authors presented 25 individuals with psychopathy and 30 comparison individuals with measures preferentially indexing the orbitofrontal cortex (OFC; object alternation task), dorsolateral prefrontal cortex (DLPFC; spatial alternation task), and anterior cingulate cortex (ACC; number-Stroop reading and counting tasks). The individuals with psychopathy showed significant impairment on the measure preferentially sensitive to OFC functioning. In contrast, the 2 groups did not show impairment on the measures preferentially sensitive to the functioning of the DLPFC or ACC. These results are interpreted with reference to executive dysfunction accounts of the disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies of brain dysfunction in schizophrenia.

The purpose of this paper is to bring to the attention of the psychologist the extensive research literature concerned with the physiological correlates of behavior. Research concerned with the electroencephalographic, histopathological, and biochemical analysis of schizophrenics receives concentrated attention. The review also includes "several psychological and physiological studies which focus specifically on the question of brain disorder in schizophrenia." The studies made within the last twenty to twenty-five years are included. 81-item bibliography. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial and object working memory impairments in schizophrenia patients: A Bayesian item-response theory analysis.

This study reports evidence that schizophrenia patients are significantly impaired in both spatial and object (shape) working memory. A 3-s delay between exposure and recall of targets was used and Bayesian item-response theory was applied to compensate for the tasks' differential difficulty while simultaneously taking account of missing data from participant attrition. Weaker evidence was found that in schizophrenia both domains are equally impaired on average, that spatial and object working memory appear to be more highly correlated with each other in the schizophrenia population than in the normal population, and that schizophrenia patients show greater variability in spatial than in object working memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal communication impairments and cognitive control components in people with schizophrenia.

Schizophrenia involves multiple communication impairments, including (a) disorganized speech, or formal thought disorder (FTD); and (b) decreased speech output, or poverty of speech. Both FTD and poverty of speech have been hypothesized to be associated with deficits in executive functioning or cognitive control. The current study examined whether FTD and poverty of speech were differentially associated with two distinct aspects of cognitive control, working memory and controlled retrieval. Compared with control participants (n = 30), people with schizophrenia (n = 47) exhibited poorer performance on both working memory and controlled retrieval tasks. However, only FTD (and not poverty of speech) was associated with poor working memory. In contrast, only poverty of speech (and not FTD) had a significant zero-order association with poor controlled retrieval. At the same time, working memory and controlled retrieval interacted to predict FTD, with the highest amount of FTD associated with both poor working memory and poor controlled retrieval. In contrast, psychometric control tasks were not associated with FTD or poverty of speech. This research suggests that FTD and poverty of speech are differentially associated with deficits in distinct aspects of cognitive control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low-level temporal coding impairments in psychosis: Preliminary findings and recommendations for further studies.

The authors investigated whether difficulties with temporal event coding, previously reported in patients with schizophrenia, are already present during first-episode psychosis (FEP). In this experiment, the subjective judgments of the simultaneity of visually presented stimuli were compared between 11 healthy controls, 9 patients with chronic schizophrenia (CSZ), and a sample of 11 FEP patients. Participants were asked to indicate whether 2 vertical bars appeared at the same time or at different times on a computer monitor. CSZ patients' thresholds were elevated, and the FEP sample showed higher thresholds relative to controls. Although preliminary, these findings indicate a generalized disturbance in event-structure coding at early stages of psychosis and question the specificity of its disturbance. Considering the proposed relationship between event-structure coding and the experience of time in general, this study recommends that future studies refocus on psychosis in general, rather than on schizophrenia as a particular case of abnormal temporal processing. In addition, it is suggested that the relevant psychopathology will be best determined by means of a comprehensive analysis of low-level temporal coding performance in different types of psychosis. (PsycINFO Database Record (c) 2011 APA, all rights reserved)