Although meta-analyses suggest that schizophrenia (SZ) is associated with a more severe neurocognitive phenotype than mood disorders such as bipolar disorder, considerable between-subject heterogeneity exists in the phenotypic presentation of these deficits across mental illnesses. Indeed, it is unclear whether the processes that underlie cognitive dysfunction in these disorders are unique to each disease or represent a common neurobiological process that varies in severity. Here we used latent profile analysis (LPA) across 3 distinct cognitive domains (cognitive control, episodic memory, and visual integration; using data from the CNTRACS consortium) to identify distinct profiles of patients across psychotic illnesses.
View Article and Find Full Text PDFBackground: In recent years, psychiatry research has increasingly focused on understanding mental illnesses from a cross-diagnostic, dimensional perspective in order to better align their neurocognitive features with underlying neurobiological mechanisms. In this multi-site study, we examined two measures of cognitive control (d-prime context and lapsing rate) during the Dot Probe Expectancy (DPX) version of the AX-Continuous Performance Task in patients with either schizophrenia (SZ), schizoaffective disorder (SZ-A), or Type I bipolar disorder (BD) as well as healthy control (HC) subjects. We hypothesized significantly lower d-prime context and higher lapsing rate in SZ and SZ-A patients and intermediate levels in BD patients relative to HC.
View Article and Find Full Text PDFBackground: Working memory (WM) has been a central focus of cognitive neuroscience research because WM is a resource that is involved in many different cognitive operations. The goal of this study was to evaluate the clinical utility of WM paradigms developed in the basic cognitive neuroscience literature, including methods designed to estimate storage capacity without contamination by lapses of attention.
Methods: A total of 61 people with schizophrenia, 49 with schizoaffective disorder, 47 with bipolar disorder with psychosis, and 59 healthy volunteers were recruited.
The goal of the current study was to examine the relationships between insight and both cognitive function and depression in schizophrenia and schizoaffective disorder, and to determine if there were similar relationships across diagnostic categories. We examined discrepancies between self and informant reports of function on the Specific levels of function scale as a metric of insight for interpersonal, social acceptance, work and activities. We examined two samples of individuals with schizophrenia and/or schizoaffective disorder (Ns of 188 and 67 respectively).
View Article and Find Full Text PDFMotivational and hedonic impairments are core features of a variety of types of psychopathology. An important aspect of motivational function is reinforcement learning (RL), including implicit (i.e.
View Article and Find Full Text PDFExecutive function is an important concept in neuropsychological and cognitive research, and is often viewed as central to effective clinical assessment of cognition. However, the construct validity of executive function tests is controversial. The switching, inhibition, and updating model is the most empirically supported and replicated factor model of executive function (Miyake et al.
View Article and Find Full Text PDFCogn Affect Behav Neurosci
March 2014
The goals of the present study were to assess the interrelationships among tasks from the MATRICS and CNTRACS batteries, to determine the degree to which tasks from each battery capture unique variance in cognitive dysfunction in schizophrenia, and to determine the ability of tasks from each battery to predict functional outcome. Subjects were 104 schizophrenia patients and 132 healthy control subjects recruited as part of the CNTRACS initiative. All subjects completed four CNTRACS tasks and two tasks from the MATRICS battery: Brief Assessment of Cognition in Schizophrenia Symbol Coding and the Hopkins Verbal Learning Test.
View Article and Find Full Text PDFResearch in schizophrenia has increasingly focused on incorporating measures from cognitive neuroscience, but little is known about their psychometric characteristics. Here, we extend prior research by reporting on temporal stability, as well as age and sex effects, for cognitive neuroscience paradigms optimized as part of the Cognitive Neuroscience Test Reliability and Clinical applications for Schizophrenia consortium. Ninety-nine outpatients with schizophrenia and 131 healthy controls performed 5 tasks assessing 4 constructs at 3 sessions.
View Article and Find Full Text PDFContour integration (CI) refers to the process that represents spatially separated elements as a unified edge or closed shape. Schizophrenia is a psychiatric disorder characterized by symptoms such as hallucinations, delusions, disorganized thinking, inappropriate affect, and social withdrawal. Persons with schizophrenia are impaired at CI, but the specific mechanisms underlying the deficit are still not clear.
View Article and Find Full Text PDFBackground: We sought to develop a Dot Pattern Expectancy task (DPX) to assess goal maintenance for use in clinical trials. Altering the standard task created 5 versions of the DPX to compare-a standard version and 4 others. Alterations in the interstimulus interval (ISI) length and the strength of a learned prepotent response distinguished the different tasks.
View Article and Find Full Text PDFObjectives: The Relational and Item-Specific Encoding task (RISE) was designed to assess contributions of specific encoding and retrieval processes to episodic memory in schizophrenia. This manuscript describes how a cognitive neuroscience functional imaging paradigm was translated for clinical research.
Methods: The RISE manipulates encoding by requiring participants to decide whether stimuli are "living/nonliving" (item-specific) or whether one stimulus fits inside the other (relational) and estimates familiarity (F) and recollection (R) by examining receiver operator characteristics (ROC) and assessing item and associative recognition.
The goal of the current project was to further develop a measure of gain control--the Contrast-Contrast Effect (CCE)--for use in clinical studies of schizophrenia. The CCE is based on an illusion in which presenting a medium contrast patch surrounded by a high-contrast patch induces individuals to perceive that center patch as having lower contrast than when the patch is presented in isolation. Thus, in the CCE, impaired gain control should lead to more accurate perceptions of the center patch.
View Article and Find Full Text PDFThe Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia initiative highlighted a contour integration test as a promising index of visual integration impairment because of its well-established psychometric properties; its prior validation in healthy adults, patients, and nonhuman primates; and its potential sensitivity to treatment effects. In this multisite study, our goals were to validate the task on the largest subject sample to date, clarify the task conditions and number of trials that best discriminate patients from controls, and determine whether this discrimination can occur in standard clinical trial settings. For our task, subjects briefly observed a field of disconnected, oriented elements and attempted to decide whether a subset of those elements formed a leftward- or rightward-pointing shape.
View Article and Find Full Text PDFStudies of neuropathology-cognition associations are not common and have been limited by small sample sizes, long intervals between autopsy and cognitive testing, and lack of breadth of neuropathology and cognition variables. This study examined domain-specific effects of common neuropathologies on cognition using data (N = 652) from two large cohort studies of older adults. We first identified dimensions of a battery of 17 neuropsychological tests, and regional measures of Alzheimer's disease (AD) neuropathology.
View Article and Find Full Text PDFMeasures of psychological constructs are validated by testing whether they relate to measures of other constructs as specified by theory. Each test of relations between measures reflects on the validity of both the measures and the theory driving the test. Construct validation concerns the simultaneous process of measure and theory validation.
View Article and Find Full Text PDFObjective: Cognitive impairments associated with schizophrenia might be expected to have a marked impact on the ability to produce coherent speech, yet associations between cognitive performance and speech disorder have typically been weak. Findings on this question may have been limited by measurement methods and by the heterogeneity of speech disorder. This study examined the contributions of impairments in sustained attention and sequencing abilities to schizophrenic speech disorder, measured in terms of communication failures and divided into different types of disorder.
View Article and Find Full Text PDFAims: This article investigates the subjective experience of the process of improvement and recovery from the point of view of persons diagnosed (according to research diagnostic criteria) with schizophrenia and schizo-affective disorders.
Methods: A community study of persons using psychiatric services was conducted for a sample of ninety subjects taking atypical antipsychotic medications. Sociodemographic data and clinical ratings were collected to complement the qualitatively developed Subjective Experience of Medication Interview (SEMI), which elicits narrative data on everyday activities, medication and treatment, management of symptoms, expectations concerning recovery, stigma, and quality of life.
J Neuropsychiatry Clin Neurosci
November 2005
Apathy is common in Alzheimer's disease (AD) but may be confused with depression due to overlap in symptoms queried in depression assessments. Depression and dysphoria appear to occur less frequently in AD but are better researched. This study examined the relative frequency of these syndromes and their relation to disease characteristics in 131 research participants with probable or possible AD.
View Article and Find Full Text PDFObjectives: To study the associations between dementia/mild cognitive impairment (MCI) and cognitive performance and activity levels in youth.
Design: Retrospective cohort study.
Setting: Research volunteers living throughout the United States.
The concept of gender considers masculinity and femininity as a cultural construct that varies along a continuum. Subjectively perceived, gender may affect the experience of illness among persons with schizophrenia and may have an impact on treatment and recovery. This study evaluated gender identity, according to the Bem Sex Role Inventory, among 90 men and women with schizophrenia and schizoaffective disorders.
View Article and Find Full Text PDFThe Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery was developed to evaluate cognitive impairments associated with Alzheimer's disease (AD). Previous studies have suggested that the battery is multi-dimensional, represented by either 3 or 5 dimensions. In this study a principal factor analysis was conducted using contemporary quantitative methods for determining the number of factors.
View Article and Find Full Text PDFThe relationship between respiratory sinus arrhythmia (RSA) and valence and arousal remains unclear. In the present study, the associations between emotion responses and tonic or task-related changes in RSA were assessed. Specifically, the sensitivities of changes in interbeat interval, RSA, and skin conductance to the valence and arousal values of emotional stimuli were examined.
View Article and Find Full Text PDFThe generalizability of research data depends on the degree to which the studied sample represents the larger population of interest. By influencing the likelihood of research participation, socio-demographic and clinical factors could bias a sample. To evaluate this, we retrospectively identified 155 consecutive admissions over an 18-month period to a general acute male psychiatry inpatient unit in a Veterans Affairs Hospital on which all competent patients were offered the opportunity to participate in low-risk clinical research.
View Article and Find Full Text PDFNeuropsychiatry Neuropsychol Behav Neurol
September 2002
Objective: To standardize a new rating scale for the assessment of apathy in Alzheimer disease (AD) and report on its reliability, structure, and relation to other clinical features of AD.
Background: apathy is a common prominent behavioral syndrome accompanying AD and is associated with excess disability and increased caregiver burden. Current instruments for the assessment of apathy in AD do not explicitly and systematically attempt to differentiate limited activity and engagement due to lack of interest from inability or longstanding, premorbid personality traits.