Neurocognitive basis of impaired empathy in schizophrenia.

Patients with schizophrenia show impaired emotional and social behavior, such as lack of theory of mind and misinterpretation of social situations. However, there is a paucity of work focusing on the empathic abilities of these patients. The present study was designed to examine the degree of impairment in cognitive and affective empathy in schizophrenia and to evaluate the contribution of executive prefrontal functions to empathy in these patients. To explore the neurocognitive processes that underlie the empathic ability in schizophrenic patients, the relationship between empathy scores and the performance on a cognitive flexibility task that assesses dorsolateral and orbitofrontal functioning (set shifting and reversal, respectively) was examined in 26 patients with schizophrenia and 31 healthy control subjects. Results indicated that patients with schizophrenia were significantly impaired in both cognitive and affective empathy compared with healthy control subjects. The degree of impaired empathy related to the severity of negative symptoms. In addition, patients showed impaired performance on measures of both shifting and reversal. However, while cognitive empathy was particularly related to measurements of orbitofrontal (rather than dorsolateral) functioning, affective empathy was related to measures of social functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurocognitive abnormalities during comprehension of real-world goal-directed behaviors in schizophrenia.

Origins of impaired adaptive functioning in schizophrenia remain poorly understood. Behavioral disorganization may arise from an abnormal reliance on common combinations between concepts stored in semantic memory. Avolition–apathy may be related to deficits in using goal-related requirements to flexibly plan behavior. The authors recorded event-related potentials (ERPs) in 16 patients with medicated schizophrenia and 16 healthy controls in a novel video paradigm presenting congruous or incongruous objects in real-world activities. All incongruous objects were contextually inappropriate, but the incongruous scenes varied in comprehensibility. Psychopathology was assessed with the Scales for the Assessment of Positive and Negative Symptoms (SAPS/SANS) and the Brief Psychiatric Rating Scale. In patients, an N400 ERP, thought to index activity in semantic memory, was abnormally enhanced to less comprehensible incongruous scenes, and larger N400 priming was associated with disorganization severity. A P600 ERP, which may index flexible object–action integration based on goal-related requirements, was abnormally attenuated in patients, and its smaller magnitude was associated with the SANS rating of impersistence at work or school (goal-directed behavior). Thus, distinct neurocognitive abnormalities may underlie disorganization and goal-directed behavior deficits in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Callosal dysfunction in schizophrenia and schizo-affective disorder.

Studies of corpus callosum dysfunction in schizophrenia have typically relied on measures that reveal impairment in commissurotomy patients, but measures that distinguish people with callosal agenesis may be more appropriate. Four of these indexes were included in the present study. Tests of associated movements, cross-localization of touch, interocular transfer of spiral aftereffect, and transfer of blind formboard learning were administered to 18 chronic schizophrenics, 19 schizo-affectives, and 20 normal volunteers. Both schizophrenics and schizo-affectives were impaired on all measures except transfer of blind formboard learning. Schizophrenics also made significantly more associated movements than schizo-affectives and exhibited a different pattern of cross-localization deficit. These results support the hypothesis of developmental callosal dysfunction in schizophrenia and schizo-affective disorder, although the nature of this dysfunction differs in part from that exhibited by acallosals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional capacity dysfunction and arousal in schizophrenia.

Criticizes 2 influential premises underlying most of current research on schizophrenia and attention: (a) belief in the existence of a specific information-processing deficit and (b) acceptance of a framework of "cold cognition." Capacity theory is proposed as an alternative theoretical framework within which the various phenotypically diverse attentional deficits in schizophrenia reflect a deficit in the control function that governs the mobilization and allocation of attention. Attentional deficits, therefore, are most manifest when effortful processing in short-term storage is required. Research on short-term memory processes in schizophrenics shows that the magnitude of the attention deficit correlates positively with the attentional requirements of the cognitive operations involved. The dysfunction is thought to reflect the high levels of arousal characteristic of schizophrenics. Parallels in the performance of schizophrenics and essentially normal but hyperaroused Ss are outlined in support of this hypothesis. The failure to consider the possible mediating effects of hyperarousal in attentional performance of schizophrenics is an omission in the research on schizophrenic cognition. Causality between arousal and information processing is addressed. (101 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye-tracking dysfunction and birth-month weather in schizophrenia.

The prevalence of eye-tracking dysfunction (ETD) is significantly elevated in individuals with a diagnosis of schizophrenia and in their nonschizophrenic relatives, suggesting that ETD marks a familial (most likely genetic) risk factor for schizophrenia. Birth in a season with intemperate weather is also a widely reported risk factor for schizophrenia and is particularly marked for the subgroup with no family history of the disorder. This study examined how these two risk factors covaried in 78 patients with a Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) diagnosis of schizophrenia. Eye tracking and birth-month weather were independently assessed. As hypothesized, patients without ETD were significantly more likely to be born in months with intemperate weather (both hot and cold) than either patients with ETD or people in the general population. Etiologic factors associated with severe weather near birth may be important sources of nonfamilial schizophrenia. (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)     

Detection of alcoholism in schizophrenia using the MAST

1. alpha-toxin of Staphylococcus aureus readily permeabilized rat uterine smooth muscle after incubation for a short time. 2. The permeabilized muscle responded to Ca2+ dose-dependently and repeatedly in the same manner. 3. The threshold concentration of Ca2+ for contraction was 0.1-0.3 microM and the maximal contraction was achieved with 1 or 3 microM Ca2+. 4. GTP gamma S or GTP augmented the contractile response to Ca2+. 5. GDP beta S or GDP suppressed the contraction. 6. The role of GTP-binding protein in sensitization of Ca(2+)-induced contractile response of smooth muscle is discussed.     

Left hemisphere dysfunction and left hemisphere overactivation in schizophrenia.

Reports 2 experiments relating schizophrenia to functional brain asymmetry. In Exp I, 24 schizophrenics (mean age, 30.8 yrs) were compared to 24 matched controls (mean age, 37.3 yrs) on 2 tachistoscopic tasks (Syllable Test and Dot Location Test) designed to measure verbal and spatial information processing in the 2 hemispheres. Unlike the controls, the schizophrenics showed a right hemisphere superiority both on the verbal and on the spatial tests, indicating left hemisphere dysfunction in the initial processing of verbal information. In Exp II, lateral eye movements, as an index of contralateral hemispheric activation, were measured in a group of 24 paranoid schizophrenics (mean age, 28.9 yrs), 24 nonparanoid schizophrenics (mean age, 32.7 yrs), and 24 matched controls (mean age, 31.2 yrs). The eye movements were elicited by presenting the Ss with verbal neutral, verbal emotional, spatial neutral, and spatial emotional questions. The schizophrenics had significantly more rightward eye movement, compared to controls, regardless of question type, indicating left hemisphere overactivation. Results suggest that schizophrenia is associated with a pattern consisting of both left hemisphere dysfunction and overactivation. (63 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Periacinar collagenization in patients with chronic alcoholism

To examine the development of pancreatic fibrosis in alcoholics, the fibrosis types grouped according to Martin's classification were examined by immunohistochemistry using an antibody against alpha-smooth muscle actin (alpha-SMA). The initial stage of periacinar collagenization was also investigated by electron microscopy. The total incidence of pancreatic fibrosis at autopsy of the 29 alcoholics was significantly higher than that of the 40 non-alcoholics. Intralobular sclerosis was observed to be the most frequent type of fibrosis regardless of alcohol intake. No differences in the enhancement of alpha-SMA expression in each type of fibrosis were found between the alcoholics and non-alcoholics. Electron microscopically, myofibroblasts were found around acini in the early stage of periacinar collagenization, and were accompanied by numerous fine filaments (8-15 nm in diameter). The various changes in zymogen granules (ZG), lysosomes and lipid droplets were augmented in the acinar cells of alcoholics. Medium-density materials were also found in dilated rough endoplasmic reticulum (RER). The contents of ZG and RER occasionally leaked out. In conclusion, pancreatic fibrosis was increased in alcoholics; myofibroblasts may play an important role in the initial stage of periacinar collagenization; and the intracellular transport blockage of protein as represented by abnormalities of ZG, ER and lysosomes may contribute to the development of periacinar collagenization.     

A multivariate study of attention dysfunction in schizophrenia.

Administered 5 tests purported to measure attention dysfunction to 60 schizophrenic and 60 nonschizophrenic male psychiatric patients. There was 30 chronic and 30 acute Ss in each group. The measures used were: size estimation, reaction time, and vigilance tasks, the Goldstein-Scheerer Object Sorting Test, and a proverb-interpretation task. Contrary to previous assumptions, these tests did not intercorrelate highly. In addition, individual-difference variables, as measured by staff ratings on the Psychotic Reaction Profile, failed to correlate significantly with task performance. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurocognitive deficit in schizophrenia: a quantitative review of the evidence

The neurocognitive literature on test performance in schizophrenia is reviewed quantitatively. The authors report 22 mean effect sizes from 204 studies to index schizophrenia versus control differences in global and selective verbal memory, nonverbal memory, bilateral and unilateral motor performance, visual and auditory attention, general intelligence, spatial ability, executive function, language, and interhemispheric tactile-transfer test performance. Moderate to large raw effect sizes (d > .60) were obtained for all 22 neurocognitive test variables, and none of the associated confidence intervals included zero. The results indicate that schizophrenia is characterized by a broadly based cognitive impairment, with varying degrees of deficit in all ability domains measured by standard clinical tests.     

Experimental and clinical neuropsychological measures of prefrontal dysfunction in schizophrenia.

Eighteen chronic schizophrenia patients and 14 controls were given tests that have been linked primarily to ventral (orbitofrontal) or to dorsolateral prefrontal dysfunctions in neurological patients and in nonhuman animal Ss having discrete frontal lesions. Schizophrenia patients were significantly impaired on object alternation and delayed alternation tasks but not on classical delayed response (DR). Schizophrenia patients performed well on the classical version of the DR task and their DR performance correlated significantly with measures of sustained attention. Future research is needed to interpret the contributions of attention, interference, and memory load to neuropsychological performance in schizophrenia. Additional studies are required to determine whether the frontal deficits reflect diffuse brain damage, circumscribed prefrontal damage, or damage in other brain regions having prefrontal connections. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antisaccade performance in patients with schizophrenia and affective disorder.

The authors examined psychotic patients with schizophrenia, major depression, and bipolar disorder; "normal" participants; and 1st-degree relatives of patients with schizophrenia on an antisaccade task in which participants were instructed to move their eyes in the opposite direction of a target that moved unpredictably and abruptly either to the left or right of central fixation. Patients with schizophrenia were found to make significantly more errors than their relatives, and the latter made more errors than the controls. The poor performance of the relatives could not be attributed to their having a psychiatric disorder. Comparison of the 3 patient groups indicated that antisaccade deficits were more pronounced in schizophrenia and bipolar disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of content, contextual, and working memory impairments in schizophrenia and nonamnesic alcoholism.

This study used tests of content memory (item recognition of words and abstract designs), context memory (order recognition of verbal and nonverbal items), and working memory (recognition at a short retention interval) to examine patterns of performance in 27 schizophrenic patients, 52 chronic alcoholic patients, and 66 healthy control participants. When performance was age- and IQ-adjusted the schizophrenia group was significantly impaired in item and order recognition of verbal and nonverbal material; the alcoholic group was impaired only in order recognition for both material types. Item- and order-recognition deficits in the schizophrenia group were greatest at the shortest retention intervals, a pattern previously observed in patients with Parkinson's disease, suggesting a prominence of a working memory deficit in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modal attention asymmetry in patients with schizophrenia and bipolar disorder.

This cross-sectional study examined modal attention asymmetries in patients with schizophrenia (n?=?47) and bipolar disorder (n?=?42), as contrasted to a matched-sample comparison group of normal participants (n?=?89). A test of continuous auditory and visual attention was the primary measure. The data were analyzed from 2 experimental conditions: simple modal responses (auditory and visual) and modal switching responses (ipsimodal and cross-modal switching). In the simple modal condition, patients with schizophrenia demonstrated a visual over auditory asymmetry; patients with bipolar disorder showed no differences. In modal switching conditions, however, patients with bipolar disorder displayed a significant auditory over visual asymmetry. No main effect was detected between medications and attention functioning. Results are discussed in light of differentiating these 2 populations on the basis of modal specificity of attention functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship between cognitive and social dysfunction in schizophrenia

Cytogenetic monitoring was carried out on a group of 38 nurses who reconstitute antineoplastic drugs in order to determine the extent of chromosomal damage. Genotoxic activities of antineoplastic drugs are studied by chromosome aberration assay, micronucleus assay, sister chromatid exchange (SCE) frequency high frequency cells (HFC) analysis, and mitotic activity of peripheral lymphocytes. Results confirmed that occupational exposure to a mixture of antineoplastic drugs may cause genome damages. The results of this study show that biomonitoring after exposure to a mixture of antineoplastic drugs which express clastogenic and aneugenic activity should involve a battery of cytogenetic methods.     

Treatment of aggression for an adult diagnosed with schizophrenia at a public psychiatric hospital.

The effectiveness of a behavioral program to treat chronic aggression in an adult male individual diagnosed with schizophrenia at a public psychiatric hospital was evaluated. A behavioral plan was developed to provide the client with positive social interactions, social skills training, and positive reinforcement for prosocial behavior; no negative consequences were implemented. The number of aggressive acts declined with the introduction of the behavioral plan and ultimately remitted even without ongoing reinforcers. This article demonstrates the value of psychological intervention in treating aggression with a treatment-resistant client in an in-patient setting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response-monitoring dysfunction in schizophrenia: An event-related brain potential study.

Error-monitoring abnormalities may underlie positive symptoms of schizophrenia. Response-synchronized event-related potentials during picture-word matching yielded error- and correct-response-related negativity (ERN, CRN) and positivity (Pe, Pc) and preresponse lateralized readiness potentials (LRP) from 18 schizophrenic patients and 18 controls. Both groups responded faster to matches than nonmatches, although patients were generally slower and made more errors to nonmatches. Compared with controls, patients, particularly with paranoid subtype, had smaller ERNs and larger CRNs, which were indistinguishable. LRPs showed evidence of more response conflict before errors than before correct responses in controls but not patients. Despite ERN/CRN abnormalities, post-error slowing and Pe were normal in patients, suggesting a dissociation of ERN and error awareness. Anterior cingulate and dorsolateral prefrontal cortical dysfunction in schizophrenia are implicated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal discounting of rewards in patients with bipolar disorder and schizophrenia.

Patients with bipolar disorder (BD) and schizophrenia (SZ) often show decision-making deficits in everyday circumstances. A failure to appropriately weigh immediate versus future consequences of choices may contribute to these deficits. We used the delay discounting task in individuals with BD or SZ to investigate their temporal decision making. Twenty-two individuals with BD, 21 individuals with SZ, and 30 healthy individuals completed the delay discounting task along with neuropsychological measures of working memory and cognitive function. Both BD and SZ groups discounted delayed rewards more steeply than did the healthy group even after controlling for current substance use, age, gender, and employment. Hierarchical multiple regression analyses showed that discounting rate was associated with both diagnostic group and working memory or intelligence scores. In each group, working memory or intelligence scores negatively correlated with discounting rate. The results suggest that (a) both BD and SZ groups value smaller, immediate rewards more than larger, delayed rewards compared with the healthy group and (b) working memory or intelligence is related to temporal decision making in individuals with BD or SZ as well as in healthy individuals. (PsycINFO Database Record (c) 2011 APA, all rights reserved)