Loneliness is associated with mentalizing and emotion recognition abilities in schizophrenia, but only in a cluster of patients with social cognitive deficits

OBJECTIVE

Loneliness is a concern for patients with schizophrenia. However, the correlates of loneliness in patients with schizophrenia are unclear; thus, the aim of the study is to investigate neuro- and social cognitive mechanisms associated with loneliness in individuals with schizophrenia.

METHOD

Data from clinical, neurocognitive, and social cognitive assessments were pooled from two cross-national samples (Poland/USA) to examine potential predictors of loneliness in 147 patients with schizophrenia and 103 healthy controls overall. Furthermore, the relationship between social cognition and loneliness was explored in clusters of patients with schizophrenia differing in social cognitive capacity.

RESULTS

Patients reported higher levels of loneliness than healthy controls. Loneliness was linked to increased negative and affective symptoms in patients. A negative association between loneliness and mentalizing and emotion recognition abilities was found in the patients with social-cognitive impairments, but not in those who performed at normative levels.

CONCLUSIONS

We have elucidated a novel mechanism which may explain previous inconsistent findings regarding the correlates of loneliness in individuals with schizophrenia.

MCCB cognitive profile in Spanish first episode schizophrenia patients

The objective of the study was to examine the cognitive profile of Spanish patients with a first episode of schizophrenia (FESz) and to compare that to the profile of patients with a chronic schizophrenia (CSz) and non-psychiatric (NP) control subjects. The study included 106 FESz, 293 CSz, and 210 NP, assessed with the Spanish version of the MATRICS Consensus Cognitive Battery (MCCB). The MCCB cognitive profile in a Spanish sample of FESz was similar to the cognitive profile of CSz with some discrepancies in select domains. The scores of both patient samples were about 1-2 SD below the scores of non-psychiatric control subjects.

Childhood adversity and cognitive function in schizophrenia spectrum disorders and healthy controls: evidence for an association between neglect and social cognition

BACKGROUND

Childhood adversity is associated with cognitive impairments in schizophrenia. However, findings to date are inconsistent and little is known about the relationship between social cognition and childhood trauma. We investigated the relationship between childhood abuse and neglect and cognitive function in patients with a first-episode of schizophrenia or schizophreniform disorder (n = 56) and matched healthy controls (n = 52). To the best of our knowledge, this is the first study assessing this relationship in patients and controls exposed to similarly high levels of trauma.

METHODS

Pearson correlational coefficients were used to assess correlations between Childhood Trauma Questionnaire abuse and neglect scores and cognition. For the MCCB domains displaying significant (p < 0.05) correlations, within group hierarchical linear regression, was done to assess whether abuse and neglect were significant predictors of cognition after controlling for the effect of education.

RESULTS

Patients and controls reported similarly high levels of abuse and neglect. Cognitive performance was poorer for patients compared with controls for all cognitive domains except working memory and social cognition. After controlling for education, exposure to childhood neglect remained a significant predictor of impairment in social cognition in both patients and controls. Neglect was also a significant predictor of poorer verbal learning in patients and of attention/vigilance in controls. However, childhood abuse did not significantly predict cognitive impairments in either patients or controls.

CONCLUSION

These findings are cross sectional and do not infer causality. Nonetheless, they indicate that associations between one type of childhood adversity (i.e. neglect) and social cognition are present and are not illness-specific.

Familial aggregation of MATRICS Consensus Cognitive Battery scores in a large sample of outpatients with schizophrenia and their unaffected relatives

BACKGROUND

The increased use of the MATRICS Consensus Cognitive Battery (MCCB) to investigate cognitive dysfunctions in schizophrenia fostered interest in its sensitivity in the context of family studies. As various measures of the same cognitive domains may have different power to distinguish between unaffected relatives of patients and controls, the relative sensitivity of MCCB tests for relative-control differences has to be established. We compared MCCB scores of 852 outpatients with schizophrenia (SCZ) with those of 342 unaffected relatives (REL) and a normative Italian sample of 774 healthy subjects (HCS). We examined familial aggregation of cognitive impairment by investigating within-family prediction of MCCB scores based on probands' scores.

METHODS

Multivariate analysis of variance was used to analyze group differences in adjusted MCCB scores. Weighted least-squares analysis was used to investigate whether probands' MCCB scores predicted REL neurocognitive performance.

RESULTS

SCZ were significantly impaired on all MCCB domains. REL had intermediate scores between SCZ and HCS, showing a similar pattern of impairment, except for social cognition. Proband's scores significantly predicted REL MCCB scores on all domains except for visual learning.

CONCLUSIONS

In a large sample of stable patients with schizophrenia, living in the community, and in their unaffected relatives, MCCB demonstrated sensitivity to cognitive deficits in both groups. Our findings of significant within-family prediction of MCCB scores might reflect disease-related genetic or environmental factors.

Developing an international scoring system for a consensus-based social cognition measure: MSCEIT-managing emotions

BACKGROUND

Measures of social cognition are increasingly being applied to psychopathology, including studies of schizophrenia and other psychotic disorders. Tests of social cognition present unique challenges for international adaptations. The Mayer-Salovey-Caruso Emotional Intelligence Test, Managing Emotions Branch (MSCEIT-ME) is a commonly-used social cognition test that involves the evaluation of social scenarios presented in vignettes.

METHOD

This paper presents evaluations of translations of this test in six different languages based on representative samples from the relevant countries. The goal was to identify items from the MSCEIT-ME that show different response patterns across countries using indices of discrepancy and content validity criteria. An international version of the MSCEIT-ME scoring was developed that excludes items that showed undesirable properties across countries.

RESULTS

We then confirmed that this new version had better performance (i.e. less discrepancy across regions) in international samples than the version based on the original norms. Additionally, it provides scores that are comparable to ratings based on local norms.

CONCLUSIONS

This paper shows that it is possible to adapt complex social cognitive tasks so they can provide valid data across different cultural contexts.

Repurposing Drugs for Cognition in Schizophrenia

Currently approved treatments for schizophrenia only minimally affect the cognitive features of the illness that are the most closely related to disability. Hence, there is now considerable effort to repurpose drugs for schizophrenia, and to seek agents that can improve cognition by targeting receptor systems other than the dopaminergic system. The results of these studies have been mixed thus far; however, this continues to be a high-priority area of schizophrenia research and an important unmet need.

The MCCB impairment profile in a Spanish sample of patients with schizophrenia: Effects of diagnosis, age, and gender on cognitive functioning

The MATRICS Consensus Cognitive Battery (MCCB) was administered to 293 schizophrenia outpatients and 210 community residents in Spain. Our first objective was to identify the age- and gender-corrected MCCB cognitive profile of patients with schizophrenia. The profile of schizophrenia patients showed deficits when compared to controls across the seven MCCB domains. Reasoning and Problem Solving and Social Cognition were the least impaired, while Visual Learning and Verbal Learning showed the greatest deficits. Our second objective was to study the effects on cognitive functioning of age and gender, in addition to diagnosis. Diagnosis was found to have the greatest effect on cognition (Cohen's d>0.8 for all MCCB domains); age and gender also had effects on cognitive functioning, although to a lesser degree (with age usually having slightly larger effects than gender). The effects of age were apparent in all domains (with better performance in younger subjects), except for Social Cognition. Gender had effects on Attention/Vigilance, Working Memory, Reasoning and Problem Solving (better performance in males), and Social Cognition (better performance in females). No interaction effects were found between diagnosis and age, or between diagnosis and gender. This lack of interactions suggests that age and gender effects are not different in patients and controls.

Cognitive functioning in first-episode schizophrenia: MATRICS Consensus Cognitive Battery (MCCB) Profile of Impairment

BACKGROUND

Although many studies have assessed cognitive functioning in first-episode schizophrenia (FESz), the pattern and severity of impairment across cognitive domains remain unclear. Moreover, few studies have directly compared the pattern of cognitive performance between FESz and chronic schizophrenia (CSz). In this study we examined the cognitive impairment profile in FESz using a standardized neurocognitive battery (MATRICS Consensus Cognitive Battery; MCCB).

METHODS

MCCB data were compared from 105 FESz patients, 176 CSz patients and 300 non-psychiatric (NP) participants. Mixed model analysis evaluated group differences in MCCB profiles and relative strengths and weaknesses in the MCCB profiles of patients. Clinical implications of MCCB performance were also examined; we compared the proportion of participants from each group who exhibited clinically-significant global cognitive impairment based on the MCCB Overall Composite score.

RESULTS

FESz and CSz showed impaired performance across all MCCB domains relative to NP. With the exception of relative preservation of working memory and social cognition in FESz, the MCCB domain scores were similar in FESz and CSz. The distribution of impairment on the Overall Composite score did not significantly differ between FESz and CSz; compared to NP, both patient groups were overrepresented in moderate and severe impairment categories.

CONCLUSION

The pattern, magnitude, and distribution of severity of impairment in FESz were similar to that observed in CSz. However, early in the illness, there may be relative sparing of working memory and social cognition.

Impaired emotion regulation in schizophrenia: evidence from event-related potentials

BACKGROUND

Although several aspects of emotion seem to be intact in schizophrenia, there is emerging evidence that patients show an impaired ability to adaptively regulate their emotions. This event-related potential (ERP) study examined whether schizophrenia is associated with impaired neural responses to appraisal frames, that is when negative stimuli are presented in a less negative context.

METHOD

Thirty-one schizophrenia out-patients and 27 healthy controls completed a validated picture-viewing task with three conditions: (1) neutral pictures preceded by neutral descriptions ('Neutral'), (2) unpleasant pictures preceded by negative descriptions ('Preappraised negative'), and (3) unpleasant pictures preceded by more neutral descriptions ('Preappraised neutral'). Analyses focused on the late positive potential (LPP), an index of facilitated attention to emotional stimuli that is reduced following cognitive emotion regulation strategies, during four time windows from 300 to 2000 ms post-picture onset.

RESULTS

Replicating prior studies, controls showed smaller LPP in Preappraised neutral and Neutral versus Preappraised negative conditions throughout the 300-2000-ms time period. By contrast, patients showed (a) larger LPP in Preappraised neutral and Preappraised negative versus Neutral conditions in the initial period (300-600 ms) and (b) an atypical pattern of larger LPP to Preappraised neutral versus Preappraised negative and Neutral conditions in the 600-1500-ms epochs.

CONCLUSIONS

Modulation of neural responses by a cognitive emotion regulation strategy seems to be impaired in schizophrenia during the first 2 s after exposure to unpleasant stimuli.

Event-related potential examination of facial affect processing in bipolar disorder and schizophrenia

BACKGROUND

Patients with bipolar disorder exhibit consistent deficits in facial affect identification at both behavioral and neural levels. However, little is known about which stages of facial affect processing are dysfunctional.

METHOD

Event-related potentials (ERPs), including amplitude and latency, were used to evaluate two stages of facial affect processing: N170 to examine structural encoding of facial features and N250 to examine decoding of facial features in 57 bipolar disorder patients, 30 schizophrenia patients and 30 healthy controls. Three conditions were administered: participants were asked to identify the emotion of a face, the gender of a face, or whether a building was one or two stories tall.

RESULTS

Schizophrenia patients' emotion identification accuracy was lower than that of bipolar patients and healthy controls. N170 amplitude was significantly smaller in schizophrenia patients compared to bipolar patients and healthy controls, which did not differ from each other. Both patient groups had significantly longer N170 latency compared to healthy controls. For N250, both patient groups showed significantly smaller amplitudes compared with controls, but did not differ from each other. Bipolar patients showed longer N250 latency than healthy controls; patient groups did not differ from each other.

CONCLUSIONS

Bipolar disorder patients have relatively intact structural encoding of faces (N170) but are impaired when decoding facial features for complex judgments about faces (N250 latency and amplitude), such as identifying emotion or gender.

The causal relationships between neurocognition, social cognition and functional outcome over time in schizophrenia: a latent difference score approach

BACKGROUND

Social cognition has been identified as a significant construct for schizophrenia research with relevance to diagnosis, assessment, treatment and functional outcome. However, social cognition has not been clearly understood in terms of its relationships with neurocognition and functional outcomes. The present study sought to examine the empirical independence of social cognition and neurocognition; to investigate the possible causal structure among social cognition, neurocognition and psychosocial functioning.

METHOD

The sample consists of 130 individuals diagnosed with schizophrenia. All participants were recruited as they were admitted to four community-based psychosocial rehabilitation programs. Social cognition, neurocognition and psychosocial functioning were measured at baseline and 12 months. The empirical independence of social cognition and neurocognition was tested using confirmatory factor analysis (CFA) and the possible causal structure among social cognition, neurocognition and psychosocial functioning was investigated using latent difference score (LDS) analysis.

RESULTS

A two-factor model of social cognition and neurocognition fit the data very well, indicating the empirical independence of social cognition, whereas the longitudinal CFA results show that the empirical independence of neurocognition and social cognition is maintained over time. The results of the LDS analysis support a causal model that indicates that neurocognition underlies and is causally primary to social cognition, and that neurocognition and social cognition are causally primary to functional outcome.

CONCLUSIONS

Social cognition and neurocognition could have independent and distinct upward causal effects on functional outcome. It is also suggested that the approaches for remediation of neurocognition and social cognition might need to be distinct.

Impaired neural response to internal but not external feedback in schizophrenia

BACKGROUND

Accurate monitoring and integration of both internal and external feedback is crucial for guiding current and future behavior. These aspects of performance monitoring are commonly indexed by two event-related potential (ERP) components: error-related negativity (ERN) and feedback negativity (FN). The ERN indexes internal response monitoring and is sensitive to the commission of erroneous versus correct responses, and the FN indexes external feedback monitoring of positive versus negative outcomes. Although individuals with schizophrenia consistently demonstrate a diminished ERN, the integrity of the FN has received minimal consideration.

METHOD

The current research sought to clarify the scope of feedback processing impairments in schizophrenia in two studies: study 1 examined the ERN elicited in a flanker task in 16 out-patients and 14 healthy controls; study 2 examined the FN on a simple monetary gambling task in expanded samples of 35 out-patients and 33 healthy controls.

RESULTS

Study 1 replicated prior reports of an impaired ERN in schizophrenia. By contrast, patients and controls demonstrated comparable FN differentiation between reward and non-reward feedback in study 2.

CONCLUSIONS

The differential pattern across tasks suggests that basic sensitivity to external feedback indicating reward versus non-reward is intact in schizophrenia, at least under the relatively simple task conditions used in this study. Further efforts to specify intact and impaired reward-processing subcomponents in schizophrenia may help to shed light on the diminished motivation and goal-seeking behavior that are commonly seen in this disorder.

The MATRICS consensus cognitive battery (MCCB): co-norming and standardization in Spain

The MATRICS Consensus Cognitive Battery (MCCB), developed by the National Institute of Mental Health (NIMH) Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative, has been recommended as the standard battery for clinical trials of cognition-enhancing interventions for schizophrenia. Normative data for the MCCB has been previously obtained in the U.S. Extrapolation of these normative data to different countries may be problematic due to the translation of the different tests, as well as potential cultural influences. We present the process of obtaining normative data for the MCCB in Spain with administration of the battery to a general community standardization sample. In addition, we examine the influence of age, gender, and educational level on test performance. The MCCB was administered to a total sample of 210 healthy volunteers, at three Spanish sites. For each site, recruitment of the sample was stratified according to age, gender, and educational level. Our findings indicate significant age, gender, and education effects on the normative data for the MCCB in Spain, which are comparable to those effects described for the original standardized English version in the U.S. The fact that the normative data are comparable, and that the variables age, gender, and education have a similar influence on performance, supports the robustness of the MCCB for use in different countries.

Schizophrenia patients are impaired in empathic accuracy

BACKGROUND

Empathy is crucial for successful social relationships. Despite its importance for social interactions, little is known about empathy in schizophrenia. This study investigated the degree to which schizophrenia patients can accurately infer the affective state of another person (i.e. empathic accuracy).

METHOD

A group of 30 schizophrenia patients and 22 healthy controls performed an empathic accuracy task on which they continuously rated the affective state of another person shown in a video (referred to as the 'target'). These ratings were compared with the target's own continuous self-rating of affective state; empathic accuracy was defined as the correlation between participants' ratings and the targets' self-ratings. A separate line-tracking task was administered to measure motoric/attentional factors that could account for group differences in performance. Participants' self-rated empathy was measured using the Interpersonal Reactivity Index, and targets' self-rated emotional expressivity was measured using the Berkeley Expressivity Questionnaire.

RESULTS

Compared with controls, schizophrenia patients showed lower empathic accuracy although they performed the motoric tracking task at high accuracy. There was a significant group×target expressivity interaction such that patients showed a smaller increase in empathic accuracy with higher levels of emotional expressivity by the target, compared with controls. Patients' empathic accuracy was uncorrelated with self-reported empathy or clinical symptoms.

CONCLUSIONS

Schizophrenia patients showed lower empathic accuracy than controls, and their empathic accuracy was less influenced by the emotional expressivity of the target. These findings suggest that schizophrenia patients benefit less from social cues of another person when making an empathic judgement.

Visual masking by object substitution in schizophrenia

BACKGROUND

Schizophrenia patients demonstrate impairment on visual backward masking, a measure of early visual processing. Most visual masking paradigms involve two distinct processes, an early fast-acting component associated with object formation and a later component that acts through object substitution. So far, masking paradigms used in schizophrenia research have been unable to separate these two processes.

METHOD

We administered three visual processing paradigms (location masking with forward and backward masking, four-dot backward masking and a cuing task) to 136 patients with schizophrenia or schizoaffective disorder and 79 healthy controls. A psychophysical procedure was used to match subjects on identification of an unmasked target prior to location masking. Location masking interrupts object formation, four-dot masking task works through masking by object substitution and the cuing task measures iconic decay.

RESULTS

Patients showed impairment on location masking after being matched for input threshold, similar to previous reports. After correcting for age, patients showed lower performance on four-dot masking than controls, but the groups did not differ on the cuing task.

CONCLUSIONS

Patients with schizophrenia showed lower performance when masking was specific to object substitution. The difference in object substitution masking was not due to a difference in rate of iconic decay, which was comparable in the two groups. These results suggest that, despite normal iconic decay rates, individuals with schizophrenia show impairment in a paradigm of masking by object substitution that did not also involve disruption of object formation.

Pathways between early visual processing and functional outcome in schizophrenia

BACKGROUND

Early visual processing deficits are reliably detected in schizophrenia and show relationships to poor real-world functioning. However, the nature of this relationship is complex. Theoretical models and recent studies using statistical modeling approaches suggest that multiple intervening factors are involved. We previously reported that a direct and significant association between visual processing and functional status was mediated by a measure of social perception. The present study examined the contribution of negative symptoms to this model.

METHOD

We employed structural equation modeling (sem) to test several models of outcome, using data from 174 schizophrenia out-patients. Specifically, we examined the direct and indirect relative contributions of early visual processing, social perception and negative symptoms to functional outcome.

RESULTS

First, we found that, similar to social perception, a measure of negative symptoms mediated the association between visual information processing and functional status. Second, we found that the inclusion of negative symptoms substantially enhanced the explanatory power of the model. Notably, it was the experiential aspect of negative symptoms (avolition and anhedonia) more than the expressive aspect (affective flattening and alogia) that accounted for significant variance in functional outcome, especially in the social component of the construct of functional outcome.

CONCLUSIONS

Social perception and negative symptoms play relevant roles in functional impairment in schizophrenia. Both social perception and negative symptoms statistically mediate the connection between visual processing and functional outcome. However, given the lack of association between social perception and negative symptoms, these constructs appear to have an impact on functioning through separate pathways.

Neurocognitive change, functional change and service intensity during community-based psychosocial rehabilitation for schizophrenia

BACKGROUND

This study examined the magnitude of neurocognitive change during 1 year of community-based psychosocial intervention, whether neurocognitive change and functional change were linked, and how neurocognitive change combined with service intensity to facilitate functional change.

METHOD

A total of 130 individuals diagnosed with schizophrenia were recruited upon admission to four community-based psychosocial rehabilitation programs. Subjects were assessed at baseline, 6 and 12 months on role functioning and symptom measures. Neurocognition was measured at baseline and 12 months. Service intensity was the number of days of treatment attendance during the study period. Latent mean difference tests and Latent Growth Curve Models (LCGMs) were used to examine the study hypotheses.

RESULTS

There was statistically and clinically significant functional improvement over 12 months. Neurocognition improved significantly over time. Seventy-six (58%) of the sample showed neurocognitive improvement and 54 (42%) did not. There was a significant rate of functional enhancement in the neurocognitive improver group. There was a non-significant rate of functional change in the neurocognitive non-improver group. Neurocognitive improvers showed functional improvement that was 350% greater than neurocognitive non-improvers. Service intensity did not vary between neurocognitive improvers and non-improvers but there was a strong interaction between neurocognitive improvement, service intensity and rate of functional improvement such that service intensity was strongly related to functional improvement for neurocognitive improvers but not for neurocognitive non-improvers. Medication usage and symptomatology did not confound these findings.

CONCLUSIONS

These findings suggest that neurocognitive improvement may be a foundation for functional change and treatment responsiveness during community-based psychosocial rehabilitation for individuals with schizophrenia.

Disturbances in the spontaneous attribution of social meaning in schizophrenia

BACKGROUND

Schizophrenia patients show disturbances on a range of tasks that assess mentalizing or 'Theory of Mind' (ToM). However, these tasks are often developmentally inappropriate, make large demands on verbal abilities and explicit problem-solving skills, and involve after-the-fact reflection as opposed to spontaneous mentalizing.

METHOD

To address these limitations, 55 clinically stable schizophrenia out-patients and 44 healthy controls completed a validated Animations Task designed to assess spontaneous attributions of social meaning to ambiguous abstract visual stimuli. In this paradigm, 12 animations depict two geometric shapes 'interacting' with each other in three conditions: (1) ToM interactions that elicit attributions of mental states to the agents, (2) Goal-Directed (GD) interactions that elicit attributions of simple actions, and (3) Random scenes in which no interaction occurs. Verbal descriptions of each animation are rated for the degree of Intentionality attributed to the agents and for accuracy.

RESULTS

Patients had lower Intentionality ratings than controls for ToM and GD scenes but the groups did not significantly differ for Random scenes. The descriptions of the patients less closely matched the situations intended by the developers of the task. Within the schizophrenia group, performance on the Animations Task showed minimal associations with clinical symptoms.

CONCLUSIONS

Patients demonstrated disturbances in the spontaneous attribution of mental states to abstract visual stimuli that normally evoke such attributions. Hence, in addition to previously established impairment on mentalizing tasks that require logical inferences about others' mental states, individuals with schizophrenia show disturbances in implicit aspects of mentalizing.

Theory of mind deficits for processing counterfactual information in persons with chronic schizophrenia

BACKGROUND

Interpersonal communication problems are common among persons with schizophrenia and may be linked, in part, to deficits in theory of mind (ToM), the ability to accurately perceive the attitudes, beliefs and intentions of others. Particular difficulties might be expected in the processing of counterfactual information such as sarcasm or lies.

METHOD

The present study included 50 schizophrenia or schizo-affective out-patients and 44 demographically comparable healthy adults who were administered Part III of The Awareness of Social Inference Test (TASIT; a measure assessing comprehension of sarcasm versus lies) as well as measures of positive and negative symptoms and community functioning.

RESULTS

TASIT data were analyzed using a 2 (group: patients versus healthy adults) x 2 (condition: sarcasm versus lie) repeated-measures ANOVA. The results show significant effects for group, condition, and the group x condition interaction. Compared to controls, patients performed significantly worse on sarcasm but not lie scenes. Within-group contrasts showed that patients performed significantly worse on sarcasm versus lie scenes; controls performed comparably on both. In patients, performance on TASIT showed a significant correlation with positive, but not negative, symptoms. The group and interaction effects remained significant when rerun with a subset of patients with low-level positive symptoms. The findings for a relationship between TASIT performance and community functioning were essentially negative.

CONCLUSIONS

The findings replicate a prior demonstration of difficulty in the comprehension of sarcasm using a different test, but are not consistent with previous studies showing global ToM deficits in schizophrenia.

Positive symptoms and duration of illness predict functional laterality and attention modulation in schizophrenia

OBJECTIVE

Dichotic listening (DL) performance in schizophrenia, reflecting hemispheric asymmetry and the functional integrity of the left temporal lobe, can vary with clinical characteristics. Previous studies have not taken the co-linearity of clinical variables into account. The aim of the present study was to evaluate the roles of positive symptoms and duration of illness in DL through Structural Equation Modeling (SEM), thus allowing for complex relationships between the variables.

METHOD

We pooled patients from four previous DL studies to create a heterogeneous group of 129 schizophrenic patients, all tested with a consonant-vowel syllables DL procedure that included attentional instructions.

RESULTS

A model where positive symptoms predicted a laterality component and duration of illness predicted an attention component in DL was confirmed.

CONCLUSION

Positive symptoms predicted reduced functional laterality, suggesting involvement of left temporal lobe language processing. Duration of illness predicted impaired attention modulation, possibly reflecting the involvement of frontotemporal networks.

Forward and backward visual masking in schizophrenia: influence of age

BACKGROUND

Visual masking tasks assess the earliest stages of visual processing. This study was conducted to address: (1) whether schizophrenia patients show masking deficits after controlling for sensory input factors; (2) whether patients have relatively intact forward masking (when the mask precedes the target) compared with backward masking (when the mask follows the target); and (3) whether the masking deficits in schizophrenia reflect an accelerated age-related decline in performance.

METHOD

A staircase method was used to ensure that the unmasked target identification was equivalent across subjects to eliminate any confounding due to differences in discrimination of simple perceptual inputs. Three computerized visual masking tasks were administered to 120 schizophrenia patients (ages 18-56) and 55 normal comparison subjects (ages 19-54) under both forward and backward masking conditions. The tasks included: (1) locating a target; (2) identifying a target with a high-energy mask; and (3) identifying a target with a low-energy mask.

RESULTS

Patients showed deficits across all three masking tasks. Interactions of group by forward versus backward masking were not significant, suggesting that deficits in forward and backward masking were comparable. All three conditions showed an age-related decline in performance and rates of decline were comparable between patients and controls. Two of the masking conditions showed increased rates of decline in backward, compared to forward, masking.

CONCLUSIONS

We found age-related decline in performance that was comparable for the two groups. In addition, we failed to find evidence of a relative sparing of forward masking in schizophrenia. These results suggest that: (1) early visual processing deficits in schizophrenia are not due to a simple perceptual input problem; (2) sustained channels are involved in the masking deficit (in addition to transient channels); and (3) for the age range in this study, these deficits in schizophrenia are not age-related.

Does 'errorless learning' compensate for neurocognitive impairments in the work rehabilitation of persons with schizophrenia?

BACKGROUND

Because neurocognitive impairments of schizophrenia appear to be 'rate limiting' in the acquisition of skills for community functioning, it is important to develop efficacious rehabilitative interventions that can compensate for these impairments. Procedures based on errorless learning may facilitate work rehabilitation because they effectively automate training of work and other skills, thereby reducing the cognitive burden on persons with schizophrenia.

METHOD

The present study examined the ability of a training method based on errorless learning to compensate for neurocognitive deficits in teaching two entry-level job tasks (index card filing and toilet-tank assembly) to a sample of 54 unemployed, clinically stable schizophrenic and schizoaffective disorder out-patients. Participants were randomly assigned to one of two training groups, errorless learning v. conventional trial-and-error type instruction. Prior to randomization, all subjects were administered a neurocognitive battery. Job task performance was assessed by percentage accuracy scores immediately after training.

RESULTS

For three of the six inter-relationships among neurocognitive functioning and training condition, the pattern was the same: the errorless learning group scored high in job task performance regardless of neurocognitive impairment, whereas the conventional instruction group showed a close correspondence between job task performance and degree of neurocognitive impairment.

CONCLUSIONS

These findings support errorless learning as a technique that can compensate for neurocognitive deficits as they relate to the acquisition of new skills and abilities in the work rehabilitation of persons with schizophrenia.

Neuropsychological functioning as a moderator of the relationship between psychosocial functioning and the subjective experience of self and life in schizophrenia

Psychosocial interventions and models of quality of life in schizophrenia are based on the notion that increases in psychosocial functioning will be related to improvements in subjective experience outcomes such as self-esteem and satisfaction with life. However, studies have repeatedly failed to demonstrate a direct relationship between psychosocial functioning and subjective experience in schizophrenia. This study of 40 individuals diagnosed with schizophrenia examined whether neurocognitive measures of executive functioning moderated the relationship between psychosocial functioning and subjective experience. Subjective experience was represented by measures of satisfaction with life and self-esteem. The Global Assessment Scale measured psychosocial functioning, and the Wisconsin Card Sorting Test measured executive functioning. Multiple regression and correlation analyses indicated that executive functioning was a strong moderator. Specifically, individuals with schizophrenia with impaired executive functioning displayed a positive and statistically significant association between psychosocial functioning and both measures of subjective experience (r = 0.55 and 0.61). However, among schizophrenia patients with intact executive performance, psychosocial functioning was negatively associated with self-esteem and satisfaction with life (r = -0.24 and -0.46). And the findings were internally replicated using two other neuropsychological measures relevant to executive functioning. These findings indicate that executive functioning plays a major role in moderating the relationship between subjective experience and psychosocial functioning in schizophrenia. Implications for biosocial models, psychosocial interventions, and models of quality of life in schizophrenia are discussed.

Attentional characteristics of schizophrenia patients differing in learning proficiency on the Wisconsin Card Sorting Test

The Wisconsin Card Sorting Test (WCST), a test of concept formation, was given to 49 schizophrenia inpatients in three blocks of 64 cards each with the second block comprising special instructions and trial-by-trial feedback. With the help of a psychometric algorithm based on linear regression analysis, the patients were classified according to their response to these specific interventions. Results yielded 15 high scorers, 23 learners, and 11 nonlearners. This a priori classification was confirmed by cluster analysis. Next, these groups were further analyzed with the Degraded Stimulus Continuous Performance Test (DS-CPT), a test of target discrimination, and the Test of Attentional Style (TAS), which assesses habitual, subjectively experienced attentional problems. A significant difference between high scorers and nonlearners was found for discriminative sensitivity (d'), with the learners achieving intermediate scores. Results for only the DS-CPT response criterion (beta) and a TAS subscale (Distractibility) tended to be significant. Discriminant analysis also revealed that d' is the most powerful variable for discriminating among the subgroups. The article also addresses baseline versus dynamic assessment, specific rehabilitation needs in subgroups of schizophrenia patients different in learner status, and the neurocognitive characteristics of the subgroups.

Risperidone versus haloperidol on secondary memory: can newer medications aid learning?

The introduction of the new generation of antipsychotic medications for the treatment of schizophrenia has been accompanied by a growing interest in the neurocognitive effects of these drugs. The present study compared the effects of risperidone and haloperidol on secondary memory in a group of treatment-resistant schizophrenia patients. The study design included a baseline phase and two double-blind phases in which patients were randomly assigned to medication under two different dose conditions (fixed dose and flexible dose). Secondary memory was assessed at baseline, fixed-dose, and flexible-dose phases, using the California Verbal Learning Test (CVLT). Six measures were selected, which formed three factors (general verbal learning ability, retention, and learning strategy). Risperidone-treated patients showed greater improvement than haloperidol-treated patients in general verbal learning ability, a finding characterized by significant treatment effects on CVLT measures of learning acquisition, recall consistency, and recognition memory. After controlling for benztropine status, differences on the measures of learning acquisition and recall consistency remained significant, and differences in recognition memory weakened slightly (p = 0.07). No significant treatment effects were noted on retention or learning strategy. These findings suggest that risperidone may exert a facilitating effect on the acquisition of new verbal information, an effect that does not appear to be due to the activation of semantic encoding strategies.

Translating the basic and clinical cognitive neuroscience of schizophrenia to drug development and clinical trials of antipsychotic medications

Neurocognitive deficits have become increasingly important defining features of schizophrenia and its treatment. Multiple domains of neurocognitive functions are impaired in schizophrenia patients, and these impairments are considered to be core features of the disorder. Many recent reports support the importance of the relationship of these neurocognitive deficits to measures of "functional outcome" such as social skills acquisition, social problem solving, and community outcome. Neurocognitive deficits appear to be improved with newer (atypical) antipsychotic medications across a broad range of domains in schizophrenia patients. Together with clinical neuroscience advances, basic research in cognitive neuroscience ranging from animal models of gating functions to early gene expression induced by antipsychotic medications has illuminated the specific neural basis of neurocognitive deficits in schizophrenia and the neurobiology of antipsychotic actions. These translational basic and clinical studies provide powerful screening tools and strategies for drug development and the subsequent assessment of the clinical efficacy of new antipsychotic medications. These interlocking clinical and basic research findings have substantial implications for improving both drug development and improving clinical trials methodology for antipsychotic medications. Thus, there is an informed translation and cross-fertilization between basic and clinical research focused on the development and assessment of putative new antipsychotic compounds.

Neurocognitive deficits and functional outcome in schizophrenia: are we measuring the "right stuff"?

There has been a surge of interest in the functional consequences of neurocognitive deficits in schizophrenia. The published literature in this area has doubled in the last few years. In this paper, we will attempt to confirm the conclusions from a previous review that certain neurocognitive domains (secondary verbal memory, immediate memory, executive functioning as measured by card sorting, and vigilance) are associated with functional outcome. In addition to surveying the number of replicated findings and tallying box scores of results, we will approach the review of the studies in a more thorough and empirical manner by applying a meta-analysis. Lastly, we will discuss what we see as a key limitation of this literature, specifically, the relatively narrow selection of predictor measures. This limitation has constrained identification of mediating variables that may explain the mechanisms for these relationships.

Concurrent validity of negative symptom assessments in treatment refractory schizophrenia: relationship between interview-based ratings and inpatient ward observations

The concurrent validity of interview-based ratings of negative symptoms in 35 inpatients with chronic, treatment refractory schizophrenia was evaluated. Correlations were examined between interview-based ratings of negative symptoms, measured by the Brief Psychiatric Rating Scale and the Positive and Negative Syndrome Scale, and the naturalistic behavior of inpatients as assessed by the Time Sample Behavior Checklist. Higher levels of interview-based negative symptoms were related to reduced interpersonal activity on the inpatient ward, but not to entertainment, instrumental or self-maintenance activities. These findings offer partial support for the concurrent validity of office-based ratings of negative symptoms, and highlight the importance of longitudinal observations of patients for accurate identification of negative symptoms.

Risperidone in treatment-refractory schizophrenia

OBJECTIVE

The purpose of this study was to evaluate the clinical safety and efficacy of risperidone compared to haloperidol in patients with treatment-refractory schizophrenia.

METHOD

Sixty-seven medication-unresponsive subjects were randomly assigned to treatment with risperidone (N = 34) or haloperidol (N = 33). After a 3-7 day-placebo washout period, there was a 4-week, double-blind, fixed-dose comparison trial that was followed by a 4-week, flexible-dose phase. Measures of clinical change were quantified by standard psychopathologic and neuromotor instruments.

RESULTS

Risperidone demonstrated clinical efficacy superior to that of haloperidol on the total Brief Psychiatric Rating Scale (BPRS) after the first 4 weeks of treatment. Risperidone did not show any advantage over haloperidol after an additional 4 weeks. Overall improvement on the BPRS at 4 weeks was significantly better for the risperidone group (24%) than for the haloperidol group (11%). Risperidone-treated subjects were significantly less likely than haloperidol-treated subjects to require concomitant anticholinergic medication after 4 weeks (20% versus 63%); they also had significantly les observable akathisia (24% versus 53%) and significantly less severe tardive dyskinesia. Baseline characteristics that correlated significantly with risperidone response were positive symptoms, conceptual disorganization, akathisia, and tardive dyskinesia.

CONCLUSIONS

Risperidone was better tolerated and more effective in a subset of patients with treatment-refractory schizophrenia. Positive psychotic symptoms and extrapyramidal side effects at baseline appear to be powerful predictors of subsequent response to risperidone.

Backward masking in unmedicated schizophrenic patients in psychotic remission: possible reflection of aberrant cortical oscillation

OBJECTIVE

Patients with schizophrenia consistently show performance deficits on measures of visual backward masking, but the nature of these deficits is not well understood. Performance deficits on backward masking tasks may indicate an underlying predisposition instead of the presence of illness, because deficits are present in unaffected first-degree relatives. Performance deficits in remitted patients would constitute converging support for this hypothesis.

METHOD

Eleven patients with recent-onset schizophrenia who were in a period of no medication use during remission of psychosis were compared with a matched normal group on three visual masking conditions. These conditions included target identification tasks with a high-energy mask, a low-energy mask, and a blurred target.

RESULTS

Patients in psychotic remission showed significant deficits across all conditions. In addition, trend analyses revealed significant group differences in the shape of the masking functions: the comparison group showed an oscillating performance pattern across all masking conditions, whereas the patients did not exhibit this pattern on any condition.

CONCLUSIONS

These data from patients in well-documented psychotic remission add converging support for the hypothesis that deficits on backward masking procedures are indicators of vulnerability to schizophrenia. Because visual masking procedures may reflect underlying neural oscillations of 30 to 70 Hz in the visual cortex, the pattern of results is consistent with the theory that visual masking deficits in schizophrenia stem from an underlying failure to establish cortical oscillations.

Should schizophrenia be treated as a neurocognitive disorder?

The search is on for meaningful psychopharmacological and cognitive/behavioral interventions for neurocognitive deficits in schizophrenia. Findings in this area are emerging rapidly, and in the absence of integrating frameworks, they are destined to emerge chaotically. Clear guidelines for testing neurocognitive interventions and interpreting results are critical at this early stage. In this article, we present three models of increasing complexity that attempt to elucidate the role of neurocognitive deficits in schizophrenia in relation to treatment and outcome. Through discussion of the models, we will consider methodological issues and interpretive challenges facing this line of investigation, including direct versus indirect neurocognitive effects of antipsychotic medications, selection of particular neurocognitive constructs for intervention, the importance of construct validity in interpreting cognitive/behavioral studies, and the expected durability of treatment effects. With a growing confidence that some neurocognitive deficits in schizophrenia can be modified, questions that seemed irrelevant only a few years ago are now fundamental. The field will need to reconsider what constitutes a successful intervention, what the relevant outcomes are, and how to define treatment efficacy.

Trait versus state aspects of the MMPI during the early course of schizophrenia

Scores on the Minnesota Multiphasic Personality Inventory (MMPI)-168 item version were examined during periods of clinical remission and of psychosis for recent-onset schizophrenia patients (n = 19) and at comparable time intervals for demographically matched normal participants (n = 19). To determine diagnostic specificity, MMPIs for participants with bipolar affective disorder in remission (n = 12) were also examined. Methods for distinguishing between stable vulnerability indicators, mediating vulnerability factors and episode indicators of psychopathology were adapted from Nuechterlein and Dawson (1984). MMPI scales Pa, Sc and validity scale F showed a combination of trait and state qualities, characteristic of mediating vulnerability factors. These scales reflect changes that occur during psychotic episodes but also apparently tap personality characteristics that endure into periods of clinical remission. Unexpectedly, some MMPI scales that are not typically associated with psychotic disorders (i.e. Hs, D, and Hy) were significantly higher in schizophrenia patients across psychotic and clinically remitted states than in normal participants. In clinical remission, higher scores on scales Hs, D and Hy, showed some specificity to schizophrenia relative to bipolar disorder. While MMPI-168 scales Pd and Pt fit the pattern for vulnerability indicators, it was uncertain whether they belonged to the 'stable' versus 'mediating' subtype. MMPI scores that continue to be higher in remission than in a normal sample may reflect either enduring vulnerability factors or the impact of schizophrenia and the individuals' attempts to cope with the disorder. Studies of first-degree relatives will be needed to provide converging evidence that certain personality characteristics reflect genetic predisposition to schizophrenia.

Backward masking performance as an indicator of vulnerability to schizophrenia

Several types of design have been used to identify neurocognitive measures that indicate vulnerability to schizophrenia rather than the presence of the illness. These designs include studies of first-degree relatives of patients, studies of patients in symptomatic remission, and studies of subjects who are considered to be prone to psychosis. The backward masking procedure is one promising indicator of vulnerability to schizophrenia. Backward masking is a procedure in which identification of an initial stimulus (the target) is disrupted by a later stimulus (the mask). Schizophrenic patients show performance deficits on backward masking. Unaffected siblings of patients, remitted patients, and individuals prone to psychosis also show performance deficits on backward masking. This pattern of results suggests that backward masking is a promising indicator of vulnerability to schizophrenia. It provides an alternative phenotype for schizophrenia that is separate from the disorder. The composite nature of masking procedures helps investigators to parse a performance deficit into its smallest meaningful elements and relate them to vulnerability to schizophrenia.

Atypical handedness in schizophrenia: some methodological and theoretical issues

An updated review of the literature strongly supports the view that in schizophrenia there is an atypical leftward shift in the handedness distribution that, while comprising different subtypes, is characterized by a more variable and less completely lateralized pattern of manual preference, referred to as mixed handedness (MH) or ambiguous handedness (AH). Only two studies revealed an increased prevalence of left-handedness suggestive of pathological left-handedness (PLH). This article also examines the current status of neurodevelopmental factors and mechanisms in schizophrenia that purport to explain these pathological shifts in handedness (PLH, MH, AH). Different theoretical positions were evaluated, each involving some aspect of left hemisphere insult (unilateral or bilateral). Finally, it was shown that these shifts predict certain key symptoms and neural substrates in schizophrenia including thought disorder, negative symptoms, neuropsychological impairment, family history, and brain anatomy. These subtypes may represent neurodevelopmental markers of insult during intrauterine life that are nongenetic in origin.

Hemispheric asymmetry in schizophrenia: a "dual deficits" model

BACKGROUND

The aim was 1) to investigate left hemisphere functional integrity for auditory language processing in schizophrenic patients; and 2) to investigate the interaction between brain laterality and attentional processing by having subjects shift attention to the left or right ear.

METHODS

The subjects were 33 schizophrenic inpatients, and 33 healthy comparison subjects with the same age, handedness, and gender distribution as the patient subjects. All subjects were tested with dichotic listening (DL) to consonant-vowel syllables, which is a measure of lateralized temporal lobe language processing. The subjects were tested under three different attentional conditions: a non-forced attention condition, attention focused to the right ear stimulus, and attention focused to the left ear stimulus.

RESULTS

The main findings were 1) an absence of the expected right ear advantage in the schizophrenic group during the non-forced attention condition; and 2) a failure to modify DL performance through shifting of attention to either the right or left ear. The comparison group showed a right ear advantage during the non-forced and forced-right attention conditions (increased right ear advantage during the forced-right condition), and a left ear advantage during the forced-left attention condition. There were no significant effects of handedness.

CONCLUSIONS

This pattern of results may indicate a "dual deficit" involving both automatic and controlled processing deficits in schizophrenia.

Monetary reinforcement and Wisconsin Card Sorting performance in schizophrenia: why show me the money?

The Wisconsin Card Sorting Test (WCST) is a measure of concept formation and cognitive flexibility that has been associated with the integrity of the dorsolateral prefrontal cortex. Although patients show deficits on the WCST, training techniques that rely on enhanced instruction are often effective at improving performance, at least temporarily. The beneficial effects of monetary reinforcement alone, however, have not shown such clear-cut effects. Thirty-two schizophrenic inpatients were initially administered a computerized version of the WCST according to standard instructions and then assigned to one of four groups that differed by type of intervention. The level of reinforcement (high vs. low) and enhanced instruction (present vs. absent) were manipulated across the four groups. All patients received a repeat standard administration of the WCST at a 1-week follow-up. Although enhanced instruction showed an initial effect, performance gains fell off at the 1-week retest and approached baseline levels of performance. The level of reinforcement did not make a significant difference. The results indicate that the addition of enhanced verbal instruction yields a benefit, but that contingent monetary reinforcement does not. It appears that deficits on this test are not easily remediated by incentive manipulations.

Perception of emotion and neurocognitive functioning in schizophrenia: what's the link?

In schizophrenia, relatively little is known about the association between deficits in emotion perception and basic neurocognitive functioning. The present study examined perception of emotion and a discrete set of neurocognitive functions in 28 treatment-resistant schizophrenic patients. Measures of emotion perception included a facial emotion identification test (still photographs presented on videotape), a voice emotion identification test (audiotape), and an affect perception test (brief interpersonal vignettes presented on videotape). Measures of neurocognitive functioning were selected based on hypothesized relationships to perception of emotion. These measures included: (a) Span of Apprehension task, a measure of early visual processing, visual scanning, and iconic read-out; (b) Degraded-Stimulus Continuous Performance Test, a measure of visual vigilance; and (c) Digit Span Distractibility Test, a measure of immediate or working memory. Among these measures, performance on the Span of Apprehension strongly correlated with performance on all three emotion perception tasks. The associations between perception of emotion and the other two measures were in the same direction, but were significantly smaller than those of the Span of Apprehension. These findings implicate the importance of early perceptual processing (i.e. visual scanning) in the ability of schizophrenic individuals to perceive emotion.

Risperidone vs. haloperidol on reaction time, manual dexterity, and motor learning in treatment-resistant schizophrenia patients

BACKGROUND

The present study compared the effects of risperidone vs. haloperidol on reaction time, manual dexterity, and two types of motor learning in a sample of treatment-resistant schizophrenia patients.

METHODS

Fifty-six DSM-III-R diagnosed schizophrenia inpatients participated in a randomized, double-blind comparison of risperidone vs. haloperidol. Measures of reaction time, manual dexterity, motor sequence learning, and gross motor learning were administered at baseline, after 4 weeks of fixed-dose medication, and after 4 weeks of flexible-dose medication.

RESULTS

The results indicated that patients receiving risperidone showed greater improvement in reaction time and manual dexterity than patients receiving haloperidol. After covarying symptom changes and movement disorder ratings, the results remained significant. The two treatment groups did not differ on either measure of motor learning.

CONCLUSIONS

The differences in performance in reaction time and manual dexterity may be due to a specific beneficial effect of risperidone, as opposed to a general reduction in extrapyramidal symptom liability, compared to haloperidol.

Prediction of the deficit syndrome from initial deficit symptoms in the early course of schizophrenia

The Proxy for the Deficit Syndrome (PDS) was used with longitudinal symptom assessment data to identify recent-onset schizophrenia patients with the deficit syndrome. We evaluated the stability of deficit symptoms using repeated assessments. Symptom ratings were examined at an initial point of outpatient stabilization on antipsychotic medication as well as prospectively over the subsequent 12 months of outpatient treatment and assessment in 83 recent-onset schizophrenia patients. The vast majority of patients who were classified as non-deficit at the cross-sectional baseline assessment continued to remain non-deficit throughout the first year of treatment. However, patients classified as deficit at baseline did not consistently remain classified as showing deficit syndrome during the follow-through period. Thus, the presence of deficit symptoms detected in a single cross-sectional rating may be an inaccurate way to rate the deficit syndrome, yielding excessive false positives. Our use of longitudinal data allowed the stability criterion of the deficit syndrome to be evaluated using the PDS.

Training and quality assurance with the Structured Clinical Interview for DSM-IV (SCID-I/P)

Accuracy in psychiatric diagnosis is critical for evaluating the suitability of the subjects for entry into research protocols and for establishing comparability of findings across study sites. However, training programs in the use of diagnostic instruments for research projects are not well systematized. Furthermore, little information has been published on the maintenance of interrater reliability of diagnostic assessments. At the UCLA Research Center for Major Mental Illnesses, a Training and Quality Assurance Program for SCID interviewers was used to evaluate interrater reliability and diagnostic accuracy. Although clinically experienced interviewers achieved better interrater reliability and overall diagnostic accuracy than neophyte interviewers, both groups were able to achieve and maintain high levels of interrater reliability, diagnostic accuracy, and interviewer skill. At the first quality assurance check after training, there were no significant differences between experienced and neophyte interviewers in interrater reliability or diagnostic accuracy. Standardization of training and quality assurance procedures within and across research projects may make research findings from study sites more comparable.

Risperidone versus haloperidol for perception of emotion in treatment-resistant schizophrenia: preliminary findings

Currently, little is known about the pharmacological effects of the new generation of antipsychotic medications on perception of emotion in schizophrenia. The present study was designed to compare the effects of risperidone versus haloperidol on the ability to perceive emotion in 20 treatment-resistant schizophrenia patients, using a double-blind design. Measures of emotion perception included a facial emotion identification test (still photographs presented on videotape), a voice emotion identification test (audiotape), and an affect perception test (brief interpersonal vignettes presented on videotape). These measures were administered during the final week of baseline and after 8 weeks of double-blind medication. Risperidone treatment produced a greater effect on patients' ability to perceive emotion compared with haloperidol treatment. Additionally, all patients who received risperidone demonstrated improvement in performance between baseline and retest, compared with four of the nine patients who received haloperidol. When changes in positive symptoms were statistically controlled, the results remained significant. These findings suggest that resperidone may facilitate patients' ability to accurately perceive emotion, an effect which may be mediated either directly by risperidone's pharmacological action or perhaps indirectly by its influence on basic neurocognition.

Neurocognitive impairments associated with ambiguous handedness in the chronically mentally ill

One form of atypical handedness, ambiguous handedness, is found in roughly one-quarter of chronic schizophrenic patients. Despite its prevalence, relatively little is known about the neurocognitive underpinnings of ambiguous handedness. In the present study we examined the performance of ambiguous (n = 19) and non-ambiguous (n = 39) handed chronically mentally ill inpatients on selected measures of verbal learning, motor learning and manual dexterity. The results revealed that ambiguous handers were more impaired than non-ambiguous handers in verbal learning, but not motor learning. Group differences in manual dexterity were significant for the entire sample, but not when analyses were limited to males. These findings suggest that impairments in verbal learning may be linked to the pathogenesis of ambiguous handedness in chronic psychiatric patients.

Normal neurocognitive performance after extended practice in patients with schizophrenia

This study evaluated new methods for improving the performance of patients with schizophrenia on specific neurocognitive tasks. Patients (n = 22) practiced sustained perceptual, memory and motor tasks 5 times/week for 10 weeks. Tasks were initially easy enough for patients to do well, but were made gradually more difficult over the 10 weeks. Patients received base pay and performance-based monetary supplements. No coaching or ongoing instruction was provided, and performance gains were assumed to depend upon implicit learning. High functioning healthy controls (n = 5) were given the same tasks at difficulty levels comparable to those achieved by patients after 10 weeks of practice. After 10 weeks of practice, 16 of the 22 patients performed as well or better than the best control on the perceptual and memory tasks, and 11 patients performed within the range of control subjects on the motor task. Half of the patients retested 6 months after training maintained supranormal performance, while the others showed marked performance declines. Patients with schizophrenia appear to have greater potential for neurocognitive improvement, and potentially for employment, than generally appreciated.