Biomedical subjects

Steven M Silverstein

Publications and source records attributed to Steven M Silverstein.

At least 19 recordsLinked to original sources

PubMed2026

The effect of monetary versus point-based rewards on effort-cost decision making in individuals at clinical high risk for psychosis.

OBJECTIVE: The dissemination of inexpensive computerized behavioral tasks indexing amotivation may enhance the assessment of clinical high risk (CHR) across settings. However, the impact of varying reward value in such tasks is unclear. If point-based rewards engage participants, this could improve the scalability of computerized assessments. We tested how point-based rewards versus money impacted effort-cost decision-making in CHR individuals. We further assessed how negative symptom severity and household income interacted with reward-type to impact behavior. METHODS: Participants completed the Effort Expenditure for Reward Task (EEfRT). Participants were randomly assigned to receive either money or points for their performance during the EEfRT. Data from a large sample of CHR (N = 233) individuals and healthy controls (HC; N = 157) were collected. RESULTS: Across diagnostic groups, we observed heightened effort expenditure when money was used as a reward (b = 0.13, p = 0.018). We did not find an interaction of CHR status (b = 0.07, p = 0.845) or negative symptoms (b = 0.01, p = 0.429) with reward-type. Within CHR individuals, heightened negative symptom severity was associated with reduced expended effort (b = -0.03, p = 0.016), regardless of reward type. In an exploratory analysis, we found that individuals in the money condition with relatively high household income expended less effort during high reward, high probability trials (b = -0.24, p = 0.046). CONCLUSIONS: Across CHR and HC individuals, individuals pursuing money expended greater effort. While we did not find a group by reward type interaction, CHR individuals with heightened negative symptom severity expended less effort across trials, replicating prior work. Present findings support further study of point-based rewards in tasks indexing amotivation.

Humans↗

PubMed2006

Perceptual grouping in disorganized schizophrenia.

This study evaluated visual perceptual grouping in schizophrenia to test the hypothesis that the disorganization syndrome in schizophrenia is related to a deficit in cognitive coordination. Perceptual grouping was examined with three psychophysically well-controlled tasks in patients with disorganized schizophrenia (n=11), non-disorganized schizophrenia (n=24), psychotic disorders other than schizophrenia (n=31) and non-psychotic psychiatric disorders (n=35). These measures assessed processing of both concurrent and preceding stimulus context. Deficits in perceptual grouping were observed on all three tasks in disorganized schizophrenia patients. Dysfunctional perceptual grouping mechanisms produced both enhanced and impaired task performance suggesting that the pattern of performance observed was the result of a specific deficit in the grouping of stimulus elements. We interpret these data as further support for the hypothesis that the disorganization syndrome in schizophrenia reflects a widespread deficit in the cognitive coordination of contextually related stimuli, leading to dysfunctional grouping of stimulus features in vision, thought and language.

Adult↗

PubMed2006

Learning potential as a predictor of readiness for psychosocial rehabilitation in schizophrenia.

It has been suggested that learning potential (LP), a patient's ability to benefit from training and practice, may mediate the relationship between cognition and functional outcome. Aims of this study were to (1) assess whether performance on a verbal memory-based measure of LP is associated with readiness for psychosocial rehabilitation; and (2) assess whether explicit cognitive training in memory strategies improves task performance beyond any implicit learning of organizational strategies that occurs with repeated exposure to to-be-learned material. Fifty outpatients with schizophrenia or schizoaffective disorder were administered three different versions of a list-learning test, the California Verbal Learning Test (CVLT-II). Some patients also received explicit training in semantic memory strategies before administration of the second word list. Based on performance across the three assessments, participants were categorized as "learners", "high scorers", and "non-learners". Participants were also administered the Micromodule Learning Test (MMLT), a measure that predicts performance in manualized skill training groups. LP categorization was associated with performance on the MMLT. High scorers performed better than the other two groups, and as found in earlier studies, education level was associated with performance for the learners. Explicit semantic clustering training was associated with increases in the use of the trained strategy.

Adult↗

PubMed2006

Reduced top-down influences in contour detection in schizophrenia.

INTRODUCTION: Chronic schizophrenia patients have previously demonstrated performance deficits in contour integration tasks. The purpose of this study was to investigate whether schizophrenia patients, spanning a range of illness severity, would demonstrate responsiveness to manipulations that recruit top-down processing strategies involving learning and sequencing effects in a contour integration task. METHODS: We administered a contour integration test over four consecutive days and in two different presentation conditions each day. In one condition, the stimuli were administered in order of increasing difficulty, and in the other they were presented in random order. The order in which these two conditions were presented was counterbalanced across days and participants. In addition, a nonschizophrenia psychotic disorders control group was included to determine if past findings of a contour integration deficit in schizophrenia could be replicated in the presence of a symptomatically similar control group. RESULTS: All groups demonstrated similar learning curves across the four days and generally similar overall levels of performance, with the exception of the group of the most chronic schizophrenia patients. In addition, the order in which the stimuli were presented to subjects affected their performance, with higher scores achieved for all groups in the condition where the stimuli were presented in increasing order of difficulty. Interaction effects revealed that the effects of order presentation were greater for nonpatient than for psychotic patients. CONCLUSIONS: These data are further evidence that perceptual organization impairments in schizophrenia are illness severity-related, and that schizophrenia patients as a whole are less sensitive to top-down manipulations in this type of task.

Adult↗

PubMed2006

Comparing bimatoprost and travoprost in black Americans.

OBJECTIVE: To compare the intraocular pressure-lowering efficacy and safety of topical bimatoprost 0.03% with that of travoprost 0.004% for the treatment of black patients with open-angle glaucoma (OAG) and ocular hypertension (OHT). RESEARCH DESIGN AND METHODS: Multicenter, prospective, randomized, investigator-masked trial of 94 black patients previously diagnosed with OAG or OHT. All patients completed washout of ocular hypotensive medications before study participation. Patients were assigned to either once-daily bimatoprost 0.03% or once-daily travoprost 0.004% for 3 months. MAIN OUTCOME MEASURES: The primary outcome measures were mean intraocular pressure (IOP), mean change from baseline IOP, and percentage of patients who reached a target IOP reduction. Secondary measures included ophthalmologic examination and adverse events. RESULTS: Both bimatoprost and travoprost significantly lowered IOP at all study visits (p < 0.001). Bimatoprost provided mean IOP reductions from baseline that ranged from 6.8 mmHg to 7.8 mmHg (27% to 31%). Travoprost provided mean IOP reductions from baseline that ranged from 6.2 mmHg to 6.9 mmHg (25% to 28%). By month 3, 85% of participants in the bimatoprost group had a mean IOP reduction of at least 20%, compared with 68% of those in the travoprost group. Furthermore, 31.9% of those in the bimatoprost group had a mean IOP reduction of more than 40% at month 3 compared with 20.9% of those in the travoprost group. There were no significant differences in biomicroscopy, ophthalmoscopy, or visual acuity. Ocular redness was the most commonly reported adverse event in both treatment groups. No serious adverse events were reported. CONCLUSIONS: Bimatoprost and travoprost each effectively lowered IOP in this population of black patients. More patients achieved clinically relevant IOP reductions with bimatoprost.

Administration, Topical↗

PubMed2005

Histories of childhood maltreatment in schizophrenia: relationships with premorbid functioning, symptomatology, and cognitive deficits.

A number of studies have demonstrated an increased rate of histories of childhood maltreatment among adults with serious mental illness. The present investigation documented the presence of childhood maltreatment in a sample of 40 psychiatric inpatients with schizophrenia spectrum disorders. The type (neglect, physical abuse, sexual abuse), duration, and severity of childhood maltreatment was examined along with measures of premorbid functioning, current symptomatology, and cognitive functioning. Participants with histories of maltreatment were significantly more likely to have poorer peer relationships in childhood, more difficulty in school, an earlier age at first hospitalization, more previous hospitalizations, elevated symptoms of anxiety, depression, and suicidality on the Brief Psychiatric Rating Scale (BPRS), and more impaired performance on a task of visual-perceptual organization. Severity and frequency of childhood maltreatment were both positively correlated with hallucinations and delusions on the BPRS. Linear trend analysis indicated a pattern of more severe impairment as the number of types of maltreatment increased. No relationships were found between maltreatment and measures of executive functioning, verbal fluency, or verbal processing speed. A history of childhood maltreatment appears to be a significant determinant of premorbid functioning, illness-related symptom expression, and specific forms of cognitive dysfunction.

Adult↗

PubMed2005

Poor premorbid social functioning and theory of mind deficit in schizophrenia: evidence of reduced context processing?

Investigations have demonstrated deficits in theory of mind (ToM) ability in schizophrenia. Yet, the development of, and mechanisms associated with these deficits are not well understood. The present investigation examined the hypothesis that, among chronic schizophrenia patients, impaired ToM is associated with failures in context processing, greater disorganized symptoms, and poor premorbid functioning. Forty-two inpatients with schizophrenia spectrum disorders were assessed on tests of ToM, visual and linguistic context processing, executive functioning, and verbal IQ. Symptomatology and premorbid functioning were also assessed. Results revealed that more impaired ToM was associated with poorer performance on both visual and linguistic context processing measures and higher ratings of disorganization on the BRRS. ToM was also associated with poorer childhood social functioning and an earlier age of illness onset. ToM was not associated with verbal processing speed, verbal fluency, response inhibition, sequence learning, or estimated verbal IQ. A significant regression model including measures of childhood peer problems and visual and language context processing significantly predicted ToM performance and accounted for 43% of the variance. These findings suggest that, among chronic schizophrenia patients, deficits in ToM ability may be the result of context processing impairments. These impairments may be a factor in both poor social functioning during childhood and greater disorganized symptoms after illness onset.

Adult↗

PubMed2005

The micro-module learning tests: work-sample assessments of responsiveness to skills training.

While outcome of psychiatric rehabilitation has been successfully predicted by cognitive tests, efforts to design a measure to assess responsiveness to rehabilitation have been lacking. In this report, we describe the rationale for and development of a face-valid measure of responsivity to the three core components of skills training: responsiveness to verbal instruction, ability to learn from viewing the behavior of a model, and ability to demonstrate skills observed during a subsequent role-play. Seven alternate forms of the new measure, called the Micro-Module Learning Test (MMLT), demonstrated adequate internal consistency and alternate-form reliability. We also present results from four studies in which the MMLT was used to collect normative data as well as data on relationships with symptoms, cognitive tests, and treatment outcome. Results indicate that the MMLT is associated with cognitive factors found to predict treatment outcome in prior studies (e.g., verbal memory and fluency), as well as lesser investigated functions such as theory of mind ability. In addition, MMLT scores were correlated negatively with psychotic disorganization and positively with performance during a full-length skills training group. The MMLT appears to be a reliable and valid measure for rapidly assessing responsiveness to skills training procedures.

Adult↗

PubMed2005

Effectiveness of a two-phase cognitive rehabilitation intervention for severely impaired schizophrenia patients.

BACKGROUND: Several small-N, uncontrolled reports have demonstrated that the behavioral technique of attention shaping has significantly increased attention span among severely ill schizophrenia patients. METHOD: In this study, we evaluated the effectiveness of using an individually administered intervention for improving sustained attention, Attention Process Training (APT), followed by an attention-shaping procedure within the context of an ongoing skills training group. Patients were randomly assigned to receive either the APT and attention-shaping sequence (n = 18) or equivalent hours of treatment in the same intensive behavioral rehabilitation program (n = 13). RESULTS: Results indicated dramatic improvements in attentiveness in the cognitive rehabilitation condition compared with the control condition, which demonstrated essentially no change in attentiveness over the 12 weeks of treatment. The attention-shaping intervention appeared to account for the majority of the effect. In contrast to the observational data, performance on neuropsychological tests was unaffected by the cognitive interventions. CONCLUSIONS: This two-phase intervention demonstrated effectiveness in promoting attentive behavior among chronic schizophrenia patients with severe attentional impairment.

Adult↗

PubMed2005

Perceptual organization in schizophrenia spectrum disorders: empirical research and theoretical implications.

The research into perceptual organization in schizophrenia spectrum disorders has found evidence for and against a perceptual organization deficit and has interpreted the data from within several different theoretical frameworks. A synthesis of this evidence, however, reveals that this body of work has produced reliable evidence for deficits in schizophrenia, as well as for the clinical, stimulus, and task parameters associated with normal and abnormal performance. Recent models of cognition have also advanced understanding of the underlying pathophysiological processes of perceptual organization dysfunction in schizophrenia spectrum disorders. These suggest that deficits in perceptual organization may be one manifestation of a wider disturbance in the integration of contextually related information across space and time.

Empirical Research↗

PubMed2005

Effects of stimulus structure and target-distracter similarity on the development of visual memory representations in schizophrenia.

INTRODUCTION: In a previous study (Silverstein, Bakshi, Chapman, & Nowlis, 1998a, Cognitive Neuropsychiatry) we demonstrated that while schizophrenia patients showed similar learning curves as nonpatient controls when determining whether a configural pattern of elements has been seen before or not, they did not demonstrate any learning curve with nonconfigural stimuli (in contrast to controls). Methodological limitations of that study, however, precluded generalisability of those effects. METHODS: In the present study, therefore, different groups of schizophrenia patients (n = 18) and controls (n = 22) were administered a modified version of the familiarity judgement task used in Silverstein et al. (1998a). In the new version of the task: (1) the patterns that repeated were different for each participant; and (2) half of the nonrepeating patterns were configural and half were nonconfigural. RESULTS: These indicated stronger perceptual learning effects for the configural compared to the nonconfigural patterns, and overall better performance and more pronounced learning effects for the control group. CONCLUSIONS: The data provide further evidence for a schizophrenia-related impairment in perceptual organisation and in the ability to develop memory representations for novel stimuli.

Journal Article↗

PubMed2004

The course and clinical correlates of dysfunctions in visual perceptual organization in schizophrenia during the remission of psychotic symptoms.

This study evaluated deficits in visual perceptual organization in schizophrenia over the course of inpatient treatment, in relation to the remission of particular psychotic symptoms. Disorganized (n=14) and non-disorganized (n=33) schizophrenia patients were tested upon admission to an inpatient psychiatric unit, and again after 3 weeks of treatment, on two measures of visual perceptual organization. Performance of schizophrenia patients was compared to groups of patients with psychotic disorders other than schizophrenia (n=19) and non-psychotic psychiatric disorders (n=25). Symptom ratings were collected at both assessment points. Deficits in visual perceptual organization were observed for both tasks in disorganized schizophrenia patients at index and these deficits improved during the course of treatment. Moreover, improvement in visual perceptual organization correlated significantly with reductions in disorganized symptoms in the schizophrenia group. We interpret these data as further support for the hypothesis that the disorganization syndrome in schizophrenia reflects a widespread deficit in the cognitive coordination of contextually related stimuli, leading to dysfunctional organization of stimulus features in vision, thought and language.

Adult↗

PubMed2004

Evidence for impaired visual context processing in schizotypy with thought disorder.

Visual context processing was examined in relation to schizotypy in a large nonclinical university population. Schizotypal status was assessed with the Schizotypal Personality Questionnaire (SPQ) [Schizophr. Bull. 17 (1991) 555]. Schizotypal (n=32) and non-schizotypal (n=37) subjects were tested on a contour integration task (where context processing is necessary for good performance) and a visual size perception task (where context processing impairs accurate performance). In addition, a short form of the Thought Disorder Index (TDI) [Psychol. Assess. 5 (1993) 75] was administered to 28 schizotypal subjects. Thought disordered schizotypal subjects showed significantly impaired performance on the contour integration task but more accurate performance on the visual size perception task. These results support the hypothesis that deficits in visual context processing are the manifestation of a larger disturbance of cognitive coordination in schizotypy and schizophrenia.

Adult↗

PubMed2004

At issue: The future of cognitive rehabilitation of schizophrenia.

Cognitive rehabilitation is becoming an increasingly popular intervention in treatment programs for people with schizophrenia. Despite this increased acceptance, however, the evidence base on its effectiveness is not impressive. Moreover, given the evidence of cognitive recovery in treated patients who do not receive cognitive rehabilitation--from newer medications and from other evidence-based psychosocial interventions--it is not clear whether cognitive rehabilitation is worth its expense in time and resources. We believe that the slow progress in the field of cognitive rehabilitation of schizophrenia is related to failure to address several critical issues: (1) the importance of manipulating stimulus and context structure in rehabilitative interventions; (2) the need to base a cognitive rehabilitation of schizophrenia on cognitive neuroscience as opposed to neuropsychology; (3) the importance of systematically addressing motivation, self-esteem, and affective factors when designing cognition-enhancing interventions; (4) the need to move beyond one-size-fits-all interventions and develop individualized treatments; and (5) the need to address abnormalities in the experience of the self when designing interventions to optimize cognitive and behavioral performance. Suggestions for addressing these issues are discussed.

Affect↗

PubMed2004

Dimensions of premorbid functioning in schizophrenia: a review of neuromotor, cognitive, social, and behavioral domains.

After a brief discussion of methods for studying the premorbid period in schizophrenia, the authors review relevant experimental literature to assess the validity of current theories. A critical review is provided that includes representative empirical investigations on premorbid functioning in schizophrenia in the domains of neuromotor, intellectual, academic, cognitive, social, emotional, and behavioral functioning. Limitations of past research, such as lack of specificity to schizophrenia populations, high incidences of false positives, questionable definitions of the premorbid period, inconsistent measures of premorbid functioning, and problems with the current method of DSM classification are discussed. Alternative approaches to studying early functioning in schizophrenia are highlighted.

Achievement↗

PubMed2004

[Clinical management and rehabilitation of the treatment refractory patient: conceptual foundations and outcome data].

Despite advances in psychopharmacology for people with schizophrenia, many patients remain too disabled to be discharged from public psychiatric facilities. This paper describes the development of a public-private partnership which led to the creation of a specialized, intensive behavioral rehabilitation program for schizophrenia patients who were considered to be treatment-refractory at public hospitals. The essential elements of this treatment program are described, along with the philosophical bases of its treatment. Outcome data are discussed to emphasize the point that when evidence-based treatment is implemented with this population, outcomes can be positive in most cases, and therefore, the number of "treatment-refractory" patients is actually less than is estimated based on response to medication alone.

Humans↗

PubMed2004

[Interpersonal techniques for optimizing positive outcomes in the inpatient psychiatric rehabilitation of schizophrenia].

There now exist a number of milieu-based and group-based behavioral treatments that have demonstrated effectiveness with so-called "treatment-refractory" schizophrenia patients. These interventions are not likely to achieve their maximal impact, however, unless program staff consistently employ behavioral principles in their moment-to-moment interactions with patients throughout the day. In this paper we describe a number of interpersonal techniques that are effective in dealing with a variety of institutionalized/dependent and provocative/aggressive behaviors. Each technique is explained and detailed examples are given to demonstrate appropriate and inappropriate staff responses to patient behavior. The discussion ends with the description of a successful behavior contract that employed a number of these techniques.

Behavior Therapy↗

PubMed2004

[Techniques for improving attentiveness and treatment engagement among "treatment refractory" schizophrenia patients with severe cognitive impairment].

While many effective group-based psychiatric rehabilitation interventions now exist, many severely disabled patients are unable to benefit from them due to a reduced ability to pay attention in group sessions. Moreover, inattentiveness can be due to one or more of multiple factors, including a sustained attention deficit, poor motivation, sedating side effects of medication, and the interfering effects of hallucinations and disturbing thoughts. Existing cognitive rehabilitation interventions for schizophrenia typically do not address these factors, instead targeting higher level functions such as memory, learning, problem-solving, and executive functioning. In this paper, we describe techniques for promoting attentiveness and treatment engagement among severely disabled "treatment-refractory" patients. This includes both individual and group-based interventions.

Attention↗