Nadine Revheim

Sensory Contributions to Impaired Prosodic Processing in Schizophrenia

BACKGROUND Deficits in affect recognition are prominent features of schizophrenia. Within the auditory domain, patients show difficulty in interpreting vocal emotional cues based on intonation (prosody). The relationship of these symptoms to deficits in basic sensory processing has not been previously evaluated. METHODS Forty-three patients and 34 healthy comparison subjects were tested on two affective prosody measures: voice emotion identification and voice emotion discrimination. Basic auditory sensory processing was measured using a tone-matching paradigm and the Distorted Tunes Test (DTT). A subset of subjects was also tested on facial affect identification and discrimination tasks. RESULTS Patients showed significantly impaired performance on all emotion processing tasks. Within the patient group, a principal components analysis demonstrated significant intercorrelations between basic pitch perception and affective prosodic performance. In contrast, facial affect recognition deficits represented a distinct second component. Prosodic affect measures correlated significantly with severity of negative symptoms and impaired global outcome. CONCLUSIONS These results demonstrate significant relationships between basic auditory processing deficits and impaired receptive prosody in schizophrenia. The separate loading of auditory and visual affective recognition measures suggests that within-modality factors may be more significant than cross-modality factors in the etiology of affect recognition deficits in schizophrenia.

Impaired visual object processing across an occipital-frontal-hippocampal brain network in schizophrenia: an integrated neuroimaging study.

CONTEXT Perceptual closure is the ability to identify objects based on partial information and depends on the function of a distributed network of brain regions that include the dorsal and the ventral visual streams, prefrontal cortex (PFC), and hippocampus. OBJECTIVE To evaluate network-level interactions during perceptual closure in schizophrenia using parallel event-related potential (ERP), functional magnetic resonance imaging (fMRI), and neuropsychological assessment. DESIGN Case-control study. SETTING Inpatient and outpatient facilities associated with the Nathan Kline Institute for Psychiatric Research. Patients Twenty-seven patients with schizophrenia or schizoaffective disorder and 23 healthy controls. Intervention Event-related potentials were obtained from 24 patients and 20 healthy volunteers in response to fragmented (closeable) and control-scrambled (noncloseable) line drawings. Functional MRI was performed in 11 patients and 12 controls. Main Outcome Measure Patterns of between-group differences for predefined ERP components and fMRI regions of interest were determined using both analysis of variance and structural equation modeling. Global neuropsychological performance was assessed using standard neuropsychological batteries. RESULTS Patients showed impaired generation of event-related components reflecting early sensory and later closure-related activity. In fMRI, patients showed impaired activation of the dorsal and ventral visual regions, PFC, and hippocampus. Impaired activation of dorsal stream visual regions contributed significantly to impaired PFC activation, which contributed significantly to impaired activation of the hippocampus and ventral visual stream. Impaired ventral stream and hippocampal activation contributed significantly to deficits on neuropsychological measures of perceptual organization. CONCLUSIONS Schizophrenia is associated with severe activation deficits across a distributed network of sensory and higher order cognitive regions. Deficit in early visual processing within the dorsal visual stream contributes significantly to impaired frontal activation, which, in turn, leads to dysregulation of the hippocampus and ventral visual stream. Dysfunction within this network underlies deficits in more traditional neurocognitive measures, supporting distributed models of brain dysfunction in schizophrenia.

Remediation of problem-solving skills in schizophrenia: evidence of a persistent effect

Neuropsychological deficits in problem solving are commonly found in patients with schizophrenia. We have previously presented the results of a study examining the feasibility of utilizing problem-solving teaching techniques developed within educational psychology, for remediating the problem-solving deficits of inpatients with schizophrenia spectrum disorders. These techniques emphasize the importance of intrinsic motivation on therapeutic outcome and promote this through contextualization, personalization and control of learning activities. We present here the results of the follow-up assessment, which found that the gains made by the problem-solving group persisted for 4 weeks after cessation of problem-solving remediation ended. These results provide more evidence of the therapeutic benefit of problem-solving training techniques that promote intrinsic motivation and generic problem-solving strategies.

Neurocognitive and symptom correlates of daily problem-solving skills in schizophrenia

Functional outcome for individuals with schizophrenia has been associated with cognitive impairment. Deficits in attention, memory, speed of information processing and problem-solving skills affect independent functioning, vocational performance, and interpersonal functioning. This study investigated the relationship between neurocognitive functioning, clinical symptoms and daily problem-solving skills in seriously and persistently ill persons. Thirty-eight inpatients and outpatients were administered a neurocognitive battery for attention, working memory, processing speed, perceptual organization, and executive functioning; and semi-structured clinical interviews using the BPRS and SANS. Estimates of daily problem-solving skills were obtained using the relevant factor subscale from the Independent Living Scales (ILS-PB). Daily problem-solving skills were significantly correlated with negative symptoms, processing speed, verbal memory, and working memory scores. A regression model using an enter method suggests that working memory and negative symptoms are significant predictors of daily problem-solving skills and account for 73.2% of the variance. Further analyses demonstrate that daily problem-solving skills and negative symptoms were significantly different for inpatients and outpatients and significantly correlated with community status. The findings suggest the ILS-PB has utility as a proxy measure for assessing real-world functioning in schizophrenia.

Auditory Emotion Recognition Impairments in Schizophrenia: Relationship to Acoustic Features and Cognition

OBJECTIVE Schizophrenia is associated with deficits in the ability to perceive emotion based on tone of voice. The basis for this deficit remains unclear, however, and relevant assessment batteries remain limited. The authors evaluated performance in schizophrenia on a novel voice emotion recognition battery with well-characterized physical features, relative to impairments in more general emotional and cognitive functioning. METHOD The authors studied a primary sample of 92 patients and 73 comparison subjects. Stimuli were characterized according to both intended emotion and acoustic features (e.g., pitch, intensity) that contributed to the emotional percept. Parallel measures of visual emotion recognition, pitch perception, general cognition, and overall outcome were obtained. More limited measures were obtained in an independent replication sample of 36 patients, 31 age-matched comparison subjects, and 188 general comparison subjects. RESULTS Patients showed statistically significant large-effect-size deficits in voice emotion recognition (d=1.1) and were preferentially impaired in recognition of emotion based on pitch features but not intensity features. Emotion recognition deficits were significantly correlated with pitch perception impairments both across (r=0.56) and within (r=0.47) groups. Path analysis showed both sensory-specific and general cognitive contributions to auditory emotion recognition deficits in schizophrenia. Similar patterns of results were observed in the replication sample. CONCLUSIONS The results demonstrate that patients with schizophrenia show a significant deficit in the ability to recognize emotion based on tone of voice and that this deficit is related to impairment in detecting the underlying acoustic features, such as change in pitch, required for auditory emotion recognition. This study provides tools for, and highlights the need for, greater attention to physical features of stimuli used in studying social cognition in neuropsychiatric disorders.

Verbal memory, problem-solving skills and community status in schizophrenia

Neuropsychological deficits have been associated with poor community functioning in individuals with schizophrenia. Previous research suggests that verbal memory capacity is related to functional capacity. The purpose of this study was to investigate the relationship between verbal memory, problem-solving skills and community functioning, as measured by treatment status (inpatient vs. outpatient) in people with schizophrenia spectrum disorders. Evaluations were done on 162 individuals with schizophrenia or schizoaffective disorder, seen in inpatient (n=87) and outpatient settings (n=75). Verbal memory was assessed using narrative recall and list recall measures. Problem-solving skills for independent living were assessed using a social reasoning measure and a daily problem-solving skills measure. Better verbal memory performance was associated with better problem solving for independent living. However, inpatient vs. outpatient status was best determined by problem-solving skills for independent living rather than verbal memory performance. The results reveal the importance of daily problem-solving skills for community status in schizophrenia. Although verbal memory performance is associated with problem-solving skills for independent living, predictive probability of community status does not improve when memory performance is taken into account.

Reading deficits in schizophrenia and individuals at high clinical risk: relationship to sensory function, course of illness, and psychosocial outcome.

OBJECTIVE The ability to read passages of information fluently and with comprehension is a basic component of socioeconomic success. Reading ability depends on the integrity of underlying visual and auditory (phonological) systems. This study investigated the integrity of reading ability in schizophrenia relative to the integrity of underlying visual and auditory function. METHOD The participants were 45 schizophrenia patients, 19 clinical high-risk patients, and 65 comparison subjects. Reading was assessed using tests sensitive to visual or phonological reading dysfunction. Sensory, neuropsychological, and functional outcome measures were also obtained. RESULTS Schizophrenia patients displayed reading deficits that were far more severe (effect size >2.0) than would be predicted based on general neurocognitive impairments (effect size 1.0-1.4). The deficits correlated highly with both visual and auditory sensory measures, including impaired mismatch negativity generation (r=0.62, N=51, p=0.0002). Patients with established schizophrenia displayed both visual and phonological impairments, whereas high-risk patients showed isolated visual impairments. More than 70% of schizophrenia patients met criteria for acquired dyslexia, with 50% reading below eighth grade level despite intact premorbid reading ability. Reading deficits also correlated significantly (rp=0.4, N=30, p=0.03) with failure to match parental socioeconomic achievement, over and above contributions of more general cognitive impairment. CONCLUSIONS Patients with schizophrenia display severe deficits in reading ability that represent a potentially remediable cause of impaired socioeconomic function. Such deficits are not presently captured during routine clinical assessment. Deficits most likely develop during the years immediately surrounding illness onset and may contribute to the reduced educational and occupational achievement associated with schizophrenia.

Computer Assisted Learning in Psychiatric Rehabilitation

Abstract Psychiatric rehabilitation models are increasingly acknowledging the importance of cognitive remediation to improve basic cognitive processes like attention, memory and reasoning skills. Computers are an important tool in the cognitive rehabilitation process, and have been linked to positive treatment outcomes. This paper reviews studies on the effectiveness of computer based remediation techniques with individuals with psychiatric illness, and presents a theoretically based model for treatment that can be used in clinical and research settings.

Impaired magnocellular/dorsal stream activation predicts impaired reading ability in schizophrenia

In healthy humans, passage reading depends upon a critical organizing role played by the magnocellular/dorsal visual pathway. In a recent study, we found a significant correlation between orthographic reading deficits in schizophrenia and deficits in contrast sensitivity to low spatial frequency stimuli, suggesting an underlying magnocellular processing abnormality. The interrelationship between magnocellular dysfunction and passage reading impairments in schizophrenia was investigated in 21 patients with schizophrenia and 17 healthy control volunteers using behavioral and functional MRI (fMRI) based measures. fMRI activation patterns during passage- and single-word reading were evaluated in relation to cortical areas with differential sensitivity to low versus high spatial frequency cortical regions indentified using a phase-encoded fMRI paradigm. On average, patients with schizophrenia read at the 6th grade level, despite completion of more than 12 years of education and estimated normal pre-morbid IQ. Schizophrenia patients also showed significantly impaired contrast sensitivity to low spatial frequencies and abnormal neural activity in response to stimulation with low spatial frequencies, consistent with dysfunction of magnocellular processing. Further, these magnocellular deficits were predictive of poor performance on a standardized psychoeducational test of passage reading. These findings suggest that reading is an important index of cognitive dysfunction in schizophrenia and highlight the contribution of magnocellular dysfunction to overall cognitive impairments in schizophrenia.

It's all in the cards: effect of stimulus manipulation on Wisconsin Card Sorting Test performance in schizophrenia.

Patients with schizophrenia can be taught the Wisconsin Card Sorting Test (WCST) sorting rules based upon expanded feedback. However, few task manipulations have been reported that differentially improve patient performance without altering the nature of feedback provided. The present study tests the hypothesis that deficits in WCST performance in schizophrenia reflect, in part, impaired ability to manipulate abstract stimulus features, rather than impaired ability to utilize feedback. We developed a modified stimulus set - the Rockland Face Sorting Test (RFST) - in which abstract shapes were replaced with faces, which we hypothesized would be more tractable to sorting by patients. Task rules and feedback remained unchanged. Relative RFST and WCST performance was examined in 19 patients as well as 15 normative controls. A comparison group of 15 patients received only repeated WCST administrations. Patients performed significantly better on the RFST vs. the WCST in categories completed, total correct responses and conceptual level responses, whereas no improvement was seen in either the normative or repeated WCST comparison groups. Furthermore, progressive improvement was seen following repeated RFST administration. These findings demonstrate that stimulus characteristics, as well as executive deficits, contribute to impaired WCST performance in schizophrenia.