Perceptual organization in schizophrenia: The processing of symmetrical configurations.

The hypothesis that the perceptual organization dysfunction of patients with poor premorbid schizophrenia is due to a deficit in global visual sensory store processing was tested by assessing their ability to process symmetrical configurations that develop early and have strong prepotent structures. Two same–different judgment tasks in which performance varies as a function of the symmetrical organization and task demands were administered to participants with good and poor premorbid schizophrenia, those with mood disorders, and normal controls. Like the other groups, poor premorbid schizophrenics' latency and error response patterns closely paralleled the a priori model of adequate processing. The results support their competence in perceptually processing symmetrical configurations and disconfirm the hypothesis that their input deficiencies represent a general deficiency in all forms of perceptual organization. The implications for specifying their early input dysfunction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related practice effects across longitudinal neuropsychological assessments in older people with schizophrenia.

Objective: The relationship between aging and practice effects on longitudinal neuropsychological assessments was investigated in middle-aged and older people with schizophrenia and healthy controls. Method: Older people with schizophrenia (n = 107; M age = 56.1) and age-comparable nonpsychiatric controls (n = 107; M age = 57.7) were scheduled to receive annual assessments on a comprehensive battery of neuropsychological tests for an average of 2.5 years (range 11 months to 4 years). Mixed-model analyses were used to separately examine the effects of practice and age on test performance. Results: Number of prior assessments (practice) was associated with significant performance improvement across assessments, whereas older age was associated with significant decline in performance. The groups did not differ significantly in extent of age-related cognitive decline, but a three-way interaction among group, age, and practice was found, such that greater age-related decline in practice effects were found for older people with schizophrenia relative to nonpsychiatric participants. Conclusions: This study did not find any evidence of neurodegenerative age-related decline in neuropsychological abilities in middle-aged and older people with schizophrenia, but older age was associated with diminished ability to benefit from repeated exposure to cognitive tasks in people with schizophrenia. Cognitive impairment in schizophrenia may combine with cognitive decline associated with normal aging to reduce practice effects in older patients. These findings have important implications for the design of studies examining the longitudinal trajectory of cognitive functioning across the life span of people with schizophrenia, as well as clinical trials that attempt to demonstrate cognitive enhancement in these individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in neuropsychological functioning of first-episode and chronically ill schizophrenic patients

OBJECTIVE: The purpose of this study was to determine whether men and women with schizophrenia demonstrate differences in cognitive abilities. METHOD: Two cohorts of patients with schizophrenia, an acute first-episode and a chronically hospitalized group, were evaluated with a neuropsychological battery and compared with a normal group of subjects. RESULTS: After adjustment for age, age at onset, and premorbid IQ, male chronic patients performed worse than female chronic patients on measures of visual memory. These differences were eliminated after control for symptom severity. No other differences were found in cognitive function between men and women in either cohort. CONCLUSIONS: Sex differences in cognitive function in schizophrenic patients are not robust findings.     

Highly active antiretroviral treatment in HIV infection: benefits for neuropsychological function

OBJECTIVES: To determine whether highly active antiretroviral therapy (HAART) is associated with reduced HIV-associated neuropsychological impairment. DESIGN: Cross-sectional analysis in a natural history study of adaptation to HIV/AIDS. METHOD: A sample of 130 homo-/bisexual men with HIV/AIDS (mean age, 41 years; 42% non-white) were evaluated with a neuropsychological battery assessing attention, concentration, psychomotor speed, learning, memory and executive function. Subjects taking HAART were compared with those not taking HAART on demographics, CD4 cell count, viral load, scores on individual neuropsychological tests and proportion with neuropsychological impairment. RESULTS: Sixty-nine (53%) subjects were taking HAART, and 48 (37%) were neuropsychologically impaired. Subjects taking HAART had lower mean CD4 cell counts than those not taking HAART (254 versus 342 x 10(6)/l; P < 0.05), although they were more likely to have undetectable viral load (42 versus 20%; P < 0.01) and were less likely to be neuropsychologically impaired (22 versus 54%; P < 0.0001). Subjects taking HAART performed significantly better on tests of attention, concentration, learning, memory, and psychomotor speed. After excluding subjects with potential non-HIV confounders of neuropsychological function, those without neuropsychological impairment had significantly lower mean viral load levels and were more likely to have undetectable viral load than those with impairment. CONCLUSION: These preliminary findings suggest that HAART benefits neuropsychological function through the reduction of viral load.     

Sex differences in neuropsychological function in non-psychotic relatives of schizophrenic probands

Some recent studies suggest that men with schizophrenia may have greater neuropsychological deficits than women. It is not known, however, whether similar sex differences may be present in biological relatives of schizophrenic patients. We evaluated neuropsychological functioning of 54 relatives of schizophrenic patients and 72 normal volunteers. It was hypothesized that, if sex differences were present, they would be accounted for largely by deficits in male relatives. We were particularly interested in three neuropsychological functions that we previously identified as putative neuropsychological vulnerability indicators for schizophrenia: (1) abstraction/executive function; (2) verbal memory; and (3) auditory attention. There were significant group x sex interactions for verbal memory and motor function, and trends toward significant interactions for auditory attention and mental control/encoding. However, with the exception of motor function, it was the female relatives who accounted for most of the impairment. A speculative explanation for the findings is that women may have a higher threshold than men for developing schizophrenia. If so, female relatives might be able to withstand greater impairments than men before developing psychotic symptoms. Consequently, in a sample that was limited to non-psychotic relatives--as in the present study--there could be over-representation of both less impaired men and more impaired women. Alternative explanations and limitations of the study are also discussed.     

Everyday action in schizophrenia: Performance patterns and underlying cognitive mechanisms.

Everyday action is impaired among individuals with schizophrenia, yet few studies have characterized the nature of this deficit using performance-based measures. This study examined the performance of 20 individuals with schizophrenia or schizoaffective disorder on the Naturalistic Action Test (M. F. Schwartz, L. J. Buxbaum, M. Ferraro, T. Veramonti, & M. Segal, 2003). Performance was coded to examine overall impairment, task accomplishment, and error patterns and was compared with that of healthy controls (n = 28) and individuals with mild dementia (n = 23). Additionally, 2 competing accounts of everyday action deficits, the resource theory and an executive account, were evaluated. When compared with controls, the participants with schizophrenia demonstrated impaired performance. Relative to dementia patients, participants with schizophrenia obtained higher accomplishment scores but committed comparable rates of errors. Moreover, distributions of error types for the 2 groups differed, with the participants with schizophrenia demonstrating greater proportions of errors associated with executive dysfunction. This is the 1st study to show different Naturalistic Action Test performance patterns between 2 neurologically impaired populations. The distinct performance pattern demonstrated by individuals with schizophrenia reflects specific deficits in executive function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive functioning and neuroanatomic volume measures in schizophrenia.

Magnetic resonance imaging (MRI) and neuropsychological tests were administered to 68 patients with schizophrenia and 68 healthy controls. MRIs were analyzed with a partially automated segmentation method that quantifies the volume of each cerebral hemisphere and its cerebrospinal fluid (CSF). Whereas patients had higher ventricular-brain ratio (VBR), ventricular CSF (vCSF) volume was equivalent to controls. Brain volume was lower. Cognitive function did not correlate with VBR or vCSF volume in either group, but cognitive function did correlate with brain volume. Divided as deficit (DF) and nondeficit (NDF), only DF patients had lower brain volume than controls. Whereas NDF patients showed little correlation between anatomy and cognitive function, there were more correlations between brain volume and cognition in DF patients. Changes in DF/NDF subtype with time and treatment reduced the significance of these findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical outcome of mild fetal ventriculomegaly

The presence of antibodies against neural antigens was investigated in the serum of patients with schizophrenia, major depression and normal controls. Different immunological abnormalities, humoral and cellular, were reported in schizophrenia and major depression. The pathogenesis of schizophrenia is multifactorial. An autoimmune mechanism was suggested as a possible factor. We tested the serum of 26 patients with schizophrenia, eight patients with major depression and 22 normal controls. The serum samples were tested for antibody binding to protein extracts of IMR-32 neuroblastma cell line using Western blot analysis. Immunoglobulins of eight patients with schizophrenia (30.71%) reacted with a protein of 80-85 kDa. Serum samples from subjects of other groups did not react with this protein. Sera of all patients with major depression but one, and all normal controls reacted with HSP 60 kDa to different extent. This is an apparent discrepancy with the findings of Kilidireas et al. [Kilidireas, K., Latov, N., Strauss, D.H., Gorig, A.D., Hashim, G.A., Gorman, J.M., Sadig, S.A., 1992. Antibodies to the human 60 kDa heat shock protein in patients with schizophrenia. Lancet 340, 569-572.] who demonstrated the presence of antibodies against HSP 60 kDa in 44% of patients with schizophrenia tested and 8% of normal subjects. HSP 60 kDa is an antigen of many pathogens and antibodies against it might be a result of an infection and cannot be a good indicator for an autoimmune process. The presence of antibodies against a protein of 80-85 kDa should be investigated as a possible specific indicator.     

Validation of the Child Premorbid Intelligence Estimate method to predict premorbid Wechsler Intelligence Scale for Children-Fourth Edition Full Scale IQ among children with brain injury.

Determination of neuropsychological impairment involves contrasting obtained performances with a comparison standard, which is often an estimate of premorbid IQ. M. R. Schoenberg, R. T. Lange, T. A. Brickell, and D. H. Saklofske (2007) proposed the Child Premorbid Intelligence Estimate (CPIE) to predict premorbid Full Scale IQ (FSIQ) using the Wechsler Intelligence Scale for Children-4th Edition (WISC-IV; Wechsler, 2003). The CPIE includes 12 algorithms to predict FSIQ, 1 using demographic variables and 11 algorithms combining WISC-IV subtest raw scores with demographic variables. The CPIE was applied to a sample of children with acquired traumatic brain injury (TBI sample; n = 40) and a healthy demographically matched sample (n = 40). Paired-samples t tests found estimated premorbid FSIQ differed from obtained FSIQ when applied to the TBI sample (ps ≤ .01). When applied to healthy peers, estimated and obtained FSIQ did not differ (ps > .02). The demographic only algorithm performed well at a group level, but estimates were restricted in range. Algorithms combining single subtest scores with demographics performed adequately. Results support the clinical application of the CPIE algorithms. However, limitations to estimating individual premorbid ability, including statistical and developmental factors, must be considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal fluency deficits in patients with schizophrenia: Semantic fluency is differentially impaired as compared with phonologic fluency.

Patients with schizophrenia show deficits in phonologic (ability to name words that begin with a specific letter, e.g., F) and semantic (ability to name members of a category, e.g., "animals" fluency.) Whereas the former deficit has been presumed to reflect a dysfunction of the frontal lobe, the latter has been linked to frontal and temporoparietal brain areas. These 2 verbal fluency measures were studied in a sample of 27 schizophrenia patients and 24 normal controls who were matched on age and a putative measure of premorbid intellectual ability. A 2-min production task of switching between letters and between categories measured demand for flexibility. On switching and nonswitching tasks controls produced more words during semantic versus phonologic fluency. Conversely, schizophrenia patients produced more words for letters than for categories, suggesting dysfunction of the frontal and temporoparietal areas of the brain. Furthermore, the greater impairment of semantic fluency may be related to a breakdown of semantic information processing beyond "executive" search and retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Another look at parastichies

The conditioning-testing (S1-S2) P50 auditory evoked potential (EP) has been well-documented and accepted as an important tool for measuring sensory gating in schizophrenia research. However, the physiological mechanism of the phenomenon is not known. In this study a single-trial analysis was used to determine the influence of the latency variability of the responses in the formation of the averaged P50. Ten schizophrenic patients and 10 normal controls were tested in the dual-click EP paradigm. Using ensemble averaging analysis, we replicated the previous finding of a lower S1 P50 amplitude and higher S2/S1 ratio in schizophrenics compared with normal controls. The single-trial analysis revealed that patients had significantly higher trial-to-trial latency variability in S1 responses than normal subjects, while the S2 showed the same variability as in controls. Measured by the single-trial procedure, the arithmetic mean amplitudes of P50 responses to S1 and S2 were similar between normal and schizophrenic subjects. The same measure also eliminated the difference in averaged P50 amplitude between S1 and S2 for both groups. Temporal variability appears to be an important factor in the assessment of averaged EPs and thus contribute to the change of P50 amplitude observed in schizophrenia.     

Estimation of WAIS—R premorbid intelligence: Current ability and demographic data used in a best-performance fashion.

The validity of a technique for estimating premorbid intellectual functioning based on Wechsler Adult Intelligence Scale—Revised (WAIS—R; D. Wechsler, 1981) subtest performance and demographic information used in a best-performance fashion was investigated. Premorbid IQ scores were predicted using the highest score from (a) all 11 R. D. Vanderploeg and J. A. Schinka (see record 1996-13380-001) regression equations (BEST-11) and (b) the 3 most robust regression equations (BEST-3). These results were compared with premorbid estimates based solely on demographic information. In the WAIS—R standardization sample the BEST methods were more highly correlated with actual WAIS—R IQ than were A. Barona et al (see record 1985-04035-001) estimates. The BEST-11 and BEST-3 approaches resulted in overestimates of about 9 points and 5 points, respectively. In matched samples of neurologic patients and normal controls, Pearson correlations between actual and estimated IQ scores were significantly higher for the BEST-3 than the Barona et al method. The BEST-3 method also was superior at predicting group membership (normal vs brain-damaged). These studies support the use of the BEST-3 approach to premorbid estimation of cognitive abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological Correlates of Diffusion Tensor Imaging in Schizophrenia.

Patients with schizophrenia (n = 41) and healthy comparison participants (n = 46) completed neuropsychological measures of intelligence, memory, and executive function. A subset of each group also completed magnetic resonance diffusion tensor imaging (DTI) studies (fractional anisotropy and cross-sectional area) of the uncinate fasciculus (UF) and cingulate bundle (CB). Patients with schizophrenia showed reduced levels of functioning across all neuropsychological measures. In addition, selective neuropsychological-DTI relationships emerged. Among patients but not controls, lower levels of declarative-episodic verbal memory correlated with reduced left UF, whereas executive function errors related to performance monitoring correlated with reduced left CB. The data suggested abnormal DTI patterns linking declarative-episodic verbal memory deficits to the left UF and executive function deficits to the left CB among patients with schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurobiological findings in first admission patients with schizophrenia or schizophreniform disorder

Fifty patients with a DSM-III-R diagnose of schizophrenia or schizophreniform disorder were compared to 25 healthy volunteers on structural and functional brain measurements. The patients were studied during their first admission to psychiatric hospital. In the patient group correlations between structural and functional brain measurements and clinical symptoms were performed. Brain structure was studied by CT scans. The schizophrenic patients had significantly smaller brain volume and brain length and more sulcal, but not ventricular, CSF than the controls. These findings were not an effect of sex, abuse, educational status or neuroleptic treatment. Brain function was studied by rCBF measurement (at baseline conditions and during mental activation), neuropsychological tests and neurological examination. The patients had significantly lower rCBF in the prefrontal regions during baseline condition and this was more pronounced during mental activation when compared with the controls. In the striatal region the patients had higher rCBF than the controls during activation. In no other region did rCBF differ between the patients and the controls. This points to a dysfunction in schizophrenic patients somewhere in th fronto-striatal-thalamic circuit. The patients performed poorer than the controls on practically all the psychological tests. Especially poor performance was seen in the more complicated tests depending on ability of abstraction, planning and sequential organisation and on semantic memory. The patients had more neurological abnormalities than the controls. Correlations between brain structure and rCBF were few. The neurological impaired patient group had more signs of structural brain deficits than the neurological normal patient group. Poor performance on a variety of psychological tests was correlated to signs of structural cerebral deficits. The significant correlations between the neurobiological measurements and clinical symptoms in the patients were sparse. However there was a trend that more symptoms both positive, negative and thought disorder were correlated to higher rCBF values in frontal, temporal and striatal regions, and that absence of positive symptoms correlated to structural brain deficits. Thus both structural and functional brain deficits can be detected early in the disease of schizophrenia. The findings point to primary cortical deficits probably located in the frontal and temporo-limbic areas.     

Exposure to different spectra of light, continuous light and treatment with melatonin affect reproduction in the Indian desert gerbil Meriones hurrianae (Jerdon)

The present article aims to examine premorbid personality traits of psychiatric patients with various diagnoses by asking their close relatives to retrospectively rate the patients' usual self with a questionnaire designed for the five-factor model of personality, a rapidly emerging comprehensive theory of personality structure. Data for 140 patients and 84 controls were analyzed. Although psychiatric patients as a group were characterized by high neuroticism and low conscientiousness when compared with the healthy controls, there were only a few traits that distinguished a particular diagnostic group from either the normal control or from the rest of the patients: neurotic disorder patients had higher neuroticism scores than the normal controls; unipolar depressives had a higher conscientiousness score than the rest of the patient group. No salient premorbid trait was noted for patients with organic mental disorders, schizophrenic disorders or bipolar disorders.     

No, It Is Not Possible to Be Schizophrenic Yet Neuropsychologically Normal.

Cognitive impairment is well documented in schizophrenia, though some reports have been interpreted to suggest that it is possible to have schizophrenia without neuropsychological impairment. The authors tested this by comparing the neuropsychological profiles of closely matched patients with schizophrenia and healthy comparison participants. Sixty-four patients with schizophrenia and 64 healthy comparison cases, matched to within 3 Full-Scale IQ points, were tested using the Wechsler Adult Intelligence Scale (3rd ed.; D. Wechsler, 1997b) and the Wechsler Memory Scale (3rd ed.; D. Wechsler, 1997c). Neuropsychological profiles for these groups were markedly different, with the group of patients with schizophrenia exhibiting performance deficits in memory and speeded visual processing but superior verbal comprehension and perceptual organization relative to the group of healthy comparison participants matched on Full-Scale IQ. Thus, scoring in the normal range does not preclude neuropsychological abnormality in schizophrenia, confirming that neuropsychological impairment is a core feature of the illness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual-Perceptual Dysfunctions Are Possible Endophenotypes of Schizophrenia: Evidence From the Psychophysical Investigation of Magnocellular and Parvocellular Pathways.

Visual information processing is impaired in schizophrenia patients and their biological relatives. The authors measured vernier thresholds in 72 schizophrenia patients, their 86 siblings, and 60 healthy control subjects. Subjects were asked to detect the direction of the horizontal displacement of 2 stimuli (left or right). During magnocellular (M) pathway tests, stimuli were dots with low contrast (5%) or counterphase-modulated gratings (25 Hz). For parvocellular (P) pathway tests, isoluminant blue-red dots with yellow-green background were used. Results revealed that patients with schizophrenia and their siblings were more impaired in M pathway conditions than in P pathway conditions. There was no color-specific impairment. The patients and their siblings displayed lower performances on tests of executive functions, psychomotor speed, and verbal memory compared with the controls. Visual-perceptual and neuropsychological data did not correlate. In conclusion, M pathway dysfunction is a potential endophenotype of schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological functioning among the nonpsychotic relatives of schizophrenic patients: A diagnostic efficiency analysis.

Numerous studies suggest that the relatives of schizophrenic patients exhibit neuropsychological impairments that are milder yet similar to those seen among schizophrenic patients. The authors assessed 35 nonpsychotic relatives of schizophrenic patients and 72 normal controls using a clinical and experimental neuropsychological test battery. Three neuropsychological functions met criteria for risk indicators of the schizophrenia genotype: abstraction, verbal memory, and auditory attention. These findings could not be attributed to parental socioeconomic status, education, general visual-spatial ability, or psychopathology. Furthermore, exploratory analyses were performed to determine whether the diagnostic efficiency of the indicators could be adjusted to meet the needs of genetic linkage analyses. These analyses suggest that psychometric considerations may help to create measures for genetic linkage studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Change in cognitive function in idiopathic Parkinson disease

OBJECTIVE: To study the effects of Parkinson disease (PD) on cognitive function by determining the frequency and amount of change in Mini-Mental State Examination (MMSE) performance. DESIGN: During a 4-year period, 77 patients with idiopathic PD and 43 normal elders were administered a neuropsychological test battery twice at 2 years apart. RESULTS: A 4-point score difference on the MMSE was the amount that was statistically calculated to be a significant difference at the .05 probability level. Using this metric, 17 (22%) patients with PD had a change in their MMSE performance during a 2-year period. Fifteen individuals performed poorer, and 2 individuals improved. Using the same metric, no normal subjects changed in their MMSE performance. The groups of patients with PD who had a change and did not have a change in their MMSE performance were not characterized by significant differences in their years of education, duration of illness, age at onset, age at test time 1, estimated premorbid intelligence, Hamilton Psychiatric Rating Scale for Depression score at test time I, or Unified Parkinson's Disease Rating Scale score. The singular difference was the higher frequency of change that was found in subjects who were taking dopamine agonists at the second test time. CONCLUSION: A change in cognitive function in patients with PD, as measured by a change of 4 points or more in their MMSE performance, was observed in only 22% of a sample of 77 patients with idiopathic PD during a 2-year period.     

Emotion recognition and social competence in chronic schizophrenia.

This study evaluated (a) whether chronic, medicated schizophrenia patients show deficits in emotion recognition compared to nonpatients, and (b) whether deficits in emotion recognition are related to poorer social competence. Two emotion recognition tests developed by S. L. Kerr and J. M. Neale (1993) and Benton's Test of Facial Recognition (A. Benton, M. VanAllen, K. Hamsher, & H. Levin, 1978) were given to patients with chronic schizophrenia and nonpatient controls. Patients' social skills, social adjustment, and symptomatology were assessed. Like Kerr and Neale's unmedicated patients, these patients performed worse than controls on both emotion recognition tests and the control test. For patients, facial perception was related to the chronicity of illness and social competence. Chronicity of illness may contribute to face perception deficits in schizophrenia, which may affect social competence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)