Emotional scene processing in biotypes of psychosis

Social-emotional deficits in psychosis may be indexed by deviations in emotional scene processing, but event-related potential (ERP) studies indicate such deviations may not map cleanly to diagnostic categories. Neurobiologically defined psychosis subgroups offer an alternative that may better capture neurophysiological correlates of social-emotional deficits. The current study investigates emotional scene-elicited ERPs in Biotypes of psychosis in a large (N = 622), well-characterized sample. Electroencephalography was recorded in healthy persons (N = 129), Biotype-1 (N = 195), Biotype-2 (N = 131), and Biotype-3 (N = 167) psychosis cases. ERPs were measured from posterior and centroparietal scalp locations. Neural responses to emotional scenes were compared between healthy and psychosis groups. Multivariate group discrimination analyses resulted in two composite variates that differentiated groups. The first variate displayed large differences between low-cognition (Biotype-1, Biotype-2) and intact-cognition groups (Biotype-3, healthy persons). The second indicated a small-to-moderate distinction of Biotypes-2 and -3 from Biotype-1 and healthy persons. Two multivariate correlations were identified indicating associations between 1) self-reported emotional experience and generalized cognition and 2) socio-occupational functioning and late-stage emotional processing. Psychosis Biotypes displayed emotional processing deficits not apparent in DSM psychosis subgroups. Future translational research may benefit from exploring emotional scene processing in such neurobiologically-defined psychosis groups.

Salience of working-memory maintenance and manipulation deficits in schizophrenia

BACKGROUND

Encoding and maintenance of information in working memory, followed by internal manipulation of that information for planning adaptive behavior, are two key components of working-memory systems. Both processes have been reported to be impaired in schizophrenia, but few studies have directly compared the relative severity of these abnormalities, or the degree to which manipulation deficits might be secondary to alterations in maintenance processes.

METHOD

Clinically stable schizophrenia patients (n=25) and a demographically similar healthy comparison group (n=24) were administered a verbal span task with three levels of working-memory load. Maintenance was assessed using sequential position questions. Manipulation processes were assessed by requiring comparison of the relative sequential position of test items, which entailed simultaneous serial search strategies regarding item order.

RESULTS

Both groups showed reduced accuracy and increased reaction time for manipulation compared with maintenance processing. There were significant patient impairments across working-memory loads. There was no differential deficit in manipulation processing, and effect sizes of relative deficit in the patient group were higher for maintenance than manipulation processing.

CONCLUSIONS

The strong correlation for maintenance and manipulation deficits suggest that impairments in the ability to internally manipulate information stored in working-memory systems are not greater than alterations in the encoding and maintaining of information in working memory and that disturbances in maintenance processing may contribute to deficits in higher-order working-memory operations.

Cytochrome P-450 metabolites of 2-arachidonoylglycerol play a role in Ca2+-induced relaxation of rat mesenteric arteries

The perivascular sensory nerve (PvN) Ca(2+)-sensing receptor (CaR) is implicated in Ca(2+)-induced relaxation of isolated, phenylephrine (PE)-contracted mesenteric arteries, which involves the vascular endogenous cannabinoid system. We determined the effect of inhibition of diacylglycerol (DAG) lipase (DAGL), phospholipase A(2) (PLA(2)), and cytochrome P-450 (CYP) on Ca(2+)-induced relaxation of PE-contracted rat mesenteric arteries. Our findings indicate that Ca(2+)-induced vasorelaxation is not dependent on the endothelium. The DAGL inhibitor RHC 802675 (1 microM) and the CYP and PLA(2) inhibitors quinacrine (5 microM) (EC(50): RHC 802675 2.8 +/- 0.4 mM vs. control 1.4 +/- 0.3 mM; quinacrine 4.8 +/- 0.4 mM vs. control 2.0 +/- 0.3 mM; n = 5) and arachidonyltrifluoromethyl ketone (AACOCF(3), 1 microM) reduced Ca(2+)-induced relaxation of mesenteric arteries. Synthetic 2-arachidonoylglycerol (2-AG) and glycerated epoxyeicosatrienoic acids (GEETs) induced concentration-dependent relaxation of isolated arteries. 2-AG relaxations were blocked by iberiotoxin (IBTX) (EC(50): control 0.96 +/- 0.14 nM, IBTX 1.3 +/- 0.5 microM) and miconazole (48 +/- 3%), and 11,12-GEET responses were blocked by IBTX (EC(50): control 55 +/- 9 nM, IBTX 690 +/- 96 nM) and SR-141716A. The data suggest that activation of the CaR in the PvN network by Ca(2+) leads to synthesis and/or release of metabolites of the CYP epoxygenase pathway and metabolism of DAG to 2-AG and subsequently to GEETs. The findings indicate a role for 2-AG and its metabolites in Ca(2+)-induced relaxation of resistance arteries; therefore this receptor may be a potential target for the development of new vasodilator compounds for antihypertensive therapy.

Integration of neuropsychological and cognitive theory in rehabilitation

Clinical neuropsychology has focused on the diagnosis and localization of brain damage. Much of the early progress in the field relied upon an atheoretical-actuarial approach. Recently a link between neuropsychology and cognitive psychology has emerged. From the early focus upon brain-behavior relationships, neurocognitive theories have emerged to explain observed brain functions. Although many researchers have enjoyed the collaboration between neuropsychology and cognitive psychology, others continue to investigate functions without considering the merging of finds. This article reviews integrative elements of cognitive and neuropsychological research and the emergence of cognitive neuropsychology.

Report of normative sensory and motor performance in children using a standardized battery

This study provided normative data for sensory and motor functioning of children from 2-15 years of age. Two hundred eighty-eight children without a history of neurological or psychiatric evaluation, diagnosis, or treatment served as subjects. Each child was administered the Dean-Woodcock Sensory and Motor Battery. This measure consists of 18 individual subtests. Nine subtests reflect visual, auditory, or tactile perception. The remaining 9 subtests involve motor functioning, with 3 of the subtests devoted to subcortical functioning. The results showed that the most rapid development occurred between the ages of 4 and 7 years. Indeed, some 76% of the sensory-motor tasks administered reached a plateau by age 7.

Controlled and automatic processing during animal word list generation in schizophrenia

Controlled and automatic aspects of semantic-associative functioning in schizophrenia were investigated by evaluating performance on animal word list generation (WLG). Responses from control (n = 47) and patient (n = 38) participants were subjected to multidimensional scaling (MDS), cluster analysis (CA), and indices on the basis of number of shared attributes (SA) between consecutive responses. Patient MDS results accounted for less variance and contained more error than control data. CA results yielded fewer and less clear animal-response subgroups among patients yet demonstrated intact associations among strongly related exemplars. The SA indices revealed better clustering and more effective switching among response clusters in controls than patients. Results suggest that animal WLG in schizophrenia is compromised both by aberrant automatic semantic-associative network activation and by controlled processes such as search, access, and selection. This pattern is consistent with prominent frontotemporal pathology evident in the disorder.

Neuropsychological differences among empirically derived clinical subtypes of schizophrenia

Neuropsychological profile differences between empirically derived clinical subtypes of schizophrenia were examined. Two hundred five patients and 209 demographically matched controls were administered a neuropsychological battery examining 8 domains. Subtypes included negative, disorganized, paranoid, Schneiderian, and mild. All subtypes displayed a neuropsychological profile of generalized impairment with greater deficits in learning, memory, and attention. Results were suggestive of diffuse cognitive dysfunction in schizophrenia with more severe deficits in learning and memory relative to executive skills. This pattern of greater learning and memory impairment was pronounced for disorganized patients. In contrast, paranoid patients outperformed disorganized and negative patients in several domains. These findings reflect bilateral frontal-temporal dysfunction, particularly in disorganized and negative patients. Subtype differences highlight the importance of conceptualizing schizophrenia as a multifocal disorder.

Constructs underlying measures of sensory-motor functions

Many pathognomonic indicators of brain damage are characterized by deficits in sensory and/or motor functions. The strength of these pathognomonic signs has led to reliance on clinical administration and interpretation in the assessment of sensory and motor functions. Subsequently, the majority of measures designed to assess sensory and motor functions lack adequate reliability and psychometric confirmation of their utility. The Dean-Woodcock Sensory-Motor Battery (DWSMB) was designed to standardize the administration and interpretation of sensory-motor functions and has demonstrated satisfactory reliability. The present study further examined the psychometric properties of the DWSMB through factor analysis. It was hypothesized that at least two factors would emerge representing sensory and motor functions, respectively. A third possible factor that would reflect subcortical functioning was also hypothesized. Principal components analysis on data from over 600 participants supported a three-factor solution which accounted for 50.9% of the total variance. However, factor loadings revealed more dual loadings than expected, and factors emerged according to complexity rather than basic sensory, motor, and subcortical factors. Regardless, these data provide empirical evidence for the conceptualization of sensory-motor skills in a manner that incorporates subcortical abilities. These data also provide support for the underlying constructs of the DWSMB.

Utility of the Maternal Perinatal Scale (MPS) in distinguishing normal from learning disabled children

This study examined perinatal complications and risk factors as predictors of learning disabilities in schoolaged children. Specifically, the Maternal Perinatal Scale (MPS) was used to distinguish between normal children and those classified as learning disabled (LD) by their school system. One hundred and eight participants, 54 in each classification, were selected from a small Midwestern area. A stepwise discriminant analysis demonstrated that all four factors of the MPS contribute significantly to the prediction. A linear composite of MPS factor scores correctly classified 93.5% of all participants, with only two normal and five LD children being misclassified. Repeating the results with other clinical populations, these results support the use of the MPS in assessing the perinatal history. More importantly, these data are consistent with the notion that perinatal complications increase the likelihood of future impairment. Moreover, the MPS shows promise as a screening device for use in early preventative programs which diminish the negative psychological, sociological, and neuropsychological outcomes for children with neurological disorders.

Developmental and sex differences in sensory and motor functioning

The sensory and motor functioning of normal children (N = 119) ages 4 to 13 years old were examined for developmental and sex differences in relation to neuropsychological functioning. Sensory and motor subtests of the Dean-Woodcock Neuropsychological Assessment System (D-WNAS), a standardized instrument, were administered. Significant differences between the older and younger children were found, suggesting that developmental differences exist for sensory and motor functioning. The older children significantly outperformed the younger children on all subtests except for visual confrontation. Differences between males and females and the interaction between sex and age were not significant. The present findings coincide with previous research showing clear maturational differences in sensory and motor functions.

Validity and reliability of rapidly alternating movement tests

Two studies investigated the interrater reliability and concurrent validity of tests of rapidly alternating movement. Study I examined the interrater reliability of three different tests, "finger tapping" to the adjacent thumb, "table tapping," and "hand to thigh" alternating movements. Using normal participants the results indicated poor interrater agreement for the "hand to thigh" test and modest relationship for both types of finger tapping. However, for each test the number of recorded repetitions differed significantly between raters. Study 2 examined the concurrent validity of two mechanical measures of finger tapping. The scores of 36 normal participants was compared using a mechanical digital counter and a calculator. Results indicated that the use of the calculator as a counter was highly related to the results with a mechanical digital counter. Conclusions suggested the use of a mechanical apparatus is more reliable than human observations. In addition, the use of an inexpensive apparatus will produce results similar to the manual finger tapping apparatus commonly used in neuropsychological batteries.

The neuropsychological significance of lateral preference for complex visual activities in children with learning disabilities

In the present study the relationship between neuropsychological functioning and lateral preference for visual activities was examined with learning disordered children. Specifically, the relationship between measures of the Lateral Dominance Exam (LDE), scores on the Halstead-Reitan Neuropsychological Battery (HRNB), and the Wechsler Intelligence Scale for Children-Revised (WISC-R) were explored. A canonical analysis suggested that composites of neuropsychological functioning and lateral preference shared 22% of variance. Learning disabled children with strong right or left preference for visually guided motor activities showed lower performance in spatial tasks on the ipsilateral side and in simple motor skills on the contralateral side. Children in the present study with strong right preference patterns for visually assisted motor activities also showed low performance on visual tracking tasks. These data offer some support for assessing lateral preference in learning disabled children.