Level of aspiration risk-taking behavior, and projective test performance: A search for coherence.

37 student nurses performed in tasks that have served as criteria for differentiating persons with internal vs. external control expectancies. Correlations were obtained between level of aspiration, gambling, and projective test variables. While the obtained relationships with the Internal-External Control of Reinforcement scale were negligible, the relationships among performance variables were pronounced. 2 distinctive response patterns were observed and labeled task-inappropriate and task-appropriate responding. Achievement-oriented behaviors in the level of aspiration task and in the gambling task were related to each other, and both were related to the adequacy of response to sexual stimuli in projective testing. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An attentional assessment of foster children at risk for schizophrenia.

Investigated whether processes observed in adult schizophrenics could be detected in children who were not schizophrenic but were at heightened risk for the disorder. A battery of 8 attention-demanding tasks was administered to (a) 9 foster children at heightened risk for schizophrenia by virtue of having a schizophrenic biological mother, (b) 10 foster children without a family history of psychiatric disorder, and (c) 10 children living with their biological parents, none of whom had a history of psychiatric disorder. The tasks included in the battery had been demonstrated in previous research to be sensitive discriminators of adult schizophrenic pathology. Results indicate the presence of attentional dysfunction in high-risk children prior to the onset of clinical symptoms. The high-risk group showed significantly lower levels of performance on certain tasks, notably the complex versions of the span-of-apprehension and Spokes tests from the Halstead-Reitan Test Battery, and the simple conditions of the concept attainment task. Examination of low-scoring Ss, intercorrelations between tasks, and the results of a cluster analysis revealed that within the high-risk group there was a subset of Ss who showed impairment across these tasks to produce the overall low group means. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relation between latency and redundancy-associated deficit in schizophrenic reaction time performance.

Evaluated the independence of 2 well-established measures of information-processing difficulties in process schizophrenics, namely, reaction time measures of latency and redundancy-associated deficit. Training exercises were designed to improve the speed of reaction time performance in 16 male Ss (average age 32.5 yrs). These exercises were successful in reducing latency over the course of training and from pre- to posttraining assessments to levels falling around the range of performance expected of normals. Redundancy-associated deficit, however, did not change from pre- to postassessment, indicating that this index is not a simple reflection of latency and is not responsive to training procedures involving positive motivation. Intercorrelations of the 2 indexes also showed that these measures were independent, at least within the process end of the schizophrenic spectrum. Furthermore, the 2 measures correlated with different types of S factors. Latency measures correlated with measures of chronicity, and the redundancy-deficit measure was correlated with prognosis. Findings help to clarify the utility of reaction time indexes as markers of various aspects of schizophrenic pathology. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Redundancy-associated deficit in schizophrenic reaction time performance.

Examined the influence of information redundancy on the reaction-time performance of 3 groups of females: 36 hospitalized schizophrenics defined as process or reactive by the Elgin Prognostic Rating Scale; 18 nonschizophrenic psychiatric-patient controls; and 18 normal hospital staff controls. The influence of information redundancy was assessed by manipulating the degree of regularity in the presentation of preparatory interval (PI) durations. Runs of 2 and 4 identical PIs, defined as low and high redundant sets, respectively, were embedded in an irregular order of trials to test the influence associated with regular presentation. In contrast to previous analyses showing that the irregular vs. regular presentation condition interacts with PI duration, the interaction was found for process patients only. This interaction took the form of a "crossover" in which the regular PI trials yielded worse performance than the irregular trials at long PI durations; the opposite was true for short durations. Redundant PIs tended to show an improved performance immediately and then, for the process group only, a progressive loss on successive trials. An interpretation in light of D. Shakow's (see record 1965-08514-001) "set theory" and an inhibitory process explanation are disucssed. (25 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Accreditation: At what cost?

Comments on the article by Conway (see record 1985-10567-001). Professor Conway makes a compelling case for the development of a national accreditation service for the review of applied training programmes. Although his historical account of the development of professional psychology in Canada has portrayed a rocky--at times, impassable--road, we have seemingly survived the trip. It is clear that Conway and some others feel that the benefits far outweigh the discomfort. The rest of us will be propelled--or perhaps dragged, kicking and screaming--forward into meeting our responsibilities for a better-defined and a higher-quality training enterprise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual influences on crossover in the reaction time performance of schizophrenics.

Conducted 3 investigations with a total of 55 female process schizophrenics and 54 normal controls to test the resilience of the crossover phenomenon observed in schizophrenic reaction time performance. The crossover effect portrays an interaction of the predictability (regularity) and the duration of the delay (preparatory interval) factors in the simple reaction time procedure. The effect, believed pathognomonic of schizophrenic reaction time performance, shows performance on regular trials to be faster than irregularly presented trials at short duration, but the regular presentation of trials is slower at longer duration preparatory intervals. The present studies tested an interpretation that the difference between the regular and irregular trials with long preparatory intervals might be dependent on the influence of certain contextual influences operating within the arrangement of trials. Findings show that the contextual factors studied did not account for this difference. Neither eliminating the presence of shorter trials preceding the irregular test trials nor loading the series with short duration trials substantially influenced the extent to which the long regular trials were slower than the long irregular trials. As observed before, the crossover characterized the process schizophrenic group and was not characteristic of the reactive schizophrenic or normal control groups. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of segmental set and inhibitory deficit explanations of the crossover pattern in process schizophrenic reaction time.

Obtained significant crossover patterns in the simple reaction time performances of 42 process schizophrenic patients. The crossover pattern is manifested in the interaction between preparatory interval duration and regularity of trial presentation. A within-S comparison of the effect of 2 intertrial interval conditions (2 and 7 sec) on the crossover was performed. The outcome showed a greater crossover pattern for the 2-sec than the 7-sec condition, a greater level of impairment on the regular than irregular trials (redundancy-associated deficit), and a trend for progressively slower performances as a function of the number of trials. Results support an inhibitory process concept over D. Shakow's set theory explanation of the deficit performance. Defensive (protective) inhibition and reactive inhibition constructs were found useful in considering the results. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polydimethylsiloxane as a macromolecular additive for enhanced performance of molecular bulk heterojunction organic solar cells

The effect of the macromolecular additive, polydimethylsiloxane (PDMS), on the performance of solution processed molecular bulk heterojunction solar cells is investigated, and the addition of PDMS is shown to improve device power conversion efficiency by ～70% and significantly reduce cell-to-cell variation, from a power conversion efficiency of 1.25 ± 0.37% with no PDMS to 2.16 ± 0.09% upon the addition of 0.1 mg/mL PDMS to the casting solution. The cells are based on a thiophene and isoindigo containing oligomer as the electron donor and [6,6]-phenyl-C61 butyric acid methyl ester (PC(61)BM) as the electron acceptor. PDMS is shown to have a strong influence on film morphology, with a significant decrease in film roughness and feature size observed. The morphology change leads to improved performance parameters, most notably an increase in the short circuit current density from 4.3 to 6.8 mA/cm(2) upon addition of 0.1 mg/mL PDMS. The use of PDMS is of particular interest, as this additive appears frequently as a lubricant in plastic syringes commonly used in device fabrication; therefore, PDMS may unintentionally be incorporated into device active layers.     

Initial characterization of autoprocessing and active-center mutants of CMV proteinase

Human cytomegalovirus (CMV) encodes a unique serine proteinase that is required in the maturation of the viral capsid. The CMV proteinase can undergo autocatalytic activation and is subject to proteolytic self-inactivation. Mutant enzyme forms were prepared to eliminate the initial autoprocessing site and thus form an active single-chain protein for structure-function studies. Two mutants of CMV proteinase were cloned and expressed in Escherichia coli. The A143V mutant was a conservative substitution at the first internal cleavage site. The S132A mutant modified one of the triad of residues responsible for catalytic activity. Through the use of computer-controlled high-cell-density fermentations the mutant proteins were expressed in E. coli at approximately 170 mg/L as both soluble (approximately 40% of total) and inclusion-body forms (approximately 60% of total). The soluble enzyme was purified by standard methods; inclusion-body protein was isolated by standard methods after refolding and solubilization in guanidine or urea. Sedimentation equilibrium and sedimentation velocity analyses reveal that the enzyme undergoes concentration-dependent aggregation. It exhibits a monomer <==> dimer equilibrium (Kd = 1 microM) at low concentrations and remains dimeric at high concentrations (28 mg/ml). Differential scanning calorimetry data for protein thermal unfolding fit best to a non-two-state model with two components (Tm = 52.3 and 55.3 degrees C) which subsequently aggregate upon unfolding. Analysis of the short-UV circular dichroism spectra of protein forms resulting from expression as soluble molecules (not refolded) reveals that the two mutants have very similar secondary structures which comprise a mixed structural motif of 20% alpha-helix, 26% beta-sheet, and 53% random coil. Though soluble and active (A143V mutant only), CD analysis revealed that protein refolded from inclusion bodies did not exhibit spectra identical to that of protein expressed only in soluble form.     

"Span of apprehension deficits in children vulnerable to psychopathology: A failure to replicate": Comment.

Discusses the differences in task and sample characteristics that might explain why significant group differences in span of apprehension performance were found by the present 1st author and colleagues (see record 1978-05788-001) and those found by P. D. Harvey et al (see record 1985-01308-001). It is suggested that the procedure used in the latter study (Procedure A) places greater demands on sustained attention and/or orientation to the stimuli than did the former procedure (Procedure B). Procedure B (particularly on complex arrays) appears to make greater demands on those processes involved in visual search than did Procedure A. Possible differences in the characteristics of the schizophrenic parents of the high-risk children and in the characteristics of the normal control children studied in the 2 projects are also discussed. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)