Frontosubcortical neuroanatomy and the continuous performance test in mania

OBJECTIVE: The authors examined whether Continuous Performance Test scores correlate with frontosubcortical volumes in bipolar disorder. METHOD: The subjects were 17 patients hospitalized for an acute manic episode and 12 group-matched comparison subjects. They underwent magnetic resonance imaging and completed the Continuous Performance Test. RESULTS: The patients performed worse on the Continuous Performance Test and had smaller prefrontal cortical volumes than the comparison subjects. Within the patient group, Continuous Performance Test performance significantly correlated with prefrontal and hippocampal volumes. CONCLUSIONS: These results suggest that certain neuroanatomic structures may be associated with attentional dysfunction in mania.     

Memory complaints in epilepsy: correlations with cognitive performance and neuroticism

Experimental results are presented to show that the adhesion force is the single most important limiting factor in high-resolution atomic force microscopy of DNA in air, prepared by the cytochrome-C-assisted spreading method. It is also shown that humidity plays a minor role in the control of probe force. Using a pure carbon film as the substrate to clean the AFM tip prior to imaging, it is demonstrated that 4-6 nm resolution on DNA can be routinely obtained by the atomic force microscope with commercial Si3N4 pyramid cantilevers. We also show that in organic solvents a resolution of up to 3 nm can be obtained under optimal conditions.     

Acoustic neuroma: correlations between morphology and otoneurological manifestations

Forty-two patients with acoustic neuroma (AN) were studied to determine whether different types of neuroma could be correlated with specific signs and symptoms of the disease. Based on gadolinium-enhanced TI-weighted MRI sequences, the 42 cases of AN could be divided into three groups, either by size (small: 11.9%, medium: 50%, and large: 38.1%) or by site of origin of the tumour (lateral: 16.7%, intermediate: 69%, and medial: 14.3%). Relations were found between the size and the site of origin of the neuromas and certain clinical, audiological and vestibular findings. The clinical presentation seemed to vary with the site of origin and the size of the tumour: patients with lateral neuromas generally had small tumours, sometimes only located in the internal auditory canal (IAC), and presented early subjective hearing loss while patients with medial neuromas had larger tumours which grew without causing significant audiological symptoms. Normal hearing function was seen only in the patients with medial ANs; however, a significant relation between the size or the site of origin of the AN and the average hearing threshold was not demonstrated. The sensitivity of the stapedial reflex test (SR) was higher for lateral ANs. Anomalies in the brainstem auditory evoked potentials (BAEPs) did not seem to be related to either the size or the site of origin of the AN. The vestibular tests demonstrated a higher frequency of central vestibular involvement in the large tumours, while normal function was more frequent in the lateral tumours. In the group studied the combination of BAEPs and vestibular tests allowed us to identify all the ANs with an optimal level of sensitivity.     

Developmental plasticity of respiratory behavior in Lymnaea

The authors investigated the contribution of experience to development and maintenance of pulmonary respiration in Lymnaea stagnalis. Respiration in L. stagnalis is bimodal via both the skin and the lung. Rearing snails from eggs to adulthood while preventing lung respiration (differentially reared snails) showed that L. stagnalis can develop and survive without pulmonary respiration. These snails were able to open and close their pneumostome when given the opportunity as adults. However, quantitative aspects of their respiratory behavior were significantly altered. Prevention of pulmonary respiration in adult, normally reared snails also induced behavioral changes. Comparison of these changes with those in differentially reared snails revealed specific developmental effects, which were reversible. Thus, this is a suitable model system for studying questions related to behavioral plasticity.     

Brain development, plasticity, and behavior.

Damage to the infant brain is associated with a complex array of behavioral and anatomical effects. Recent research is leading to a new understanding of the nature of, and mechanisms underlying, recovery from brain damage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationships between leader behavior and subordinate satisfaction and performance: A test of some situational moderators.

Examined the effects of 4 situational moderators on the relationships between (a) leader behavior and subordinate satisfaction and (b) leader behavior and subordinate performance, in a social services organization. Respondents--54 Black counselors and people-helping workers--described their job satisfaction, role clarity, and the behavior of their leaders ( n = 19), while the leaders evaluated the respondents' job performance. Using subgroup moderator analyses, the effect of work unit size was significant, with leader structure related to satisfaction in larger units and consideration related to satisfaction in smaller units. Results confirm earlier findings that in low-stress jobs consideration enhances satisfaction and performance but that in high-stress jobs, structure is helpful. Also confirmed were results of previous studies showing that high structure had dysfunctional effects only when accompanied by low consideration. Finally, role clarity did not moderate the relationship between leader behavior and subordinate satisfaction and performance. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interpreting correlations between children's perceived control and cognitive performance: Control, agency, or means€nds beliefs?

The types of beliefs responsible for correlations between children's perceived control and cognitive performance were investigated in 180 2nd, 4th, and 6th graders. Children were interviewed for control beliefs regarding the attainment of desired goals, for agency beliefs regarding the accessibility of different types of means to the self, and for means–ends beliefs regarding the efficacy of different types of means. Cognitive performance variables included fluid and crystallized intelligence as well as short-term and recognition memory. Of the three types of beliefs, only agency beliefs were strongly and consistently related to cognitive performance. Correlations were greater than zero beginning in 4th grade, increased monotonically from 2nd to 6th grade, and occurred for all cognitive performance measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processes mediating the relationship between cooperating-teacher behavior and student-teacher classroom performance.

To explain previously detected relationships between cooperating-teacher behavior and student-teacher behavior subsequent to microteaching training, 2 alternate hypotheses were tested: (a) the model of target skill utilization provided by the cooperating teacher encourages student-teacher skill utilization, and (b) the classroom ecological system as shaped by cooperating-teacher skill utilization supports student-teacher skill utilization. 32 credential students were randomly assigned to 2 levels of each treatment that reflected the 2 hypotheses, were provided wth microteaching training in the target skill, and were subsequently observed during classroom teaching. A 2-way ANOVA of skill-utilization scores supported hypothesis (b). Implications for teacher education and classroom based research are discussed. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Percentage discounts, initial price, and bargain hunting: A heuristic-systematic approach to price search behavior.

Consumer decisions concerning price search were investigated using the heuristic-systematic model of social judgment (S. Chaiken, A. Liberman, & A. H. Eagly, 1989). Consumers used the size of the percentage discount as a heuristic cue to help decide whether a better price was likely to be available elsewhere. However, as predicted, participants relied on this cue only when the initial base price of the item was low. In contrast, search was continued despite the offer of a large percentage discount when consumers were shopping for items that were relatively expensive. This finding was attributed to the higher potential costs associated with missing a better price when consumers were shopping for more expensive items. In general, the heuristic-systematic model proved to be a useful way to characterize price search decisions. It was also suggested that these findings might be useful in explaining some conflicting results in the price search literature. Implications for behavioral price theories are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous carotid-cavernous fistula: correlations between clinical findings and venous drainage

OBJECTIVE: The purpose of this study was to compare the routine pre-natal surveillance carried out in nine European Gyneco-Obstetric units. MATERIAL AND METHOD: A survey was carried out between October 1992 and November 1993 with the aid of a questionnaire. The questionnaire contained 118 questions covering clinical examinations and explorations undertaken systematically during the first, second and third trimesters and at the end of pregnancy before delivery. To ensure that the replies were accurate, the survey was carried out on the spot in the units concerned with the head of the unit. RESULTS: The survey revealed a certain number of differences in the surveillance carried out in the various units. The units did not all carry out systematic blood tests for toxoplasmosis, AIDS and hepatitis B at the first examination. The same applied to fasting blood glucose and the bacterial culture of the urine. Nor did all the units automatically undertake vaginal examination during the second and third trimesters and the English departments were not all convinced of the need for systematic ultrasound tests. Only five of the nine units undertook routinely cardiotocographic recordings of the fetal heart rate at the end of the pregnancy. CONCLUSION: The differences observed in the various surveillance procedures simply reflect our uncertainty regarding the different tests we use to monitor pregnancies. At a time when financial constraints are forcing us to make choices, there is an urgent need to assess the effectiveness and the cost of the various elements of our prenatal monitoring.     

Evaluation of laboratory methods for the study of driver behavior: Relations between simulator and street performance.

Road performance data on 304 taxi drivers were obtained by pairs of trained observers using behavioral checklists. Drivers did not know they were being observed. 66% of the drivers then agreed to participate in the laboratory study, which involved performance on 2 different driving simulators and on 4 perceptual–motor tests. Officially recorded accidents and violations over a 5-yr period were obtained for each S for comparison with performance data. Results show that few of the scores from the simulators or tests were significantly correlated with road performance; however, a number of significant relations were found between perceptual–motor test performance and simulator performance. Although these correlations were not high, they tended to be more significant than those between performance on the 2 simulators. Age was negatively correlated with simulator performance. Relations between all performance measures and officially recorded accident and violation data were low. Some significant predictors of certain classes of violations were achieved from road performance measures obtained in the study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Brain–behavior correlations: Relationships between mother–stranger face processing and infants' behavioral responses to a separation from mother.

Event-related potentials (ERPs) were recorded from 6-month-olds (N = 30) as they looked at pictures of their mother's face and a stranger's face. Negative component (Nc) and P400 component responses from the ERP portion of the study were correlated with behavioral responses of the infants during a separation from their mothers. We measured the mother-directed infant behaviors of distress and visual search for mother during separation in order to determine if they were predictive of infants' brain responses to pictures of the mother's face versus a stranger's face. These behavioral measures are important because they likely reflect the functioning of the emerging mother–child relationship and inform debates about interactions between social experience and face processing. Infant distress and visual search for mother during separation were predictive of face processing ERPs, and this relationship differed across mother and stranger face presentations. In particular, distress was associated with larger amplitude P400 and Nc responses to the mother's face, and visual search for mother was associated with longer P400 and Nc latencies to the stranger's face. Implications for the developing mother–child relationship and face processing system are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-strain-rate behavior of low-alloy multiphase aluminum- and silicon-based transformation-induced plasticity steels

High-strength, low-alloy transformation-induced plasticity (TRIP) steels are advanced multiphase steel grades that combine high-strength levels with an excellent ductility, making them ideally suited for application in crash-relevant parts of automotive car bodies. The enhanced plastic hardening and deformability are due to a complex interaction between the microstructural phases and to the transformation of metastable austenite to martensite during plastic deformation. During high-strain-rate loading, not only the material but also the transformation will be influenced by adiabatic heating. The impact-dynamic properties of CMnAl- and CMnSi-TRIP steels were determined in the range of 500 to 2000 s⁻¹ using a split Hopkinson tensile bar (SHTB) setup. Bake-hardening treatments were applied to study the effect of strain aging. The experiments show that strain-rate hardening is superior to thermal softening: yield stresses, deformation, and energy dissipation increase with the strain rate. Phenomenological material models were investigated to describe the strain-rate and temperature-dependent behavior of TRIP steels. Both the Johnson-Cook model and an extended version of the Ludwig model were found to give good agreement with the experimental data.     

Allowing for correlations between correlations in random-effects meta-analysis of correlation matrices.

Practical meta-analysis of correlation matrices generally ignores covariances (and hence correlations) between correlation estimates. The authors consider various methods for allowing for covariances, including generalized least squares, maximum marginal likelihood, and Bayesian approaches, illustrated using a 6-dimensional response in a series of psychological studies concerning prediction of exercise behavior change. Quantities of interest include the overall population mean correlation matrix, the contrast between the mean correlations, the predicted correlation matrix in a new study, and the conflict between the existing studies and a new correlation matrix. The authors conclude that accounting for correlations between correlations is unnecessary when interested in individual correlations but potentially important if concerned with a composite measure involving 2 or more correlations. A simulation study indicates the asymptotic normal assumption appears reasonable. Because of potential instability in the generalized least squares methods, they recommend a model-based approach, either the maximum marginal likelihood approach or a full Bayesian analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of task interdependence on the relationship between helping behavior and group performance.

The authors examine whether task interdependence moderates the relationship between the helping form of organizational citizenship behavior (OCB) and group performance. In a laboratory study, 62 groups with 3 members each completed a card-sequencing activity in which the level of task interdependence among group members was manipulated. Independent evaluators assessed helping by viewing videotapes of the groups' interactions during the sequencing activities. Performance was measured as a combined function of group speed and accuracy. Two prior field studies reported contradictory results regarding the impact of helping on group performance. Results from this study suggest that task interdependence may explain these results, and that the relationship between helping and group performance depends on the level of task interdependence required of group members. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between adhesion molecules and neuronal plasticity

1. It is presently widely assumed that structural reorganization of synaptic architectures subserves the functional gains that define certain neuronal plasticities. 2. While target molecules thought to participate in such morphological dynamics are not well defined, growing evidence suggests a pivotal role for cell adhesion molecules. 3. Herein, brief discussions are presented on (i) the history of how adhesion molecules became implicated in plasticity and memory processes, (ii) the general biology of some of the major classes of such molecules, and (iii) the future of the adhesion molecule/plasticity relationship.     

Dopaminergic control of light-adaptive synaptic plasticity and role in goldfish visual behavior

Dopamine has been implicated in processes of retinal light and dark adaptation. In goldfish retina, horizontal cell dendrites elaborate neurite processes (spinules) into cone terminals, in a light- and dopamine-dependent manner. However, the functions of retinal dopamine and the horizontal cell spinules in visual behavior are unknown. These issues were addressed in behavioral, electroretinographic, and anatomical studies of normal fish and those with unilateral depletion of retinal dopamine induced by intraocular (i.o.) injections with 6-hydroxydopamine (6-OHDA). Dopamine interplexiform cells (DA-IPC) disappear within 2 weeks after 6-OHDA injection; cell bodies appear at the marginal zone within 6 weeks at which time neurites slowly reinnervate the retina with a sparse plexus over the next 12 months. We found that dopamine depletion increased light sensitivity at photopic but not scotopic backgrounds by 2.5 log units, an effect mimicked by i.o. injections of dopamine D1 and D2 antagonists. The ERG b-wave increment thresholds were the same for control and dopamine depleted eyes, indicating a normal transition from rod to cone systems in the ON pathway. Light-dependent spinule formation was reduced by about 60% in dopamine-depleted retinas, but returned to normal by 3 months and 9 months after injection in the entire retina, even areas not directly innervated with DA-IPC processes. Spinule formation in vivo was inhibited 50% with i.o. injection of SCH 23390 in control retinas as well as throughout 3 month 6-OHDA injected retinas, including DA-IPC free areas. This latter result indicates a volume effect of dopamine, diffusing laterally through the retina over several millimeters, in regulating spinules. We conclude that DA-IPCs regulate sensitivity to background at photopic levels not via the ON pathway, but perhaps the OFF pathway. Goldfish display both increased sensitivity to light and a normal Purkinje shift in the ERG b-wave whether or not horizontal cell spinules are present, indicating that dopamine control of photopic vision in fish is not mediated through light-induced spinule formation of horizontal cell dendrites.