Synaptic plasticity in the hypoglossal nucleus of female canaries: structural correlates of season, hemisphere, and testosterone treatment

The caudal portion of the hypoglossal nucleus (nXIIts) contains the motor neurons that control the syrinx in songbirds. In canaries, song occurs seasonally, is principally produced by males, and appears to be produced predominantly by muscles on the left side of the syrinx. The present study measures the effect of seasonal change and manipulation of testosterone levels on synapse number and morphology in nXIIts in adult female canaries. We find that synapse density is lower in testosterone-treated birds than in control birds and lower in fall than in spring. The number of vesicles per presynaptic profile increases in the spring as a result of a general increase in this measure in all synapses. The number of vesicles per presynaptic profile also increases with testosterone treatment, primarily due to an increase in the proportion of synapses associated with unusually high vesicle counts. Together, these changes suggest that large reserves of neurotransmitter may be necessary to sustain singing. Several ultrastructural differences between hemispheres are found. Postsynaptic thickenings are longer, and postsynaptic processes are larger on the left side than on the right side. In the spring, there are more vesicles per synapse on the left than on the right, but this lateralization is reversed in the fall. Thus, lateralization of song production is associated with lateral asymmetries in synapse morphology. These hemispheric differences are relatively small, like those seen at the light microscope level, encouraging further consideration of peripheral as well as CNS sources of functional lateralization. The seasonal and testosterone-induced changes in synapse number and morphology may be components of the periodic reorganization of canary vocalization.     

A FIELD STUDY OF THE RELATIONSHIP BETWEEN THE ORGANIZATIONAL FEEDBACK ENVIRONMENT AND PERFORMANCE

This field study used the Job Feedback Survey (Herold & Parsons, 1985) and performance data gathered from multiple sources to examine the relationship between the perceived organizational feedback environment and performance. Regression analyses indicated that, while holding the other feedback variables constant, feedback from supervisory and organizational sources was related to reported job performance while feedback from peers and self was not. Most of the unique variance in performance explained by feedback was also accounted for by feedback from organizational and supervisory sources. Negative expressions from organizational/supervisory sources (e.g., the supervisor expressing anger, the company communicating dissatisfaction with poor performance) were related to lower performance, and positive job changes initiated by these sources (e.g., increasing responsibility, assignment to special jobs) were related to higher performance. Higher performers did not receive more feedback than lower performers but did receive more total positive feedback. Supplemental issues, possible explanations, and implications of the findings are discussed.     

Internal consistency reliability of the fractionated and whole University of Pennsylvania Smell Identification Test

The internal consistency reliability (ICR) of the 40-item University of Pennsylvania Smell Identification Test (UPSIT) and its 10-, 20-, and 30-item fractions was explored, as well as the relationships between the fractions and the entire 40-item test. Pearson correlation coefficients (rs) were computed among all independent combinations and permutations of the four 10-item UPSIT booklets using data from 774 subjects. The median r values of the 10- and 20-item combinations were used to establish the ICRs of the 10- and 20-item tests. The ICRs of the 30- and 40-item tests were estimated using the Spearman-Brown formula and the median rs of the 20-item combinations. Additional ICR estimates of the 40-item UPSIT were obtained from nonsymmetrical fractions using the Horst formula. The ICRs for the UPSIT and its 10-, 20-, and 30-item fractions were 0.922, 0.752, 0.855 and 0.898, respectively. No major sex differences emerged. Estimates of correlations between (1) single booklets and two-booklet combinations and (2) the 40-item UPSIT using Guilford's (1953) correction for nonindependence ranged from 0.812 to 0.871. Overall, these results indicate that (1) the UPSIT and its 10-, 20-, and 30-item fragments have very high ICRs and (2) individual UPSIT booklets or their combinations can be used to assess smell function in a reliable manner where extreme time constraints are present (e.g., in surveys and in brief neuropsychological test batteries).     

Obstacle perception by congenitally blind children

The ability to perceive objects from a distance and navigate without vision depends principally on auditory information. Two experiments were conducted in order to assess this ability in congenitally blind children aged 4 to 12 years who had negligible amounts of visual experience or formal mobility training. In Experiment 1, children walked along a sidewalk toward a target location to get some candy. A box was placed along the path on some trials, and the children were instructed to avoid the box if it was present. The children spent more time in the region just in front of the box than in the region just behind it, indicating that they perceived the box and acted so as to navigate around it. In Experiment 2, children attempted to discriminate whether a nearby disk was on their left or on their right. The children performed at above-chance levels, again indicating distal perception of objects. The results of both experiments suggest that blind children with little or no visual experience or formal training utilize nonvisual information, presumably auditory, to perceive objects. The specific nature of this auditory information requires further investigation, but these findings imply that the underlying perceptual ability does not require experience in spatial vision or deliberate training and intervention.     

'Commitment-adequate' personality diagnosis using the Seitz (revised) Personality Questionnaire for Prisoners within the scope of forensic-psychologic-psychiatric expert assessment

In this contribution, the necessity and expediency, but also the limits of the application of psychodiagnostic methods within the scope of forensic-psychological-psychiatric expertises are discussed. A survey is given on results of statistical analysis, revision and validation gained with a personality questionnaire relevant to prison situation (PFI acc. Seitz, 1983).     

Child Behavior Profile types in a general population sample of boys 6 to 11 years old

Characteristics of Child Behavior Profile (CBP) types were studied in a general population sample of 202 boys aged 6 to 11 years. Parents completed the Child Behavior Checklist and teachers simultaneously rated the Teacher's Report Form. Overall, 39.7% of the boys were classified within a CBP type: 28.8% Internalizing and 10.9% Externalizing. The most common specific type was Somatic Complaints. Teachers rated the Externalizing CBP boys as showing robust externalizing behaviors in school. Also, boys with Externalizing profile types showed severe degrees of psychopathology in both home and school environments. An intraclass correlation of 35 or greater was found to identify boys with sufficiently severe psychopathology to warrant further clinical evaluation. Findings in this general population sample appear consistent with previous results in outpatient samples, and extend our understanding of the validity and clinical value for CBP types.     

A neuroscience model of stuttering

Using motor control systems analysis and a reductionist approach, we provide a unified model of stuttering. This model views stuttering as a momentary instability in a complex multiloop control system. The model predicts the temporal conditions under which this instability will occur. Furthermore, these temporal conditions account for the efficacy of fluency-evoking maneuvers, therapy, and the variability of speech output in stutterers.     

Identifying depression in children: A comparison of alternative selection criteria

This study evaluated commonly used methods of identifying depressed children and examined the extent to which the conclusions about correlates of dysfunction vary among different selection criteria. Child psychiatric patients (N=237,ages 7–12) and their parents participated and completed measures to permit identification of depressed children on the basis of three separate criteria, including selfreport scores on the Children's Depression Inventory, parent-reported scores for the same measure, and a DSM-III diagnosis of major depression. The study examined whether depressed and nondepressed children, defined separately by the different criteria, differed in a variety of depression-related symptoms, cognitive processes, and social activity. The results indicated little overlap in the persons identified as depressed on the basis of child-or parent-completed CDI scores or DSM-III diagnosis. Depressed and nondepressed children tended to differ across all domains (depression-related symptoms, cognitive processes, and social activity) for each selection criterion. However, significant differences were evident in these domains only when the selection criterion and other domains were assessed with the same informant (e.g., self-report) and hence shared a common method (rater) component. The findings underscore the potential influence that method factors may have in influencing the conclusions that are drawn regarding the correlates of childhood depression.Completion of this research was supported by a Research Scientist Development Award (MH00353) and by a grant (MH35408) from the National Institute of Mental Health. The author is grateful to Debra Bass, Antoinette Rodgers, and Todd Siegel for assistance with this project.