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.     

Visual gap and offset discrimination and its relation to categorical identification in brief line-element displays

Visual processing was investigated in judgments of relative line position. Stimulus continua were generated by bisecting a straight line and displacing the segments. Experiment 1 measured discrimination of pairs of longitudinally displaced segments at equal steps along the continuum. At long (2 s) durations discrimination fell smoothly, but at short (100 ms) durations it was sharp-peaked. In Experiment 2 the short-duration stimuli were labeled with subsets of the labels no gap, just a gap, and more than just a gap. Theoretical discrimination performances were computed and the one based on no gap and just a gap closely fitted observed performance. Experiments 3 and 4 were similar to 1 and 2, with lateral replacing longitudinal displacement. Similar "categorical" performance was obtained. It was concluded that there are discrete mechanisms for early detection of relative line position and that 2 labels can be used to characterize performance in each direction.     

Characteristics of Alcoholism Among Catholic Sisters: Results of a National Survey

In this article the author reports results from a national survey of recovering alcoholic Catholic Sisters, describing their addiction history, treatment, and the role of the community.     

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.     

Aversiveness of denatonium saccharide and quinine in grasshopper mice Onychomys leukogaster

The responses toward denatonium saccharide and quinine by three rodent species differ from those exhibited by humans. This study measured the relative aversiveness of these two compounds in grasshopper mice (Onychomys leucogaster) to determine if this species responded similarly to or differently from these other rodents. In a choice test, the mice clearly preferred quinine over denatonium saccharide at concentrations of 1/10,000 and 1/50,000, but only marginally preferred quinine at a concentration of 1/1000. When denatonium or quinine was paired with toxicosis, both suppressed drinking at concentrations from 1/10,000 to 1/50,000, but only denatonium suppressed drinking at 1/100,000. Neither compound suppressed drinking at 1 part in million. Grasshopper mice perceived denatonium saccharide as more aversive than quinine in both experiments. Such a response resembled the behavior of humans more than that of the other three rodents previously tested.     

Relation of cognitive operational performance to comprehension and production of dimensional adjectives

This study compared normal developing children, aged 34 to 51 mo., on comprehension and production of relative dimensional adjectives using object manipulations in a close elicitation procedure and on Piagetian operational tests of conservation of continuous quantity, length, reversibility and seriation. Analysis indicated a significant difference on the expressive language performance of the transitional and the concrete operational children over the preoperational children, but no significant differences occurred between the first two groups. Children who performed better on seriation were significantly better on expressive language performance. Children classified as operational for length performed better on all language measures than those classified as nonoperational. Reversibility and conservation of a continuous quantity did not differentiate children.     

Stereotypical beliefs about overweight and smoking and decision-making in assignments to sales territories

This study examined job bias associated with business students' role-playing as sales managers who assigned trainees to sales territories. Personal characteristics of being extremely overweight and being a heavy smoker were studied. Research participants were given a personnel record (training record) of a sales trainee and asked to make a sales territory assignment decision; three vacant territories were also described. The participants were told to assign the trainee to one of the territories or to indicate a preference to not have the recruit assigned to any territory within the role-playing manager's region. Analysis indicates that a sales recruit described as extremely overweight was less likely to be assigned to an important or desirable sales territory and more likely to be assigned to an undesirable territory or not selected at all for an assignment within a sales region. Those described as heavy smokers were similarly treated but to a lesser degree. Overweight saleswomen were discriminated against more than overweight salesmen.     

Free visual imagery sequences in reactors and nonreactors

The technique of Free Visual Imagery Sequences was used with 32 outpatients, M age of 33.9, to determine the differences between Visual Imagery Reactors and Nonreactors as defined in previous studies. Reactors showed significantly more responses associated with Affect/Conflict material, frequently including bizarre and distorted images. The Affect/Conflict responses occurred earlier and had longer duration spans in Reactors. Neutral content was more prevalent in Nonreactors. An interpretive approach involving a regulatory processing system is proposed. Free Visual Imagery Sequences appears to be a simple and efficient clinical technique which can contribute data useful in determining the extent to which imagery techniques could be employed in certain forms of psychotherapy.