Synergistic influences of sensory and central stimuli on non-voluntary rhythmic arm movements

In recent years, neuromodulation of the cervical spinal circuitry has become an area of interest for investigating rhythmogenesis of the human spinal cord and interaction between cervical and lumbosacral circuitries, given the involvement of rhythmic arm muscle activity in many locomotor tasks. We have previously shown that arm muscle vibrostimulation can elicit non-voluntary upper limb oscillations in unloading body conditions. Here we investigated the excitability of the cervical spinal circuitry by applying different peripheral and central stimuli in healthy humans. The rationale for applying combined stimuli is that the efficiency of only one stimulus is generally limited. We found that low-intensity electrical stimulation of the superficial arm median nerve can evoke rhythmic arm movements. Furthermore, the movements were enhanced by additional peripheral stimuli (e.g., arm muscle vibration, head turns or passive rhythmic leg movements). Finally, low-frequency transcranial magnetic stimulation of the motor cortex significantly facilitated rhythmogenesis. The findings are discussed in the general framework of a brain-spinal interface for developing adaptive central pattern generator-modulating therapies.     

Multicultural training practices in community psychology programs

Surveyed the directors of 56 community psychology graduate programs to assess multicultural training practices and attitudes. Although most program directors agreed that multicultural training is important in their mission to educate students, less than half the programs (48%) required their students to take any relevant course work and only half of the programs surveyed had any faculty who were members of an ethnic minority group and one third had only one such faculty member. Furthermore, less than half the programs had a combination of training opportunities in place to integrate classroom, research, and field experiences relevant to multicultural issues. Finally, only 23% of program directors believed their training programs were successful for most students, suggesting the need to improve training.     

Within-session changes in responding during several simple schedules

Pigeons' key pecking was reinforced by food delivered by several fixed-interval, variable-ratio, and differential-reinforcement-of-low-rate schedules. Rate of responding, number of responses per reinforcer, length of postreinforcement pause, running response rate, and the time required to collect an available reinforcer changed systematically within sessions when the schedules provided high rates of reinforcement, but usually not when they provided low rates. These results suggest that the factors that produce within-session changes in responding are generally similar for different schedules of reinforcement. However, a separate factor may also contribute during variable-ratio schedules. The results question explanations for within-session changes that are related solely to the passage of time, to responding, and to one interpretation of attention. They support the idea that one or more factors related to reinforcement play a role.     

In vitro reinforcement of hippocampal bursting: a search for Skinner's atoms of behavior.

A novel "in vitro reinforcement" paradigm was used to investigate Skinner's (1953) hypotheses (a) that operant behavior is made up of infinitesimal "response elements" or "behavioral atoms" and (b) that these very small units, and not whole responses, are the functional units of reinforcement. Our tests are based on the assumption that behavioral atoms may plausibly be represented at the neural level by individual cellular responses. As a first approach, we attempted to reinforce the bursting responses of hippocampal units in a highly reduced brain-slice preparation with local micropressure applications of behaviorally reinforcing dopaminergic drugs. The same injections were administered independently of bursting to provide a "noncontingent" control for nonspecific stimulation or facilitation of firing. It was found that the bursting responses of individual CA1 pyramidal neurons may be progressively facilitated in a dose-related manner by response-contingent (but not noncontingent) injections of dopamine itself, the dopamine D1-preferring agonist SKF 82958, the D3-preferring agonist quinpirole, and the D2-like selective agonist (+)-4-propyl-9 hydroxynapthoxazine. These findings support the conclusion that unit bursting responses can be reinforced in vitro in hippocampal slices, and they further suggest that the same dopamine receptor subtypes are involved in both cellular and behavioral operant conditioning. The results thus provide indirect support for Skinner's atoms-of-behavior hypothesis.     

A Survey of 25 Years of Research on Legal Argumentation

This essay discusses the developments and trends of research in legalargumentation of the last 25 years. The essay starts with a survey of thevarious approaches which can be distinguished: the logical approach, therhetorical approach, and the dialogical approach. Then it identifies varioustopics in the research, which constitute the various components of aresearch programme of legal argumentation: the philosophical component, thetheoretical component, the reconstruction component, the empiricalcomponent, and the practical component. It concludes with a discussion ofthe main trends in the research of the last 25 years.     

A KANTIAN PERSPECTIVE ON POLITICAL VIOLENCE

Rejecting Kant's absolute opposition to revolution, I propose a modified Kantian perspective for reflecting on political violence, drawing from Kant's basic ideas but abandoning some dubious assumptions. Developing suggestions in earlier papers, the essay sketches a model for moral legislation that combines the core ideas of each of Kant's formulas of the Categorical Imperative. Though only a framework for deliberation, not a complete decision procedure, this excludes extremist positions, prohibitive and permissive, about political violence. Despite Kant's hopes, the values implicit in his fundamental principle fail to support easy, inflexible solutions; but they place strong presumptions against lawless coercion and killing, undermining social order, treating persons as dispensable, underestimating options, arrogant faith in one's own judgment, and reckless simplicity in political thinking.     

EFFECTS OF REINFORCEMENT CHOICE ON TASK RESPONDING IN INDIVIDUALS WITH DEVELOPMENTAL DISABILITIES

The effects of reinforcement choice on task performance were examined with 6 individuals who had been diagnosed with severe to profound mental retardation. Five highly preferred items were identified for each participant via stimulus preference assessments. Participants then were exposed to choice and no-choice conditions that were alternated within reversal and multielement designs. During choice sessions, participants were permitted to select between two preferred stimuli contingent on responding. During no-choice sessions, the therapist delivered a single item contingent on responding. Preference for the stimuli was held constant across conditions by yoking the items delivered during no-choice sessions to those selected during the immediately preceding choice sessions. All participants exhibited similar rates of responding across choice and no-choice conditions. These findings indicate that for individuals with severe disabilities, access to choice may not improve task performance when highly preferred items are already incorporated into instructional programs.     

中国近现代学习心理学发展轨迹之初探

中国近现代,自公元1900年到公元1949年,这一阶段中国学习心理学发展的轨迹可归纳为三个方面,理论研究：从翻译到评价再到独立探讨;实证研究：从实验法的倡导到大量实验研究的出现,实践研究：从近代学校的建立到大量有实践价值的学习观的提出。     

Stuttering theory,research, and therapy: A five-year retrospective and look ahead

This article reviews events in stuttering theory, research, and therapy that have transpired during the past 5 years. After the retrospective review, current work in the area of stuttering is examined. This analysis of the past and present was conducted in an effort to give clearer direction to future efforts to understand the disorder, and to study and treat it more effectively.     

The Boston Naming Test: Norm data and cue utilization in a sample of normal 6- and 7-year-old children

The object-naming abilities of 83 normal children were examined using the Boston Naming Test developed by E. Kaplan, H. Goodglass, and S. Weintraub (1976, The Boston Naming Test (experimental edition), unpublished test, Veterans Hospital, Boston, Massachusetts). There is currently a lack of available norms for this instrument, especially for populations of younger children. Cue utilization in this sample is explored and attention is focused upon possible gender differences in naming performance and cue strategies. Seven summary scores derived from the test are presented in this report. Results indicate that the Boston Naming Test can discriminate within a normal population sample of young children and provides a relatively normal distribution for six of seven derived scores. Boys were found to have a significantly greater number of items correctly named but no gender differences in cue utilization were evident. A major proportion of the children in this sample of 6- and 7-year-olds used phonological cues almost exclusively, rather than semantic cues also provided. Cue use was not related to age or spontaneously given responses, and none of the children were found to be highly proficient at using both types of cues.