The evolution of leadership during group development

This paper is based on the view that the theory of the group-as-a-whole is illuminated and clarified by a developmental perspective. Beck's theory of group development is used as the framework within which the evolution of four leadership roles across nine developmental phases are discussed. Leadership is defined as a shared function in which four participants play important roles in a dialectical process through which the structure of a group is developed, maintained, reinterpreted or modified as needed. Data are presented on verbal participation and on a sociometric questionnaire to illustrate changes in the four leaders' behavior and the members' perceptions of them across the phases of group development.     

Dopaminergic modulation of prospective memory in Parkinson's disease

Growing interest is present in literature on the study of prospective memory functioning in Parkinson's disease (PD). Current data indicate that prospective memory may be impaired in PD and a relationship with general executive dysfunctioning has been suggested. However, although the dopamine dependency of cognitive dysfunction in PD has been widely investigated, poor is known on the dopaminergic modulation of PM. In the present study we explored the effect of acute administration of levodopa on the performance of a PD sample (n=20) in a time-based prospective memory task. PD patients were evaluated in the morning after a 12-hour therapy wash-out in two experimental conditions: i) after levodopa assumption ("on"); ii) without drug administration ("off"). The experimental task required to execute three uncorrelated actions after 10' for three consecutive trials. Distinct scores for the spontaneous recall of the intention to perform the actions (prospective component) and for the correct execution of the actions (retrospective component) have been computed. Results showed that in the "off" condition PD patients were selectively impaired on the prospective component of the task. However, L-dopa administration significantly improved PD patients' performance actually restoring the prospective memory deficit. These results support a critical role of dopaminergic modulation in prospective memory processes in PD patients, possibly through the replacement of dopamine levels in fronto-striatal pathways.     

Book Review: Allocating Scarce Medical Resources

Theoretical Medicine and Bioethics -