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Injection of apomorphine, a dopaminergic agonist drug, decreases akinesia and increases cortical activityThe main driving force for the increased discharge of cells in GPi and SNr is thought to be overactivity of bl.the subthalamic nucleus (STN), which has excitatory projections to both structures. As a result, both GPi and STN have been identified as potential targets for neurosurgical procedures aimed at reducing basal ganglia outputs [6-111. Pallidotomy has now been performed successfully by many groups [6, 7, 9, 111. Two PET activation studies have confirmed that pallidotomy is accompanied by improvement of cortical activity during movement [12][13][14]. Theoretically, STN surgery has an advantage over pallidal surgery in that it can influence SNr as well as GPi activity and therefore could be more effective. A recent procedure has been to implant electrodes in STN or GPi for chronic electrical stimulation [8, lo]. Continuous high-frequency stimulation is believed to inactivate the target structure and to have an effect similar to a lesion.The advantage of the technique is that the effect is reversible and easily graded by changing electrical parameters. The effect is dependent on the frequency; frequencies lower than 30 Hz are ineffective and those greater than 50 Hz are effective [lo]. The aim of our study was to compare the effect of STN and GPi stimulation on the pattern of cortical activation during selfselected movements. We wanted (I) to examine the

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It is commonly recognized that interpersonal mesagefunction in the senriceofmultiple social goals. Despite this, relatively little is known ofthe encoding processes underlying the production of such messages. One possible account of these encoding processes is found in action assembly theory. This article explicates the production of multiple-goal messages from the perspectiw of action assembly theory and reports an experimental inwsfigation of this account. In this study, the speech of participants assigned the task of pursuing multiple social goals was contrasted with that of people assigned a single task Consistent with the theory, the results revealed that participants pursuing multiple gmIs had longcr onset latencies than their counterparts given a single gml. Similarly, multiple goals were associuted with greater pauselphonation ratios after the onset of speech. The effects of opportunity for advance message preparation were also examined. As expected, participants given the opportunity for advance planning exhibited shorter response latencies than those whospokespon taneously. In keeping with previous research in this area, filled-pause rate was not significantly affected by either number of goals or the opportunityfor advance preparation.here are few properties of human communication more frequently noted than that interpersonal messages func-T tion in the service of multiple social goals ( e g , Brown ). However, while the multifunctionality of messages stands as a fundamental characteristic of interpersonal communication, relatively little is known of the encoding processes underlying the production of such messages. An exigency thus exists for communication scholars to move beyond recognition of the multifunctional nature of messages and toward the development of theoretical accounts that explicate the processes of message design and execution.Iohn 0. Greene is an Associate Professor, and A. E. Lindsey is a doctoral candidate in the