Behavioural functions of the frontal cortex

灵长类动物的额叶皮质由大量区域组成，这些区域具有独特的细胞结构，并与大脑的其他区域相连。这些不同的区域形成了不同的额叶功能子系统。在试图了解额叶皮质的功能组织时，我的研究重点一直是从解剖学上识别这些不同的子系统，研究它们受损后认知和行为障碍的性质，并研究这些功能子系统之间的相互作用，以影响行为和认知的高级控制，这是额叶功能的领域。在我的研究中，我已经证明，额叶皮质切除的患者在工作记忆中的监控过程中表现出特定的障碍，以及在基于习得的条件规则在不同动作之间进行选择方面的障碍。在与猴子的合作中，我证明了额叶背外侧皮质的特定区域构成了这两类损害的基础：用于监测工作记忆中的信息的额中背外侧皮质(区46和9)，以及用于在反应之间进行条件性规则选择的后背外侧额叶皮质(区8和6)。在目前拨款申请中提出的工作中，我将探索腹外侧额叶皮质(特别是控制口腔面部动作的系统)和额叶极地皮质(第10区)的功能贡献，它们与第46区和第9区相互作用，可能参与一种超监控功能，这将奠定我们多任务处理的能力。这些问题现在可以用一种强有力的方式来解决，因为：a)我们最近开发的新的实验范式(适用于人类和猴子的研究)，b)对不同额叶皮质区域的解剖连接的详细知识(我们对此做出了贡献)，以及c)我们最近对人和猴子的额叶皮质进行的比较解剖学研究的结果。我的研究计划利用对损伤影响的行为分析，以及记录特定区域中个别神经元的活动，以努力阐明灵长类大脑中这一最复杂部分的功能。

The primate frontal cortex comprises a large number of areas that have distinct cellular architecture and connectivity with other areas of the brain. These different areas form distinct functional frontal subsystems. In trying to understand the functional organization of the frontal cortex, the focus of my research has been to identify anatomically these different subsystems, to study the nature of the cognitive and behavioural impairments that follow damage to them, and to study the interactions between these functional subsystems in effecting the high-level control of behaviour and cognition that is the domain of frontal function. In my research, I have shown that patients with frontal cortical excisions exhibit specific impairments in monitoring processes within working memory, as well as impairments in selection between different actions based on learned conditional rules. In work with the monkey, I have shown that specific areas of the dorsolateral frontal cortex underlie these two classes of impairment: the mid-dorsolateral frontal cortex (areas 46 and 9) for the monitoring of information in working memory and the posterior dorsolateral frontal cortex (areas 8 and 6) for conditional rule-based choices between responses. In the work proposed in the present grant application, I shall explore the functional contribution of the ventrolateral frontal cortex (particularly a system that controls orofacial action) and the frontal polar cortex (area 10) which, in interaction with areas 46 and 9, may be involved in a hyper-monitoring function that would underlie our ability to multitask. These issues can now be approached in a powerful way because of: a) new experimental paradigms (appropriate for human and monkey studies alike) that we have recently developed, b) the availability of detailed knowledge of the anatomical connectivity of the various frontal cortical areas (to which we have contributed), and c) the results of our recent comparative anatomical studies of the human and the monkey frontal cortex. My research program utilizes behavioural analysis of lesion effects as well as recording the activity of individual neurons in particular areas in an effort to elucidate the functions of this most complex part of the primate brain.