Behavioural Functions of the Frontal Cortex

灵长类动物的额叶皮层包括大量的区域，这些区域具有不同的细胞结构和与大脑其他区域的连接。这些不同的区域形成不同的功能性额叶子系统。在试图了解额叶皮层的功能组织时，我的研究重点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，以影响对行为和认知的高水平控制，这是额叶功能的领域。在我的研究中，我发现额叶皮层切除的患者在工作记忆的监控过程中表现出特定的障碍，以及在基于学习的条件规则的不同行为之间的选择障碍。在对猴子的研究中，我发现背外侧额叶皮层的特定区域是这两类损伤的基础：中背外侧额叶皮层（第46和第9区）负责监控工作记忆中的信息，后背外侧额叶皮层（第8和第6区）负责在反应之间进行基于规则的条件选择。在本申请中提出的工作中，我将探索腹外侧额叶皮层在记忆提取中的功能贡献，以及额叶极皮层（第10区）与第46区和第9区的相互作用，可能涉及超监控功能，这将成为我们多任务处理能力的基础。此外，猴子布罗卡区在基于规则的口面反应的功能作用将被检查。这些问题现在可以以一种强有力的方式来解决，因为：a）我们最近开发的新实验范式（适用于人类和猴子的研究），B）各种额叶皮层区域的解剖连接的详细知识的可用性（我们做出了贡献），以及c）我们最近对人类和猴子额叶皮层的比较解剖研究的结果。我的研究项目利用猴子和人类受试者的损伤效应的行为分析，以及猴子前额叶皮层区域的连接研究，以阐明灵长类动物大脑中最复杂部分的功能。

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 in memory retrieval 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. In addition, the functional role of monkey Broca's area in rule-based orofacial responses will be examined. 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 in monkey and human subjects and study of the connections of the prefrontal cortical areas in the monkey in an effort to elucidate the functions of this most complex part of the primate brain.