Center for Neural Science, New York University, New York, NY, USA.
Prog Brain Res. 2012;195:431-42. doi: 10.1016/B978-0-444-53860-4.00021-0.
Basic tendencies to detect and respond to significant events are present in the simplest single cell organisms and persist throughout all invertebrates and vertebrates. Within vertebrates, the overall brain plan is highly conserved, though differences in size and complexity also exist. The forebrain differs the most between mammals and other vertebrates. The classic notion that the evolution of mammals led to radical changes such that new forebrain structures (limbic system and neocortex) were added has not held up nor has the idea that so-called limbic areas are primarily involved in emotion. Modern efforts have focused on specific emotion systems, like the fear or defense system, rather than on the search for a general purpose emotion systems. Such studies have found that fear circuits are conserved in mammals, including humans. Animal work has been especially successful in determining how the brain detects and responds to danger. Caution should be exercised when attempting to discuss other aspects of emotion, namely subjective feelings, in animals since there are no scientific ways of verifying and measuring such states except in humans.
检测和响应重大事件的基本趋势存在于最简单的单细胞生物中，并贯穿所有无脊椎动物和脊椎动物。在脊椎动物中，大脑的整体结构高度保守，但也存在大小和复杂性的差异。在哺乳动物和其他脊椎动物之间，前脑的差异最大。经典观点认为，哺乳动物的进化导致了根本性的变化，以至于新的前脑结构（边缘系统和新皮质）被添加进来，但这种观点以及所谓的边缘区域主要参与情感的观点都站不住脚。现代研究的重点是特定的情绪系统，如恐惧或防御系统，而不是寻找通用的情绪系统。此类研究发现，恐惧回路在包括人类在内的哺乳动物中是保守的。动物研究在确定大脑如何检测和响应危险方面尤其成功。在尝试讨论动物的其他情感方面，即主观感受时，应该谨慎，因为除了人类之外，没有科学的方法可以验证和测量这些状态。
