Hastings Cent Rep. 2014 Mar-Apr;Spec No:S8-18. doi: 10.1002/hast.294.
Neuroscientists have long sought to study the dynamic activity of the human brain-what's happening in the brain, that is, while people are thinking, feeling, and acting. Ideally, an inside look at brain function would simultaneously and continuously measure the biochemical state of every cell in the central nervous system. While such a miraculous method is science fiction, a century of progress in neuroimaging technologies has made such simultaneous and continuous measurement a plausible fiction. Despite this progress, practitioners of modern neuroimaging struggle with two kinds of limitations: those that attend the particular neuroimaging methods we have today and those that would limit any method of imaging neural activity, no matter how powerful. In this essay, I consider the liabilities and potential of techniques that measure human brain activity. I am concerned here only with methods that measure relevant physiologic states of the central nervous system and relate those measures to particular mental states. I will consider in particular the preeminent method of functional neuroimaging: BOLD fMRI. While there are several practical limits on the biological information that current technologies can measure, these limits-as important as they are-are minor in comparison to the fundamental logical restraints on the conclusions that can be drawn from brain imaging studies.
神经科学家长期以来一直致力于研究人类大脑的动态活动——即在人们思考、感受和行动时大脑中发生的事情。理想情况下，对大脑功能的深入观察应该同时连续测量中枢神经系统中每个细胞的生化状态。虽然这种神奇的方法还只是科幻小说，但神经影像学技术一个世纪的进步已经使这种同时连续的测量成为一种合理的虚构。尽管取得了这些进展，但现代神经影像学的实践者仍面临着两种限制：一种是我们今天所拥有的特定神经影像学方法的限制，另一种是无论成像神经活动的方法多么强大，都会限制这种方法。在本文中，我考虑了测量人类大脑活动的技术的缺点和潜力。我这里只关心那些测量中枢神经系统相关生理状态并将这些测量结果与特定心理状态联系起来的方法。我特别关注功能神经影像学的卓越方法：BOLD fMRI。虽然当前技术可以测量的生物信息存在一些实际限制，但与从脑成像研究中得出的结论所受到的基本逻辑限制相比，这些限制虽然重要，但却微不足道。
