Henson R N A
Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, UK.
Prog Neurobiol. 2003 May;70(1):53-81. doi: 10.1016/s0301-0082(03)00086-8.
This article reviews functional neuroimaging studies of priming, a behavioural change associated with the repeated processing of a stimulus. Using the haemodynamic techniques of functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), priming-related effects have been observed in numerous regions of the human brain, with the specific regions depending on the type of stimulus and the manner in which it is processed. The most common finding is a decreased haemodynamic response for primed versus unprimed stimuli, though priming-related response increases have been observed. Attempts have been made to relate these effects to a form of implicit or "unconscious" memory. The priming-related decrease has also been used as a tool to map the brain regions associated with different stages of stimulus-processing, a method claimed to offer superior spatial resolution. This decrease has a potential analogue in the stimulus repetition effects measured with single-cell recording in the non-human primate. The paradigms reviewed include word-stem completion, masked priming, repetition priming of visual objects and semantic priming. An attempt is made to relate the findings within a "component process" framework, and the relationship between behavioural, haemodynamic and neurophysiological data is discussed. Interpretation of the findings is not always clear-cut, however, given potential confounding factors such as explicit memory, and several recommendations are made for future neuroimaging studies of priming.
本文综述了有关启动效应的功能性神经影像学研究，启动效应是一种与刺激的重复加工相关的行为变化。运用功能磁共振成像（fMRI）和正电子发射断层扫描（PET）的血液动力学技术，已在人类大脑的众多区域观察到与启动效应相关的作用，具体区域取决于刺激的类型及其加工方式。最常见的发现是，与未启动刺激相比，启动刺激的血液动力学反应有所降低，不过也观察到了与启动效应相关的反应增强。人们已尝试将这些效应与一种内隐或“无意识”记忆形式联系起来。与启动效应相关的反应降低也已被用作一种工具，来描绘与刺激加工不同阶段相关的脑区，这种方法据称具有更高的空间分辨率。这种降低在非人灵长类动物单细胞记录所测量的刺激重复效应中可能存在类似情况。所综述的范式包括词干补全、掩蔽启动、视觉对象的重复启动和语义启动。本文尝试在“成分过程”框架内阐述研究结果，并讨论行为、血液动力学和神经生理学数据之间的关系。然而，鉴于存在诸如外显记忆等潜在混杂因素，研究结果的解释并不总是清晰明确的，本文针对未来启动效应的神经影像学研究提出了若干建议。
