Friston K J, Price C J, Fletcher P, Moore C, Frackowiak R S, Dolan R J
Wellcome Department of Cognitive Neurology, Institute of Neurology, London, United Kingdom.
Neuroimage. 1996 Oct;4(2):97-104. doi: 10.1006/nimg.1996.0033.
In this paper we present a critique of pure insertion. Pure insertion represents an implicit assumption behind many (but not all) studies that employ cognitive subtraction. The main contention is that pure insertion is not valid in relation to the neuronal instantiation of cognitive processes. Pure insertion asserts that there are no interactions among the cognitive components of a task. It is possible to evaluate and refute this assumption by testing explicitly for interactions using factorial experimental designs. It is proposed that factorial designs are more powerful than subtraction designs in characterizing cognitive neuroanatomy, precisely because they allow for interactions and eschew notions like pure insertion. In particular we suggest that the effect of a cognitive component (i.e., an effect that is independent of other components) is best captured by the main (activation) effect of that component and that the integration among components (i.e., the expression of one cognitive process in the context of another) can be assessed with the interaction terms. In this framework a complete characterization of cognitive neuroanatomy includes both regionally specific activations and regionally specific interactions. To illustrate our point we have used a factorial experimental design to show that inferotemporal activations, due to object recognition, are profoundly modulated by phonological retrieval of the object's name. This interaction implicates the inferotemporal regions in phonological retrieval, during object naming, despite the fact that phonological retrieval does not, by itself, activate this region.
在本文中，我们对纯粹插入法提出批判。纯粹插入法是许多（但并非全部）采用认知减法的研究背后隐含的一个假设。主要论点是，就认知过程的神经元实例化而言，纯粹插入法是无效的。纯粹插入法断言，一项任务的认知成分之间不存在相互作用。通过使用析因实验设计明确测试相互作用，可以评估和驳斥这一假设。有人提出，在表征认知神经解剖学方面，析因设计比减法设计更有效力，恰恰是因为它们允许存在相互作用，并且摒弃了诸如纯粹插入法这样的概念。特别是，我们认为，认知成分的效应（即独立于其他成分的效应）最好由该成分的主（激活）效应来体现，而成分之间的整合（即在另一个认知过程的背景下一个认知过程的表达）可以用交互项来评估。在这个框架下，对认知神经解剖学的完整表征包括区域特异性激活和区域特异性相互作用。为了说明我们的观点，我们使用了析因实验设计来表明，由于物体识别而产生的颞下回激活，会受到物体名称语音检索的深刻调制。这种相互作用表明，在物体命名过程中，语音检索时颞下回区域也会参与其中，尽管语音检索本身并不会激活该区域。
