The decomposition of mental life into activities such as perception, memory, and decision making provided the takeoff point for the development of cognitive accounts of the mind. Textbooks and courses on cognition have traditionally divided the subject matter into such categories. One of the most potent contributions of the attempt to localize memory and other activities in the brain may be the realization that such decompositions may not reflect how the brain organizes its functioning. When a variety of mental operations have been convincingly identified and localized in the appropriate brain areas, it may turn out that the characterization of the operations are orthogonal to these long-standing categories of mental phenomena.
Already in their original paper, Tulving, Kapur, Craik, et al. (1994) drew attention to the fact that the areas active in their episodic encoding task were very close to those Steven Petersen and his colleagues had found in their pioneering PET study using a task in which subjects were asked to generate a verb appropriate to a noun (Petersen, Fox, Posner, Mintun, & Raichle, 1989; Petersen, Fox, Posner, Mintun, & Raichle, 1988). The focus of Petersen and his collaborators was to identify brain areas involved in different language processes, including semantic processing. The fact that the same area is active in a memory task raises the question as to whether the operation the area performs is best understood as a language operation or a memory operation. Tulving and his collaborators took the view that the verbgenerate task was, in fact, a semantic recall and episodic encoding task and that the operation of the area in left prefrontal cortex belongs to memory:
The verb generation task and the noun repetition task perform two functions concurrently: retrieval of information from semantic memory and encoding of information into episodic memory. For the subject to be able to respond with an appropriate verb to a presented stimulus noun, he or she must retrieve relevant information from semantic memory. But information about the event of doing so also is encoded into episodic memory: the subject, with a certain probability, can subsequently remember the event of hearing "car" and saying "drive" (p. 2017).24
Rather than settling whether the left prefrontal cortex is a language or memory area, another perspective is to view it as performing an operation deployed in both types of mental activity. Further evidence for this interpretation is provided by the fact that the same areas are active in working memory tasks, and their activation increases parametrically in relation to memory load in working memory tasks (Braver et al., 1997). Gabrieli, Poldrack, & Desmond (1998), in reviewing some of this evidence, concluded that the "operations may be the same whether they are considered in the context of language, working memory, episodic memory, or implicit memory. The left prefrontal cortex thus serves as a crossroads between meaning in language and memory" (p. 912).
Although the view that memory involves storing information in a location separate from where it might be processed (as references to memory stores suggest) seems compelling from the perspective of devising an artificial mind, it looks increasing less plausible when considering the range of areas that seem to be activated in memory tasks as well as in other cognitive activities. An alternative view is that remembering is simply one aspect of various mental phenomena; that as the mind performs the operations that generate those phenomena, it is altered in ways that alters future performance and in some cases allows it to remember what has happened to it. This is the view advanced by theorists such as Robert Crowder under the label proceduralism: "Proceduralism, in memory theory, is the idea that memory storage for an experience resides in the same neural units that processed that experience when it happened in the first place" (Crowder, 1993, p. 139). If such a view should turn out to be right, the
24In other research, Tulving and his collaborators demonstrated that subjects exhibited high levels of episodic recall for words they generated in the verb-generate task (Kapur et al., 1994; Tulving, Kapur, Craik., et al., 1994).
operations involved in memory will have more in common with those involved in other cognitive activities than generally acknowledged.
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