It is important that researchers in this field identify the appropriate domain of cognitive function to investigate. Although “cognition enhancement” is an acceptable generic term, as is “health promoting,” science and regulators require targets that are more specific and which respect the independence of different domains when considering specific claims. For example, in the medical field, why would one expect a drug that helps pulmonary function to also help the liver? This illustrates the limitation of global scores of cognition for nutritional claims and should serve as a guide for researchers seeking to assess specific target domains of function. There are a number of core cognitive domains that can be evaluated, including attention, information processing, reasoning, memory, motor control, problem solving, and executive function. Taking memory as an example, there are four major types: episodic or declarative memory, working memory, semantic memory, and procedural memory.1 As Budson and Price1 illustrate, few conditions are associated with impairments to semantic memory and procedural memory, whereas working and episodic memory are impaired in a wide variety of neurological, psychiatric, surgical, and medical conditions. This creates a rationale for directing testing toward working and episodic memory as potentially more fruitful areas to evaluate in novel conditions, and most test systems recognize this approach. Furthermore, tests specific to particular domains are ideal, when available, because they help facilitate the substantiation of any claims made on the basis of the research findings. The most specific tests are tests of attention tests, because well-designed tests of this type do not require aspects of memory or reasoning for task performance, and changes in performance can, thus, be relatively clearly attributed to effects on attentional processes. Because attention is important for the performance of any task, when seeking to evaluate other domains, it is useful to also assess attention so that the relative contribution to any effects of changes to attention can be established. For example, the Digit Span Test assesses working memory by measuring how many digits a subject can hold in memory at one time. Changes in attention could influence performance on this task, but this can only be established if attention tests are performed concurrently. Nonetheless, Digit Span is not a direct test of attention. Overall, most well-established test batteries include assessments of attention, working memory, episodic memory, motor control, and aspects of executive function.