As shown in Table 1, most of the tests reviewed here have been used in studies assessing the effects of nutrition on cognitive abilities. The tests of attention have been found to be sensitive to zinc supplementation, iodine, PUFAs, and vitamin B12 deficiencies.
There is some evidence that the tests of memory may be sensitive to vitamin B12 deficiency and to supplementation with folate, vitamin B12, and vitamin Bin Australian women. The construct of executive function has not been specifically investigated as a cognitive outcome of nutritional deficiency or intervention.
However, there is some evidence that Block Design may be sensitive to vitamin B12 and iodine deficiency and iodine supplementation Performance on the Black-and-White Stroop test improved after iron, vitamin A, or a combination of both supplementation. This test, along with a test of semantic fluency, showed no effect of iodine deficiency
By contrast, tests of speed of information processing have not been found to be sensitive to iodine or B deficiencies. Interventions with folate, vitamin B12, vitamin B6, and iron have not affected the performance of these tests of speed of processing. The results are surprising as speed of processing is a cognitive ability that is expected to develop during childhood and the tests reviewed here have been found to be sensitive to other impacts on the CNS.