Fig. 4.

Averaged fMRI activation in slices 2–6 for the working-memory, motoric rehearsal, and finger-tapping tasks. Sections represent oblique coronal slices taken parallel to the dorsal surface of the brain stem, as illustrated in Figure 2, and slice numbers appear on the left. Slice 1, which was the most anterior slice, exhibited almost no activation and was therefore omitted from the figure. The maps for working memory and motoric rehearsal were averaged across eight subjects, whereas finger tapping was averaged across five subjects. Regions depicted incolor represent areas that exhibited increased activation in high relative to low load conditions (in working memory and motoric rehearsal) or during finger tapping relative to rest. Decreases in activation during high load or finger tapping relative to their contrasting conditions were negligible and so are not depicted in this figure or in Figure 5. The color scale on theright represents the significance levels (one-tailedp values) of averaged Z scores and is scaled differently for finger tapping than for working memory and motoric rehearsal. The right side of the brain is depicted on theright. WM, Working memory;R, motoric rehearsal; FT, finger tapping.