Cerebral Activation during Multiplication: A Functional MR Imaging Study of Number Processing

Regional brain activation during matching and multiplication tasks.

Top and Bottom, Composite activation maps comparing control trials with matching (Top) and multiplication trials (Bottom), respectively. Each column (1–11) represents composite images every 1.5 seconds. The first two columns were collected during stimulus presentation. Columns 3–10 represent the 12 seconds during which the subjects performed either the task or the control. The last column was collected during the subjects' response to target stimuli. Rows a–g indicate the slice position along the z -axis of the Talairach atlas system (50, 40, 32, 24, 12, 4, and−4, respectively). Numbers represent brain regions that were more active (P < .005, red-yellow color scale) during the task trials than during the control trials. Letters indicate brain regions that were more active (P< .005, blue-purple color scale) during the control trials than during the task trials. Both tasks produced a similar activation pattern in columns 2–6. The main differences in activation include a larger area of activation early during the matching task than during the multiplication task in the middle frontal gyrus bilaterally (A, rows c and d, columns 2–4), and during multiplication, activation in the posterior aspect of the left middle frontal gyrus (B, rows c and d, columns 3–9) was slightly delayed in onset and was seen for a longer period. Activation in the left intraparietal sulcus also lasted slightly longer during the multiplication task compared with the matching task (B, row b, columns 2–7). Areas of activation were: 1) superior frontal gyrus, 2) central sulcus region, 3) superior parietal lobule, 4) precuneus, 5) anterior cingulate gyrus and sulcus, 6) intraparietal sulcus (becomes superior occipital sulcus in row d), 7) superior frontal sulcus and adjacent gyri, 8) precentral sulcus and gyrus 9) inferior frontal gyrus and inferior frontal sulcus, 10) middle frontal gyrus 11) thalamus, 12) basal ganglia, 13) calcarine sulcus and cuneus, 14) anterior aspect of superior temporal gyrus, 15) lateral occipital gyrus, 16) lingual gyrus, 17) posterior aspect of middle temporal gyrus, 18) inferior occipital gyrus, 19) supramarginal gyrus, 20) head of caudate nucleus, (a) middle aspect of cingulate gyrus and sulcus, (b) posterior cingulate gyrus and sulcus, (c) postcentral gyrus (d) angular gyrus (e) posterior superior temporal sulcus and adjacent superior and middle temporal gyri and (f) lateral occipital gyri.