artery that is labeled in the middle image in Figure 1, and this comes around the side of the cortex and branches as it comes off. In fact, it meets up with another artery that comes through the midline called the anterior cerebral artery. The point is that the redundancy actually begins to break down, and if a block is made in the main trunk of the middle cerebral artery, which has been a favorite model system of the neurology community, large swathes of your brain will start to die off.
We are now going to look in finer scale at the region marked with the “X” in Figure 1, which is fed by the branches of these major cerebral arteries, and discuss what’s known from the past. Others besides me, notably Rob Harrison, also got intrigued by the idea of variability between neural signals and blood flow. He did a beautiful experiment. He had done imaging studies and saw a lot of variability across the cortex. He wanted to see if this variability could be