A processor also operates with a high level of indirection. The 6502 doesn't have transistors dedicated to jumping or shooting; it has transistors dedicated to

A processor also operates with a high level of indirection. The 6502 doesn't have transistors dedicated to jumping or shooting; it has transistors dedicated to 'add value to accumulator', an instruction that might appear hundreds of times in the game code even on a 6502, with a different purpose each time. If they instead tried the lesioning approach on software, i.e. nopping out one instruction at a time, I think they could relatively easily identify the function of various sections of the code. Alternatively, if they analyzed a video game implemented directly in hardware rather than using a CPU (say, the original Breakout), that would probably work better too. Of course, nobody really knows how much indirection is used by the brain, but it's probably closer to a direct hardware implementation than a CPU. One respect in which it differs from both, of course, is plasticity; neither hardware nor software created by humans is given to constant self-modification.