There can be feelings without thoughts. There can be thoughts without feelings. PET scans give more accurate timing than Event-Related Potentials. The subtractive method was developed before brain imaging. Imagery requires a homunculus.
Mental images are publicly observable.
Brain images are publicly observable. The shape of an image is arbitrary. A symbol resembles what it symbolises. The proximal reason we eat food is because it tastes good. The distal reason we eat food is because it promotes survival.