Answer:
temporal, parietal and frontal
Step-by-step explanation:
A PET scans or positron emission tomography test is done to check the functioning of our body tissues and organs.
The temporal lobe is situated at the middle hemisphere of the brain. It main functions is to process memory storage, visual recognition of objects or faces, hearing processes, etc. Thus the temporal lobes helps to identify objects.
Whereas the parietal and frontal lobes of our brain helps in cognitive functions such as remembering, logical thinking and also controls voluntary activities.
Thus in the context, the PET scan shows activation in the temporal lobe when the subjects are recognizing the colors of the objects and the activation in the parietal and frontal lobes when the subjects are remembering the activities associated with the objects.
Hence the answer is --
temporal, parietal and frontal