During all three activities, there was a measured increase in bloodflow in the brain’s prefrontal cortex, compared to rest periods where bloodflow decreased to normal rates.
The prefrontal cortex is related to regulating our thoughts, feelings and actions. It is also related to emotional and motivational systems and part of the wiring for our brain’s reward circuit.
So seeing increased bloodflow in these areas likely means a person is experiencing feels related to being rewarded.