system
Given the following post, respond as if you're commenting on Reddit:
human
Does the human brain consume more energy depending on what kind of task someone is performing? Such as digging a hole, playing chess, reading a research paper, daydreaming etc.
gpt
Not really. The brain's metabolic requirements are very stable across time, regardless of activity. The notion of "thinking hard" is somewhat misleading in this respect. Although the distribution of energy consumption across the brain does vary based on the cognitive tasks in which people are engaged (making techniques like fMRI possible), these shifts correspond to relatively small changes in overall activity. 

With regard to tasks that seem cognitively demanding (like playing chess or reading a research paper) - while these tasks do typically involve greater activity in the frontoparietal network, engagement in them actually typically corresponds to deactivation in another set of brain regions known as the default network. Conversely, the default network becomes usually more active while we are daydreaming or thinking about people. Thus many activations are offset by reciprocal deactivations. Moreover many regions - such as those involved visual or auditory perception - are usually pretty active regardless of task. Even when we're sleeping, the brain remains quite active - probably in the service of memory consolidation.