A 2010 study found that caffeine enhanced cognitive performance specifically by providing Increased ability to concentrate and focus attention; increased ability to solve problems requiring reasoning; and increased ability to make correct decisions.

However, other recent discoveries in neuroscience suggest that when we’re wired on caffeine and intensely focused on a project, we are much less able to link abstract ideas.

Detailed MRI studies of people’s brain activity show that the “left brain, right brain” theory of how rational and creative thinking works, is far from accurate; we actually use different “networks” incorporating multiple parts of our brains — an “executive attention network” (including the frontal lobe) that activates when we pay attention, plan, and make decisions, versus an “imagination network” associated with divergent thinking: Daydreaming, free association, and exploring ideas. Significantly, areas of the brain associated with the executive attention network — such as the frontal lobe — were often inactive when the imagination network was active.

An Inc. article about increasing creativity suggests “if we stop drinking coffee, we let our mind drift. We may daydream. And that’s when we are creative.”

Basically, caffeine works best for the executive attention network by sharpening our attentiveness and reasoning, but at the expense of the imagination network’s free association: Caffeine is great for focus but not so hot for brainstorming. Yeah, we agree — that kind of sucks.