Sketchnotes engage the brain thanks to their use of both the verbal and visual centers. This, along with other aspects of 
sketchnotes character provide several benefits.
The creative limits help you to focus on what is most important for you. You can’t fit everything in, so you need to cut somethings out. This requires you to process the information and evaluate, is this really important? Is this a key element?
Sketchnoting requires concentration to focus on what the source material (a speaker or a text) is telling you and avoiding distractions around you. This practices of sketchnoting building your concentration by requiring this regular focus.
This can lead to a state of “flow” where you are stretched by the challenge of listening, analyzing and noting all at the same time. A highly rewarding state to be in.
Sketchnotes are better for remembering information. They require you to draw connections between data and show how they are connected in your notes. They also require personalization beyond simple words as you make choices over the correct font, graphic or item to include or not. And studies have shown that drawing information helps you to recall it better than simply writing a word down.
FURTHER READING
What's Lost as Handwriting Fades (NYTimes article)
Why a Media Professor Just Banned Technology in Class (WaPo article)
