second brain

Noun

second brain (plural second brains)

1. (informal) The enteric nervous system.
   • Although our ‘second brain’ doesn't make executive decisions like our actual brain, the two do communicate back and forth via electrical impulses through a pathway of nerves—the gut-brain axis—and this pathway influences our endocrine, immune and neural systems.2018, Lee Holmes, Supercharge Your Gut: Supercharged Food, Allen & Unwin, →ISBN
   • This network can function nearly independently from the brain; indeed, its complexity has earned it the nickname “the second brain.” And just like the brain, it’s made up of two kinds of nervous system cells: neurons and glia.[2023 November 21, Yasemin Saplakoglu, “In the Gut’s ‘Second Brain,’ Key Agents of Health Emerge”, in Quanta Magazine
2. (colloquial) The practice of unloading information to digital storage, such as notetaking applications, and using software to ease and enhance one's mind's own use of such information; the applications, the associated data, and the practical use of them, collectively.
   • Near-synonyms: personal knowledge base, personal knowledge management, Zettelkasten, digital garden
   • Camille is the cofounder and lead designer of a start-up in Quebec, Canada. She uses her Second Brain to save excerpts from the many research reports and studies she reads as part of her work designing electric vehicle charging stations for large residential buildings.2022, Tiago Forte, Building a Second Brain: A Proven Method to Organise Your Digital Life and Unlock Your Creative Potential, Profile Books, →ISBN

   Synonyms:

   personal knowledge base, personal knowledge management, Zettelkasten, digital garden