Definition of Brain-in-a-Vat

What is Brain-in-a-Vat?

A philosophical thought experiment in which a brain is surgically removed from the body, placed in a nutrient vat, and connected to a machine that provides electrochemical stimulations that mimic the stimulations the brain would receive from embodied worldly active experience. The question: is this possible, and if so – would the brain notice any difference? This analogy has been used by brain-bound approaches to consciousness to argue that consciousness is a computational algorithm running in the brain and, as such, is nothing more than a sequence of transferable code. This logic is also critical to the assumption that AI is intelligent (and for tech-bro fantasies of consciousness uploading and living forever). 

Ultimately, this thought experiment is a fantasy based on a fundamental misunderstanding of consciousness as the internal manipulation of data as a representation of an external and separate environment. But as the Enactive approach to consciousness has compellingly argued, cognition is best understood as a form of active sensemaking by which a living being actively and collaboratively brings forth its own world through ongoing skilled activity under precarious circumstances. Thompson and Cosmelli's paper Brain in a Vat or Body in a World? provides the detailed critique.

See also: Enaction, Worldmaking, Affordances