The Severance procedure refers to the insertion of a Lumon Industries Severance chip into the brain of the person undergoing the procedure. Before undergoing this procedure, severed employees record a video of themselves consenting to the procedure to help explain the situation to their Innie when they wake up.
According to what is shown in the episode Half Loop, the insertion is performed by a neurosurgeon in an operating theater within the Lumon building. The patient is awake but under local anesthesia during the procedure. After making an opening in the subject's scalp, the surgeon uses a drill to make a hole in the back of the skull. A package containing a sterilized chip is opened. The surgeon inserts the chip into a specialized needle using surgical tweezers. The needle is guided by the surgeon deep into the patient's brain, in the vicinity of the amygdala. The chip is placed and apparently locks into position via anchors that automatically deploy. After this the patient is sedated and placed on the table in a special conference room to begin their orientation upon waking.
The effect of the procedure is that one's “perceptual chronologies are surgically split.” Memories from one's work life and one's personal life separated. Access to either of those kinds of memory is spatially dictated.
The statement which is read on video is as follows:
My name is Innie Name]. I’m making this video roughly two hours before it will be shown to me. I have, of my own free accord, elected to undergo the procedure colloquially known as severance. I give consent for my perceptual chronologies to be surgically split, separating my memories between my work life and my personal life. I acknowledge that, henceforth, my access to my memories will be spatially dictated. I will be unable to access outside recollections whilst on Lumon’s severed basement floor, nor retain work memories upon my ascent. I am aware that this alteration is comprehensive and irreversible. I make these statements freely.