Project Mentem

 is a machine created by Stanford Pines.

History
In "The Last Mabelcorn," Ford takes Dipper to his private study, where he puts the machine's helmet on Dipper, projecting his thoughts onto the machine's screen. For intended to use the machine to block Dipper's mind from Bill's influence. After sitting in the machine for a while, Dipper decides to put the helmet on Ford, in order to find out what he was hiding.

The Computers
The machine is a combination of computers and screens. In the center is the largest computer. To his right and left are smaller machines with smaller screens, and on top of the main computer are two smaller screens. Below the main screen is a control console.

At the bottom of the main computer there is a drawer with a plaque reading "Project Mentum". The inside of the drawer is cushioned with a red pillow, on top of which is a helmet that has a bundle of cables coming from its top, connecting it to the computer.

When a person is attached to the machine, their thoughts are projected onto the 5 computer screens. The thoughts take the form of text, images, and sound. On the center screen, thoughts are typically displayed in 7 or 8 lines that scroll to the right, each at a different rate. Each line is a different sentence or train of thought. In an abnormal situation, the text lines may separate and be replaced by an image (see Stanford's thoughts below).

The Helmet
The helmet is composed of two parts: the top (where it sits on the user's head) and metal strips (that encompass the user's head). Both parts are brown.

The top of the helmet looks similar to a strainer, as one would use for cooking spaghetti, and it appears to have some rust on it. At the top most part of the helmet there is a cluster of black cables that lead to the main computer. to the side of the cluster of wires is a small silver switch.

At the back of the top part of the helmet, a piece of metal extends to the base of the user's neck. Four curved pieces of metal stick out of the main piece, with two on each side, resembling a small rib cage. When the helmet is placed on the user, the four curved pieces of metal close in towards the user's face, wrapping around his/her cheeks.

Other Equipment
There appears to be an EKG.

Beside the various computers and machinery, there is a file cabinet. Inside this cabinet is The Cipher File.

Function/Purpose
It can scan one's mind, bioelectrically encripting one's thoughts so Bill can't read them.

Dipper
 First Display  Phrases superimposed over the 8 lines accompanied by Dipper's voice saying them: Clips shown:  Second Display  Superimposed over the 8 lines is written "Scanning Thoughts 15%", above which is a progress bar.
 * Line 1: Oh man, I can't believe I'm with the author!
 * Line 2: Gosh, I hope no one was looking!
 * Line 3: Maybe if I cross my legs, no one will notice!
 * Line 4: Kinda kinda hungry, but could also not eat.
 * Line 5: I should really try out the president's key sometime.
 * Line 6: I could probably I could probably rob a bank.
 * Line 7: I miss Tyrone!
 * Line 8: That red bathing suit, man!
 * "Oh man, I can't believe I'm with the author!"
 * "Is my fly down?"
 * (sung) "Disco girl coming through!"
 * (seven times) "Wendy"
 * Dipper finding Journal 3 in Tourist Trapped.
 * Dipper, Wendy, Soos and Mabel entering the hidden bunker in Into the Bunker
 * Dipper frustrated/angry during the confrontation with Stanley in Not What He Seems.
 * Line 1: Ugh, this is so hard! I've been here forever!
 * Line 2: Eeeny meeny miney you.
 * Line 3: Does Ford like me?
 * Line 4: Is Bill indestructible?
 * Line 5: What's his secret?
 * Line 6: Who stole the capers?
 * Line 7: Why does he have to be so mysterious about Bill?
 * Line 8: I can handle the truth!

 Third through Fifth Displays 

The text displayed were accompanied by an audio of Dipper's thoughts. In several instances, the audio of his thoughts were in response to something he said aloud.
 * Audio (via the machine): I wonder what Great Uncle Ford is thinking.
 * Lines 1-8: I wonder what Great Uncle Ford is thinking?
 * Audio (via the machine): Use the machine, it'll show you his thoughts!
 * Lines 1-7: Use the machine, it'll show you his thoughts!
 * Dipper speaking aloud: I shouldn't.
 * Audio (via the machine): He won't know. He's going to tell you eventually.
 * Lines 1-7: Just a peek!
 * Audio (via the machine): The more you know about Bill, the more you can help.
 * Lines 1-7: He wants your help he just doesn't know it
 * Dipper speaking aloud: Man, I am really good at rationalizing.
 * Audio (via the machine) repeated several times: Yes you are!
 * Lines 1, 3, 5, 7: Yes, you are!
 * Lines 2, 4, 6: Astute, I would say. Good observation Dipper!