The Memory Visualizer is a piece of alien technology that appears in Issue 39 of the Invader Zim comic series.

Summary

The Memory Visualizer is a device created by the alien race known as the Inquisitorians as a means of examining memories. It works by placing a helmet on a person's head, which transmits their memories into a container of goo, in which the memories are rendered in images for the viewer to observe.

Since a person's personal bias can affect their remembrance of events, it is apparently standard procedure to use the Visualizer on multiple witnesses when possible in order to ensure that a more complete picture is recovered.

The Visualizer is first seen in use by Inquisitous the Observer, the Inquisitorian assigned to the sector of space containing Earth, when he's trying to determine who is responsible for the destruction of the probe and robot he sent to examine the planet.

His investigation is stymied by the fact that the people he's interrogating (Dib and Zim) have such strong personal biases that they display totally incompatible stories, making it impossible to tell what really happened. And since Gaz wasn't actually paying attention to the fight that destroyed his probe, meaning her memories aren't helpful, a desperate Inquisitous uses the Visualizer on GIR, whose insane and random thoughts overwhelm the Visualizer and destroy Inquisitous' entire ship.

Inquisitous survives and is interrogated by his leaders with another Visualizer about what caused the destruction of his ship. When they fail to believe him, thinking his own personal bias is at play, they plug GIR into the Visualizer (ignoring Inquisitous' warning not to), which causes it to overload as well, seemingly destroying the leaders' ship as well.

Gallery

Facts of Doom

• The way that the Memory Visualizer works is similar to how the Control Brains can view an Irken's memories by locking onto their PAK.
• Inquisitous implies that the Visualizer on his ship is untested and being used for the first time, yet the existence of the other Visualizer on his leaders' ship would suggest that it's been in use for some time.
• The Visualizer on the Inquisitorian Elders' ship is significantly bigger and more complex than the one on Inquisitous' ship.
• The Visualizer presents the memories of the people placed in it in third person, when it would make more sense to be in first person. Dib points this out to Inquisitous, but is ignored.
• The Visualizer makes the user's eyes glow while being used. Irkens have their PAKs glow in addition to their eyes. Gaz's eyes did not appear to glow while using it, though this is probably because she always keeps her eyes closed.
• In Issue 49, a Visualizer is used by Zib to analyze Zim's memories and determine what differentiates him from the other Zims in the Zimvoid.