The Summerholt Neurological Institute is a research facility located on the outskirts of Metropolis that focuses on abnormal cranial activity.
When Dr. Curtis Knox started removing powers from meteor freaks, Lex Luthor insisted that Dr. Knox also remove their memories of their stay at Level 33.1. Given Lex's level of access to Project Starhawk, it's possible that this memory manipulation was done using technology perfected at Summerholt.
In Finale, Part 2, Tess Mercer uses a neurotoxin that was created by Summerholt to wipe Lex Luthor's memories. Ironically, Lex helped fund and start the memory projects to retrieve his lost memories from his electroshock therapy, only to lose all his memories in the end due to Tess, 7 years after beginning to work with them.
- Dr. Lawrence Garner was the Chief Neurologist and founder of the Institute, specializing in memory tampering, which he used to erase or modify memories in people.
- Lawrence Grady worked in the memory department of Summerholt.
- Mary was a receptionist at Summerholt who denied that Ryan was a patient.
- Erica Poss was a receptionist at Summerholt who tried to deny access to Lois Lane and Sheriff Adams.
- Cornell was a security guard who worked at Summerholt. (Delete)
Summerholt also employed a number of orderlies.
- Ryan James was taken into Dr. Garner's legal custody and subjected to experiments on his psychic abilities.
- Molly Griggs was an engineering prodigy whose computer skills and mind control abilities were exploited by Dr. Garner in an attempt to prevent the publication of an article about Summerholt.
- Lex Luthor blackmailed Dr. Garner into helping him recover lost memories. Dr. Garner fashioned a treatment which involved submersion into a tank filled with a kryptonite liquid. The treatments proved to be dangerous and Lionel Luthor undermined Lex by striking a deal with Dr. Garner to stop treating Lex in exchange for Clark Kent. Although Lex's treatments were stopped before he regained the seven weeks preceding his shock therapy, he successfully recovered a repressed childhood memory of his brother's death.
- Clark Kent was kidnapped and placed in a memory-treatment tank full of liquid kryptonite. The equipment connected to it shorted out and exploded, electrocuting Dr. Garner and sending him into a coma.
- Kevin Grady's memories were altered by his father to prevent him from knowing the truth about his brother's death.
- Chloe Sullivan was caught emailing videos of Kevin Grady's treatments to Lois by Dr. Grady who subsequently prepared to erase her memory. However, the experiment failed and Clark came to Chloe's rescue. Coincidentally, Chloe, Lois and Nancy Adams witnessed Clark's super-strength in the process. Luckily, Kevin Grady erased Chloe's, Lois' and Sheriff Adams' memories of the rescue.
In Other Media
- The Summerholt Institute is mentioned in The Flash episode "Memorabilia". It is said to exist on Earth-221.
- Season Two: Ryan
- Season Three: Delete, Memoria
- Season Four: Blank
- Season Seven: Lara (Mentioned only)
- Season Nine: Pandora (Mentioned only)
- Season Ten: Finale Part 2 (Mentioned only)
- Season Eleven: Guardian (Mentioned only)
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