Star Trek is no stranger to the concept of cyborgs. Perhaps the most obvious example can be found with the Borg, who are usually viewed as villains. We also find more positive examples, however, where cybernetic technology is used as a treatment, such as Geordi La Forge's VISOR helping him to see. Lower Decks' Samanthan Rutherford offers a more complicated view of cybernetic implants.
When we first meet Rutherford (Eugene Cordero) in Star Trek: Lower Decks, he is an upbeat, cheerful Ensign. He does complain, however, that his new Vulcan cybernetic implant is suppressing his emotions. A slight adjustment is able to relieve Rutherford of this issue, though, and we are set up for many future gags where fiddling with Rutherford's implant alters his personality in various ways.
While the tech-based pliability of Rutherford's personality is usually presented as a joke, there is also something a bit sinister about it. This is made even more apparent when it is revealed that Rutherford's cybernetic implant was forcibly installed to manipulate and suppress Rutherford's memories about the illegal Texas-class AI starship project.
In addition to manipulating Rutherford's memories, this procedure also changed his personality. Rather than being chipper and friendly, Rutherford was originally aggressive and belligerent. All of these changes lead to a question: Who is the true Rutherford? By extension, it leads to the question of who any of us "truly" are.
While there are many philosophies that describe of our inner selves as being separate and distinct from our physical bodies, there is considerable evidence that our existence is not one of mind over matter, but rather our minds are a manifestation of that matter.
A classic example is that of Phineas Gage, who experienced dramatic changes in his personality due to the destruction of most of his left frontal lobe. On the not-so-severe side, some people will use beta blockers to alleviate short-term stress. The beta blockers do not even act on the brain, but rather on the heart rate, which cuts the feedback loop of stress responses.
Rutherford demonstrates a similar phenomenon in a Star Trek-y sci-fi context. The physical presence of his cybernetic implant greatly influences who Rutherford is on numerous levels. It can put his long-term memories in peril, it can stifle his feelings, and most notably, it completely changes his personality.
The fact that Rutherford so drastically changed after receiving the implant is ethically questionable in itself. The fact that it was forced upon him unnecessarily makes it doubly so. While we might prefer post-implant Rutherford out of familiarity and the fact he's much nicer, is it right that the "mean" Rutherford was destroyed in the process?
This question evokes memories of earlier Star Trek episodes, such as "Life Support" (DS9) or "Tuvix" (VOY), which explore what makes a person who they are. These are the sorts of ethical dilemmas that Star Trek has traditionally explored. They don't always give perfect answers or solutions, but they still encourage us to face those questions.
Unfortunately, the nature of Lower Decks as a comedy means that these ethical questions are not even fully presented, much less given a thoughtful conclusion. After his whole backstory reveals arc, Rutherford was left to be who he was at the start of the series, and the audience is meant to accept it, presumably because he's the nice version.
For a comedy, perhaps, this is okay. At the same time, the brain is such a fantastically complex organ and the way it—along with the rest of one's body—is the source of one's self could be a fascinating thing to explore in Star Trek. Samanthan Rutherford could be an excellent window into that exploration if only he were in a Star Trek show that dealt with ethical dilemmas in that way.
For some reason, I doubt that Rutherford will get much more character development in Season 5, which is a shame. He could have allowed us to explore notions of identity and self in a way that other Star Trek characters could not. Instead, he's a friendly source of cyborg jokes. Of all of the main Lower Decks cast, I feel Rutherford's character arc has been the most disappointing.