Basically, it's MY scene. So given this, would it be copyright to use
some/or all parts of that AI's response?
The US copyright Office has not changed it's position on non-human authors (machine or animal generated works), but in March 2023 released 'guidance' for works that have been AI generated, or partially generated.
There are several fallacies I encounter while trying to explain copyright to AI fans:
Human rights are only for humans
First, copyright protection is granted only to human authorship. The issues with AI-generation are not about derivative content or violating other people's copyright – it doesn't even get to that stage because copyright is a human right and will never be granted to a work that was not human-authored.
Imagine trying to get a divorce and collect alimony from a tractor, or entering a legally-binding partnership with a sewing machine. These things would be too absurd to ever be considered legally binding. They would never go to trial because there is no recognition of these situations as having ever been valid in the first place.
This is the same approach when the Copyright Office reviews a case of AI authorship: inanimate objects (and animals) can not 'author' a creative work. It won't be tested in courts because the law already says an author must be human. There is no grey area about AI being legally human.
Copyright is not 'all or nothing'
The US Copyright Office can piecemeal a work into parts that are under copyright, and parts that are not eligible for copyright. They are not 'confused' by the concept of a work with some original authorship, They will grant the copyright to the parts that deserve it, and deny copyright to the parts that don't.
It's always up to the author to defend their own copyright – the Copyright Office has no skin in the game. Once the case goes to court, a judge will consider the validity of a copyright claim before they make a legal ruling. To my knowledge no copyright claim has ever been about a 100% copy, word-for-word, from cover-to-cover. ALL courtcases involving copyright are about 'which parts' and 'how much'.
It's never all-or-nothing. Simply including a paragraph or two generated by AI does not invalidate the rest of your novel being under copyright. As you say, you do not intend to keep hitting the Generate button to copy/paste the entire novel.
The guidance linked above says an author must disclose which parts were AI generated. I will go on a limb and say: as long as you are re-writing the AI's suggestions into your own narrative voice, there can't be any copyright issue because the only copyright you'd be violating is the AI's (which doesn't exist).
Procedural methods can be used to aid human creativity
AI fans sometimes bring up the example of a (the only?) computer-generated artwork that was granted copyright. The 'art' is a continuous line connecting randomly generated positions on a canvas.
What AI fans ignore is that this work was denied copyright many times on the basis of being computer generated. It was also initially claimed by the employer of the artist, Bell Laboratories because it was created at their research dept (consider if OpenAI decided to claim your novel because it was created in some small part with ChatGPT).
Eventually Bell Labs decided to support the artist's claim, and years later it was eventually given a copyright exception (basically approved on the technicality of a giant corporation-backed publicity campaign) because the artist had authored the computer program that generated the random numbers.
The generative program was extremely simplistic and a similar result could have been achieved with any random number generation (like rolling dice) and a ball-point pen – but this was 1961 and low-effort computer art was in its infancy. None of his other computer-generated artworks were ever granted a copyright.
The Copyright Office has since denied art that was generated by far more sophisticated AI text-to-image generation because the 'artist' did not have anything to do with the creation of the generator. Any person could type the same prompt and generate the same results because the generator was doing the 'creative work'.
According to the guidance, procedural methods can be utilized in human creativity, but it needs to be disclosed so the Copyright Office can determine whether the human's creativity outweighs the procedural method.
Public Domain is not a 'protection'
'Public domain' is the presumption that a copyright has lapsed or is unenforceable – it's not a legal 'status', rather it is the absence of copyright.
A similar idea is the concept of 'outside' – when you build a house there is an 'inside' which you build, but the idea of 'outside' is not something you can build on the house. 'Outside' is the normal state that was already there before you built the house. It's just a word we use to say that it isn't 'inside' (which is something that is clearly defined). Before you built the house everything was 'outside', and then you created an exception: 'inside'.... Someday the house will collapse and it will all be 'outside' again.
According to law, works created by AI (and animals) are 'public domain' which is not a protection. It's just a way of saying 'not eligible for copyright'.
You should think in terms of 'copyright' and not in terms of 'public domain'. "Is my work copyrightable?" "Does my work violate someone else's copyright?" As it stands now, anything directly output from an AI is not eligible, so you cannot be in violation for using AI-generated content.
Who would know?
There are currently no lawsuits about AI stealing a creative author's narrative text. Their are several lawsuits pending in US and UK over AI text-to-image generation, and over the unlicensed re-use of opensource code (opensource is a copyright license, not public domain).
I have answered your actual question: "If a writer uses an AI tool and enters a prompt then uses the tool's output, is that copyright infringed?" No, because the AI gets no copyright protection.
The un-asked question is whether you're violating some other (human) author's copyright (an author the AI has been trained on). The answer is currently 'no', because no artist/author has been able to prove the AI is copying their work.
The crux is whether your human-authored content outweighs what the AI has suggested. Considering there are now AI tools for detecting AI-written text, if you passed your novel through an 'AI detector' would it be able to tell your prose was based off suggestions from a GPT? From your description that sounds unlikely.