2. I thought rare individuals who did not develop language abilities (e.g due to isolation) still had memories of their time prior to thought. The most obvious example to me is Helen Keller, who writes about her time prior to meeting her teacher.
I am convinced that teaching material to other people helps us remember concepts better. Doing it verbally just so happen to be the most common and convenient form of knowledge transmission between individuals.
Explaining things to others - imaginary or not - engages the parts of my brain imagining how they will receive and understand it.
This is primarily so I can phrase it in a way other people can understand. But that imagined model of other minds is often smart enough to imagine what they would answer.
Which I guess means my "social brain" is smarter than my "thinking" brain in some ways.
Don't know how universal that is. My brain tends to be an outlier.
1. Rubber duck maybe just help with attention issues. All the studies I heard of do not try to untangle the mechanism. People tend to use language for a multi-brain thinking, and in this mode people do not think their thoughts fully, they propose ideas allowing other to support them or dismiss them. In this way they've got combined knowledge and experience to do the work, simplifying the early rejection of bad ideas. And I'm sure this mode of thinking shapes mind and in particular attention processes. You need to track which bits of information you told already and which you didn't, and you trained for that. Rubber duck can be just a trigger for that mode of attention.
2. I didn't hear about externalities, but to my mind what really helps to remember it is a number of associated details. I believe that ideas extracted from the memory when some of these details is popped up in your thought. It serves like a key in an associative map. When you name a concept with a word, and then use this word in different combinations with other words building associations, then sometimes your mind just like LLM will suggest the first word when you used words associated with it. It seems like externalities you talk about. Language plays its role with this, but you can achieve the same result without a language but thinking about all connected concepts of a concept you are trying to remember. You can build associations this way.
tldr; Language is not required for thought, but on page 3 of the link, "Instead, these tasks engage other brain areas that are non-overlapping with the language network (Fig. 1b), although they sometimes lie in close proximity to the language areas"
I used to do rubber duck debugging, but instead i turned into listing exact step-by-step instructions in inline comments. It seems to work like rubber duck debugging, and all it took was for me to "Externalize the steps" so i can think about what needs to happen at each level of the thought heirarchy.
and section 2. you describe memory and thought as similiar in nature but those are handled in two entirely different regions of the brain.
1. The existence of “rubber duck debugging”, and a whole bunch of studies on verbally explaining a concept indicate that language is essential for thought. In rubber duck debugging, programmers tell their problem to an object and this is beneficial in finding the solution. There are studies that show when we verbally teach material to someone we remember it better. Also the act of taking a test increases learning and memory, but why should this be if learning is secondary?
2. Everything we know about memory tells us that externality is essential for memorizing something. If there’s nothing visual, aural, or sensory then it is unlikely to be remembered. Language acts as an externality even as inner speech, meaning that thoughts can be said in language (ascribed onto the words) and remembered for short-term and long-term memory. A thought without externality seems more like a passing whim, unrooted in any more permanent mode of cognition and thus liable to be forgotten. I can imagine thinking in visuals, melodies, words, but if there is a kind of thought that isn’t occurring based off of these then it probably can’t be sophisticated.