BenVitale said:
I got the feeling it is both: visual and language
In Penrose's example, his "inane" linguistic commentary, "that thing goes there", seems like a kind of underlining or highlighting of the visual image, directing his attention to certain aspects of it, but not embodying the complexity of the ideas he's having at that moment.
A very different mode of thought is described by Brent Silby in
Revealing the language of Thought.
http://www.scribd.com/doc/3033742/Revealing-the-Language-of-Thought-by-Brent-Silby
He writes from a philosophical viewpoint, arguing for the identity of natural language and thought. For example, he imagines an interior monologue about realising that he's forgotten to bring coffee: "...oh no, there's no coffee. What will I do? Where will I get some? Damn! What a hassle, I'll have to get some. But I put some in my bag last night..." (3.3.1). But Penrose's description sounds much more like my own experience than Silby's. I don't laboriously spell out all my thoughts in an internal monologue. When I subvocalise, I tend to leave gaps. If anyone could hear the words in my head, even if they could see the pictures too, they'd probably not make much sense without knowing the context of what I was simultaneously
thinking about, what connections I was making between ideas.
Silby: "If someone asks us what we are thinking, our expression of the thought is the same as our inner experience of that thought" (4.3.4).
Galton: "It often happens that after being hard at work, and having arrived at results that are perfectly clear and satisfactory to myself, when I try to express them in language, I feel that I must begin putting myself on quite another intellectual plane. I have to translate my thoughts into a language that does not run very evenly with them. I therefore waste a vaste deal of time seeking words or phrases, and am conscious when required to speak of a sudden, of being often very obscure through mere verbal maladroitness, and not through want of clearness of perception."
Penrose: "I had noticed, on occasion, that if I had been concentrating hard for a while on mathematics and someone would engage me suddenly in conversation, then I would be unable to speak for several seconds."
In my experience, sensory imagery, including especially visuals and fragmentary subvocalisation seem like a notepad for my thoughts, or an anchor, an aid to memory, and a tool for directing and structuring them. But the visuals and bits of natural language usually don't fully embody the thought, because I could conceive of seeing the same mental picture and subvocalising the same words while thinking something different (having a different idea about them, or noticing different conections between things). And like Galton, I'm familiar with the experience of knowing clearly what I wanted to say, but being unable to find the right words.
BenVitale said:
Consider arithmetic, word problems
Even there, unless the problem was immediately obvious, I suppose we might convert it into some other format, arithmetic, algebraic, geometric to solve it, then translate back into words. But when the problem involves definitions or concepts that are new to me, I do like to repeat them to myself and try to find the clearest and simplest way of verbalising them to help bed them in.
This made me chuckle. Penrose: "That is not to say that I do not sometimes think in words, it is just that I find words almost useless for
mathematical thinking. Other kinds of thinking, perhaps such as
philosophizing, seem to be much better suited to verbal expression. Perhaps this is why so many philosophers seem to be of the opinion that language is essential for intelligent or conscious thought."