More on "inner speech". (For earlier posts on inner speech see here and here and here and here.)
Say something silently to yourself. "Peter Piper picked a peck of pickled peppers." If you're like most, you'll have, in some sense, imagined the words auditorially. You'll have heard the words in an "inner voice" of some sort. At least, this is how it seems to me! Here's one way of expressing that fact, if it is a fact: Inner speech involves auditory imagery.
Now, some of the philosophers and psychologists who discuss the phenomenon of inner speech simply call inner speech auditory imagery, as if the auditory experience exhausts the phenomenology of it.
Maybe it does. Or maybe there's something else -- motor imagery perhaps? Just as one can (I think one can) motorically (as opposed to visually) imagine swinging one's leg or raising one's arms, or preparing to leap from a high place (I spent the last two nights in a 35 story hotel, so that particular vertiginous experience is vivid in my memory), so also can one motorically imagine speaking.
Now if I try, deliberately, to involve motor imagery in my inner speech, it seems that I can do so. But does inner speech normally involve such imagery? Hm! Why does this seem a hard question to answer?
Let's say it does. Here, then, is a further question: Is the motor aspect really only motor imagery? Some behaviorists speculated that what we call inner speech really involves subtle activation of the vocal apparatus -- actual sensed movement, not just private imagery. (I have the impression there's some work on this, but all I can seem to find right now are a few studies suggesting that the vocal apparatus is active during auditory hallucination in schizophrenia, and studies suggesting that brain areas associated with the motor aspects of speaking may be active during inner speech.)
Further: Is there a feeling of control or willing in inner speech? A number of people I've asked, including on this blog, seem ready to acknowledge an experiential difference between inner speech (experienced as actively created) and inner hearing (experienced as passively received).
So I'm puzzled about the phenomenology of inner speech. I don't want to overpopulate our inner lives with excessive complexity. Perhaps inner speech is pretty thinly experienced, and the richness we might be tempted to attribute to it -- feelings of motor imagery, feelings of control -- exists only when set our attention to such matters. (See my discussion of the refrigerator light error.) On the other hand, if such experiences generally belong to inner speech, that seems a fairly fundamental and basic thing to leave out in a phenomenological survey.
The cool thing here -- to my taste -- is that it seems like such matters should be obvious to a moment's reflection and introspection. And yet they're not, or not to me.