RM: This was quite a long post, Bruce. I’m just replying to what I see as the substance of the two main points in your post: 1) that the Test involves conflict and 2) the Katseff et al was a good example of using the Test in linguistic research.
RM: Katseff et al’s method of doing the Test contradicts your model of how the Test is done. Your model has E in conflict with S over the state of the hypothetical controlled variable. In the Katseff et al study there was no conflict; the computer (E) did not increase its disturbance to the formant when S varied her output to compensate for it. The disturbance (which was a change in the feedback connection between S’s output and input) was applied completely passively.
BN: I believe that your unstated assumption is that when two control systems have conflicting reference values for the same variable, the output of each is a disturbance to the other, and each increases its output until one or both reach maximum output capacity. As discussed many times elsewhere, this is true unless, as in a living control system, a higher-level control loop intervenes in some way. …In a prior post, earlier in this topic, I have presented a partial block diagram that includes both subject and experimenter to illustrate this interdependency. Here it is again:
RM: The higher level system of which you speak is the system carrying out the Test. It is the system that is controlling the program that constitutes doing the Test. When you do the Test you are controlling for for seeing whether disturbances, however applied, have the expected effect on the hypothesized controlled variable. If they do, then the variable is not controlled; if they don’t, then the variable is likely to be controlled but continued Testing is necessary.
RM: This Test should not involve creating a conflict like the one you show in the diagram above. This is because the higher level system doing the Test would not be able to reliably tell whether the hypothetical controlled variable, Q.i, was actually controlled. If Q.i were not a controlled variable then E would have no difficulty bringing Q.i to the reference state, r.E, and the higher level could correctly conclude that Q.i was not under control. But this would also be the case if Q.i were under control and S’s reference for it, r.S were equal to r.E. In this case E would also have no difficulty bringing Q.i to E’s reference for it and the higher order system would again conclude that S is not controlling Q.i when, in fact, it is.
RM: I think it’s best to see E as controlling, not for the same variable that S is controlling for but, rather, for detecting an effect of a disturbance that should have an effect on the hypothetical controlled variable if that variable is not under control. If such an effect is perceived (by the higher level system doing the test) it is evidence that the hypothetical controlled variable is not under control; if such an effect is not perceived – or the effect is much smaller than expected – then it is evidence that you are hot on the trail of a controlled variable.
RM: I didn’t say that the Katseff et al. work shows that formants are not controlled. I said it “suggests that formant frequency is not the controlled variable”. Other possibilities include the value of the disturbed formant frequency relative to the frequencies of the other relevant formants.
BN: Bingo. But to control a relationship R between A and B you must control A as an input to R and you must control B as an input to R. Formants are controlled as means of controlling the relationship between formants which is heard as a given vowel.
RM: But they didn’t Test to see if this is what was going on. That’s my only complaint about the Katseff et al research. They didn’t do a complete version of the Test; they didn’t identify a controlled variable.
BN: The relationship is called phonemic contrast.
RM: The idea that the S’s were controlling “phonemic contrasts” is a conclusion based on the observations of conventional acoustical phoneticians who didn’t understand speech as the control of input. It is not based on the results of the Katseff et al research.
BN: Katseff (pp. 19f) reviews some of the numerous studies of what speakers do when disturbances of various kinds are introduced, demonstrating that speakers control both auditory and ‘somatosensory’ perceptual inputs concurrently.
RM: Yes, concurrently but certainly not in parallel. The somatosensory (actually, proprioceptive is probably a better term) variables that, when, controlled result in the articulatory configurations of the vocal tract, are the output functions that result in the acoustic sounds that we hear as speech. Variations in articulation are the means by which speech sounds are controlled.
RM: If the vowel sounded ok nevertheless then that’s evidence that they were controlling for the desired perception ok, it just wasn’t the absolute formant frequency that they were controlling for.
BN: But the vowel didn’t sound OK to the subject, as evidenced by their resistance to the disturbance. I suppose you’re getting this idea from e.g. p. 43: Post-session interviews indicated that subjects did not notice either formant shifts or delays.
RM: I think I got that idea from you. I think you said that with the partially compensated disturbance the word they wanted to say. The main thing the people in the experiment were controlling was the word wasn’t what they wanted to say; I think you sad they said something between “hid” and “head”. This strongly suggests to me that the Ss were unable to find a way to change their articulation so that they were saying “head”; they just managed to change their their articulation so that the word sounded more like “head” than it did without compensation for the disturbance.
BN: Your point that subjects were not controlling the absolute frequency of the disturbed formant (assuming that’s your meaning) is better illustrated when disturbance to one formant was resisted by changing two formants so as to approximate the target relationship of formants. But we already know that speakers do not control absolute formant frequencies, because we know they (we) control phonemic contrasts when the formants are at very different frequencies, e.g. shifted higher or lower by variable length of the vocal tract, for regional and social-class dialects, and so on. Speaking with helium in the lungs is a fun example.
RM: It would have been nice if Katsoff et al had demonstrated this using control of input methodology.
RM:: I think the idea that the observed failure to compensate for the disturbance results from a conflict between auditory and motor feedback simply reflects Katseff et al’s lack of understanding of how hierarchical control works. There can be no conflict involving different types of variables
BN: By “different types of variables” I assume you mean different levels. What is involved here is different sensory modalities providing input to control of phonemic contrast. The auditory perceptions and the tactile/kinesthetic perceptions are at the same level, they are just in different sensory modalities.
RM: Control of articulatory perceptions is the means of control of auditory perceptions. The idea that speaking involves producing auditory and articulatory perceptions simultaneously (the “motor” theory of speech) was developed by people who thought speech was a generated output. It’s not. It’s a controlled input.
BN: To resist disturbance to the sound, the subject changes references for articulation.
RM: Correct.
BN: There are three adjacent vowels, call them V1, V2, and V3. The subject’s intended vowel is V2 and V1 is the target toward which the disturbance is moving the sound perception S. As the disturbance is increased, so that the sound is more like V1, and the articulation is changed so as to maintain the perception of the sound of V2,
RM: Couldn’t have said it better myself. Although I would leave out the “and” that I have bolded. That “and” boded ill as indicated but this incorrect addition:
BN: at some point the articulatory perceptions A are farther out of range to be perceived as the intended vowel V2 and begin to be perceived as the opposite adjacent vowel V3.
RM: This makes no sense. If the articulation has been varying so as to keep the vowel sounding like V2 despite the disturbance then if the articulation is still doing it even if the compensatory articulation would have produced V3 if there were no disturbance it is still the articulation that keeps the sound under control. The speaker couldn’t care less if the articulation would have produced V3; if the articulation keeps the controlled variable under control then it’s the right articulation.
BN: Control of articulatory perceptions A is the means of controlling the sound perceptions S.
RM: Right, and the means are varied as needed to produce the intended output. Variations in articulation are like the mouse movements in a tracking task, with cursor position, like speech, as the controlled result. Variations in the mouse movements depend on variations in the disturbance and/or feedback function; sometimes leftward movement moves the cursor left and sometimes right. Same with articulation; sometimes articulation that produce one vowel (V3) will produce another (V2) when the disturbance is taken into account.
BN: Articulatory perception of the ‘feel’ of pronouncing V3 creates error in control of the intended perception of the sound of V2. By means of the disturbance, the experimenter is in conflict with the subject’s control of the word which contains V2. When the disturbance is small, the subject maintains good control. As the disturbance increases, the subject’s control is compromised in each sensory modality, sound and ‘feel’. So long as the perception S and the perception A are both within their respective ranges (as one modality extends into the intersection with V3 and the other into the intersection with V1) the subject does not notice.
RM: I think this is just the motor theory of speech being dragged into PCT.
Best
Rick