[From Rick Marken (2014.11.29.1030)]
···
Martin Taylor (2014.11.28.11.48)–
MT: Very handsome of you, and I thank you for it, while adding my own
apology for participating in the conflict escalation.
MT: With luck, we should be able to terminate this and the ancestor
thread at this point.
RM: OK, then why don’t we start a new thread based on your proposal about controlling perceptions partially in imagination. In PCT as it now stands control is either of sensory based perceptions – perceptions of aspects of the environment – or control of imagined perceptions – perceptions that are replays of reference signals retrieved from memory (as per Figure 15.3, p. 223 of B:CP, 2nd Ed). So in the original version of PCT, whether we are controlling perceptions or imagined perceptions was conceived of as an all or none process – the result of throwing the neural “switches” from one connection to another.
RM: You have proposed (and I know that we have discussed this on CSGNet before so I know that Bill agreed) that it is possible that the perceptual signals that are controlled could be partially the result of sensory based and partially the result of memory based inputs to a perceptual function. The memory inputs would be there to “fill in” what might be missing from the sensory based input (due to brief obstructions or whatnot).
RM: I think it would be a great contribution to PCT if you could determine how (and, of course, whether) this mixed sensory/memory perception concept should be incorporated into the PCT model. I just ran a quick little simulation where I had systems controlling a sensory based perception p = aX+bY and switched X from being an environmental variable to being a reference signal from memory(an imagined input, call it X’) and what I found was that control of the now partially imagined perception – p = aX’+bY – remained intact but the environmental correlate of that perception – aX+bY seemed to be completely uncontrolled. I haven’t done the quantitative calculations yet to determined whether control of aX+bY is really lost completely when only X is imagined, so it may be true that control of aX+bY is not completely lost when one component of the perception of that variable is imagined. But this would be a nice thing to determine to see how control of a partially imagined perception might work.
RM: Another aspect of this that might be good to look into is whether having an imagined component of a perception improves control when the sensory component is lost, at least for a short time. I think you have suggested that this may be the case and I think it’s is possibly true. For example, suppose you have a person do a pursuit tracking task where the target intermittently and briefly disappears. You could then compare two versions of the PCT model in terms of how well they are able top account for the behavior in this experiment. One version would be the plain vanilla, sensory based perception version of the PCT model; the other would be a version that fills in the imagined position of the target when it disappears. If the model with the imagination component works best then you would have made a significant improvement to the PCT model.
RM: Anyway, just some thoughts derived from this thread. I’d love to hear your (and anyone else’s) thoughts about this.
Best regards
Rick
–
Richard S. Marken, Ph.D.
Author of Doing Research on Purpose.
Now available from Amazon or Barnes & Noble
In nature there’s no blemish but the mind
None can be called deformed but the unkind.
Shakespeare, Twelfth Night
RM: Yes you should. I shouldn't have said what I said
and I humbly apologize. Not only was it wrong – you have
done much excellent empirical research – but it was an ad
hominum attack. I have no idea what got into me; I hope
you will accept my apology. I was wrong, wrong, wrong.