terry.stewart
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Ooo, very good questions! :) I think there are a few different reasons why.... one small clarification, though, I don't think ACT-R shrunk to a small group -- I'd say more that it gradually grew from a small group (starting out of John Anderson's lab at CMU) up to about 100 active researchers around the world, and then sort of stabilized at that level for the last decade or two.
But, as for why it didn't take over everything or at least get more widely known, I'd say one big reason is that the tasks it historically focused on were very specific -- usually things involving looking at letters and numbers on a... (read 537 more words →)
That's a very good point, CounterBlunder, and I should have highlighted that as well. It is definitely fairly common for cognitive science researchers to never work with or make use of ACT-R. It's a sub-community within the cognitive science community. The research program has continued past the 90's, and there's probably around 100 or so researchers actively using it on a regular basis, but the cognitive science community is much larger than that, so your experience is pretty common.
As for whether ACT-R is "actually amazing and people have been silly to drop it", well, I definitely don't think that everyone should be making use of it, but I do think more people... (read 590 more words →)
Hi Vanessa, hmm, very good question. One possibility is to point you at the ACT-R reference manual http://act-r.psy.cmu.edu/actr7/reference-manual.pdf but that's a ginormous document that also spends lots of time just talking about implementation details, because the reference ACT-R implementation is in Lisp (yes, ACT-R has been around that long!)
So, another option would be this older paper of mine, where I attempted to rewrite ACT-R in Python, and so the paper goes through the math that had to be reimplemented. http://act-r.psy.cmu.edu/wordpress/wp-content/uploads/2012/12/641stewartPaper.pdf
Yes, that Tenison paper is a great example of arithmetic modelling in ACT-R, and especially connecting it to the modern fMRI approach for validation! For an example of the other sorts of math modelling that's more psychology-experiment-based, this paper gives some of the low-level detail about how such a model would work, and maps it onto human errors:
- "Toward a Dynamic Model of Early Algebra Acquisition" https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.53.5754&rep=rep1&type=pdf
(that work was expanded on a few times, and led to things like "Instructional experiments with ACT-R “SimStudents”" http://act-r.psy.cmu.edu/?post_type=publications&p=13890 where they made a bunch of simulated students and ran them through different teaching regimes)
As for other cool tasks, the stuff about playing some simple... (read more)
I think that sort of task might be modellable with ACT-R -- the hardest part might be getting or gathering the animal data to compare to! Most of the time ACT-R models are validated by comparing to human data gathered by taking a room full of undergraduates and making them do some task 100 times each. It's a bit trickier to do that with animals. But that does seem like something that would be interesting research for someone to do!
That sounds right to me. It gives what types of information are processed in each area, and it gives a very explicit statement about exactly what processing each module performs.
So I look at ACT-R as sort of a minimal set of modules, where if I could figure out how to get neurons to implement the calculations ACT-R specifies in those modules (or something close to them), then I'd have a neural system that could do a very wide variety of psychology-experiment-type-tasks. As far as current progress goes, I'd say we have a pretty decent way to get neurons to implement the core Production system, and the Buffers surrounding it, but much less of a clear story for the other modules.
No particularly strong reason -- the main thing is that, when building these models, you also have to build a model of the environment that the system is interacting with. And the codebase for helping people build generic environments is mostly focused on handling key-presses and mouse-movements and visually looking at screens, while there's a separate codebase for handing auditory stimuli and responses, since that's a pretty different sort of behaviour.
As for mapping ACT-R onto OpenWorm, unfortunately ACT-R's at a much much higher level than that. It's really meant for modelling humans -- I seem to remember a few attempts to model tasks being performed by other primates by doing things like not including the Goal Buffer, but I don't think that work went very far, and didn't map well to simpler animals. :(
As someone who can maybe call themselves an ACT-R expert, I think the main thing I'd say about the intentional module being "not identified" is that we don't have any fMRI data showing activity in any particular part of the brain being correlated to the use of the intentional module in various models. For all of the other parts that have brain areas identified, there's pretty decent data showing that correlation with activity in particular brain areas. And also, for each of those other areas there's pretty good arguments that those brain areas have something to do with tasks that involve those modules (brain damage studies, usually).
It's worth noting that there's no... (read more)
I agree that there isn't an overarching theory at the level of specificity of ACT-R that covers all the different aspects of the mind that cognitive science researchers wish it would cover. And so yes, I can see cognitive scientists saying that there is no such theory, or (more accurately) saying that even though ACT-R is the best-validated one, it's not validated on the particular types of tasks that they're interested in, so therefore they can ignore it.
However, I do think that there's enough of a consensus about some aspects of ACT-R (and other theories) that there are some broader generalizations that all cognitive scientists should be aware of. That's the... (read more)