There is now a super useful (although still somewhat flaky) tool to probe arbitrary model element parameters (models, productions, chunks, modules, buffers), across time. It comes in two part: runtime probe and viewer.
To use it, you need to enable the GeneralProbe in run configuration and provide it the location of a probe file.
The probe file (typically stored under configuration/probes/) tells the runtime what elements to probe, what parameter to record, and how frequently. The use of regular expressions to select model elements is a little messy, but functional. I'm using the following probe file to record base level activations of attended and updated spatial representations:
<!-- how frequently to poll -->
<instrument window="1">
<!-- what models to probe -->
<model pattern=".*">
<!-- only probe configural chunk types -->
<chunk-type pattern="configural">
<!-- attended -->
<chunk pattern="configural-.">
<probe pattern="BaseLevel.*" poll="true" />
</chunk>
<!-- updated -->
<chunk pattern="configural-\p{Alpha}-.*">
<probe pattern="BaseLevel.*" poll="true" />
</chunk>
</chunk-type>
<!-- log retrieval threshold -->
<!--
<module pattern=".*Retrieval.*">
<probe pattern=".*Threshold" poll="true" />
</module>
-->
<!--
production probe
<production pattern=".*">
<probe pattern="Utility" poll="true"/>
</production>
-->
<!-- or a model parameter probe
<probe pattern="Age" poll="true"/>
-->
</model>
</instrument>
Then, when you open the jACT-R Probes view, you can follow the values over time.
You can also export the current time frame to a CSV or PNG file.
There are a few bugs, particularly with respect to auto-scaling (probing modules seems to screw that up.. no clue why) and some performance issues, but otherwise it's quite usable.
Enjoy.