> The /errormessage command only seems to allow us to specify one stimulus. What would you advice?
Either (1) use /responsemessage attributes, of which you may define multiple (as opposed to /errormessage, of which there may only be a single one), or (2) /branch to a separate <trial> element in case of an error that displays your various stimuli as usual:
<trial mytrial>
...
/ branch = [if (trial.mytrial.error) trial.errortrial]
</trial>
<trial errortrial>
/ stimulusframes = [1=errorstim1, errorstim2, errorstim3, ...]
/ validresponse = (0)
/ trialduration = 1000
</trial>
> Secondly, we were wondering if it is possible to somehow present a page on another occassion aside from the start of a new block, for
> example incorporate it into our "break trial"?
No. <page> elements can only be displayed via /pre- and /postinstructions at the start or end of a <block> or <expt>. You need to incorporate your additional instructions as regular stimuli (<text>, <picture>, etc.) which you can then display in your "break" <trial> just like any other stimuli. You can also use a <surveypage> instead of a <trial>; <surveypage> elements are special types of trial.