Millisecond Forums

As detailed in the documentation, the <summarydata>'s /columns attribute only accepts *properties* (as well as values and expressions). I.e.

<summarydata>
/ file = "FaceDotProb_summary.iqdat"
/ columns = [date, subject, blockcode, latency, error, percentcorrect, ...]
...
</summarydata>

needs to read

<summarydata>
/ file = "FaceDotProb_summary.iqdat"
/ columns = [script.startdate, script.subjectid, ...]
...
</summarydata>

Things like 'error', 'latency' or 'blockcode' make no sense in a summary data file. A summary data file is supposed to capture *a single line of summary statistics*, and 'error' or 'latency' are neither. Those things belong in the trial-by-trial raw data file.

You don't need to write an expression to capture the mean latency for each <trial> element to the summary file. You can directly log the respective property:

<summarydata>
...
/ columns = [..., trial.abbl.meanlatency, trial.abbl.totalmeanlatency, trial.abbr.meanlatency, trial.abbr.totalmeanlatency, ...]
...
</summarydata>

meanlatency and totalmeanlatency should be identical in your case, but note the difference as detailed in the documentation:

meanlatency property:
The mean response latency for the specified element within the current block.

totalmeanlatency property:
The mean response latency for the specified element over the entire experiment.