@drpaulralph says:

Please clean up the bibliography entries for the suggested readings and exemplars, and put them all in ACM style.

But the refs seem fine to me.

Problem

The sample column in events.tsv encodes the following:

OPTIONAL. Onset of the event according to the sampling scheme of the recorded modality (i.e., referring to the raw data file that the events.tsv file accompanies).

As identified by @robertoostenveld, we do