Hypothesis
Real-world objects, unlike simple coloured squares, benefit from extra encoding time and escape the usual three-to-four-item working-memory limit, as shown behaviourally and in the contralateral delay activity (CDA) by Brady et al. (2016).
What failed
Three replications with more participants and more trials per condition did not reproduce the key result that objects gain more than colours from longer viewing, and found no object-specific CDA increase. Extra encoding time helped both colours and objects.
Broken assumption
Familiar, complex objects have a special working-memory capacity that longer encoding unlocks.
Why
The abstract offers no account of the original result; the data simply give no support for a different capacity for real-world objects.
From the published paper: Quirk et al. eNeuro, 2020. ↗CC BY