Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:We also compared the easy selected and easy nonselected conditions with a t-test, because this contrast provides a replication of the main conditions included in previous studies (Duque et al. 2010, 2012; Labruna et al.
2014).
Category: