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:In a follow-up study using a clinical sample (Amir et al. 2012), individuals with SAD similarly lacked a positive reaction time bias relative to controls without SAD but, interestingly, did not differ in their reaction time to endorse or reject negative interpretations of social sentences.
Category: