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:This is in line with several fMRI studies that detected bilateral activation in participants with hemiplegia both in motor and sensory areas (Staudt et al. 2002; Guzzetta et al. 2007; Sutcliffe et al. 2009; You et al. 2005).
Category: