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:…et al. 2003, 2004; Ceponiene et al. 2003; Jansson-Verkasalo et al. 2003; Gervais et al. 2004; Kasai et al. 2005; Lepisto et al. 2005, 2006), including reports of deWcient cortical processing speciWc
to prosody (Erwin et al. 1991; Wang et al. 2001; Kujala et al. 2005; Korpilahti et al. 2006).
Category: