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:Prompted by these observations, recent modeling approaches rely on excitable dynamics to describe gradient sensing and chemotaxis (Xiong et al., 2010; Hecht et al., 2011; Neilson et al., 2011; Cooper et al., 2012; Huang et al., 2013; Knoch et al., 2014).
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