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:Haruno & Kawato, 2006), it is important to note that there is ample evidence from functional magnetic imaging experiments that in humans prediction errors are indeed encoded in the dorsal striatum (e.g. Valentin & O’Doherty, 2009; Cooper et al., 2011), including regions of dorsal putamen most comparable to rat DLS (e.
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