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:Such neurons exist not only in higher-order association areas but also in low-level, modality-specific sensory areas (Ghazanfar & Schroeder, 2006), supporting the notion that multisensory interactions can influence early sensory processing.
Category: