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:Indeed, recordings from awake behaving animals routinely demonstrate populations of Purkinje cells with reciprocal simple spike firing rates, each of which encodes movementrelated variables (Frysinger et al. 1984; Lisberger and Fuchs 1978; Mano and Yamamoto 1980; Medina and Lisberger 2008).
Category: