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:tulated that frontal lobe dysfunction plays a major role, while others have suggested that hydrocephalus contributes to the interruption of the subcortical circuit connecting the frontal lobe and basal ganglia [3, 19, 28].
Category: