Fig. 5.

Change in delta band power in response to cannulation. The change in delta band power between cannulation and background activity, compared with the change between 2 background periods at Cz and CPz in (A) the naïve group, and (B) the local anaesthetic (LA) group. Cannulation evoked a significant increase in delta power in the naïve group (^∗P < 0.05), which was not seen in the LA group. (C) Change in delta power between cannulation and background activity at each of the electroencephalogram (EEG) channels (ordered according to mean response). Error bars indicate SEM.