Randomisation and blinding
There were six drug orders. Each order was used with eight participants (one sixth of total sample), to ensure that drug order was balanced. Drug order was balanced within age‐group and gender. Within these groups, participants were randomly allocated to drug order using a blocked randomisation sequence. All experimental researchers and participants were blinded to treatment allocation. At the end of each session, participants were asked to guess which drug they thought they had received that day.