text: There were no intergroup differences for catecholamines plasma levels ( adrenaline P = 0.123 ; noradrenaline P = 0.281 ; dopamine P = 0.173 ) , but there were for serotonin levels ( P = 0.045 ; F ( 1,38 ) = 4.296 ; R ( 2 ) = 0.10 ) .