short cut keys on a mac for chanding blending modes

[ARCMUSICGRAPHICS04]

Hi,

Can someone tell me the mac shortcut keys for going through the blending modes so you can preview the effect quickly? someone showed me once before and for the life of all the key combos iv tried I cant do it

Thanks
Sarah

 

[Hoogle]

isnt it Shift + Option + (plus) or - (minus) but dont quote me on that 1