You cannot do this. That is, there are only a few specific classes of rounds you can do, embodied in round, fix, floor, and ceil. (I think I listed them all.) There are no flags you can set that will control rounding.
You want to round down, for non-integer parts that are strictly less than 1/2, and round up for non-integer parts greater than 1/2, but leave those values that are exactly at 1/2 alone?
I suppose with some code, and some small effort, do what you want.
x = [1.5;rand(8,1)*10 - 5]
Does that do as required?
function xround = strangeround(x)