Updated: Mar 19
This technique is the basic setup row, if you are looking to transition from a 1x1 rib into a brioche rib. I use this technique in one of my designs with is due to be released later this year.
On this row, you are going to knit all the knit stitches as normal when you come to them, and for all purl stitches, you are working the slyo (slip and yarn over) that is the staple of brioche knitting.
Slyo: Bring the yarn forward in between the two needles. Slip the next stitch (which is a purl stitch) from left to right needle as if you are purling it, and keep the working yarn at the back to work the next knit stitch. You have now added a yarn over to the purl stitch.