How to defocus/blur certain areas using adobe light room

Question

I need to make certain things blur or defoucs in the photo. For Eg: in the below link apart from the face rest of the background should be defoucsed. Is there any filter or setting to make only background as defocused?
http://www.hackfew.com/7-simple-tips-live-life-happily/

Answer 1

To add to what Rikk said..
Local Sharpness = -1 will mask .5% of global sharpening
Local Sharpness = -50 will mask 100% of global sharpening (without blurring) - I still use this setting along with noise reduction to clean up sky etc.
Local Sharpness = -51 will blur a tiny bit.
Local Sharpness = -100 will blur as much as possible.
Summary:
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local sharpness has 3 distinct ranges:
positive: add to global sharpening
negative (-1 to -50): mask global sharpening
more negative (-51 to -100): blur
In my opinion, it's worthwhile knowing where the cut-off is, exactly, since an inadvertent blur when you don't want blurring is a real bummer, and if you think you'll be blurring a little at -50, you won't be.
Beware: overlapping pins are additive, so if you have two pins at -50, overlapping strokes will blur, whereas non-overlapping strokes will not..
Rob