Wadler says it's wrong to draw a line between steroids and growth hormone.

NPR: Baseball Considers Human Growth Hormone Tests

These brain systems infuse our mind with meaning, make us aware of what might harm us, alert us to what might go wrong, draw us toward what's good for us and highlight the sheer joys and pleasures of living.

CNN: Make your 'rainy brain' sunnier

But calling on the wrong person can draw all the focus away from the campaign's main themes and raise serious concerns about the competence of the candidate.

CNN: Romney, make a boring pick for VP