saw this on the planet green [one of my new cable stations btw, watch the british show, rich, fabulous & homeless] website. the study tested people looking at technologically reproduced nature [tv] and actual time in real, live nature. those watching nature on tv had the same heartrate as those staring at a blank wall, ha! those that spent even 5 minutes in a city park felt the vital benefits. link here.
for your blank wall-like viewing pleasure, photo © by moi, new mexico enchanted forest