Is attention and mood such a new concept that we need an entire article for it? Am I the only one that sees this as obvious and intuitive? You only look for what's relevant to you. There's no need to "see" the vast majority of things you come across every day.
There are many ways to study attention and mood. What I took from the press release which appears to be novel (though I've not read the original research article) is that our higher-order representations of facial emotions are able to be influenced by stimuli presented to the participant unconsciously. Although the participant was not aware of the happy faces being presented to them, their representation of the emotion of a separate face was affected. This is very different from the obvious "our mood influences what we attend to in the world".
Also highlighted in the press release is the fact that this was robust for unconsciously presented happy faces -- it is unusual for positive stimuli to have a stronger effect on most psychological measures. This is usually due to negative stimuli causing higher levels of arousal (as far as I know, though I'd need to confirm this in the literature), so it's really due to a confounding of valence and arousal.
My main question from this article would be how they controlled for low-level visual properties of the stimuli presented. The hope is that their upside-down face experiment was able to account for any possible confounding of face emotion with something like spatial frequency characteristics influencing the participant's subjective judgement of the neutral face, but there will never be a way to fully claim that it was the emotion of the face alone. If you fully control the underlying visual properties of the stimulus, you remove the emotion!
The article is about the methods of new studies that are attempting to quantify something that many - but not all - find intuitive. Yeah, there are bigger fish to fry, but I found it interesting.
