Resolving the controversy of the proportion validity effect: Volitional attention is not required, but may have an effect
Attention Perception & Psychophysics (2015) - Comment
pubmed: 26178857  doi: 10.3758/s13414-015-0956-8  issn: 1943-393x  issn: 1943-3921 

Sophie N. Lanthier, David W.-L. Wu, Craig S. Chapman, Alan Kingstone