Anchoring the deficit of the anchor deficit: dyslexia or attention?

In the anchoring deficit hypothesis of dyslexia (Trends Cogn. Sci., 2007; 11: 458-465), it is proposed that perceptual problems arise from the lack of forming a perceptual anchor for repeatedly presented stimuli. A study designed to explicitly test the specificity of the anchoring deficit for dyslexia is presented. Four groups, representing all combinations of reading skills (high or low) and attention (high or low), were given a time estimation task in which a standard tone was compared with tones of varying length. Poor readers showed problems only if they had limited attentional skills as well, while poor readers with good attention were unaffected. It is concluded that a single deficit in time estimation is not sufficient to cause reading deficits.