In some fields such as neuroimaging, where identification of foci rather than effect sizes is the goal, one approach evaluates whether the number of claimed discovered foci is related to the sample size of the performed studies [22]. In the absence of bias, one would expect larger studies to have larger power and thus detect more loci. Lack of such a relationship, or even worse, an inverse relationship with fewer foci discovered with larger studies, offers indirect evidence of bias.
