The link to the original research is not working, presumably that's because it's "closed access" according to the reference: https://www.clinicalkey.com/content

The link to the original research is not working, presumably that's because it's "closed access" according to the reference: https://www.clinicalkey.com/content/playBy/pii/?v=S0006322321006521&returnurl=https://linkinghub.elsevier.com/retrieve/pii/S0006322321006521?showall=true&referrer= https://www.clinicalkey.com/content/playBy/pii/?v=S000632232... I wonder what criteria they used to measure the improvement in focus. Was it the children themselves saying "yes, I feel more focused now", or was it a test of the children's ability of focus, or something else?