You get the help of science (here neuroscience) to help you to make your point. To do this, you cite 3 studies that seem to go in your direction. The big problem is that you (and the studies) imply a causal relationship.

Have you ever considered that it could be the opposite? That people with learning disabilities, poor memory and mental health problems stay on the screen just because they are stupid or depressed... and not the other way around.

The truth is that medicine is not really a science, much more of an art or a skill. The link between health and behaviour is much more complex than a causal one.