“Banking against Alzheimer's,” by David A. Bennett, provides a fascinating perspective, showing that the etiology of Alzheimer's disease and dementia in general is very complex, much like depression and schizophrenia. I wonder if researchers should investigate protective factors beyond the cognitive, such as aspects of emotion, which are increasingly recognized as part of the integrated function of the brain. Larger social networks, finding meaningful purpose in life, musical inclination and the motivation to start learning a second language may all be summed up as evidence of a positive emotional drive.

In addition, late-life depression has been associated with an increased risk of all-cause dementia, emphasizing the role that affective disturbances can play in our cognitive health. Perhaps emotional well-being can supply a buffering role against the harms of neuropathology.

Rowena Kong
via e-mail


In 1990 an optometrist who specialized in vision therapy told me that he and his father, also an optometrist, had been for years tracking the statistics on the close correlation of earlier mandatory schooling with younger eyes needing prescription lenses. He said that children were being given “close work” (and this was before handheld electronic devices) when they should have been outside walking along fence tops, swinging from vines, playing hopscotch—gross motor play. I doubt he knew about the connection of sunlight with lessening of myopia, as Diana Kwon explains in “Losing Focus,” but he was on the right track. The trending decline in recess periods (especially outdoors) in schools needs to be reversed for many reasons.

Michele Bartlett
Littleton, Colo.

Kwon talks about how sunlight can reduce the likelihood of a child developing myopia. Does it depend on the wavelength of the light? Does it have to be white light? Will blue, for instance, of the same intensity work as well? Is UV required?

What happens if the child wears sunglasses? Is the positive effect of the sunlight reduced? If so, we'll have to look at the risk of myopia compared with the risk of harming the eyes with overly bright light.

Ted Grinthal
Berkeley Heights, N.J.

KWON REPLIES: Research suggests that color does matter. Scientists have found that chicks and guinea pigs that grow up under red light become nearsighted, whereas those raised under blue light do not. Some studies show that rearing chicks in blue light can even induce hyperopia (farsightedness caused by an eyeball that is too short). Sunlight contains more blue wavelengths than indoor lighting, pointing again to the importance of sending children outdoors to prevent myopia.

As far as I can tell, researchers have yet to compare the effects of wearing sunglasses to not wearing them, but keeping them on is probably a good idea. Excessive exposure to UV light can damage the eyes and increase the risk of conditions such as cataracts.


The article “Mind over Meat,” by Marta Zaraska, was quite interesting, especially the techniques employed by us meat eaters to reduce our cognitive dissonance over eating animals we profess to care about. I believe, however, that she missed an effective technique, which I employ. These animals would not be living in the first place were it not for us meat eaters. So their lives and their meat are going to waste if we do not eat them. Their care and killing should be strictly regulated, not only so that their short lives can be more comfortable but also for the health of us humans.

Doug Griffith
via e-mail

Thank you for the article on the cognitive dissonance involved in eating meat. I wonder to what degree history may play into the creation of such different terms and practices to assist in dissolving the meat-eating paradox.


For example, the Norman conquest in England may well have separated meat-eating terms into French and Anglo-Saxon, perhaps reflecting the distribution of labor (Anglo-Saxon herders and Francophone eaters). When it's on the hoof, it's “sheep” (a word with Germanic roots); when it's on the table, it's “mutton” (from the French). Likewise with “pig” (Anglo-Saxon) and porcus (Latin, the progenitor of French); “cow (ox)” (Old English) and bouef (French).

In German, there appears to be no effort to dissolve the cognitive dissonance into “eating” and “noneating” stuff. Fleisch is both “flesh” and “meat.” Disambiguation occurs by way of added nouns: Pferdefleisch (“horseflesh”), Rindfleisch (“beef)” but also Menschenfleisch (“human flesh”).

Reinhold Schlieper
Palm Coast, Fla.


I just read “Finding His Wings,” by David J. Hellerstein [Cases]. The analyses of behavioral-activation and cognitive-behavioral therapy were insightful. As a psychology student, as well as an inmate currently incarcerated in a system where mental health continues to be a hot-button topic, it gave me a look at what exactly is not being done to engage individuals in rehabilitative programs who struggle with mental illness. The infrastructure of mental health treatment in the prison system is inexplicably flawed, to say the least. For those inmates who eventually are paroled, they reenter society with no definitive progress in regard to their mental well-being. Can we as human beings continue to turn a blind eye to this subject?

Joseph Kelly
Pleasant Valley State Prison
Coalinga, Calif.


Regarding the answer to “Why does time seem to speed up with age?” in Ask the Brains, I suggest that we perceive time relative to how long we have lived. When you are two years old, another year adds 50 percent to your life. When you are 50, another year has added only 2 percent. There is also the fact that a day when you are two years old is full of new things. A day at 50 has very few, if any, new experiences or information.

Shane Kennedy
Balbriggan, Ireland


I just read the answer to “Do statins produce neurological effects?” in Ask the Brains. I am continually hearing negative news about long-term uses of statins. I tried confronting my doctor at the VA about this because I have been taking them for going on 18 years. His reply was that the benefits far outweigh the side effects. I am not sure I believe him, but studies are so easily sensationalized that I am looking for something conclusive.

I am experiencing an increase in muscle aches and fatigue at 68 years old, and I wonder if I discontinue statins on my own if they would stop.

Jay Clark
via e-mail

THE EDITORS REPLY: Research shows that for people who have high cholesterol, taking a statin can help prevent a heart attack or stroke. That said, there are different types of drugs and treatment approaches available, and if you feel that you are experiencing negative side effects, it is always worth discussing it with your doctor or seeking a second opinion.


In “Would You Vote for a Psychopath?” by Kevin Dutton [September/October 2016], the “Psychopathic Leader Board” box contains an error: Bernie Sanders's total score should be 129, not 139 as printed.