Parapraxis, or speech errors, is common in typical adult communication. We’ve all experienced a “slip of the tongue.” However, the frequency, consistency and nature of Mr. Trump’s errors are outside the norm.

His patterns of derailment (switching from one topic or thought to another without a logical connection), circumlocutions (struggling to find the right word and using descriptions instead) and phonemic errors (sounding out words) suggest more than just a careless speaking style. His use of words like moron and other youth-like insults also indicates a possible impairment.

Research has long established that communication changes can be an early indicator of neurodegenerative diseases like Alzheimer’s. It is essential for a physician to provide a detailed assessment of Mr. Trump’s cognitive health beyond just stating that his physical health is excellent.

We deserve transparency about the fitness of those seeking the highest office. I urge the full release of his medical records, including cognitive and neurological evaluations, and for Congress to establish more stringent fitness for duty assessments for presidential candidates.

Michael J. Salamon

Hewlett, N.Y.

To the Editor:

It has been a long time coming to finally see The New York Times focus on the ramblings and incoherence of Donald Trump. Mr. Trump’s calling Kamala Harris “mentally impaired” is just one more example of a long-running propensity he has to attribute his own vast shortcomings to his enemies.

You are to be commended for pointing out the irrational ravings of a man who cares nothing about anybody but himself. But why did it take so long for you to more forcefully acknowledge what millions of Americans have seen for a very long and tortuous span of time?

Michael Zimmer

Auburndale, Mass.

To the Editor:

The question of age should not be reignited by the increase in anger, rambling, incoherency and confusion in Donald Trump’s speeches as described in your article. There are real age-related changes in cognition, but these are not among them.

With age, it’s harder to learn and remember new things, one needs to pay more attention, multitasking is harder, strategies may be needed to help with memory, words can be harder to retrieve — but most older adults can do this. Attention span, language comprehension, usage and vocabulary don’t decline. Personality in general remains stable throughout life.

Emotional intelligence — the ability to understand one’s own and others’ feelings and emotions and use this information to guide thinking and actions — generally improves with age. Wisdom grows, imparting a larger store of coping mechanisms and problem-solving strategies.

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I am a geriatrician who for over 40 years has cared for thousands of people far older than 78-year-old Donald Trump. With many, I have quite nuanced and on-point conversations about complex and difficult topics.

I have never spoken with or examined Mr. Trump, but the article reports a concerning progressive loss of cognitive function and behavioral control that is unlikely to be simply “normal” aging.

Rosanne M. Leipzig

New York

The writer is a professor of geriatrics and palliative medicine at the Icahn School of Medicine at Mount Sinai and the author of the book “Honest Aging.”

(http://www.autoadmit.com/thread.php?thread_id=5609486&forum_id=2\u0026mark_id=5310893",#48183177)