What are cognitive tests and how easy are they?

In brief cognitive tests, medical professionals ask patients a variety of learning and memory questions.

Longer clinical evaluations include cognitive tests plus a physical and neurological exam and a full history of a patient.

The latter could paint a clearer picture of the cognitive abilities of both Mr Biden and Trump, said Dan Mungas, an associate director of the University of California’s Davis Alzheimer’s Disease Research Center.

Often medical professions will start with a brief test, such as the MoCa, and if their score is lower than expected, they move to a more comprehensive examination.

More in-depth tests assess language, executive function and visual-spatial abilities.

For example, a medical professional may read a story to a patient then ask them to recall parts of the story to test memory and learning abilities.

A patient might be asked to recall a list of words, name objects in pictures or name items that start with a specific letter.

In addition to questioning the patient, Dr Mungas suggests speaking with people who spend time with the patient regularly to determine symptoms of cognitive decline.

Dr Mungas said it is important to see if someone’s abilities have changed over time, adding that a one-time assessment can be misleading.

“You have to understand where a person started out, if they’re declining from where they’ve been before, that’s a bad sign,” he said.

But he notes, cognitive tests are not everything.

“The idea that there’s a simple cognitive test that says this person’s going to be a good president doesn’t make any sense and I’ve been doing cognitive testing all my career,” Dr Mungas said.