Over the past few weeks, US President Donald Trump has been bragging about how well he performed on a recent cognitive test, mainly to challenge presumptive Democrat presidential nominee Joe Biden to take the same test he did.

On July 9, he told Fox News's Sean Hannity that he took the test at Walter Reed Medical Center in Washington in front of doctors, and "they were very surprised. They said, ‘That’s an unbelievable thing. Rarely does anyone do what you just did.’” Not one for modesty, he of course crowed about it on Twitter.

On Sunday, July 19, during an interview with Fox News's Chris Wallace, Trump was presented with a poll conducted by Fox that found 47 percent of people that answered think Joe Biden has the mental soundness to serve effectively as president, compared to 43 percent who thought the same of Trump.

In response, Trump again boasted about the test he had passed, as evidence that he was fit to be president, and challenged Biden to do the same test as him. Wallace, however, challenged the President on the difficulty of the test, declaring that he too had taken it. Among the highlights, Wallace describes one of the questions on the test: "They have a picture and it says 'what's that?' and it's an elephant". Trump insisted the test gets more difficult towards the end, at which point Wallace reveals one of the last questions involve counting back from 100 by 7, before performing the feat.

Let's be clear, this is not an intelligence or IQ test. The test that Trump took was the Montreal Cognitive Assessment, a screening tool used for detecting mild cognitive impairment, particularly in a clinical setting to help diagnose early Alzheimer's or dementia. The test scores participants out of 30, with anything over 26 considered normal. On average, people without cognitive impairment score 27.4, those with mild cognitive impairment score 22.1, and those with Alzheimer's score 16.2.

Part of the test is indeed to identify animals, with one point being awarded per animal. Another part of the test involves a short-term memory test, with the subject having to remember a list of five words, and then a second list of five words before being asked to recite them back to the doctor. No points are given for remembering the words, instead, points are deducted from the total if words are wrong or incomplete. Later on in the test, you have to recite the list again. Here, a point is awarded for each word.

Visuospatial abilities are tested by having the subject draw a clock face, showing a time specified by the physician. The patient draws the clock, and is awarded one point each for drawing the clock face as a circle (slight imperfections are allowed), getting the numbers correct and in the correct order, and putting the right time, with the hour hand being shorter than the minute hand.

In the vocabulary and fluency part of the test, the patient is given a letter to list as many words beginning with that letter as possible in 1 minute. Just like in Scrabble, you aren't allowed to use proper nouns. One point is awarded for getting more than 11 words within the time limit.  

The test should of course be administered by a medical professional. You can see a demonstration of the full test below.

Again, this isn't an intelligence or IQ test, so it's fair to say that while it's not good practice to speculate on someone's mental health, if Trump's doctors were genuinely surprised that he passed the test, that says something about what his doctors believe his mental state to be.

"Docs don't give a cognitive test to measure intellect," Dr Ankur Dave explained on Twitter. "We give it to assess cognitive defects. Trump calling questions on this test difficult should raise some red flags about dementia and inability to serve."

"MOCA is a screening test for cognitive dysfunction overall not just dementia," he added. "Low score means more testing needed. But someone calling this test difficult, challenging others to take it prob shouldn't be in charge of our military or our Covid response."

Basically, the test is an indication of the most basic cognitive function. Whilst it's good to know the person in charge of the US's nuclear codes can pass, it's nothing to brag about on Twitter.