Man shows his dad with Alzheimer's drawing of a clock that has people noticing a 'missing link'

A clock that a dad with Alzheimer's disease - the most common type of dementia - drew has gone viral online and people have noticed something incredible about it.

Before we get into it, lets talk about the clock-drawing test which is used to check for signs of dementia.

Alzheimer sufferers are asked to draw a clock and the depiction is used to gauge their mental capacity (Getty stock image)

According to Very Wealth Health, it measures several cognitive abilities at once, including attention, hearing comprehension, visual memory, and motor skills.

Alzheimer's sufferers are asked to draw a clock with hands pointing to a specific time.

The drawing is then scored - which can be done in several different ways - but usually there are points awarded based on the sequence of numbers, placement of numbers, and the placement of the hands.

Taking to Reddit, one user explained his take on the drawing, touching on the dementia sufferer's 'missing link' in what he drew.

They wrote: "It is interesting how you can still see the individual perceptions of 'clock' and 'time' in this drawing, as well as the missing link between them.

"The 12 and 6 for the whole and half hour. The 4 for a 'quarter' of time (1/4th of the clock), like 'a quarter past X'. And the three most likely by the same reasoning for 'three-quarters' of the clock.

A Reddit user shared this clock that his dad drew with users on the platform (Reddit/YoeriValentin)

"The individual thoughts are there, but they seem to lack the connection to create one coherent image."

Commenting on their take, the original poster on the social media platform said: "Indeed! He'll not really realize that he's messing it up either. In the video, he also instantly recognizes that the clock I drew is good."

Reacting to how the first commenter viewed it, they said: "Yeah!! Thats literally alzheimer, short version it has to do with depletion of levels of dopamine that affect neurons and how they communicate, how they interact with each other.

"And that can make for cognitive, memory, emotional ( limbic system ) and language to be 'scattered' and unregulated set of behaviors that turn out to not make a lot of sense.

"A notion ( genetic and environmental growth factors) might be seen once in a while inside that messy set."

Interestingly one dyslexic Reddit user explained he uses the same theory as the dad who drew the clock (Getty stock image)

Adding: "Best of wishes to everyone affected by this. It's a hell of a thing."

While someone with dyslexia, a learning disability that affects the way people read and write, added: "I thought this was interesting too! This looks like something I do. I'm dyslexic but I'm pretty good with numbers.

"The best way I can describe it is sometimes my brain forgets how to write a symbol so chooses something else related to it to write instead, all subconsciously.

"9 and 6s are interchangeable because they look similar 9s can also be 3s because its the square root etc. The only difference is that I remember that the 3 I wrote is a substitute for 9.

"It looks like he's done similar just without remembering to swap it back."