There are many ways to kill time on a long train journey, sitting on a bus, or whilst in a waiting room. Reading a book, scrolling social media, or picking up a copy of a newspaper are some of the most common ways to make that time go by a little easier.

Another option is trying out a brainteaser and giving the mind a little exercise, but with a fun twist. There are three main types of brainteasers. They can be observational, analytical, or mathematical.

Mathematical brainteasers ask users to solve a maths question as quickly as possible whilst analytical brainteasers require you to solve a complex riddle.

Observational brainteasers, such as the one above by FishInAquarium, require the user to spot an anomaly in an image in the shortest time they can manage. The task in this one is to scan the image carefully for the hidden seashell.

Did you spot the seashell? No worries if not, the answer is above. The seashell can be found in the bottom right-hand corner of the image, just underneath a bright blue fish.

While brainteasers like this one might not seem particularly difficult, they can still provide useful exercise for the mind. Like the muscles around the body, the mind needs to be stimulated to remain healthy.

The healthier the brain the less likely it could be to develop neurological conditions such as dementia. This doesn’t mean that doing brainteasers will stop someone from developing dementia – other factors can play a much bigger role – but they can help keep the mind sharp.

In recent years, new treatments for dementia have been developed to slow the condition, but there is as yet no cure for a disease which can come in many different forms and cause an array of symptoms that affect millions of people around the world.