Top five YouTube channels to train your brain

Inspirational speeches are not the only type of videos TED posts on YouTube. They also have a separate channel called TED-Ed showcasing "lessons worth sharing" to more than a million subscribers. This is a great resource which covers a variety of topics such as the science-related "How does sugar affect the brain?" or "The Oxford Comma debate".

TED-Ed videos (above) are made with unique, colourful animation, and they usually have a voice-over explaining the topic in detail. Lessons on TED-Ed are accurate and very engaging. They also have the special feature that all TED videos have: ideas that will motivate you. However, TED-Ed covers only the most basic principles, so if you're looking for something deeper you'll have to surf on.

Unlike TED-Ed , Khan Academy does venture deep into topics in their videos. For example, there is Simple Equations and then the more advanced Equation 2.

Created by Salman Khan, Khan Academy has more than two million subscribers. It covers many different subjects, but is most famous for maths.

Here, the videos are more like a classroom. The background is usually a blackboard or a picture (below), with explanations being written as the teacher speaks. This is especially useful for step-by-step procedures as it allows students to clearly see the process and understand what is being said.

Khan Academy has separate channels that host the same content in other languages, so students can listen to the videos in their preferred language.

CrashCourse videos are visually interesting, blending animations and on-screen hosts. Since the narrator appears in the video, it makes CrashCourse videos much more engaging, and this channel now has more than three million followers. True to its name, CrashCourse gives you the quick basics of a range of subjects and topics. Each subject is usually covered by a different narrator. For example, history is covered by The New York Times' bestselling author John Green (below, The Fault in Our Stars), while biology is covered by his brother, Hank Green.

Since CrashCourse was started in the United States, most of the lessons are suited towards US schools.

But now, CrashCourse is branching into more unusual subjects such as astronomy, which are not necessarily taught in school, but are still interesting.

SciShow has answers to your life-related questions. With more than two million subscribers, SciShow's videos discuss the controversial areas of science and current affairs. The videos are narrated by different people, including Hank Green.

Although there are minimal animations, the talks feature real photos, allowing students to grasp the information more easily. SciShow is similar to CrashCourse, but the topics discussed in the videos (above right) are very different.

Created by Michael Stevens (below) in 2010, Vsauce has an audience of more than eight million subscribers.

In his videos, Stevens answers questions tweeted by the audience. These can range from "When will we run out of names?" to "Is the Earth actually flat?"

Questions are usually separated into different genres, such as human behaviour, space, or physics. Most of the time, Stevens is on-screen, explaining his answers with the occasional use of text or images.

Vsauce videos are excellent quality, with clear audio that makes it easy to understand what is being said. There are many rhetorical questions directed to the audience, giving you a lot to think about. Even though Vsauce is not exactly school-related, there are still questions that can start wonderful dinner discussions.