Twitter is like catnip for the brain, while Google can actually make us smarter, says neuroscientist Dr David Eagleman.

Dr Eagleman works from his lab at the Baylor College of Medicine in Houston, Texas, where he looks at big picture issues including what it means to be human, to think, to be conscious. Author of a new book, The Brain: The Story of You, he is credited with spawning a new spiritual movement known as "Possibilianism" (anything's possible, even God).

Dr Eagleman was at the Web Summit to talk about how modern communications technology, including social media, is changing how we think, but also pushing our primal instinct buttons. "We are wired to seek social affirmation from peers and that exquisite social aspect is what has allowed us to form civilisations.

“Social media is like catnip for what our brains already want; if you can get this in 140 characters, then even better. It stimulates our reward system,” he says.

So is social media good or bad for us? It’s a tricky question from a neuroscience research point of view, as it is difficult to study the effects of social media because it is impossible to find a control group of teens who aren’t wired, but have the same life in every other aspect.

“In the past, we learned a lot of ‘just in case’ information, like memorising dates in British history. Now kids are learning ‘just in time’, which means they Google something when they need it or they are curious about it.”

This act of getting information on the back of curiosity rather than rote learning is important because when you are curious you have the right cocktail of chemicals for neuroplasticity and this means that the information is more likely to stick.