Repeated exposure to social networking sites leaves users with an 'identity crisis', wanting attention in the manner of a toddler saying: 'Look at me, Mummy, I've done this.'

　　Baroness Greenfield, professor of pharmacology at Oxford University, believes the growth of internet 'friendships' – as well as greater use of computer games – could effectively 'rewire' the brain.

　　This can result in reduced concentration, a need for instant gratification and poor non-verbal skills, such as the ability to make eye contact during conversations.

　　More than 750million people across the world use Facebook to share photographs and videos and post regular updates of their movements and thoughts. Millions have also signed up to Twitter, the 'micro-blogging' service that lets members circulate short text and picture messages about themselves.

　　Baroness Greenfield, former director of research body the Royal Institution, said: 'What concerns me is the banality of so much that goes out on Twitter.

　　'Why should someone be interested in what someone else has had for breakfast? It reminds me of a small child (saying): “Look at me Mummy, I'm doing this”, “Look at me Mummy I'm doing that”.

　　'It's almost as if they're in some kind of identity crisis. In a sense it's keeping the brain in a sort of time warp.'

　　The academic suggested that some Facebook users feel the need to become 'mini celebrities' who are watched and admired by others on a daily basis. They do things that are 'Facebook worthy' because the only way they can define themselves is by 'people knowing about them'.

　　'It's almost as if people are living in a world that's not a real world, but a world where what counts is what people think of you or (if they) can click on you,' she said.

　　'Think of the implications for society if people worry more about what other people think about them than what they think about themselves.'

　　Vocabulary:

　　obsessed: 着迷的，痴迷的，迷恋的。

　　toddler: a child who has only recently learnt to walk(学步的儿童;刚学会走路的孩子)

　　pharmacology: the scientific study of drugs and their use in medicine(药物学;药理学)

　　rewire: to put new electrical wires into a building or piece of equipment 给(建筑物或设备)换新电线。文中是比喻用法。

　　gratification: the state of feeling pleasure when something goes well for you or when your desires are satisfied; something that gives you pleasure(满足;满意)

　　non-verbal: not involving words or speech(不涉及言语的;非言语的)

　　circulate: to send goods or information to all the people in a group(传送)

　　banality: the quality of being banal; things, remarks, etc. that are banal(平庸;平淡乏味;陈腐的事物;陈词滥调)

　　time warp: an imaginary situation, described, for example, in science fiction, in which it is possible for people or things from the past or the future to move to the present 时间错位(如科幻小说中所描述的过去或将来的人或事都可能移到现在)