Nanny no longer knows best, the Contented Little Baby Book could undermine a child's development, and Dr Spock's advice that a child should be left to cry could cause psychological damage.

When it comes to the crowded and hotly debated world of how best to bring up baby, there is a new theory that uses brain scans to argue that controlled crying not only damages babies' brains but produces angry, anxious adults.

'If you ignore a crying child, tell them to shut up or put them in a room on their own, you can cause serious damage to their brains on a level that can result in severe neurosis and emotional disorders later in life,' said Professor Margot Sunderland, a leading expert in the development of children's brains and a British Medical Association award-winning author, who has already written more than 20 books on child mental health.

Based on her four-year study of brain scans and scientific research, Sunderland entreats parents to reject the modern theories of baby experts such as Gina Ford and Channel 4's Supernanny, Jo Frost, who preach strict discipline, routine and controlled crying.

Sunderland's book, The Definitive Child Rearing Book, to be published next month, provides step-by-step guidance on how to react to every swing in a child's mood, even down to the best way to hug an upset baby.

'The blunt truth is that uncomforted distress may cause damage to the child's developing brain,' said Sunderland, the director of Education and Training at the Centre for Child Mental Health in London.

She believes that parents often do not give adequate recognition to their children's distress. While the importance of touching, cuddling and physically soothing their babies is paramount, she also advises parents of the dangers of attempting to minimise their children's anger and emotional distress.

'Parents should never try to persuade their child out of feeling a certain emotion,' she said. 'Even if your child is reading a situation in a completely different way to you, it is important to prove to them you are empathising through the time you give them and the language and facial expressions you use.

'If your child is upset, you will reduce rather than increase their feelings of stress by not taking their upset as seriously as you would wish someone to take your own,' she added. 'Attempting to jolly them out of their mood will result in them internalising their stresses, which will take the same toll on their bodies and brain as unsoothed crying.'

Sunderland also believes parents often unwittingly discipline children through shame and fear. 'It can get quick results and parents often do not realise they are doing it,' she said. 'But the price on a child's develo ping brain can be very high and leave a legacy of anxiety and social phobia for life. It is all too easy to break a child.'

Instead, Sunderland encourages parents to be very emotional when their child is well behaved and very matter of fact when they behave badly. 'When telling a child off, parents should use low-key voices, a monotone that states calmly but firmly what the child has done wrong and what the punishment will be.'

Sunderland believes that parents who use fighting words and phrases that demand absolute and immediate obedience will create a defiant child while thinking words, that activate their brains by giving them a choice, will defuse intense states of emotional arousal.

Often, however, Sunderland advises that words are not necessary and that calmly holding the child who is refusing to listen is enough. 'Sometimes the child's brain is too hyper-aroused to respond to language and a warm and loving touch is the only thing that can calm them down without conflict.'

Sunderland offers the following advice to parents:

· Do not try to persuade the child out of their emotions, however extreme or unreasonable you might feel those emotions to be.

· Do not minimise their emotions: show through touch, tone and facial expression that you understand the intensity and quality of what they are going through.

·Be their emotional rock: be kind and calm.

·Hold them - touch is vital to calm and soothe a child.

Toni Conyers, part time teacher and mother of two: five-year-old Joshua and three-year-old Toby.

I gave up my full-time job as a finance manager three years ago, because I found raising my children so much more complicated than I had expected. Children are opaque beings: they have moods and feelings that, as a parent, it is hard to understand or know how to handle. When things did not go well at school, should I try to make them tell me what was troubling them or should I give them the space to talk to me when and if they are ready?

I try a number of different approaches when my children are upset: when my oldest son was having problems at school I attempted to encourage him to put his concerns in perspective by brushing off his comments but when I realised he was then building things up in his head, I tried very hard to tease out exactly what the problems were.

In the end, the best thing to do seemed to be to give him a big hug and constant reassurance but it took time for me to discover that, and next time it might not be the answer: I have also seen that if you play up to a child too much they begin to use it as a tool to get your attention. It is enormously hard to know when to stand firm and be consistent about how you expect them to behave, and when they are behaving badly because they genuinely need emotional support.

Parents need to have confidence to listen predominantly to themselves and to their child because they know their child best, and the worst thing for a child is to have a paranoid parent too nervous to respond naturally.