It has long been a contention that modern life is creating a new type of human being, one whose altered brain circuitry will cause them to think and act differently from our ancestors.

In 2006 Baroness Susan Greenfield, a leading neuroscientist, warned that the computer culture would change the way the brain processes information and sets it in context. She compared allowing people unfettered access to eye-to-screen technology with giving them car keys without teaching them to drive.

At a conference in Glasgow today Dr Aric Sigman will warn the dramatic recent rise in screen time allowed to today's children will result in not only higher levels of diabetes and heart disease – the consequences of physical inactivity – but long-term changes in the brain's reward circuitry that resemble drug addiction. Young people who overdose on television and computer games may get their dopamine fix, not from a syringe or a bottle, but an addiction to technology. Already there are children who spend so many hours each day alone in front of a screen their social skills are poor and they have difficulty making eye contact.

Should this be a major issue of concern? Certainly, the figures are shocking. A recent Ofcom report suggests upper primary children are spending nearly two hours a week longer on games players and consoles than in 2010. Average screen time for British adolescents is now 6.1 hours a day. Dr Sigman, a chartered biologist and psychologist, describes the passive parenting that allows this to happen as "a form of benign neglect".

There is a whiff of moral panic about this issue. Because we cannot compare today's young brains to those of the past, it is hard to chart changes. This research must not be used to take a crude pot shot at hard-pressed parents, especially those in low income families without the means to buy expensive extra-mural activities for their children. (The over-stimulation of middle-class children who are perpetually whisked from one activity to another may also inhibit normal brain development.)

It is understandable that parents struggling to maintain a work-life balance use TV and computer games as childminders. Many programmes have educational benefit. Computer games can teach everything from spelling to physical co-ordination. The Wii can even keep them fit. For children who are separated from their friends, social networking can counter human isolation rather than increase it.

As many parents consider it unsafe for children to play outside unsupervised, what are youngsters meant to do? Many of today's adults recall childhoods of unmitigated tedium and loneliness. It is a mistake to imagine some universal golden age of childhood.

As with alcohol, many children merely take their cue from their parents, who also have phenomenal levels of eye-to-screen contact. Would it be worth considering advisory levels of screen time for all family members, comparable to units of alcohol? Meanwhile this research supports the importance of parents continuing to share with children the simple, mind-expanding joy of curling up with a good book. Ultimately, however, it is not technology that is at fault. It's what we do with it that matters.