Tim Robertson: Art can help unlock prisoners' minds

As a country, we are putting more people into our prisons. For me, the crucial therapeutic benefit of art for offenders is that it helps them focus on an audience: if you are writing a poem or painting a picture, you have to think "How will this come across to the reader or viewer?" That is a crucial cognitive step for offenders who, by definition, have at some point failed to consider the effect of their actions on others.

What is important is the context and the tone in which things are exhibited, and what I believe of the gallery in Nottingham is that they exhibit in a way so as not to make judgements or take sides. They raise issues for debate and education, which I welcome. If we, as a public, are deciding that people need to be in prison, we are collectively responsible both for the punishment of those people and for their rehabilitation into a community with the rest of us.

It makes sense, therefore, that we take an interest in their educational and artistic achievements. Their work offers us a sense of how the world looks to these prisoners.

From our point of view at the Koestler Trust, I believe and hope that art can be rehabilitative, that it helps offenders change and move towards a life free of crime. But some offenders clearly are so dangerous to the community that they need to be in custody for a very long time, perhaps forever. For them, the role of the arts is a humane one. It will not necessarily rehabilitate them.

Tim Robertson is chief executive of The Koestler Trust, the national charity that has awarded and exhibited art by offenders for 47 years