The Oscar-winner received a doctorate from Stirling University, where a dementia studies centre is named after Murdoch – who developed the condition towards the end of her life.
Dame Judi opened the unit in 2003 before returning yesterday to pick up an honour for her stage, TV and film work.
She said: “Dementia is an issue close to my heart. Playing Iris Murdoch in Iris was one of my most challenging roles, but also one of the most important as it broadened my understanding of the issues facing those who develop dementia.
“Coming back to the university, it is so encouraging to see the myriad of ways the centre and its staff have informed practice and made a positive difference to people’s lives.”
Dame Judi won a Bafta in 2002 for her portrayal of Murdoch, writer of novels such as The Black Prince and The Sea, The Sea, which won the Booker in 1978.