Andrew O'Hagan talks to Matthew Sweet about identity, capturing memories and the impact of war in his new novel The Illuminations. Eddie Marsan talks about creating his character in the new film Still Life and about how much we know about a person's identity. Critic Charlotte Mullins considers the artists' obsession with capturing their image and that of their friends, as the National Portrait Gallery hosts a series of paintings by John Singer Sargent and Turner Contemporary in Margate looks at the role of the self portrait in the 21st century.