Richard Dadd's Bedlam Visions and Van Gogh's Peasant Woman Highlight London Art Week

The Guardian's weekly art dispatch features Richard Dadd's exhibition 'Beyond Bedlam' at the Royal Academy, London, from 25 July to 25 October, showcasing his terrifying pre- and post-confinement works. Felicity Powell's dreamlike cancer documentation runs at Richard Saltoun Gallery until 3 October. 'Autopsy' at Seventeen Gallery explores UFOs and digital-age truth until 15 August. Elizabeth Blackadder's tapestries at Dovecot Studios, Edinburgh, until 14 November. Clare Woods' pastoral paintings open 29 July at Pitzhanger Manor. Image of the week reveals Ray Exworth's secret Cornish sculptures. Ken Turner, at 100, continues his rebellious art. Sheffield's Designers Republic legacy is highlighted. Trent Park House museum unveils wartime 'secret listeners'. Manifesta biennale brings community spirit to German towns. 'Entangled and Woven' textiles show dazzles. Jessica Morgan becomes Tate's new director. Masterpiece of the week is Van Gogh's 'Head of a Peasant Woman' (c.1884) at the National Gallery, London, depicting rural poverty.