Hayward Gallery, London, 10 June – 6 September 2015
German scientist-turned-artist Carsten Höller challenges us to conduct our own experiments in the highly sensory environments of his exhibitions. Questioning logic and certainty at every turn, his show Decision at the Hayward presents a funfair of forking paths, mirrored reflections and recurring motifs of doubles and twins. From a flying machine that simulates the sensation of soaring across Waterloo Bridge to a pair of giant slides that cascade down the gallery’s exterior wall, Decision is determined as much by the viewer’s willingness to participate as it is the artist’s otherworldly concepts.

RIBA, London, 10 June – 16 August 2015
Last year, art and design collective Assemble unveiled Glasgow’s Baltic Street Adventure Playground for the 2014 Commonwealth Games, which turned an urban landscape into a space for imagination, excitement and risk. Now, in a new collaboration with artist Simon Terrill, the Turner Prize-nominated group recreate playgrounds from archival images of Britain’s Brutalist post-war housing estates. With the original bush-hammered concrete substituted by foam, RIBA’s latest installation alters perceptions of public space and reimagines what it means to play.

De La Warr Pavilion, Bexhill-on-Sea, 13 June – 6 September 2015
The vibrancy of colour and rhythm in Bridget Riley’s technically brilliant Op Art artworks have set her apart in British art. This summer, to celebrate its 80th anniversary, the De La Warr Pavilion examines Riley’s use of the curve motif, in an exhibition designed to create a harmony between her painting, the Pavilion’s Modernist architecture and the sea beyond. Works such as Rajasthan (2012; below) can be seen for the first time outside Germany alongside early black-and-white experimentations, to illusory and disorientating effect.

National Portrait Gallery, London, 11 June – 28 September 2015
Since graduating from Glasgow School of Art in 1991, Chantal Joffe RA and Ishbel Myerscough have shared a love for portraiture, a close friendship, and now, their first collaboration together, at the National Portrait Gallery. Although each artist has developed their own individual style of painting over the years – Myerscough painting with an honest realism and Joffe employing energetic brushstrokes to animate her female figures – both artists’ works are an intimate reflection on motherhood and friendship, many of which have yet to meet the public’s eye.

The National Gallery, London, 13 June – 8 November 2015
This summer the National Gallery initiates a dialogue between two works of art made almost 700 years apart: the Annunciation (1307) by Sienese painter Duccio and Duccio Variations No. 3 (1999-2000), one of seven sculptures made in response to Duccio’s painting by Sir Anthony Caro RA, a titanic figure in modern British sculpture. The unlikely pairing of Duccio and Caro encourages the viewer to appreciate both works in a fresh light, drawing more general comparisons between recent work and the art of the past.