Context is everything when it comes to Gaylen Gerber’s ‘collaborative’ artworks, including this Nigerian cowrie shell currency basket and a Makonde mask from Mozambique/Tanzania from mid-20th century, which the artist has titled ‘Support’ and covered in white oil paint. Questions of whose work is whose and whether Gerber is defacing, erasing or enhancing the ‘supports’ mingles with thoughts of Picasso, et al’s appropriation of African art, all to provocative effect. (At Chelsea’s Wallspace Gallery through Feb 9th).