ness ▁of ▁treatment , ▁form ▁and ▁material ”. ▁In ▁ 1 9 7 6 ▁Pet ry ▁exhib ited ▁in ▁the ▁Musée ▁d ' art ▁contempor ain ▁de ▁Montr éal ' s ▁group ▁show ▁Cent ▁On ze ▁D ess ins ▁du ▁Québec . ▁The ▁following ▁year ▁the ▁National ▁Gallery ▁of ▁Canada ▁tou red ▁One ▁H undred ▁and ▁Ele ven ▁Draw ings ▁of ▁Quebec ▁across ▁Canada . ▁ ▁In ▁the ▁mid - 7 0 s , ▁Pet ry ' s ▁art ▁evol ved ▁to ▁include ▁happen ings , ▁art ▁inter vent ions ▁and ▁new ▁media . ▁In ▁ 1 9 7 5 , ▁she ▁joined ▁the ▁artist - run ▁Vé h ic ule ▁Art , ▁Montreal ' s ▁first ▁parallel ▁gallery ▁for ▁alternative ▁art ▁including ▁installation , ▁performance ▁and ▁multi - media ▁art . ▁In ▁ 1 9 7 8 , ▁she ▁attended ▁a ▁ 1 6 mm ▁film - making ▁course ▁conducted ▁by ▁Jen ny ▁Ok un ▁at ▁the ▁London ▁Film - M akers ' ▁Co - op ▁and ▁began ▁incorpor ating ▁film ▁into ▁her ▁art . ▁In ▁ 1 9 7 9 ▁she ▁created ▁The ▁Sh adow ▁Figure , ▁collabor ating ▁with ▁d anc ers ▁Éd ou ard ▁Lock ▁and ▁Mich elle ▁F è b vre ▁at ▁Ve h ic ule ▁Art , ▁and ▁Les ▁N ai ades ▁with ▁dan cer ▁Bon nie ▁Far mer ▁at ▁Con cord ia ▁University ▁( Mont real ) ▁in ▁ 1 9 9 4 . ▁Her ▁participation ▁in ▁performance ▁art ▁resulted ▁in ▁what ▁critic ▁Jacques - B