ald ▁S inc la ir . ▁S acks ▁rec alls , ▁" I ▁had ▁been ▁s edu ced ▁by ▁a ▁series ▁of ▁v ivid ▁lect ures ▁on ▁the ▁history ▁of ▁medicine ▁and ▁nut r ition , ▁given ▁by ▁S inc la ir ." ▁S acks ▁adds , ▁" And ▁now , ▁in ▁S inc la ir ' s ▁lect ures , ▁it ▁was ▁the ▁history ▁of ▁phys i ology , ▁the ▁ideas ▁and ▁personal ities ▁of ▁phys i olog ists , ▁which ▁came ▁to ▁life ." ▁S acks ▁then ▁became ▁involved ▁with ▁the ▁school ' s ▁Labor atory ▁of ▁Human ▁N ut r ition ▁under ▁S inc la ir . ▁S acks ▁focused ▁his ▁research ▁on ▁J ama ica ▁g inger , ▁a ▁to xic ▁and ▁commonly ▁ab used ▁drug ▁known ▁to ▁cause ▁irre vers ible ▁n erve ▁damage . ▁After ▁dev oting ▁months ▁to ▁research , ▁he ▁was ▁disappoint ed ▁by ▁the ▁lack ▁of ▁help ▁and ▁guidance ▁he ▁received ▁from ▁S inc la ir . ▁S acks ▁wrote ▁up ▁an ▁account ▁of ▁his ▁research ▁find ings ▁but ▁stopped ▁working ▁on ▁the ▁subject . ▁As ▁a ▁result ▁he ▁became ▁de pressed : ▁" I ▁felt ▁myself ▁s inking ▁into ▁a ▁state ▁of ▁quiet ▁but ▁in ▁some ▁ways ▁ag itated ▁desp air ." ▁His ▁t utor ▁at ▁Queen ' s ▁and ▁his ▁parents , ▁seeing ▁his ▁lower ed ▁emot ional ▁state , ▁suggested ▁he ▁extr icate ▁himself ▁from ▁academic ▁studies ▁for ▁a ▁period . ▁His ▁parents ▁then ▁suggested ▁he ▁spend ▁the ▁summer ▁of ▁