AB068. Texture density aftereffect can be bidirectional

作     者：Hua-Chun Sun Frederick A.A.Kingdom Curtis L.Baker 

作者机构：McGill Vision ResearchMcGill UniversityMontréalQCCanada 

出 版 物：《Annals of Eye Science》 (眼科学年鉴（英文）)

年 卷 期：2018年第1期

页      面：474-474页

学科分类：1002[医学-临床医学] 100201[医学-内科学(含：心血管病、血液病、呼吸系病、消化系病、内分泌与代谢病、肾病、风湿病、传染病)] 10[医学] 

主　　题：Adaptation aftereffect texture texture density 

摘      要：Background:It has been suggested that adaptation to texture density only ever reduces,i.e.,never increases,perceived density,implying that density adaptation is‘uni-directional’and that texture density is coded as a scalar attribute(Durgin&Huk,1997).However,we have recently shown that simultaneous density contrast,which describes the effect of a surround texture on the perceived density of a centre region,is‘bi-directional’-that is,not only do denser surrounds reduce perceived density of the center but sparser surrounds enhance it(Sun,Baker,&Kingdom,2016).Therefore,we decided to re-examine the directionality of density ***:We measured the density aftereffect in random dot patterns using a 2AFC matching procedure that established a point-of-subjective-equality(PSE)between an adapted test patch and an unadapted match *** adaptors and test were presented at the same position,either at top left or bottom right of the *** match was presented at bottom left or top right *** positions were fixed within a block and switched between ***,using sequential presentation,we measured the density aftereffect for a wide range of adaptor and test ***:In the first experiment,we observed a unidirectional density aftereffect when test and match were presented simultaneously as in previous ***,when they were presented sequentially,bidirectionality was *** bidirectional aftereffect remained when the presentation order of test and match was reversed(second experiment).In the third experiment,we used sequential presentation to measure the density aftereffect for a wide range of adaptor densities(0-73 dots/deg2)and test densities(1.6,6.4,and 25.6 dots/deg2).We found bidirectionality for all combinations of adaptor and test densities,consistent with our previous SDC ***:In three experiments,we found that density adaptation is bidirectional when the test and match stimuli are presented s