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数量化维度的特征搜索

Feature Search on Quantitative Dimension

【作者】 马艳云

【导师】 沈模卫;

【作者基本信息】 浙江大学 , 应用心理学, 2001, 博士

【摘要】 Treisman和Gelade(1980)提出了注意的特征整合理论,视觉搜索研究是该理论研究的主要组成部分。视觉搜索包括特征搜索和联合搜索。特征搜索处于前注意加工水平,属平行加工;联合搜索是在特征搜索的基础上进行的注意加工,属系列加工。特征搜索主要包括颜色维度、数量化维度的搜索,其中数量化维度的特征搜索占有重要的地位。 根据以往的理论探索和实证研究,笔者指出在数量化维度的特征搜索研究中目前仍然存在两个主要问题:(1)对决定目标搜索斜率的主要因素的确定;(2)从刺激的物理属性出发,对区分平行搜索和系列搜索之间的临界点的确定。 为了解决上述问题,笔者引入目标值(T)和干扰子值(D)的差值与干扰子值的比值C(C=(T-D)/D),提出了以下三个假设:(1)目标搜索斜率对C值绝对值的函数是单调递减函数;(2)当C值相同时,其目标搜索斜率应相等;(3)当|C|≥|C_p|时,目标搜索是平行搜索,否则为系列搜索。上述假设不受刺激形状的影响。 研究一通过两种刺激形状(圆和三角形)分两个实验假设1和假设2进行了检验。实验发现在目标大于干扰子条件下,目标搜索斜率对C值的函数是单调递减函数;C相等时的目标搜索斜率也相等;C相等时的圆和三角形两种刺激形状之间的目标搜索斜率无显著差异。 研究二针对目标圆大于干扰子圆大的条件,得到的目标搜索斜率对C值的函数也是单调递减函数,并确定了平行搜索与系列搜索的临界点C_p(0.497)。当C≥0.497时的目标搜索是平行搜索,即目标搜索斜率小于或等于10毫秒/项目;当C<0.497时的目标搜索是系列搜索,即目标搜索斜率大于10毫秒/项目。 研究三对目标圆小于干扰子圆的条件进行了研究。结果发现目标搜索斜率对C值的函数是单调递增函数。在该条件下的平行搜索与系列搜索的临界点C_p为-0.57。当C>-0.57时的目标搜索是系列搜索,即目标搜索斜率大于10毫秒/项目;C≤-0.57时的目标搜索是平行搜索,即目标搜索斜率小于或等于10毫秒/项目。 研究四在研究二和研究三所得到的平行搜索范围内,通过随机选取某个C值,以检验在该范围内的目标搜索是否为平行搜索。该实验发现,在该种实验条件下,目标与干扰子互换角色,二者的目标搜索斜率无显

【Abstract】 Treisman and Gelade (1980) have put forward a Feature-Integration Theory of Attention (FIT). Visual search is an important part of FIT. It includes feature search and conjunction search. Feature search is at the preattentive processing stage and belongs to parallel processing. Conjunction search is at the attentive processing stage on the basis of feature search and attributes to serial processing. Feature search mainly contains searches on quantitative dimension and color dimension. Feature search on quantitative dimension plays an important role.Two questions on quantitative dimension that are not resolved at present are put forward according to some theories and researchers’ results. The questions are as follows: (1) Main factor that decides search slopes is determined. (2) Critical point that differentiates parallel search and serial search is fixed from physical property of stimuli.After a ratio(C) is drawn into, three hypotheses are given in order to solve the two questions. The ratio C is difference between target value(T) and distractors values(D) divided by distractors values. Three hypotheses are as follows: (1) A function of slopes to C absolute values is monotone decreasing function. (2) Slopes are equal when C values are same. (3) If C absolute value is bigger than C_p absolute value, searching for a target is parallel search, or is serial search. Moreover, forms of stimuli do not affect truth of these hypotheses.Two experiments in the first research examine the first and second hypothesis by circle and triangle stimuli. When target values are bigger than distractors values, the two experiments have found that a function of slopes to C values is monotone decreasing function, that slopes are identical under same C values, and that there is no significant difference between circles stimulus and triangles stimulus under same C values.The second research has also got that a function of slopes to C values is monotone decreasing function when target circles are bigger than distractors circles. The critical point between parallel and serial search is C_p=0.497. Searching for a target is parallel when C≥0.497. That is, slope isequal to or smaller than lOmsec/item. Searching for a target is serial when C<0.497. That is, slope is bigger than lOmsec/item.Target circles are smaller than distractors circles in the third research. The research has attained that a function of slopes to C values is monotone increasing function. The critical point between parallel and serial search is Cp=-0.57. Searches targets are serial when O-0.57. That is, slopes are bigger than lOmsec/item. Searches targets are parallel when C<-0.57. That is, slopes are equal to or smaller than lOmsec/itemFinally, a C value is randomly chosen within parallel search ranges of the second and third researches in order to test whether searches within the range are parallel search. Two slopes that experiment 4 has got before and after target and distractors are interchanged have no significant difference. Moreover, searches are symmetry when C values belong to parallel search ranges.Four researches and discussion are summarized. Main results are as follows: (1) Slopes are explained by "relative difference" concept more reasonable than "absolute difference" concept. (2) Hit rates and false alarm rates decrease when C values are small and set sizes are large (12 items). Signal Detection Theory and capacity of short-term memory (7±2) explaine the phenomenon. (3) The ratios of absent-target slopes to present-target slopes are nearly 2.0.

  • 【网络出版投稿人】 浙江大学
  • 【网络出版年期】2006年 11期
  • 【分类号】B842.2
  • 【下载频次】185
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