Iacoboni M, Rayman J, Zaidel E
Department of Neurology, UCLA School of Medicine, University of California 90095, USA.
Neuropsychologia. 1997 Jan;35(1):81-8. doi: 10.1016/s0028-3932(96)00071-1.
We investigated the effect of previous trial variables on performance in the current trial in a lexical decision task with unilateral presentation of one letter string or bilateral simultaneous presentation of two different letter strings, one cued to be processed (target) and the other uncued, to be ignored (distractor). The variables included correctness of the previous trial, visual hemifield and wordness of the previous trial, and presentation mode of the previous trial (unilateral or bilateral). An incorrect response on the previous trial enhanced the accuracy in the current trial only in the left visual field (LVF). A previous LVF target produced faster correct responses to LVF targets in the current trial and LVF word recognition was more accurate when the previous LVF target was a word rather than a nonword. Target processing in the current trial was not inhibited or facilitated if the target belonged to the same response category as the unattended stimulus in the previous trial (absence of "negative priming'). Taken together, our data suggest that previous trial effects in lateralized lexical decision are stronger for word decisions in the LVF, and may account for the inconsistency of the wordness effect in the LVF across different lateralized lexical decision experiments. Our data also suggest that behavioral laterality experiments are well advised to use random sequences that change across subjects in order to minimize previous trial effects.
我们在一项词汇判断任务中研究了先前试验变量对当前试验表现的影响。该任务中，字母串单侧呈现一个，或者双侧同时呈现两个不同的字母串，其中一个被提示进行加工（目标），另一个未被提示，需被忽略（干扰项）。这些变量包括先前试验的正确性、先前试验的视觉半视野和词汇性，以及先前试验的呈现模式（单侧或双侧）。先前试验中的错误反应仅在左视野（LVF）中提高了当前试验的准确性。先前的左视野目标在当前试验中对左视野目标产生更快的正确反应，并且当先前的左视野目标是一个单词而非非单词时，左视野单词识别更准确。如果当前试验中的目标与先前试验中未被注意的刺激属于同一反应类别，则当前试验中的目标加工不会受到抑制或促进（不存在“负启动”）。综合来看，我们的数据表明，在侧化词汇判断中，先前试验效应在左视野的单词判断中更强，这可能解释了不同侧化词汇判断实验中左视野词汇性效应的不一致性。我们的数据还表明，行为侧化实验最好使用在不同受试者间变化的随机序列，以尽量减少先前试验效应。
