The role of the agent in sentence comprehension by preschool children

24-month-olds are surprisingly good at understanding sentences, even when they cannot say any themselves and even when the verbs are ones which they have never encountered before. Some have argued that this implies that children are born with some kind of innate bias to map the agent (ie &'doer') of the action onto the first noun in a sentence.
However, previous studies have not clarified whether successful comprehension by 2-year-olds is driven by a 'first noun = agent' bias or whether their comprehension is driven by other sentential cues.
This project investigates this issue by measuring both eye-gaze and pointing preferences of 25-month-olds, 41-month-olds and adults to one of two video clips (eg girl acts on boy on one side of the screen and boy acts on girl on the other side of the screen) whilst listening to either active transitive sentences (such as 'the girl is glorping the boy') or passive sentences (such as 'the boy is being glorped by the girl'). If participants do show a 'first noun = agent' bias, they should prefer to look at the clip in which the first-mentioned noun is the agent, but only whilst they hear the initial part of the sentence.

24月龄幼儿对语句的理解能力令人惊讶，即便他们尚无法自主说出任何语句，且即便句中动词是他们从未接触过的全新词汇。有学者据此提出，幼儿天生便具备某种先天偏向：会将动作的施动者（agent，即执行者）映射至语句中的首个名词。然而，过往研究尚未厘清：2岁幼儿的成功语句理解究竟是由「首个名词=施动者」的偏向所驱动，还是受其他语句线索的影响。本研究通过测量25月龄、41月龄幼儿与成人在聆听两类语句时，对两组视频片段（例如屏幕一侧为女孩对男孩实施动作，另一侧为男孩对女孩实施动作）的眼动注视与指向偏好，来探究这一问题。两类语句分别为主动及物句（如"the girl is glorping the boy"）与被动句（如"the boy is being glorped by the girl"）。若参与者确实表现出「首个名词=施动者」的偏向，则他们应会在聆听语句的初始部分时，更倾向于注视首提及名词为施动者的那一段视频片段。