习得年龄对客体和动作图画口语命名的不同影响：ERP研究

词汇习得年龄指人们最早理解单词意义时的年龄, 已有研究发现早习得词汇的阅读反应时间短于晚习得词汇, 研究者对于词汇习得年龄效应的认知机制存在争论。本研究运用事件相关电位技术, 考察了词汇习得年龄(早与晚)对客体图画和动作图画命名的影响。研究中采用图画命名任务, 要求被试在看到图画后迅速且准确地说出图画名称。结果发现早习得名词的命名快于晚习得名词, 而早习得动词的命名却慢于晚习得动词; 习得年龄对于名词产生的影响发生在图画呈现后的250~300 ms之间, 表现为早习得名词波幅小于晚习得名词, 而习得年龄对于动词产生的影响发生在图画呈现后的200~600 ms之间, 表现为早习得动词波幅大于晚习得动词。这表明名词产生中的习得年龄效应发生在词汇选择阶段, 支持了语义假设的观点; 动词产生过程中的习得年龄效应出现在多个加工阶段, 包括了词汇选择、音韵编码和语音编码阶段, 这与动词语义的多重性及其与动作相关的脑区激活有关, 支持了网络可塑性假说的观点。

Distinct effects of age of acquisition in Chinese object and action picture naming: An ERP study

Age of Acquisition (AoA) refers to the age at which a concept is learned. Early-acquired words have an advantage over late-acquired words in processing accuracy and speed. Which stage of AoA playing its role in spoken word production remains controversial. The phonological completeness hypothesis assumes that AoA may have a phonological locus, while the semantic hypothesis assumes that AoA affects semantic processing (i.e., conceptual preparation, lexical selection). The network plasticity hypothesis assumes that AoA arises at multiple processing levels, in spoken word production.In a picture naming task, we used the event-related potential (ERP) technique to examine the loci of AoA effect in object and action pictures naming. Twenty-eight participants (9 males, mean range: 22.18, SD: 2.56) participated in this study. We selected a total of 188 words and their corresponding black and white line pictures, half of which were object pictures, and half were action pictures. Within each type of picture, half were early acquired, and half were late acquired. Therefore, the age of acquisition of picture names (early vs. late) and word type (noun vs. verb) served as within-participants variables. During the experiment, participants were asked to name each picture as accurately and quickly as possible.Behavioral data indicated a typical AoA effect in object pictures naming, showing that object pictures corresponding to early-acquired nouns were named faster than those corresponding to late-acquired ones. In contrast, action pictures corresponding to early-acquired verbs were named slower than those corresponding to late-acquired verbs. ERP data also showed distinct AoA effect patterns in object and action picture naming. For object picture naming, late-acquired nouns elicited a larger positivity than early-acquired nouns between 250~300 ms over left-prefrontal regions. In contrast, for action picture naming, early-acquired verbs evoked a larger positivity than late-acquired verbs within 200~250 ms, 300~400 ms and 450~600 ms time windows over the left hemisphere.We suggest that the AoA effect in object naming may originate in the lexical selection of spoken word production, supporting the semantic hypothesis. In contrast, the AoA effects in action naming may originate in multiple processes, such as lexical selection, phonological encoding and phonetic encoding, supporting the network plasticity hypothesis. The distinct AoA effects between the naming of object and action pictures probably relate to the distinct semantic networks that represent objects and actions. Therefore, the AoA effect in action picture naming is much more complicated than in object picture naming and needs further investigation.