Department of Psychology, Tufts University, Medford, MA, USA.
Cogn Affect Behav Neurosci. 2011 Jun;11(2):245-58. doi: 10.3758/s13415-011-0020-7.
The present study investigated the contribution of lexico-semantic associations to impairments in establishing reference in schizophrenia. We examined event-related potentials as schizophrenia patients and healthy, demographically matched controls read five-sentence scenarios. Sentence 4 introduced a noun that referred back to three possible referents introduced in Sentences 1-3. These referents were contextually appropriate, contextually inappropriate but lexico-semantically associated, and contextually inappropriate and lexico-semantically nonassociated. In order to determine whether participants had correctly linked the anaphor to its referent, the final sentence reintroduced each referent, and participants indicated whether the last two sentences referred to the same entity. Results indicated that between 300 and 400 ms, patients, like healthy controls, used discourse context to link the noun with its preceding referent. However, between 400 and 500 ms, neural activity in patients was modulated only by lexico-semantic associations, rather than by discourse context. Moreover, patients were also more likely than controls to incorrectly link the noun with contextually inappropriate but lexico-semantically associated referents. These results suggest that at least some types of referential impairments may be driven by sustained activation of contextually inappropriate lexico-semantic associations.
本研究旨在探讨词汇语义联想对精神分裂症患者参照建立障碍的影响。我们让精神分裂症患者和健康的、在人口统计学上匹配的对照组阅读五个句子的情景。在句子 4 中，引入了一个名词，它与句子 1-3 中引入的三个可能的指称物相关联。这些指称物在语境中是合适的、语境中不合适但词汇语义上相关的、语境中不合适且词汇语义上不相关的。为了确定参与者是否正确地将回指词与其指称物联系起来，最后一句话重新引入了每个指称物，参与者则表明最后两句话是否指的是同一个实体。结果表明，在 300 到 400 毫秒之间，患者和健康对照组一样，利用话语语境将名词与其前面的指称物联系起来。然而，在 400 到 500 毫秒之间，患者的神经活动仅受到词汇语义联想的调节，而不是话语语境。此外，患者比对照组更有可能错误地将名词与语境不合适但词汇语义相关的指称物联系起来。这些结果表明，至少某些类型的参照障碍可能是由持续激活语境不合适的词汇语义联想引起的。
