Wilson Lisa B, Rojas Donald C, Shatti Shireen, Tregellas Jason R
Department of Psychiatry, University of Colorado Denver, Aurora 80045, USA.
Neuroreport. 2013 Mar 27;24(5):212-6. doi: 10.1097/WNR.0b013e32835eb688.
A core feature of schizophrenia is a disturbance of associative processes. To date, no functional MRI studies have investigated semantic priming in schizophrenia under experimental conditions that measure automatic, as opposed to strategic, processing. The present study's focus was to investigate hemodynamic responses during indirect semantic priming at a short stimulus onset asynchrony (i.e., 350 ms), conditions which are considered to be a particularly sensitive measure of automatic spreading activation during semantic processing and of the associative disturbances in schizophrenia. Seventeen individuals with DSM-IV, schizophrenia and 15 comparison participants underwent functional scanning while performing a lexical decision task on directly related, indirectly related, unrelated, and word/nonword pairs. A random-effects region of interest analysis within a priori temporal and frontal regions was performed. Whereas comparison individuals exhibited hemodynamic suppression in response to priming, individuals with schizophrenia exhibited hemodynamic enhancement. Relative to the comparison group, these enhancements were observed in the left fusiform and superior temporal gyri for indirectly related word pairs relative to unrelated pairs. Greater priming-related responses within temporal regions may reflect increased and prolonged automatic spreading activation during semantic processing in schizophrenia.
精神分裂症的一个核心特征是联想过程紊乱。迄今为止，尚无功能磁共振成像研究在测量自动而非策略性加工的实验条件下，对精神分裂症患者的语义启动进行调查。本研究的重点是在短刺激起始异步（即350毫秒）的间接语义启动过程中，调查血液动力学反应，这种条件被认为是语义加工过程中自动扩散激活以及精神分裂症联想紊乱的一种特别敏感的测量方法。17名符合《精神疾病诊断与统计手册第四版》（DSM-IV）标准的精神分裂症患者和15名对照参与者在对直接相关、间接相关、不相关以及单词/非单词对执行词汇判断任务时接受了功能扫描。在先验的颞叶和额叶区域内进行了随机效应感兴趣区分析。对照个体在启动时表现出血液动力学抑制，而精神分裂症患者则表现出血液动力学增强。相对于对照组，在左侧梭状回和颞上回中，间接相关单词对比不相关单词对表现出更大的启动相关反应。颞叶区域内更大的启动相关反应可能反映了精神分裂症患者在语义加工过程中自动扩散激活的增加和延长。
