Arcuri S M, Broome M R, Giampietro V, Amaro E, Kircher T T J, Williams S C R, Andrew C M, Brammer M, Morris R G, McGuire P K
Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, UK.
Schizophr Res Treatment. 2012;2012:176290. doi: 10.1155/2012/176290. Epub 2012 Apr 19.
Formal thought disorder is a feature schizophrenia that manifests as disorganized, incoherent speech, and is associated with a poor clinical outcome. The neurocognitive basis of this symptom is unclear but it is thought to involve an impairment in semantic processing classically described as a loosening of meaningful associations. Using a paradigm derived from the n400 event-related, potential, we examined the extent to which regional activation during semantic processing is altered in schizophrenic patients with formal thought disorder. Ten healthy control and 18 schizophrenic participants (9 with and 9 without formal thought disorder) performed a semantic decision sentence task during an event-related functional magnetic resonance imaging experiment. We employed analysis of variance to estimate the main effects of semantic congruency and groups on activation and specific effects of formal thought disorder were addressed using post-hoc comparisons. We found that the frontotemporal network, normally engaged by a semantic decision task, was underactivated in schizophrenia, particularly in patients with FTD. This network is implicated in the inhibition of automatically primed stimuli and impairment of its function interferes with language processing and contributes to the production of incoherent speech.
形式思维障碍是精神分裂症的一个特征，表现为言语紊乱、不连贯，且与不良临床预后相关。该症状的神经认知基础尚不清楚，但据认为涉及语义加工受损，传统上被描述为有意义联想的松散。我们使用源自N400事件相关电位的范式，研究了语义加工过程中区域激活在伴有形式思维障碍的精神分裂症患者中改变的程度。10名健康对照者和18名精神分裂症参与者（9名有形式思维障碍，9名无形式思维障碍）在一项事件相关功能磁共振成像实验中执行语义判断句子任务。我们采用方差分析来估计语义一致性和组别对激活的主要影响，并使用事后比较来探讨形式思维障碍的特定影响。我们发现，通常参与语义判断任务的额颞叶网络在精神分裂症中激活不足，尤其是在伴有形式思维障碍的患者中。该网络与自动启动刺激的抑制有关，其功能受损会干扰语言加工，并导致不连贯言语的产生。
