Manoach Dara S, White Nathan, Lindgren Kristen A, Heckers Stephan, Coleman Michael J, Dubal Stéphanie, Goff Donald C, Holzman Philip S
Department of Psychiatry, Massachusetts General Hospital-East, Charlestown, MA 02129, USA.
Schizophr Res. 2005 Oct 1;78(1):1-12. doi: 10.1016/j.schres.2005.06.017.
Using functional MRI, we investigated whether, like healthy subjects, patients with schizophrenia show a relative hemispheric specialization in ventrolateral prefrontal cortex (PFC) for spatial and shape working memory (WM). We hypothesized that reduced specialization in schizophrenia would reflect a failure to adopt optimal domain-specific strategies and would contribute to WM deficits.
Twelve healthy subjects and 16 schizophrenia patients performed spatial and shape WM tasks and a non-WM control task. Direct comparisons of the spatial and shape WM tasks assessed specialization.
Despite deficient WM performance, both patients and controls showed a relative hemispheric specialization in ventrolateral PFC for spatial (right) and shape (left) WM and did not differ in this regard.
The finding of intact hemispheric specialization in ventrolateral PFC suggests that patients employ the same domain-specific strategies as healthy subjects during spatial and shape WM. Rather than reflecting a failure to adopt the optimal strategy, we hypothesize that WM deficits in schizophrenia reflect impairments of executive processes that are required for WM performance regardless of domain. These processes are associated with activity in the dorsolateral PFC, a region that has been repeatedly implicated in studies of WM.
利用功能磁共振成像，我们研究了精神分裂症患者是否像健康受试者一样，在腹外侧前额叶皮质（PFC）对空间和形状工作记忆（WM）表现出相对的半球特化。我们假设，精神分裂症患者特化程度降低反映出未能采用最佳的特定领域策略，这将导致工作记忆缺陷。
12名健康受试者和16名精神分裂症患者执行空间和形状工作记忆任务以及一项非工作记忆对照任务。对空间和形状工作记忆任务进行直接比较以评估特化情况。
尽管工作记忆表现存在缺陷，但患者和对照组在腹外侧前额叶皮质对空间（右侧）和形状（左侧）工作记忆均表现出相对的半球特化，在这方面并无差异。
腹外侧前额叶皮质半球特化完整这一发现表明，患者在空间和形状工作记忆过程中采用了与健康受试者相同的特定领域策略。我们推测，精神分裂症患者的工作记忆缺陷并非反映未能采用最佳策略，而是反映了工作记忆表现所需的执行过程受损，无论涉及何种领域。这些过程与背外侧前额叶皮质的活动相关，该区域在工作记忆研究中多次被提及。
