Jimenez Amy M, Lee Junghee, Wynn Jonathan K, Cohen Mark S, Engel Stephen A, Glahn David C, Nuechterlein Keith H, Reavis Eric A, Green Michael F
Desert Pacific MIRECC, VA Greater Los Angeles Healthcare System, Los AngelesCA, USA; Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los AngelesCA, USA.
Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles CA, USA.
Front Psychol. 2016 Mar 8;7:323. doi: 10.3389/fpsyg.2016.00323. eCollection 2016.
Early visual perception and attention are impaired in schizophrenia, and these deficits can be observed on target detection tasks. These tasks activate distinct ventral and dorsal brain networks which support stimulus-driven and goal-directed attention, respectively. We used single and dual target rapid serial visual presentation (RSVP) tasks during fMRI with an ROI approach to examine regions within these networks associated with target detection and the attentional blink (AB) in 21 schizophrenia outpatients and 25 healthy controls. In both tasks, letters were targets and numbers were distractors. For the dual target task, the second target (T2) was presented at three different lags after the first target (T1) (lag1 = 100 ms, lag3 = 300 ms, lag7 = 700ms). For both single and dual target tasks, patients identified fewer targets than controls. For the dual target task, both groups showed the expected AB effect with poorer performance at lag 3 than at lags 1 or 7, and there was no group by lag interaction. During the single target task, patients showed abnormally increased deactivation of the temporo-parietal junction (TPJ), a key region of the ventral network. When attention demands were increased during the dual target task, patients showed overactivation of the posterior intraparietal cortex, a key dorsal network region, along with failure to deactivate TPJ. Results suggest inefficient and faulty suppression of salience-oriented processing regions, resulting in increased sensitivity to stimuli in general, and difficulty distinguishing targets from non-targets.
精神分裂症患者的早期视觉感知和注意力受损，这些缺陷可在目标检测任务中观察到。这些任务分别激活支持刺激驱动型注意力和目标导向型注意力的不同腹侧和背侧脑网络。我们在功能磁共振成像（fMRI）期间使用单目标和双目标快速序列视觉呈现（RSVP）任务，并采用感兴趣区域（ROI）方法，以检查21名精神分裂症门诊患者和25名健康对照者中与目标检测及注意瞬脱（AB）相关的这些网络内的区域。在这两项任务中，字母为目标，数字为干扰项。对于双目标任务，第二个目标（T2）在第一个目标（T1）之后的三个不同延迟时间呈现（延迟1 = 100毫秒，延迟3 = 300毫秒，延迟7 = 700毫秒）。对于单目标和双目标任务，患者识别出的目标均少于对照者。对于双目标任务，两组均表现出预期的注意瞬脱效应，延迟3时的表现比延迟1或延迟7时更差，且不存在组间与延迟的交互作用。在单目标任务期间，患者颞顶联合区（TPJ）（腹侧网络的关键区域）出现异常增强的失活。当双目标任务中注意力需求增加时，患者顶内后皮质（背侧网络的关键区域）出现过度激活，同时TPJ未能失活。结果表明，对显著性导向处理区域的抑制效率低下且存在缺陷，导致总体上对刺激的敏感性增加，以及难以区分目标与非目标。
