Laurens Kristin R, Kiehl Kent A, Liddle Peter F
Department of Forensic Mental Health Science, Institute of Psychiatry, King's College London, University of London, London, United Kingdom.
Hum Brain Mapp. 2005 Jan;24(1):35-49. doi: 10.1002/hbm.20062.
Limited processing resources are allocated preferentially to events that are relevant for behavior. Research using the novelty "oddball" paradigm suggests that a widespread network of limbic, paralimbic, and association areas supports the goal-directed processing of task-relevant target events. In that paradigm, greater activity in diverse brain areas is elicited by rare task-relevant events that require a subsequent motor response than by rare task-irrelevant novel events that require no response. Both stimulus infrequency (unexpectedness) and novelty, however, may contribute to the pattern of activity observed using that paradigm. The goal of the present study was to examine the supramodal neural activity elicited by regularly occurring, equiprobable, and non-novel stimuli that differed in the subsequent behavior they prescribed. We employed event-related functional magnetic resonance imaging (fMRI) during auditory and visual versions of a Go/NoGo task. Participants made a motor response to the designated "Go" (target) stimulus, and no motor response to the equiprobable "NoGo" (nontarget) stimulus. We hypothesized that task-relevant Go events would elicit relatively greater hemodynamic activity than would NoGo events throughout a network of limbic, paralimbic, and association areas. Indeed, Go events elicited greater activity than did NoGo events in the amygdala-hippocampus, paralimbic cortex at the anterior superior temporal sulcus, insula, posterior orbitofrontal cortex, and anterior and posterior cingulate cortex, as well as in heteromodal association areas located at the temporoparietal junction, anterior intraparietal sulcus and precuneus, and premotor cortex. Paralimbic cortex offers an important site for the convergence of motivational/goal-directed influences from limbic cortex with stimulus processing and response selection mediated within the frontoparietal areas.
有限的加工资源会优先分配给与行为相关的事件。使用新奇“oddball”范式的研究表明，一个广泛的边缘系统、边缘旁系统和联合区域网络支持对与任务相关的目标事件进行目标导向的加工。在该范式中，与不需要反应的罕见任务无关的新奇事件相比，需要后续运动反应的罕见任务相关事件会在不同脑区引发更大的活动。然而，刺激的低频性（意外性）和新奇性都可能导致使用该范式观察到的活动模式。本研究的目的是检查由定期出现、等概率且不新奇的刺激引发的超模态神经活动，这些刺激在它们规定的后续行为上有所不同。我们在听觉和视觉版本的Go/NoGo任务中采用了事件相关功能磁共振成像（fMRI）。参与者对指定的“Go”（目标）刺激做出运动反应，而对等概率的“NoGo”（非目标）刺激不做出运动反应。我们假设与任务相关的Go事件在整个边缘系统、边缘旁系统和联合区域网络中会比NoGo事件引发相对更大的血流动力学活动。事实上，Go事件在杏仁核 - 海马体、颞上沟前部的边缘旁皮质、脑岛、眶额后皮质以及前扣带回和后扣带回皮质，以及位于颞顶交界处、顶内沟前部和楔前叶以及运动前皮质的异模态联合区域中引发的活动比NoGo事件更大。边缘旁皮质为来自边缘皮质的动机/目标导向影响与额顶叶区域内介导的刺激加工和反应选择的汇聚提供了一个重要位点。
