Clark Kelsey L, Noudoost Behrad, Moore Tirin
Montana State University.
J Cogn Neurosci. 2014 Jun;26(6):1292-9. doi: 10.1162/jocn_a_00599. Epub 2014 Mar 27.
We previously reported the existence of a persistent spatial signal in the FEF during object-based STM. This persistent activity reflected the location at which the sample appeared, irrespective of the location of upcoming targets. We hypothesized that such a spatial signal could be used to maintain or enhance object-selective memory activity elsewhere in cortex, analogous to the role of a spatial signal during attention. Here, we inactivated a portion of the FEF with GABAa agonist muscimol to test whether the observed activity contributes to object memory performance. We found that, although RTs were slowed for saccades into the inactivated portion of retinotopic space, performance for samples appearing in that region was unimpaired. This contrasts with the devastating effects of the same FEF inactivation on purely spatial working memory, as assessed with the memory-guided saccade task. Thus, in a task in which a significant fraction of FEF neurons displayed persistent, sample location-based activity, disrupting this activity had no impact on task performance.
我们之前报道过，在基于物体的短时记忆期间，额眼区（FEF）存在持续的空间信号。这种持续活动反映了样本出现的位置，而与即将出现的目标位置无关。我们推测，这样的空间信号可用于维持或增强皮层其他部位的物体选择性记忆活动，类似于注意力期间空间信号的作用。在此，我们用GABAA激动剂蝇蕈醇使部分额眼区失活，以测试观察到的活动是否有助于物体记忆表现。我们发现，尽管扫视进入视网膜空间失活部分的反应时间变慢，但出现在该区域的样本的表现并未受损。这与用记忆引导扫视任务评估的相同额眼区失活对纯空间工作记忆的破坏性影响形成对比。因此，在一项任务中，相当一部分额眼区神经元表现出持续的、基于样本位置的活动，破坏这种活动对任务表现没有影响。
