Neural correlates of short-term memory in primate auditory cortex.
Neural correlates of short-term memory in primate auditory cortex.
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DOI：
10.3389/fnins.2014.00250
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发表时间：
2014
影响因子：
4.3
通讯作者：
Poremba A
中科院分区：
文献类型：
--
作者：
Bigelow J;Rossi B;Poremba A
与行为相关的声音，如同种发声，通常只在很短的时间内可用；因此，目标导向行为往往依赖于听觉短期记忆(STM)。尽管它具有生态学意义，但听觉STM背后的神经过程仍然知之甚少。为了研究听觉皮层在短时记忆中的作用，记录了两只猴子初级听觉皮质(A1)的单个和多个单位的活动，这些猴子使用简单和复杂的声音执行听觉短时记忆任务。每个试验由样本和测试刺激组成，中间以5-S保留间隔隔开。在测试刺激之后有一段短暂的等待期，之后，如果声音相同，受试者按下按钮(匹配试验)，如果声音不同，受试者按下按钮(非匹配试验)。一些单位在保留间隔的部分时间内表现出显著的射速变化，尽管这些变化很少持续。相反，它们最常在保留间隔的早期和晚期被观察到，抑制比兴奋更频繁地被观察到。在种群水平上，与非匹配试验相比，在配对试验中引起的反应在声音时期的早期被短暂抑制。然而，在声音的后半部分，比赛试射的射击率显著增加，并在整个等待期保持较高水平。在我们实验室以前的实验中，我们观察到了相同动物的背侧颞极(DTP)和前额叶皮质(PFC)的相关活动模式。数据表明，早期的匹配抑制发生在A1和DTP中，而后期的匹配增强首先发生在PFC中，然后是A1，最后发生在DTP中。由于匹配增强首先发生在PFC中，我们推测在A1和DTP中观察到的增强可能反映了自上而下的反馈。总体而言，我们的发现表明，A1形成了在听觉STM过程中招募的更大神经系统的一部分。
Behaviorally-relevant sounds such as conspecific vocalizations are often available for only a brief amount of time; thus, goal-directed behavior frequently depends on auditory short-term memory (STM). Despite its ecological significance, the neural processes underlying auditory STM remain poorly understood. To investigate the role of the auditory cortex in STM, single- and multi-unit activity was recorded from the primary auditory cortex (A1) of two monkeys performing an auditory STM task using simple and complex sounds. Each trial consisted of a sample and test stimulus separated by a 5-s retention interval. A brief wait period followed the test stimulus, after which subjects pressed a button if the sounds were identical (match trials) or withheld button presses if they were different (non-match trials). A number of units exhibited significant changes in firing rate for portions of the retention interval, although these changes were rarely sustained. Instead, they were most frequently observed during the early and late portions of the retention interval, with inhibition being observed more frequently than excitation. At the population level, responses elicited on match trials were briefly suppressed early in the sound period relative to non-match trials. However, during the latter portion of the sound, firing rates increased significantly for match trials and remained elevated throughout the wait period. Related patterns of activity were observed in prior experiments from our lab in the dorsal temporal pole (dTP) and prefrontal cortex (PFC) of the same animals. The data suggest that early match suppression occurs in both A1 and the dTP, whereas later match enhancement occurs first in the PFC, followed by A1 and later in dTP. Because match enhancement occurs first in the PFC, we speculate that enhancement observed in A1 and dTP may reflect top–down feedback. Overall, our findings suggest that A1 forms part of the larger neural system recruited during auditory STM.
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影响因子：
3.7
作者：
Bigelow J;Poremba A
通讯作者：
Poremba A
影响因子：
2.9
作者：
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Procyk, Emmanuel
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2
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Trouche, E
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Curtis, CE
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