Latency and selectivity of single neurons indicate hierarchical processing in the human medial temporal lobe.
Latency and selectivity of single neurons indicate hierarchical processing in the human medial temporal lobe.
复制标题
单神经元的潜伏期和选择性表示人体内侧颞叶中的分层处理。
DOI：
10.1523/jneurosci.1640-08.2008
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发表时间：
2008-09-03
期刊：
影响因子：
--
通讯作者：
Koch C
中科院分区：
文献类型：
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作者：
Mormann F;Kornblith S;Quiroga RQ;Kraskov A;Cerf M;Fried I;Koch C
猴子和人类颞叶的神经元对各种视觉刺激，甚至对特定的个体，都表现出选择性的反应。在这项研究中，我们研究了在视觉对象呈现任务中，受试者的海马旁皮质、内嗅觉皮质、海马区和杏仁核微电极记录到的视觉反应神经元的潜伏期和选择性。在35名受试者的96次实验过程中，我们总共记录了3278个神经元。在这些单位中，398个单位对一个或多个呈现的刺激做出选择性反应。平均反应潜伏期比报告的猴子反应潜伏期要大得多。我们观察到潜伏期和这些神经元的选择性之间存在高度显著的相关性：潜伏期越长，选择性越强。特别是，发现海马区旁神经元的反应比其他三个区域的反应更早，选择性更低。区域分析显示，潜伏期和选择性在海马旁皮质、内嗅觉皮质和海马区显著相关，但在杏仁核内没有相关性。基线放电频率稀疏的细胞倾向于产生较晚和更具选择性的反应，反之亦然。我们的结果为感觉信息在视觉通路和边缘系统之间的界面上的分层处理提供了直接证据，通过该接口，随着时间的推移，沿着内侧颞叶的解剖通路产生了日益精细和具体的刺激身份表征。
Neurons in the temporal lobe of both monkeys and humans show selective responses to classes of visual stimuli and even to specific individuals. In this study, we investigate the latency and selectivity of visually responsive neurons recorded from microelectrodes in the parahippocampal cortex, entorhinal cortex, hippocampus, and amygdala of human subjects during a visual object presentation task. During 96 experimental sessions in 35 subjects, we recorded from a total of 3278 neurons. Of these units, 398 responded selectively to one or more of the presented stimuli. Mean response latencies were substantially larger than those reported in monkeys. We observed a highly significant correlation between the latency and the selectivity of these neurons: the longer the latency the greater the selectivity. Particularly, parahippocampal neurons were found to respond significantly earlier and less selectively than those in the other three regions. Regional analysis showed significant correlations between latency and selectivity within the parahippocampal cortex, entorhinal cortex, and hippocampus, but not within the amygdala. The later and more selective responses tended to be generated by cells with sparse baseline firing rates and vice versa. Our results provide direct evidence for hierarchical processing of sensory information at the interface between the visual pathway and the limbic system, by which increasingly refined and specific representations of stimulus identity are generated over time along the anatomic pathways of the medial temporal lobe.