Leibniz-Institut für Neurobiologie, Magdeburg, Germany.
J Cogn Neurosci. 2013 Sep;25(9):1517-26. doi: 10.1162/jocn_a_00413. Epub 2013 May 6.
Synchronized neuronal firing in cortex has been implicated in feature binding, attentional selection, and other cognitive processes. This study addressed the question whether different cortical fields are distinct by rules according to which neurons engage in synchronous firing. To this end, we simultaneously recorded the multiunit firing at several sites within the primary and the caudomedial auditory cortical field of anesthetized macaque monkeys, determined their responses to pure tones, and calculated the cross-correlation function of the spontaneous firing of pairs of units. In the primary field, the likelihood of synchronous firing of pairs of units increased with the similarity of their frequency tuning and their response latencies. In the caudomedial field, by contrast, the likelihood of synchronization was highest when pairs of units had an octave and other harmonic relationships and when units had different response latencies. The differences in synchrony of the two fields were not paralleled by differences in distributions of best frequency, bandwidth of tuning curves, and response latency. Our findings suggest that neuronal synchrony in different cortical fields may underlie the establishment of specific relationships between the sound features that are represented by the firing of the neurons and which follow the Gestalt laws of similarity in the primary field and good continuation in the caudomedial field.
皮层中神经元的同步放电与特征绑定、注意选择和其他认知过程有关。本研究旨在探讨不同的皮层区域是否按照神经元参与同步放电的规则来区分。为此，我们在麻醉猕猴的初级和尾侧听觉皮层内的几个部位同时记录多单位放电，确定它们对纯音的反应，并计算成对单位自发放电的互相关函数。在初级皮层中，成对单位同步放电的可能性随着频率调谐和反应潜伏期的相似性而增加。相比之下，在尾侧听觉皮层中，当成对的单位具有八度和其他谐波关系并且单位具有不同的反应潜伏期时，同步的可能性最高。两个区域的同步性差异与最佳频率分布、调谐曲线带宽和反应潜伏期的差异不平行。我们的发现表明，不同皮层区域的神经元同步可能是由神经元放电所代表的声音特征之间建立特定关系的基础，这些关系遵循初级区域中的相似性格式塔法则和尾侧听觉皮层中的良好延续性。
