Human gamma band activity and perception of a gestalt
Human gamma band activity and perception of a gestalt
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DOI：
10.1523/jneurosci.19-16-07152.1999
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发表时间：
1999-08-15
影响因子：
5.3
通讯作者：
Elbert, T
中科院分区：
文献类型：
--
作者：
Keil, A;Müller, MM;Elbert, T
伽马波段（30赫兹以上）的神经元振荡被认为是物体视觉表征的可能机制。本研究考察了旋转模糊（双稳）图形所影响的感知转换的伽马波段频谱功率和事件相关电位的地形图。11名健康的人类受试者被展示了两个旋转的双稳态图形：首先，一个人脸图形允许根据方向感知悲伤或快乐的脸，因此在旋转时在定义的时间点引起感知切换；其次，一个修改版本的鲁宾花瓶，允许感知花瓶或两张脸，因此开关是方向无关的。非旋转图形作为进一步的控制刺激。采用128个电极的高密度阵列记录脑电图。我们发现消极事件相关电位与悲伤-快乐图形的转换有关，这在前额叶中央部位最为明显。与站立刺激相比，旋转双稳人像枕部电极部位的伽马带活性（GBA）增强，在垂直刺激方向上的伽马带活性最大，这使得人们更容易分别识别悲伤和快乐的脸或花瓶脸。在前电极，GBA呈现互补模式，当刺激水平方向时最大。这一发现支持了视觉感知的形成可能涉及分布式神经元组装的振荡的观点。
Neuronal oscillations in the gamma band (above 30 Hz) have been proposed to be a possible mechanism for the visual representation of objects. The present study examined the topography of gamma band spectral power and event-related potentials in human EEG associated with perceptual switching effected by rotating ambiguous (bistable) figures. Eleven healthy human subjects were presented two rotating bistable figures: first, a face figure that allowed perception of a sad or happy face depending on orientation and therefore caused a perceptual switch at defined points in time when rotated, and, second, a modified version of the Rubin vase, allowing perception as a vase or two faces whereby the switch was orientation-independent. Nonrotating figures served as further control stimuli. EEG was recorded using a high-density array with 128 electrodes. We found a negative event-related potential associated with the switching of the sad-happy figure, which was most pronounced at central prefrontal sites. Gamma band activity (GBA) was enhanced at occipital electrode sites in the rotating bistable figures compared with the standing stimuli, being maximal at vertical stimulus orientations that allowed an easy recognition of the sad and happy face or the vase-faces, respectively. At anterior electrodes, GBA showed a complementary pattern, being maximal when stimuli were oriented horizontally. The findings support the notion that formation of a visual percept may involve oscillations in a distributed neuronal assembly.