Activation of the human occipital and parietal cortex by pattern and luminance stimuli: Neuromagnetic measurements
Activation of the human occipital and parietal cortex by pattern and luminance stimuli: Neuromagnetic measurements
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DOI：
10.1093/cercor/8.3.253
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发表时间：
1998-04-01
期刊：
影响因子：
3.7
通讯作者：
Hari, R
中科院分区：
文献类型：
--
作者：
Portin, K;Salenius, S;Hari, R
我们通过记录10名受试者的诱发反应和自发脑节律，用全头皮神经磁力计比较了皮质对模式和亮度刺激的反应。半球模式（黑色和白色棋盘）引起强烈的对侧枕叶V1/V2皮层的短暂激活，最大值在65-75 ms，随后在2 s刺激期间持续激活。对半野亮度刺激的反应也有枕部成分，但它们主要由内侧顶枕沟（POS）60-70 ms后的激活。POS区域同样很好地激活中心凹和中心凹外的刺激。枕叶对半场亮度刺激的反应与对模式刺激的反应在两个主要方面不同：持续激活明显较弱，并且反应几乎是对称的，这表明令人惊讶的双侧枕叶激活。这些效果与中心凹酸外中心凹刺激相似。自发的10 Hz α节律，起源主要在POS区域，被抑制后，刺激发作和偏移，更强烈的亮度比图案刺激。模式刺激后枕叶皮层的激活占主导地位，而亮度刺激的效果更强的顶枕区。枕叶和POS区域的不同信号分布表明，这两种类型的刺激激活大细胞和小细胞途径在不同程度上。这些发现也与亮度比图案刺激具有更强的吸引注意力的值相一致。
We compared cortical reactivity to pattern and luminance stimuli by recording evoked responses and spontaneous brain rhythms from 10 subjects with a whole-scalp neuromagnetometer. Hemifield patterns (black-and-white checkerboards) elicited strong contralateral transient activation of the occipital V1/V2 cortex, maximum at 65-75 ms, followed by sustained activation during the 2 s stimulus. Responses to hemifield luminance stimuli also had an occipital component, but they were dominated by activation of the medial parieto-occipital sulcus (POS) 60-70 ms later. The POS region was equally well activated by foveal and extrafoveal stimuli. The occipital responses to hemifield luminance stimuli differed from those to pattern stimuli in two main aspects: the sustained activation was significantly weaker, and the responses were almost symmetrical, indicating a surprisingly bilateral occipital activation. These effects were similar with foveal acid extrafoveal stimuli. The spontaneous 10 Hz alpha rhythm, originating predominantly in the POS region, was suppressed after both stimulus onsets and offsets, more strongly for luminance than pattern stimuli. Activation of the occipital cortex dominated after pattern stimuli, whereas the effect of luminance stimulation was stronger in the parieto-occipital region. The distinct signal distributions in the occipital and POS regions suggest that the two types of stimuli activate the magno- and parvocellular pathways to a varying degree. These findings are also in line with a stronger attention-catching value of the luminance than pattern stimuli.