Effects of a cross-modal manipulation of attention on somatosensory cortical neuronal responses to tactile stimuli in the monkey
Effects of a cross-modal manipulation of attention on somatosensory cortical neuronal responses to tactile stimuli in the monkey
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DOI：
10.1152/jn.00121.2002
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发表时间：
2002-12-01
影响因子：
2.5
通讯作者：
Chapman, CE
中科院分区：
文献类型：
--
作者：
Meftah, EM;Shenasa, J;Chapman, CE
注意力在调节触觉敏感性的作用，在初级（SI）和次级躯体感觉皮层（SII）的解决使用跨模态操作的注意，躯体感觉与视觉。两只成年猴子（Macaca mulatta）被训练完成两项任务：触觉辨别第3和第4个手指表面纹理的变化，视觉辨别光线强度的变化。在每个试验中，标准纹理（2毫米的空间周期，SP）和视觉刺激。随后是SP和/或亮度的增加。每次试验之前都有一个指示提示（彩色光），指示动物注意并响应一种模式的变化，而忽略另一种模式的任何变化。这两个任务在记录过程中交错进行，一个试验一个试验地进行。细胞外记录从178个神经元（SI，102; SII，76），所有的皮肤感受野上的刺激指尖。放电量化在这两个任务的指令，标准刺激，和纹理变化期间。结果表明，对触觉刺激的选择性注意在SII中比在SI中具有更大和更早的定性和定量效应。102个SI细胞中有24个随着注意力的方向放电发生显着变化。对于几乎所有的细胞（20/24），当注意力被引导到触觉刺激时，放电增强;在包括SP变化的分析区间（16/24）中，效果最常见。注意力敏感的SII细胞比例显著较高（47/76）。这些影响集中在质地变化期（39/47），但也包括试验的早期（指导期，n = 15;标准刺激期，n = 32）。跨越所有三个间隔（n = 11）的注意力相关调节可能反映了放电的基线变化。对于纹理敏感的细胞（43在SI，37在SII），在每个任务中的放电频率的平均变化（纹理变化后-纹理变化前）显着增加在SII，但没有SI与选择性注意。结果是一致的顶叶皮层放电的两个阶段的调制，初始阶段（SI），其中有一些增强的感觉反应的显着特征，纹理的变化，和第二阶段（SII），其中发生基线变化，沿着进一步的功能选择。这些控制可以独立地施加在SI和SII上，或者它们可以反映从SII到SI的自上而下的控制。
The role of attention in modulating tactile sensitivity in primary (SI) and secondary somatosensory cortex (SII) was addressed using a cross-modal manipulation of attention, somatosensory versus visual. Two adult monkeys (Macaca mulatta) were trained to perforin two tasks: tactile discrimination of a change in the texture of a surface presented to digits 3 and 4 and visual discrimination of a change in the intensity of a light. In each trial, standard texture (2 mm spatial period, SP) and visual stimuli were presented. These were followed by an increase in SP and/or luminance. Each trial was preceded by an instruction cue (colored light) that directed the animal to attend and respond to the change in one modality while ignoring any change in the other modality. The two tasks were interleaved during the recording, on a trial-by-trial basis. Extracellular recordings were made from 178 neurons (SI, 102; SII, 76), all with a cutaneous receptive field on the stimulated digit tips. Discharge was quantified in both tasks during the instruction, the standard-stimuli, and the texture-change periods. The results showed that selective attention to tactile stimuli had qualitatively and quantitatively greater and earlier effects in SII than SI. Twenty-four of 102 SI cells showed a significant change in discharge with the direction of attention. For almost all cells (20/24), discharge was enhanced when attention was directed toward the tactile stimuli; the effects were most frequent in the analysis interval that encompassed the change in SP (16/24). A significantly higher proportion of SII cells were attention-sensitive (47/76). The effects were concentrated in the texture-change period (39/47) but also included earlier periods in the trial (instruction period, n = 15; standard-stimuli period, n = 32). Attention-related modulation that spanned all three intervals (n = 11) likely reflected baseline changes in discharge. For the texture-sensitive cells (43 in SI, 37 in SII), the mean change in discharge frequency (post texture change - pre-texture change) in each task was significantly increased in SII but not SI with selective attention. The results are consistent with a two-stage modulation of parietal cortical discharge, an initial stage (SI) in which there is some enhancement of sensory responses to the salient feature, the texture change, and a second stage (SII) in which baseline changes occur, along with further feature selection. These controls may be independently exerted on SI and SII, or they may reflect top-down controls from SII to SI.