Response patterns in second somatosensory cortex (SII) of awake monkeys to passively applied tactile gratings.
Response patterns in second somatosensory cortex (SII) of awake monkeys to passively applied tactile gratings.
复制标题
清醒猴子的第二体感皮层（SII）对被动施加的触觉光栅的反应模式。
DOI：
10.1152/jn.2000.84.2.780
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发表时间：
2000
影响因子：
2.5
通讯作者：
Burton,H
中科院分区：
文献类型：
--
作者：
PruettJr,JR;Sinclair,RJ;Burton,H
本实验探讨了触觉光栅的三个参数，槽宽（1.07-2.53 mm）、接触力（30-90 g）和扫描速度（40-120 mm/s）的控制操作对清醒猴第二体感皮层（SII）细胞反应的影响。先前的一项涉及主动触摸范例的实验表明，猕猴SII细胞在其平均放电率中编码凹槽宽度和手部运动参数。本研究使用被动触摸协议，以消除体感激活相关的手的运动，伴随着触觉探索的表面。猴子保持恒定的手的位置，而机器人设备提供刺激与触觉光栅到一个单一的稳定的指垫。单单位记录分离出216个神经元，这些神经元在组织学标准上被回顾性地分配到SII。这些SII细胞中的86个的放电模式被详细描述，而猴子将光栅分类为粗糙的（1.90和2.53 mm槽宽）或光滑（1.07和1.42 mm槽宽），试验随机，力或速度的参数操纵;猴子在交替的试验块中比较了1.07与1.90 mm和1.42与2.53 mm。我们研究了33个细胞的系统变化的槽宽和力，49个槽宽和速度，和四个所有三个变量。63个细胞对槽宽敏感，43个细胞对力敏感（速度实验中随机力的影响对N敏感），34个细胞对速度敏感。相对相等数量的细胞改变平均放电率的正或负的功能，增加凹槽宽度，力，和/或速度。细胞通常会改变两个或三个独立变量的平均放电率。槽宽、力和速度的影响是相加的或交互的。反应功能的多样性与先前使用被动触摸的初级躯体感觉皮层（SI）研究中发现的相似。SII样本群体显示出随着凹槽宽度和力的增加，以及在较小程度上随着凹槽宽度和速度的增加，击发率的相关变化（正负）。这种相关性是一致的人类心理物理学研究，发现增加槽宽和力增加感知粗糙度的大小，它加强了SII的直接参与粗糙度感知的论点。
This experiment explored the effects of controlled manipulations of three parameters of tactile gratings, groove width (1.07–2.53 mm), contact force (30–90 g), and scanning speed (40–120 mm/s), on the responses of cells in second somatosensory cortex (SII) of awake monkeys that were performing a groove-width classification task with passively presented stimuli. A previous experiment involving an active touch paradigm demonstrated that macaque SII cells code groove-width and hand-movement parameters in their average firing rates. The present study used a passive-touch protocol to remove somatosensory activation related to hand movements that accompany haptic exploration of surfaces. Monkeys maintained a constant hand position while a robotic device delivered stimulation with tactile gratings to a single stabilized finger pad. Single-unit recordings isolated 216 neurons that were retrospectively assigned to SII on histological criteria. Firing patterns for 86 of these SII cells were characterized in detail, while monkeys classified gratings as rough (1.90 and 2.53 mm groove widths) or smooth (1.07 and 1.42 mm groove widths), with trial-wise random, parametric manipulation of force or speed; the monkeys compared 1.07 versus 1.90 mm and 1.42 versus 2.53 mm in alternating blocks of trials. We studied 33 cells with systematic variation of groove width and force, 49 with groove width and speed, and four with all three variables. Sixty-three cells were sensitive to groove width, 43 to force (effects of random force in speed experiments contributed to N), and 34 to speed. Relatively equal numbers of cells changed mean firing rates as positive or negative functions of increasing groove width, force, and/or speed. Cells typically changed mean firing rates for two or three of the independent variables. Effects of groove width, force, and speed were additive or interactive. The variety of response functions was similar to that found in a prior study of primary somatosensory cortex (SI) that used passive touch. The SII sample population showed correlated changes (both positive and negative) in firing rates with increasing groove width and force and to a lesser degree, with increasing groove width and speed. This correlation is consistent with human psychophysical studies that found increasing groove width and force increase perceived roughness magnitude, and it strengthens the argument for SII's direct involvement in roughness perception.