fMRI-Adaptation and Category Selectivity in Human Ventral Temporal Cortex: Regional Differences Across Time Scales
fMRI-Adaptation and Category Selectivity in Human Ventral Temporal Cortex: Regional Differences Across Time Scales
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DOI：
10.1152/jn.01108.2009
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发表时间：
2010-06-01
影响因子：
2.5
通讯作者：
Grill-Spector, Kalanit
中科院分区：
文献类型：
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作者：
Weiner, Kevin S.;Sayres, Rory;Grill-Spector, Kalanit
Weiner KS，Sayres R，Vinberg J，Grill-Spector K.人类腹侧颞叶皮层的fMRI适应性和类别选择性：跨时间尺度的区域差异。J Neurophysiol 103：3349-3365，2010.首次发表于2010年4月7日; doi：10.1152/jn.01108.2009。重复目标图像在腹侧颞叶皮层（VTC）产生刺激特异性重复抑制，称为功能性磁共振成像适应（fMRI-A）。然而，刺激重复对功能选择性的影响在很大程度上是未知的。我们使用高分辨率fMRI研究了短滞后（SL，即时）和长滞后（LL，许多干预刺激）重复对VTC类别选择性的影响。我们问是否重复产生缩放或锐化功能磁共振成像反应的类别选择性区域内，以及在整个VTC的分布式响应模式。结果表明，跨时间尺度的重复效果变化定量沿着的前-后轴和定性沿着的侧-中轴。在横向VTC中，SL和LL重复均产生成比例的fMRI-A，而选择性或分布响应均无变化，如比例模型所预测的。此外，无论类别选择性如何，前亚区的fMRI-A都较大。内侧VTC在SL重复期间表现出类似的缩放效应。然而，对于LL重复，无论是选择性和分布模式的变化与类别的中间VTC预测的锐化模型。具体而言，与首选类别相比，非首选类别的fMRI-A更大，并且类别选择性不能预测分布式应答模式中的fMRI-A。最后，模拟表明，不同的神经机制可能是fMRI-A在内侧相比，外侧VTC。这些结果对未来的fMRI-A实验具有重要意义，因为它们表明fMRI-A并不反映普遍的神经机制，并且fMRI-A实验的结果可能在外侧VTC中是范式独立的，但在内侧VTC中是范式依赖的。
Weiner KS, Sayres R, Vinberg J, Grill-Spector K. fMRI-adaptation and category selectivity in human ventral temporal cortex: regional differences across time scales. J Neurophysiol 103: 3349-3365, 2010. First published April 7, 2010; doi:10.1152/jn.01108.2009. Repeating object images produces stimulus-specific repetition suppression referred to as functional magnetic resonance imaging-adaptation (fMRI-A) in ventral temporal cortex (VTC). However, the effects of stimulus repetition on functional selectivity are largely unknown. We investigated the effects of short-lagged (SL, immediate) and long-lagged (LL, many intervening stimuli) repetitions on category selectivity in VTC using high-resolution fMRI. We asked whether repetition produces scaling or sharpening of fMRI responses both within category-selective regions as well as in the distributed response pattern across VTC. Results illustrate that repetition effects across time scales vary quantitatively along an anterior-posterior axis and qualitatively along a lateral-medial axis. In lateral VTC, both SL and LL repetitions produce proportional fMRI-A with no change in either selectivity or distributed responses as predicted by a scaling model. Further, there is larger fMRI-A in anterior subregions irrespective of category selectivity. Medial VTC exhibits similar scaling effects during SL repetitions. However, for LL repetitions, both the selectivity and distributed pattern of responses vary with category in medial VTC as predicted by a sharpening model. Specifically, there is larger fMRI-A for nonpreferred categories compared with the preferred category, and category selectivity does not predict fMRI-A across the pattern of distributed response. Finally, simulations indicate that different neural mechanisms likely underlie fMRI-A in medial compared to lateral VTC. These results have important implications for future fMRI-A experiments because they suggest that fMRI-A does not reflect a universal neural mechanism and that results of fMRI-A experiments will likely be paradigm independent in lateral VTC but paradigm dependent in medial VTC.