Behavioral Neurology Unit, National Institute of Neurological Disorders and Stroke, 10 Center Drive, Bethesda, MD 20814, USA.
Department of Psychological and Brain Sciences, The George Washington University, 2125 G St NW, Washington, DC 20052, USA.
Cereb Cortex. 2023 Mar 21;33(7):3651-3663. doi: 10.1093/cercor/bhac298.
Recent studies used functional magnetic resonance imaging (fMRI) population receptive field (pRF) mapping to demonstrate that retinotopic organization extends from the primary visual cortex to ventral and dorsal visual pathways, by quantifying visual field maps, receptive field size, and laterality throughout multiple areas. Visuospatial representation in the posterior parietal cortex (PPC) is modulated by attentional deployment, raising the question of whether spatial representation in the PPC is dynamic and flexible, and whether this flexibility contributes to visuospatial learning. To answer this question, changes in spatial representation within the PPC and early visual cortex were recorded with pRF mapping before and after prism adaptation (PA)-a well-established visuomotor technique that modulates visuospatial attention according to the direction of the visual displacement. As predicted, results showed that adaptation to left-shifting prisms increases pRF size in left PPC, while leaving space representation in the early visual cortex unchanged. This is the first evidence that PA drives a dynamic reorganization of response profiles in the PPC. These findings show that spatial representations in the PPC not only reflect changes driven by attentional deployment but dynamically change in response to modulation of external factors such as manipulation of the visuospatial input during visuomotor adaptation.
最近的研究使用功能磁共振成像（fMRI）的群体感受野（pRF）映射来证明，通过量化视野图、感受野大小和多个区域的偏侧性，视知觉组织从初级视觉皮层延伸到腹侧和背侧视觉通路。顶后皮质（PPC）中的视空间表示受注意力部署的调节，这引发了一个问题，即 PPC 中的空间表示是否具有动态和灵活性，以及这种灵活性是否有助于视空间学习。为了回答这个问题，使用 pRF 映射记录了棱镜适应（PA）前后 PPC 和早期视觉皮层内的空间表示变化，PA 是一种成熟的视觉运动技术，根据视觉位移的方向调节视空间注意力。正如预测的那样，结果表明，适应左移棱镜会增加左 PPC 中的 pRF 大小，而早期视觉皮层中的空间表示保持不变。这是第一个证明 PA 驱动 PPC 中反应模式动态重组的证据。这些发现表明，PPC 中的空间表示不仅反映了由注意力部署驱动的变化，而且还会根据外部因素的调制而动态变化，例如在视动适应期间对手视觉输入的操纵。
