Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK.
Purdue University School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN, 47907, USA.
Nat Commun. 2019 Jan 28;10(1):474. doi: 10.1038/s41467-019-08313-y.
Translating noisy sensory signals to perceptual decisions is critical for successful interactions in complex environments. Learning is known to improve perceptual judgments by filtering external noise and task-irrelevant information. Yet, little is known about the brain mechanisms that mediate learning-dependent suppression. Here, we employ ultra-high field magnetic resonance spectroscopy of GABA to test whether suppressive processing in decision-related and visual areas facilitates perceptual judgments during training. We demonstrate that parietal GABA relates to suppression of task-irrelevant information, while learning-dependent changes in visual GABA relate to enhanced performance in target detection and feature discrimination tasks. Combining GABA measurements with functional brain connectivity demonstrates that training on a target detection task involves local connectivity and disinhibition of visual cortex, while training on a feature discrimination task involves inter-cortical interactions that relate to suppressive visual processing. Our findings provide evidence that learning optimizes perceptual decisions through suppressive interactions in decision-related networks.
将嘈杂的感觉信号转化为感知决策对于在复杂环境中成功交互至关重要。学习被认为可以通过过滤外部噪声和与任务无关的信息来改善感知判断。然而，对于介导学习依赖抑制的大脑机制知之甚少。在这里，我们采用超高场磁共振波谱 GABA 来测试决策相关和视觉区域中的抑制性处理是否在训练期间促进感知判断。我们证明顶叶 GABA 与抑制与任务无关的信息有关，而视觉 GABA 的学习依赖性变化与目标检测和特征辨别任务中的增强表现有关。将 GABA 测量与功能脑连接相结合表明，在目标检测任务上的训练涉及视觉皮层的局部连接和去抑制，而在特征辨别任务上的训练涉及与抑制性视觉处理相关的皮质间相互作用。我们的发现提供了证据，表明学习通过决策相关网络中的抑制性相互作用来优化感知决策。
