Laboratory for Neuro-and Psychophysiology, Department of Neurosciences, KU Leuven Medical School, 3000, Leuven, Belgium.
Massachusetts General Hospital, Martinos Ctr. for Biomedical Imaging, Charlestown, MA, 02129, USA.
Nat Commun. 2019 Aug 9;10(1):3591. doi: 10.1038/s41467-019-11527-9.
Practice improves perception and enhances neural representations of trained visual stimuli, a phenomenon known as visual perceptual learning (VPL). While attention to task-relevant stimuli plays an important role in such learning, Pavlovian stimulus-reinforcer associations are sufficient to drive VPL, even subconsciously. It has been proposed that reinforcement facilitates perceptual learning through the activation of neuromodulatory centers, but this has not been directly confirmed in primates. Here, we paired task-irrelevant visual stimuli with microstimulation of a dopaminergic center, the ventral tegmental area (VTA), in macaques. Pairing VTA microstimulation with a task-irrelevant visual stimulus increased fMRI activity and improved classification of fMRI activity patterns selectively for the microstimulation-paired stimulus. Moreover, pairing VTA microstimulation with a task-irrelevant visual stimulus improved the subject's capacity to discriminate that stimulus. This is the first causal demonstration of the role of neuromodulatory centers in VPL in primates.
练习可以提高对训练有素的视觉刺激的感知能力，并增强神经表现，这种现象被称为视觉感知学习（VPL）。虽然注意力集中在与任务相关的刺激上对于这种学习很重要，但巴甫洛夫式的刺激 - 强化物关联足以驱动 VPL，甚至是在潜意识中。有人提出，强化通过激活神经调质中心促进感知学习，但这在灵长类动物中尚未得到直接证实。在这里，我们在猕猴中配对了与任务无关的视觉刺激和多巴胺能中心腹侧被盖区（VTA）的微刺激。将 VTA 微刺激与任务无关的视觉刺激配对会增加 fMRI 活动，并选择性地改善 fMRI 活动模式的分类，专门针对微刺激配对的刺激。此外，将 VTA 微刺激与任务无关的视觉刺激配对会提高受试者区分该刺激的能力。这是在灵长类动物中首次对神经调质中心在 VPL 中的作用进行因果证明。
