National Institutes of Health (NIH), Bethesda, MD, USA.
Center for Neural Science, New York University, New York, NY, USA.
Nat Commun. 2024 Apr 18;15(1):3347. doi: 10.1038/s41467-024-47356-8.
Neurons in the inferotemporal (IT) cortex respond selectively to complex visual features, implying their role in object perception. However, perception is subjective and cannot be read out from neural responses; thus, bridging the causal gap between neural activity and perception demands independent characterization of perception. Historically, though, the complexity of the perceptual alterations induced by artificial stimulation of IT cortex has rendered them impossible to quantify. To address this old problem, we tasked male macaque monkeys to detect and report optical impulses delivered to their IT cortex. Combining machine learning with high-throughput behavioral optogenetics, we generated complex and highly specific images that were hard for the animal to distinguish from the state of being cortically stimulated. These images, named "perceptograms" for the first time, reveal and depict the contents of the complex hallucinatory percepts induced by local neural perturbation in IT cortex. Furthermore, we found that the nature and magnitude of these hallucinations highly depend on concurrent visual input, stimulation location, and intensity. Objective characterization of stimulation-induced perceptual events opens the door to developing a mechanistic theory of visual perception. Further, it enables us to make better visual prosthetic devices and gain a greater understanding of visual hallucinations in mental disorders.
下颞（IT）皮层的神经元对复杂的视觉特征有选择性反应，这表明它们在物体感知中起作用。然而，感知是主观的，不能从神经反应中读出；因此，要弥合神经活动和感知之间的因果差距，就需要对感知进行独立的描述。然而，从历史上看，由于人工刺激 IT 皮层引起的感知变化的复杂性，使得它们无法量化。为了解决这个老问题，我们要求雄性猕猴检测并报告传递到他们的 IT 皮层的光脉冲。我们将机器学习与高通量行为光遗传学相结合，生成了复杂且高度特异性的图像，这些图像使动物难以将其与皮层刺激状态区分开来。这些图像，首次被命名为“知觉图”，揭示并描绘了 IT 皮层局部神经干扰引起的复杂幻觉知觉的内容。此外，我们发现这些幻觉的性质和程度高度依赖于并发的视觉输入、刺激位置和强度。对刺激诱导的感知事件的客观描述为开发视觉感知的机械论理论打开了大门。此外，它使我们能够制造更好的视觉假体，并更好地理解精神障碍中的视觉幻觉。
