Despite the past few decades of research providing convincing evidence of the similarities in function and neural mechanisms between imagery and perception, for most of us, the experience of the two are undeniably different, why? Here, we review and discuss the differences between imagery and perception and the possible underlying causes of these differences, from function to neural mechanisms. Specifically, we discuss the directional flow of information (top-down versus bottom-up), the differences in targeted cortical layers in primary visual cortex and possible different neural mechanisms of modulation versus excitation. For the first time in history, neuroscience is beginning to shed light on this long-held mystery of why imagery and perception look and feel so different.

This article is part of the theme issue ‘Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation'.

尽管过去几十年的研究提供了令人信服的证据，证明意象和感知之间在功能和神经机制上的相似性，但对于我们大多数人来说，两者的体验无可否认是不同的，为什么呢？在这里，我们回顾并讨论图像和感知之间的差异，以及这些差异从功能到神经机制的可能的根本原因。具体来说，我们讨论信息的定向流动（自上而下与自下而上）、初级视觉皮层中目标皮层的差异以及调制与兴奋可能不同的神经机制。神经科学历史上第一次开始揭示这个长期存在的谜团：为什么图像和感知看起来和感觉如此不同。

本文是主题“离线感知：不匹配外部刺激的自愿和自发的感知体验”的一部分。