Maybe. It's certainly the case that there are areas of the human brain which are specifically associated with recognizing faces, like the fusiform face area - it's an intrinsic capability of the brain, not one that's learned. But I'm not certain that's sufficient to explain what's happening here. Increasing the activation of that area would most likely result in a person perceiving faces everywhere (e.g. an extreme form of pareidolia), not entire humanoid figures.

Malkovich? Malkovich! -- https://www.youtube.com/watch?v=lIpev8JXJHQ