>...so did malnutrition/half starvation bring on all those "visions"?<

Yes, in my humble opinion, as well as herbs, fungi, chanting, dancing and heaven knows what else.

A friend, some forty years ago, once said to me, "It's all about chemicals in the brain man." I think I've been trying to convince myself ever since that it's not <i>all</i> about chemicals in the brain but haven't quite manage it yet :-)