Right concentration leads to four stages of "trance":
During the first stage of trance,passionate desires,ill will,worry,sensuous lust,restlessness,and skeptical doubts are discarded,and a feeling of joy and happiness are maintained.
During the second stage of trance,all intellectual activities are suppressed,tranquility and "one pointedness" of mind developed,and feeling of joy and happiness are maintained.
In the third stage,the feeling of joy disappears while the disposition of happiness still remains.
In the fourth stage of trance,all sensations,happiness and unhappiness,of joy and sorrow disappear.Only pure equanimity and awareness remain.
还有一点：
In the second stage of trance,the individual attempts to impose meaning and order on the involuntary images by matching them with stored memories.How the mind links the entoptics with more familiar images depends on the individual's current state of mind.In rock art imagery,such forms include entoptics that share some identifying traits with representational images.One example might be the zigzag caterpillar or snake from Kinevan Ranch (see Fig.2).Or,the so-called aquatic motifs,a simple arc with split ends suggestive of a fish (Hudson and Conti 1981).A giant caterpillar at Carneros Rocks might fit into this category as well.
