Where Are the Contents of Memory Stored?

The content of memory—all dharmas—becomes seeds stored in the tathāgatagarbha, not in the brain. Seeds are formless and without appearance, whereas the brain is material form. Material form possesses shape and appearance and is subject to destruction. If the content of memory were stored solely in the brain, then upon the brain’s destruction, all such content would vanish entirely in future lives, and there would be no cause and effect. In this present life, as brain cells arise, cease, and undergo change, the content of memory also disappears; thereafter, it cannot be recalled.

The eighth consciousness does not possess the function of memory retention. The five consciousnesses possess a weak function of retention. Both the mental consciousness and the mental faculty possess the function of memory and retention, but only the mental consciousness can engage in recollection. When the mental faculty grasps past dharma-dhātus, it is called "retention," not "recollection." Recollection is more subtle; the mental faculty cannot engage in subtle discernment and is unable to distinguish detailed particulars.