Unfortunately, the implementation is secret so we can't know what Google is doing. You can implement memory in these models in numerous ways, such as allowing

Unfortunately, the implementation is secret so we can't know what Google is doing. You can implement memory in these models in numerous ways, such as allowing it to store and recall data directly or by looping nodes in the network back to itself so past state affects current state or by allowing the nodes to change over time, modifying their connections to their neighbors. As far as we're aware, those last two are how humans store memories as well (with great simplification).