Think about your memory for changing a diaper. When you approach a changing table, you don’t actively talk yourself through the process: “OK, first place the baby on the pad. Now unzip the pajamas and remove the soggy diaper. Place the clean diaper under the baby and …”
No, none of that’s necessary because when you change a diaper, you just do it. You’ve done it so many times before, you don’t even think about what you’re doing. Your brain fires off clusters of neurons that let you undo the tabs, remove the diaper, reach for a baby wipe, and so on, all without ever even realizing that you are “remembering” how to do it. That’s one kind of memory: past experiences (changing diaper after diaper) influence your behavior in the present (changing this particular diaper) without any realization that your memory has even been triggered.
If, on the other hand, you think about that day you first changed a diaper, you might pause for a moment, scan your memory, and come up with an image of yourself nervously gripping a baby’s ankle, then cringing at the mess you find in the diaper, then struggling to figure out what to do next. When you actively think about these images and emotions, then you’re aware that you are recalling something from the past. This is also memory—but it’s different from the memory that enables you to change a diaper now without thinking about it.
These two types of memory interweave and work together in your normal everyday living. The memory that enables you to change your baby without knowing that you are remembering is called implicit memory. Your ability to recall learning to change a diaper (or to recall any other specific moment) is explicit memory. Usually when we talk about memory, we mean what is technically explicit memory: a conscious recollection of a past experience. But we need to know about both kinds of memory, for our own sake as well as for that of our children. By getting a clear handle on these two different types of memory, we can provide our kids with what they need as they grow and mature and deal with difficult experiences.
Let’s start by focusing on implicit memories, which begin forming even before we are born. Dan tells a story about an informal “research study” he performed in his own family.
When my wife was pregnant with each of our two children, I used to sing to them in the womb. It was an old Russian song that my grandmother had sung to me, a child’s song about her love for life and for her mother—“May there always be sunshine, may there always be good times, may there always be Mama, and may there always be me.” I sang it—in Russian and in English—during the last trimester of pregnancy, when I knew the auditory system was wired up enough to register sound coming through the amniotic fluid.
Then in the first week after each child was born, I invited a colleague over for a “research study.” (I know, it wasn’t controlled, but it was fun.) Without revealing the prenatal song, I sang three different songs in turn. No doubt about it—when the babies heard the familiar song, their eyes opened wider and they became more alert, so that my colleague could easily identify the change in their attention level. A perceptual memory had been encoded. (Now my kids won’t let me sing; I probably sounded better underwater.)