So many fantastic thoughts and comments lately. What a great readership! Some really interesting questions asked/points raised about memory. They jogged my own noggin' (noticeably on the decline in recent years) of a few related studies. Here are the nutshell versions:
1. One of the ways researchers get memory in people of all ages is to compare how easy it is to learn something for the first time, compared to when we have to learn it again. For example, in lots of traditional memory studies with adults, the researchers gave their participants lists of words or word pairs (sock-orange) and looked at how long it took to learn them. Then after some substantial delay, when the participants no longer consciously remembered the list, they brought them back and looked at how long it took them to learn the same list to perfect recall again. The difference in the time it took at time 1 and time 2 is termed "savings" which basically shows that you unconsciously retained or REMEMBERED some of the list. For more on this idea and the guy behind it try here.
Of course, we're not going to give a baby a list of words to learn, but just think of the task in terms of something that babies CAN do. For example, in one study infants of just a few months were put in a crib and their leg was connected to a string (such as by a a loop around their ankle). The point was to see how long it took the baby to figure out that if they kicked that leg vigorously, something fun would happen (e.g. a clown doll would appear, or they'd hear a funny sound, the lights would flash etc.). Then after a delay, they brought the babies back and put them in the same crib, same set-up etc. If they got the "leg kick = funny event" link more quickly, the researchers would conclude that the babies REMEMBERED what they needed to do. Oh there's always a way to get inside that amazing baby head...
2. The stuff you have to remember to do in future - take your medicine at 2pm, TAKE A HOLIDAY GIFT IN FOR YOUR CHILD'S TEACHER BEFORE THE LAST DAY OF SCHOOL (I'm just sayin'...) - is called prospective memory (as opposed to retrospective memory, for things in the past). It's one of the first things to go when you get older. That's your head's up.
3. Yes, there is such a thing as photographic memory - when you can picture in your mind the actual material you want to remember, in the place where you first learned it. That's as in, you are writing an exam and you can picture in your head the page in the text book where you read it AND YOU CAN SCAN THAT PAGE TO FIND WHAT YOU ARE AFTER. It's not exactly common. Usually fades by later childhood (11 or so). Any takers? Did any of you do this? I definitely relied on this in school, even later on, but it got way, way harder as the years went by. I'm not sure how good a measure of photographic memory this is...but if you have a few minutes on your hands (ha ha ha...) or insomnia, Try this.
4. Another favourite line of research (honestly, can I really call it a fave when there are so many?) specifically targets childhood amnesia. Here's a link to the primary researcher's homepage if you want to have a browse. I cannot help but highlight one of her coolest recent findings. Ya know how excited I get about these things...
The researchers visited young children (about 2-3 years of age) in their homes and taught them a novel event. A machine would actually "shrink" a toy you put inside it. Read: Child puts a big toy in the front opening of the machine, then closes the door. Some flashing lights and machine like sounds go off, then they open door and find a miniature version of the toy inside. Yes, of course, it's been replaced with the mini one by way of the back door and another researcher or something, but boy do they go for it! It's amazing!!!. This all happens at an age when language is fairly limited but then develops amazingly quickly. They know because they actually measure the children's language skills.
Then after 6 months or 1 year, they go back to visit the same children and basically probe to see if they remember what happened on that first visit, now "ages" ago as far as they are concerned. The probing includes asking them to talk about it (verbal measure), asking them to pick out pictures of e.g. some of the toys they shrunk (visual recognition) and asking them if they remember how to work the machine (behavioural re-enactment). And oh yes, they measure their language skills again. Get this: Even though children remember what happened (as shown by their performance on the visual recognition and behavioural measures - both non-verbal), their memories are limited to the vocabulary they had AT THE TIME the shrinking machine thing took place. That is, even though they now had WAY better vocabularies, they described the event only in terms of the language they had AT THE TIME THEY EXPERIENCED IT! This suggests of course that our so-called infantile amnesia is linked to our limited capacity to code or store our experiences in words when our vocabularies are so very limited. Note that as the children had good non-verbal memory of the event, they clearly registered it. It's just that they were limited in their ability to access those memories verbally. So perhaps this helps to explain why we later can no longer access those early memories and integrate them into our autobiographical memories when we are older and rely more on storing and accessing memories verbally. Hmmm...
6. Finally, to help keep your internet-using guilt at bay and to end the week on a lighter note, here's a fun clip on memory that you can actually watch WITH your kids!
Now just remember to watch it. Good weekend.