Alex was in another research study yesterday. This one was apparently tons of fun.
They're studying short-term memory. Previous studies have found that babies Alex's age have a short-term memory of about three items. So if you hide three items in a box and let them retrieve two, they'll keep searching for the third - but if you hide four items and only let them retrieve two, they may not realize that there are more in there. Adults' short-term memories can be assisted by "chunking" - grouping the information to be remembered in larger units. For example, it would be hard for most people to reproduce the letters
after only being exposed to them for a couple of seconds, but it would be relatively easy if the letters were presented as
NYC FBI LSD FDR
Babies are the same way. If they're presented with four identical toy cats which are then hidden in a box, they're more likely to keep searching until they find all of them than if they're given four totally different toys. The similarity of the items lets them chunk them together so there's less to remember.
This study was looking at the middle ground, where items are similar (four different toy cats, four different toy cars, or two cats and two cars) but not identical. The experimenter had a black box with an opening at one end shielded by two strips of Spandex. Alex could reach between the Spandex strips, but couldn't see in (although she certainly tried, by pulling one strip of Spandex way out and then peering in). The experimenter showed her the toy cats or cars, put them in the box, and then pushed the box forward to let Alex retrieve them. Unbeknownst to Alex, the experimenter was secretly holding two of the toys at the back of the box so that they were unretrievable. So she'd get the first two out, no problem, and then there would be a little pause to see if she kept searching.
Alex found the whole thing very exciting. She bounced and pointed when the toys were shown, reaching eagerly for the apparatus. After enough repetitions of the experimenter's rigid script ("Alex, look! Look! See this? See this?") she started pointing and saying "Look! Look!" herself. She also tried her best to re-hide the toys after she took them out of the box. (Hey, the experimenter
kept putting them in the box, so obviously
that was how you played with them!) I couldn't really tell how diligently she was searching for the unretrievable ones, and how the different experimental conditions affected her searching - that will be a matter for videotape coders.
She got a T-shirt and a fancy award certificate for participating. I was sorry to hear that they won't have any more studies for her until she's 28 months. Apparently they've found that research participants in the early toddler years are more trouble than they're worth.
New books she asks for by name: Where's my cow?
("Cow cow!"; a current obsession which may be demanded ten times a day), Splash!
New words: cereal, bottle, truck, tree, squirrel, grapes, strawberries ("s'raw"), go, jeans (seems to apply to any pants or shorts with a fly front), shirt, down, yes, dark, yogurt, cracker, water, head, barrette, house, food, Cheerios, night (for "good night" or going to sleep), Zoe, neck (seems to specifically mean "necklace," applied both to my flaming chalice pendant and my parents' dog's collar), hot, thank you ("daysoo"), clap, Bill, pen. "Cow" and "splash" are also new words, but I don't know if she realizes they have any meaning beyond book titles. Mostly multisyllabic words are expressed as a single syllable, so yogurt becomes "yo" and barrette is "b'reh.".
New word for which I am probably going to hell: Tie-tie
(meaning "tired"), courtesy of Cute Overload
. I did not intend to deliberately teach Alex baby talk, I swear, but one day after her nap I couldn't resist saying, "Poor Alex, she's still so tie-tie." She immediately grinned at me and said "Tie-tie" - I think she's heard enough English that she could kind of tell that it wasn't a real word, just silliness. (The ability to recognize whether something is likely to be a word in your native language develops before actual understanding does.) And then she remembered
it. A couple of days later she got me up very early in the morning, and I told her, "Mama's tired." "Tie-tie," she said, and grinned like a fool. Oops.Edited to add: Here's the picture
that forever added "tie-tie" to my vocabulary.