[SOUND] We've talked about a bilingual advantage. The question is whether there's a bilingual disadvantage. While there are some studies that have found a disadvantage, specifically when you ask bilinguals to name a single picture. This is work done by Tamar Golan and her colleagues. What's found often is that, when bilinguals have to name a picture they're slower than monolinguals, in a single language. We just take them in English. Golan then asked a group of participants to name the same picture in different blocks, across five different blocks, and if you repeat the same picture five times, people get faster and faster. The biggest jump in speed is after the, from the first to the second, it's called, it's called repetition priming. It's a very robust effect. People have found that if you repeat a stimulus, bring people into the lab, show them some stimuli, have them come back 30 days later, there's still an effect of repetition. Such that items that they saw 30 days ago are faster than items they see for the first time at day 30. So there's a huge jump from the first to the second presentation for Golan and then a little bit of an increase but not much across subsequent presentations. The monolinguals show the same effect except they're always faster. And even after five presentations of the same picture the bilinguals are never identical to the monolinguals. Suggesting again, that in a single language there's a bit of a slow down for bilinguals relative to monolinguals. Golan and colleagues also observed that there were larger tip-of-the-tongue effects. What are tip-of-the-tongue effects? Well, let me give you an example. Example I like to give in class often is, tell me the names, without looking on the Internet, of Snow White and the Seven Dwarfs. Okay, so, what are they? Now, I'm not a big Disney fan, right, so I don't know them all, but invariably there's one student in class who knows all seven. So, they give us a list of all seven. You can write them down if you'd like right now. What are the Seven Dwarfs? Write them down. And I always encourage people to guess if they don't know, because every so often they don't know the name of one, so just try to guess. So now that you've guessed the name of the Seven Dwarfs, check them. You can go on the Internet and check the name of the Seven Dwarfs. Tell me what they are. And now compare them to the list of the items you generated. And if you were really risky and actually produced some items that you weren't quite sure if they were correct, you might get something like one of my students said, Sleazy. So, oh boy, that's not exactly Snow White and Seven Dwarfs. That must be some other movie. But Sleazy, they thought was one. And that's because you have things like Sleepy, Dopey, Grumpy. Somebody else said, Hungry. That's a pretty good guess but there isn't really Hungry. I think Happy was another example that someone gave me. And so people produced those items but they rarely say things like Geronimo, right? And so that's a tip-of-the-tongue state, right? People have a idea of what they want to say. They can identify the correct item, but they can't produce it themselves. It happens a lot of times with names, right? What was that person's name? Well, Golan looked at tip-of-the-tongue states with bilinguals and found that bilinguals showed larger and more frequent tip-of-the-tongue states than monolinguals. With the idea that, in fact, it's because you have access to so many words as a bilingual, and because you have many words, you're more likely to not find the correct one. So you either get the one in the wrong language, or get the wrong one in the right language. And so that's because, of course, you have more items that you're trying to access if you speak more than one language. The tip-of-the-tongue effects that are observed with bilinguals are interesting in light of other work that's been done with older adult bilinguals. Work by Ellen Bialystok and colleagues has actually suggested and found that older adult bilinguals seemed to show an advantage relative to older adult monolinguals. The advantage is there for younger subjects in their 40s. But once we get to over 60 years of age, bilinguals show an advantage on tasks that involve having to attend to one aspect of a stimulus and ignore another aspect of a stimulus. Furthermore, Craik and Bialystok have found that there seems to be a delay in the symptoms associated with Alzheimer's in bilinguals relative to monolinguals. Now you might say, well what do you mean by a delay in the symptoms, is it the onset, is it the pathology? Well, in fact it turns out that a number of people have observed that upon autopsy, many older adults who showed no impairment in any kind of cognitive or linguistic task actually showed the plaques and tangles associated with Alzheimer's disease. So there are many people who appear to have brain pathology, but are roughly asymptomatic. They just don’t show the symptoms associated with Alzheimer’s. So in the case of the work by Craik and Bialystok and colleagues, the idea was not look at the pathology, but to look at the delay of symptoms. And in this case, some of the bilinguals seem to show a delay in symptoms of quite a few years, and on average it's about four years later. And the idea is that the type of work that's needed to overcome this interference, to overcome the constant tip-of-the-tongue states that this type of work actually leads to an advantage.
