Wednesday, May 13, 2015

Consequences of Bilingualism for Cognitive Development

Bialystok, E. (2005). Consequences of bilingualism for cognitive development. In J. F. Kroll and A. M. B. DeGroot (Eds.) Handbook of bilingualism (pp. 417-432). Oxford, UK: Oxford University Press.

            The performance of bilingual and monolingual children on cognitive tasks has been compared for decades in psychology research. Historically, research has suggested a bilingual disadvantage for cognitive tasks, such as IQ measures and mathematics problems. As Bialystok presented in this review chapter, however, many of the measures used require a considerable amount of language processing, and bilingual children may be being tested in a language they are only beginning to learn. Of course, this would offer a clear advantage to monolingual children who are being tested in their native language. In light of this bias, recent testing has focused on creating more balanced tasks for monolingual and bilingual children. And in fact, as Bialystok’s review shows, bilingual children appear to show an advantage on certain kinds of tasks.

            Bilingual children seem to show a considerable advantage in tasks that require controlling attention and inhibiting misleading information. For example, in studies involving a Towers Task, young monolingual and bilingual children were shown two towers: One made of Lego blocks, and one made of Duplo blocks. The Duplo blocks were identical to the Lego blocks, except they were twice the size. The two towers contained the same amount of blocks, and children were required to count the number of blocks in each tower. The height of the Duplo tower was hard to ignore, but it was a misleading cue. Bilingual children performed better than their monolingual peers on counting the number of blocks in each tower, and ignoring the height of the tower. Bilingual children were more able to control their attention in attending to the counting task and ignoring the misleading height cue. Advantages for bilingual children on these skills seem to fit with the idea that they are constantly inhibiting interference between their two (or more) languages when they are using language.

            There does not seem to be a bilingual or a monolingual advantage on some cognitive tasks. However, certain features of the tasks will affect children’s performance. If the task requires a high amount of language skills, such as mathematical word problem, children being tested in their native language may perform better. Or, if the task requires controlling attention and inhibiting misleading information, bilingual children may show an advantage. When testing bilingual children it is important to take into account their verbal skills in the language in which they are being tested. And, it is interesting to consider the areas in which bilingual children may be at an advantage due to their ability to use multiple languages.

Blogger: Nicolette Noonan, PhD student with Drs. Lisa Archibald and Marc Joanisse, and coordinator of the Canadian SLP blog.

Monday, May 11, 2015

Working memory in multilingual children: Is there a bilingual effect?

Pascale Engel de Abreu. (2011). Working memory in multilingual children: Is there a bilingual effect? Memory, 19(5): 529-537.

Bilingual speakers have been found to outperform their monolingual peers on several tasks of executive control (Bialystok, 2001).Working memory is an important resource that has been linked to cognitive control. The working memory system updates and manipulates information held in short-term stores. The ability to hold relevant information in mind may be considered an important component of cognitive control.
The present study examined the hypothesis that bilingual children might exhibit advantages in working memory performance because of the constant need to exert cognitive control in selection of competing linguistic representations. This longitudinal study compared the performance of 22 Luxembourgish monolingual children and 22 simultaneous bilingual children aged six to eight years over a period of three years. All children completed an assessment of working memory (simple span and complex span tasks), fluid intelligence, and language (vocabulary and syntax).

Results reveal no significant differences between bilingual and monolingual children with respect to working memory and fluid intelligence tasks, whereas the performance of bilingual children was significantly lower on language measures. As such, the study provides no evidence for a bilingual advantage related to the working memory component of cognitive control.

Blogger: Areej Balilah, PhD Candidate

Monday, March 9, 2015

Sentence Processing

Nemeth, D., Janacsek, K., Csifcsak, G., Szvoboda, G., Howard, J. H., & Howard, D. V. (2011). Interference between sentence processing and probabilistic implicit sequence learning. PLoS One, 6 (3).

The present study investigated whether sentences are processed via a language-specific mechanism, or a domain-general mechanism. The authors differentiated between two theories in the literature that account for how humans process sentences. The first is a “dual systems” theory, which suggests that humans possess two distinct systems that process language: The declarative system, which is responsible for learning words, and the procedural system, which is responsible for learning sequences, such as the learning of grammar. The second is a “single system” theory, which suggests that words and grammar are learned by the same non-language specific system. This system relies on the learning of the statistically predictable regularities within language.

To investigate whether sentences are processed by a domain-specific or domain-general system, the authors used a dual task paradigm. Participants completed a non-linguistic Alternating Serial Reaction Time (ASRT) task, which involved the learning of a non-linguistic sequence. While completing the ASRT task, participants were concurrently engaged in a sentence-processing task (linguistic), a word recognition task (linguistic control), or a mathematical addition task (non-linguistic control). The authors hypothesized that learning within the ASRT task would be diminished by concurrent engagement in the sentence-processing task, which would suggest that both tasks involve a domain-general sequence learning mechanism

The main finding was that engagement in the sentence-processing task reduced sequence learning in the ASRT task. It was interesting that the mathematics task did not diminish learning, as it was the most difficult of the concurrent tasks. This result suggested that the interference between the sentence processing and ASRT task was not due to task difficulty. Overall, the authors suggested that sentence processing involves a domain-general sequence learning mechanism.

Blogger: Nicolette Noonan, PhD Student

Thursday, March 5, 2015

Naps promote rule abstraction in language-learning infants

Gomez, R. L., Bootzin, R. R., & Nadel, L. (2006). Naps promote abstraction in language-learning infants. Psychological Science, 17(8).

Infants accomplish an incredible amount of learning during their waking hours. However, as many parents may know, infants spend most of their day asleep. It is possible that sleep is very important for an infant’s cognitive and linguistic development. The present study investigated infant’s learning of an artificial language following either a period of sleep or wakefulness, and compared learning across groups. The results demonstrated that naps promote a qualitative change in infants’ learning.

Infants, although not yet fluent in their native language, are well on their way to acquiring language. Indeed, past research using artificial language paradigms has shown that infants are incredibly adept at uncovering the regularities within speech. In the present study, infants were familiarized with a language comprised of nonadjacent dependencies. Such a structure requires participants to track the dependencies between the first and third element, for example: pel-wadim-jic, or pel-kicey-jic. Here, the first nonsense word predicts the third, and the middle nonsense word can vary. This structure is also evident within English where there is a dependency between an auxiliary and an inflection with an intervening verb, for example: is playing.

The artificial language study was composed of 48 nonadjacent dependency strings (e.g.: pel-X-jic). Infants in the experimental condition heard each string 5 times in a familiarization phase. Infants were tested on their knowledge of strings from the familiarization phase, and novel strings that followed the same nonadjacent dependency rule. Testing took place four hours after the familiarization phase. During the four-hour break, infants either took a nap or stayed awake. Results demonstrated that infants who took a nap between the familiarization and test phase were better able to abstract the nonadjacenet dependency rule to novel stimuli. Infants who did not take a nap demonstrated memory for nonadjacent word pairs from the familiarization phase, but not novel items. It might be that infants who took a nap learned the “relationship in general” between the first and third word strings. This ability to abstract from a rule and apply it to novel situations is an essential process in language and cognitive development, and results from this study suggest that sleep may play an important role in this process.

Blogger: Nicolette Noonan, PhD Student

Wednesday, March 4, 2015

Naming speed and reading: From prediction to instruction

Kirby, J. R., Georgiou, G. K., Martinussen, R., & Parrila, R. (2010). Naming speed and reading: From prediction to instruction. Reading Research Quarterly, 45(3), 341–362.

Naming speed is the ability to name a series of familiar objects or letters at a fast pace. It is known to be related to reading ability, although the exact nature of that relationship is debated among researchers. A review of research shows that naming speed predicts performance on most reading measures, including single word reading, pseudoword reading, and reading comprehension. The relation between naming speed and reading is strongest in timed reading tasks, and in languages that use consistent spelling conventions.

One way to examine the relationship between naming speed, reading, and other processes underlying reading is to look to populations with impairments. Children with dyslexia show poor performance on naming speed and phonological awareness tasks compared to peers. Wolfe and Bowers (1999) call this the double-deficit hypothesis (DDH), arguing that naming speed and phonological awareness are separate constructs and can be separately impaired. Empirical support for DDH is mixed due to a variety of factors, such as variation between studies in participant reading ability, and spelling rules of the languages studied.

Studies looking at naming speed instruction have found that interventions targeting naming speed directly tended to show limited or temporary improvements at best. In contrast, broad reading interventions lead to gains on reading measures and only sometimes on naming speed. An additional finding in intervention literature is that a child’s naming speed most strongly predicted how well she would respond to a reading intervention. Taken together, these findings suggest that although naming speed is a strong predictor of reading ability, it may be more effective to offer intervention targeting other reading processes.

Blogger: Laura Pauls, PhD Student