Brain and Language Lab
The lab investigates the neurocognition of language and memory in healthy populations and disorders. To find out more, select an option from the menu. Listed below are some recent findings and other developments that may be of interest.
Bilingualism affects the structure of the brain in adults, as evidenced by experience-dependent grey and white matter changes in brain structures implicated in language learning, processing, or control. However, limited evidence exists on how bilingualism may influence brain development. We examined the developmental patterns of both grey and white matter structures in a cross-sectional study of a large sample (n=711 for grey matter, n=637 for white matter) of bilingual and monolingual participants, aged 3-21 years. Metrics of grey matter (thickness, volume, surface area) and white matter (fractional anisotropy, mean diffusivity) were examined across 41 cortical and subcortical brain structures and 20 tracts, respectively. We used generalized additive modelling to analyze whether, how, and where the developmental trajectories of bilinguals and monolinguals might differ. Bilingual and monolingual participants manifested distinct developmental trajectories in both grey and white matter structures. As compared to monolinguals, bilinguals showed: a) more grey matter (less developmental loss) starting during late childhood and adolescence, mainly in frontal and parietal regions (particularly in the inferior frontal gyrus pars opercularis, superior frontal cortex, inferior and superior parietal cortex, and precuneus); and b) higher white matter integrity (greater developmental increase) starting during mid-late adolescence, specifically in striatal-inferior frontal fibers. The data suggest that there may be a developmental basis to the well-documented structural differences in the brain between bilingual and monolingual adults.
Education appears to protect older adults, especially women, against memory loss, according to a new study. The results suggest that children—especially girls—who attend school for longer will have better declarative memory abilities in old age. Participants were shown drawings of objects, and then were tested several minutes later on their memory of these objects. Memory performance became progressively worse with aging. However, more years of early-life education countered these losses, especially in women. In men, the memory gains associated with each year of education were two times larger than the losses experienced during each year of aging. However, in women, the gains were five times larger. For example, the declarative memory abilities of an 80-year-old woman with a bachelor’s degree would be as good as those of a 60-year-old woman with a high school education. So, four extra years of education make up for the memory losses from 20 years of aging. The study may have implications for education, as well as for memory loss in Alzheimer’s disease and other dementias.
This study tested whether learning to read depends on declarative and procedural memory, two general-purpose learning and memory systems in the brain. We investigated this hypothesis in a longitudinal study of 140 children, who were tested four times annually between 1st and 4th grade. The study found that declarative learning abilities predicted reading abilities in first grade, while procedural learning abilities predicted reading ability in second grade. The findings suggest that reading acquisition may indeed depend on these well-studied learning and memory systems. The study has educational and clinical implications.
Developmental disorders of language include developmental language disorder, dyslexia, and motor-speech disorders such as articulation disorder and stuttering. These disorders have generally been explained by accounts that focus on their behavioral rather than neural characteristics; their processing rather than learning impairments; and each disorder separately rather than together, despite their commonalities and comorbidities. Here we update and review a unifying neurocognitive account—the Procedural circuit Deficit Hypothesis (PDH). The PDH posits that abnormalities of brain structures underlying procedural memory (learning and memory that rely on the basal ganglia and associated circuitry) can explain numerous brain and behavioral characteristics across learning and processing, in multiple disorders, including both commonalities and differences. We describe procedural memory, examine its role in various aspects of language, and then present the PDH and relevant evidence across language-related disorders. The PDH has substantial explanatory power, and both basic research and translational implications.
This chapter is an updated in-depth exposition of the declarative/procedural model, particularly as it applies to second language and bilingualism. After a primer on the brain, the chapter lays out background on the declarative and procedural memory systems, then predictions for both first and second language based on this independent knowledge of the memory systems, followed by the types of evidence that can test these predictions. Further sections discuss common misunderstandings about the declarative/procedural model, including comparisons between this and other models; a description of an exemplary study that tests the model in second language; and a discussion of the model with respect to the explicit/implicit debate.
Using a novel eye-tracking version of the serial reaction time (SRT) task, this study reveals that 9-month old infants can learn sequences. Moreover, direct comparisons with adults showed that infants and adults do not differ in how well they learn the sequences. This study is the first to report learning in an SRT task in infants as young as 9 months. The results suggest that procedural memory, that is, basal ganglia-based learning, is already highly functional as early as 9 month. The study also suggests that this eye-tracking SRT protocol is a promising procedure for measuring procedural memory in infants.
In a neuroanatomical meta-analysis of the serial reaction time task, we systematically examined the neural bases of sequence learning, which underlies numerous motor, cognitive, and social skills. Controlling for visual, motor, and other factors (in sequence-random block contrasts), sequence learning yielded consistent activation only in the basal ganglia, across the striatum (anterior/mid caudate nucleus and putamen) and the globus pallidus. In contrast, when visual, motor, and other factors were not controlled for, premotor cortical and cerebellar activation were additionally observed. The study provides solid evidence that, at least as tested with the serial reaction time task, sequence learning in humans relies on the basal ganglia, whereas cerebellar and premotor regions appear to contribute to aspects of the task not related to sequence learning itself.
Grammar learning activates anterior caudate/putamen (procedural memory) structures, while word learning activates ventral stream occipito-temporal (declarative memory) structures. Moreover, grammar learning predicted to rely especially on declarative memory (e.g., with explicit training) shows hippocampal involvement, while grammar learning predicted to rely particularly on procedural memory (e.g., with implicit training) shows anterior caudate/putamen involvement.
Child first language and adult second language are both tied to general-purpose learning systems in the brain that are evolutionarily ancient, and are also found in other vertebrates.
The declarative/procedural (DP) model posits that the learning, storage, and use of language critically depend on two learning and memory systems in the brain: declarative memory and procedural memory. Thus, on the basis of independent research on the memory systems, the model can generate specific and often novel predictions for language. Till now most such predictions and ensuing empirical work have been motivated by research on the neurocognition of the two memory systems. However, there is also a large literature on techniques that enhance learning and memory. The DP model provides a theoretical framework for predicting which techniques should extend to language learning, and in what circumstances they should apply. In order to lay the neurocognitive groundwork for these predictions, here we first summarize the neurocognitive fundamentals of the two memory systems and briefly lay out the resulting claims of the DP model for both first and second language. We then provide an overview of learning and memory enhancement techniques before focusing on two techniques – spaced repetition and retrieval practice – that have been linked to the memory systems. Next, we present specific predictions for how these techniques should enhance language learning, and review existing evidence, which suggests that they do indeed improve the learning of both first and second language. Finally, we discuss areas of future research and implications for second language pedagogy.
Does being bilingual help your brain learn additional languages? The answer seems to be yes: if you've learned two languages early in life, it may help your brain learn another language later on.
Multiple micronutrient supplementation of pregnant women benefits the cognition of their children at ages 9-12 years, as shown in a study that examined 2879 children in Lombok, Indonesia.
Children with Tourette syndrome show evidence for speeded grammatical combination in phonology (in a nonword repetition task), complementing previous evidence for speeded combination in morphology.
Declarative memory compensates for multiple deficits across neurodevelopmental disorders, including deficits of social skills in autism, reading in dyslexia, and grammar in specific language impairment.
In patients with early Parkinson’s disease, subthalamic nucleus deep brain stimulation affects grammatical (but not lexical) abilities, and naming manipulated (but not non-manipulated) objects.
Evidence that grammar relies on procedural memory in typically developing (TD) children, but on declarative memory in children with specific language impairment (SLI); both rely on declarative memory for lexical abilities.
Complex linguistic forms can be stored or composed, as a function of multiple interacting factors, including regularity, sex, first vs. second language, and both length of residence and age of arrival in second language.