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.
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.