Search

Cognitive neuroscience has highlighted the cerebral cortex while often overlooking subcortical structures. This cortical proclivity is found in basic and translational research on many aspects of cognition, especially higher cognitive domains such as language, reading, music, and math. We suggest that, for both anatomical and evolutionary reasons, multiple subcortical structures play substantial roles across higher and lower cognition. We present a comprehensive review of existing evidence, which indeed reveals extensive subcortical contributions in multiple cognitive domains. We argue that the findings are overall both real and important. Next, we advance a theoretical framework to capture the nature of (sub)cortical contributions to cognition. Finally, we propose how new subcortical cognitive roles can be identified by leveraging anatomical and evolutionary principles, and we describe specific methods that can be used to reveal subcortical cognition. Altogether, this review aims to advance cognitive neuroscience by highlighting subcortical cognition and facilitating its future investigation.

Many but not all cognitive abilities decline during ageing. Some even improve due to lifelong experience. The critical capacities of attention and executive functions have been widely posited to decline. However, these capacities are composed of multiple components, so multifaceted ageing outcomes might be expected. Indeed, prior findings suggest that whereas certain attention/executive functions clearly decline, others do not, with hints that some might even improve. We tested ageing effects on the alerting, orienting and executive (inhibitory) networks posited by Posner and Petersen’s influential theory of attention, in a cross-sectional study of a large sample (N = 702) of participants aged 58–98. Linear and nonlinear analyses revealed that whereas the efficiency of the alerting network decreased with age, orienting and executive inhibitory efficiency increased, at least until the mid-to-late 70s. Sensitivity analyses indicated that the patterns were robust. The results suggest variability in age-related changes across attention/executive functions, with some declining while others improve. Contradicting the hypothesis that attention and executive functions broadly decline with age, Verissimo et al. show that efficiency of attentional orienting and executive inhibition increased into the 70s, while attentional alerting declined.

Purpose This study examined procedural and declarative learning and consolidation abilities in adults with developmental language disorder (DLD) relative to their typical language (TD) peers. Method A total of 100 young adults (age 18–24 years) with ( n = 21) and without ( n = 79) DLD participated across two sites. Performance measures on a recognition memory task and a serial reaction time task were used to assess declarative and procedural memory, respectively. Performance was measured shortly after learning (8 a.m.) and again after a 12-hr, overnight delay (8 a.m.). Results Linear mixed-effects modeling was used to examine the effects of time and group membership on task performance. For the serial reaction time task, there were significant effects of group (TD > DLD) and time (Day 1 > Day 2), but no interaction between them. For the recognition memory task, there was a significant interaction between group and time, driven by overnight gains in the TD group, combined with stable performance across days by those with DLD. Conclusions In procedural memory, adults with DLD demonstrate a learning deficit relative to adults without DLD, but appear to have comparable retention of learned information. In declarative memory, adults with DLD demonstrate a deficit in the overnight enhancement of memory retrieval, despite typical-like learning exhibited when tested shortly after encoding. Supplemental Material https://doi.org/10.23641/asha.13626485

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.

Language learning as an adult, though often difficult, is quite common. Nevertheless, the neural substrates of this process remain unclear, even though identifying them should clarify how language is learned and could lead to improved success at this endeavor. We addressed this gap by conducting multiple neuroanatomical meta-analyses to synthesize the functional neuroimaging literature of language learning. We focused on learning lexical and grammatical knowledge, two building blocks of language. Lexical and grammatical learning yielded overlapping activation in frontal (e.g., BA 44/45) and posterior parietal regions. Only lexical learning showed ventral occipito-temporal (ventral stream) activation, while only grammatical learning showed basal ganglia (anterior caudate/putamen) activation. To further elucidate the neurocognition of grammar learning, we also tested specific predictions of the declarative/procedural model of language. Consistent with the model, grammar learning predicted to rely especially on declarative memory (e.g., with explicit training) showed hippocampal involvement, while grammar learning predicted to rely particularly on procedural memory (e.g., with implicit training) showed anterior caudate/putamen involvement. Finally, given the prevalence of research on artificial grammars, we performed separate analyses of artificial grammar and non-artificial grammar (e.g., miniature language) paradigms. These yielded overlapping activation, especially in BA 44, underscoring the validity of artificial grammars as models for grammar learning in natural languages. In sum, the study elucidates the empirical and theoretical landscape of language learning and has applied implications.

Individual differences in phonological processing abilities have often been attributed to perceptual factors, rather than to factors relating to learning and memory. Here, we consider the contribution of individual differences in declarative and procedural memory to phonological processing performance in adulthood. We examined the phonological processing, declarative memory, and procedural memory abilities of 79 native English-speaking young adults with typical language and reading abilities. Declarative memory was assessed with a recognition memory task of real and made-up objects. Procedural memory was assessed with a serial reaction time task. For both tasks, learning was assessed shortly after encoding, and again after a 12-h, overnight delay. We regressed phonological processing ability with memory performance on both days. We found that declarative memory, but not procedural memory, was highly predictive of phonological processing abilities. Specifically, declarative memory scores obtained shortly after learning were associated with non-word repetition performance, whereas declarative memory scores obtained after the overnight delay were associated with phonological awareness. Procedural memory was not associated with either of the phonological processing measures. We discuss these findings in the context of adult participants with mature phonological systems. We examine possible implications for the relationship between declarative memory and phonological processing in adulthood.

Item does not contain fulltext Lexical-processing declines are a hallmark of aging. However, the extent of these declines may vary as a function of different factors. Motivated by findings from neurodegenerative diseases and healthy aging, we tested whether 'motor-relatedness' (the degree to which words are associated with particular human body movements) might moderate such declines. We investigated this question by examining data from three experiments. The experiments were carried out in different languages (Dutch, German, English) using different tasks (lexical decision, picture naming), and probed verbs and nouns, in all cases controlling for potentially confounding variables (e.g., frequency, age-of-acquisition, imageability). Whereas 'non-motor words' (e.g., steak) showed age-related performance decreases in all three experiments, 'motor words' (e.g., knife) yielded either smaller decreases (in one experiment) or no decreases (in two experiments). The findings suggest that motor-relatedness can attenuate or even prevent age-related lexical declines, perhaps due to the relative sparing of neural circuitry underlying such words. 13 p.

Rationale Brain development occurs rapidly during early childhood and continues throughout middle childhood. Early and later windows of opportunity exist to alter developmental trajectories. Few studies in low- and middle-income countries have examined the importance of the timing of exposure to risks for poor pre-adolescent cognitive and social-emotional outcomes. Methods We assessed 359 children who participated in two follow-up studies of the Supplementation with Multiple Micronutrients Intervention Trial conducted in Indonesia in 2001–2004: at 3.5 years in 2006 and 9–12 years in 2012–2014. Using structural equation models, we examined indicators of early childhood (3.5 y) and pre-adolescent (9–12 y) exposure to risks (child height-for-age z-score [HAZ], hemoglobin [Hb], maternal depressive symptoms [MDS], home environment [HOME]), with two developmental outcomes: cognitive ability and social-emotional problems. We characterized patterns of change by calculating residuals of indicators measured earlier (3.5 y) predicting the same indicators measured later (9–12 y), for example, the residual of 3.5 y MDS predicting 9–12 y MDS (rMDS). Results Three early risk indicators (HOME, Hb, and MDS) were indirectly associated with pre-adolescent cognitive scores through early cognitive scores (HOME: 0.15, [95% CI 0.09, 0.21]; Hb: 0.08 [0.04, 0.12], MDS: −0.07 [-0.12, −0.02]). Pre-adolescent cognitive scores were also associated with change in MDS (rMDS: −0.13 [-0.23, −0.02]) and Hb (rHb: 0.10 [0.00, 0.20]) during middle childhood. For pre-adolescent social-emotional problems, both early childhood MDS (0.31 [0.19, 0.44]) and change in MDS during middle childhood (rMDS: 0.48 [0.37, 0.60]) showed strong direct associations with this outcome. Conclusions Our findings confirm those of previous studies that prevention of risk exposures during early childhood is likely to support long-term child development. It also adds evidence to a previously scarce literature for the middle childhood period. Prevention of maternal depressive symptoms and child anemia during middle childhood should be assessed for effectiveness to support child development.

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, and 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, and surface area) and white matter (fractional anisotropy and 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. Electronic supplementary material The online version of this article (10.1007/s00429-020-02115-5) contains supplementary material, which is available to authorized users.

Declarative memory is critical for everyday learning. Although declarative memory abilities decline with age, evidence suggests that sex and early-life education might moderate these weaknesses. However, limitations in previous studies, such as small education ranges and unexamined potential interactions, have stymied our understanding of these possibly ‘protective’ variables. We investigated effects of sex and education on nonverbal declarative memory in 704 older adults (aged 58–98, 0–17 years of education) in a non-Western (Taiwanese) population, by probing recognition memory following incidental encoding. Items were drawings of real (e.g., hairbrush) and made-up objects. Mixed-effects regression revealed that age negatively impacted declarative memory, though this age effect was moderated by sex and object type. It was steeper for males than females (yielding a female advantage from age 70), though only for real objects. Remembering made-up objects showed shallower declines with no sex differences. Education was positively associated with memory, but also interacted with sex and object type: education benefited women more than men, and remembering real more than made-up objects. In men, the overall memory gains associated with each year of education were two times larger than the losses experienced during each year of aging; in women, they were five times larger. The findings suggest that nonverbal memory in older adults is associated negatively with age but positively with education, though both effects are modulated by sex, and by whether learning relates to pre-existing knowledge or new information. The study suggests downstream benefits from education, especially for girls.

Declarative memory abilities may be important for children who are learning to read in a second language. In the present study, we investigated declarative memory in a recognition memory task in 7-to-13-year-old, Kannada native-speaking, good (n = 22) and poor (n = 22) readers of English, in Karnataka, India. Recognition memory was tested shortly (~10 minutes) after encoding (day 1) and again on the next (day 2). Analyses revealed that the two groups did not differ in recognition memory performance on day 1. On day 2, the good readers improved from day 1, whereas poor readers did not. A partial correlation analysis suggests that consolidation – the change in performance in recognition memory between the two days – is associated with reading skills in good readers, but not in poor readers. Taken together, these results suggest that children who struggle to read in a second language may have deficits in declarative memory consolidation.

This article provides a description of eye movement data collected during an ocular-motor serial reaction time task. Raw gaze data files for 63 infants and 24 adults along with the data processing and analysis script for extracting saccade latencies, summarizing participants performance, and testing statistical differences, are hosted on Open Science Framework (OSF). Files (in Matlab format) available for download allow for replication of the results reported in "Procedural memory in infancy: Evidence from implicit sequence learning in an eye-tracking paradigm" [1]. (C) 2020 The Authors. Published by Elsevier Inc. Funding Agencies|Swedish Research Council (Vetenskapsradet)Swedish Research Council [2016-01033]

Working memory (WM), which underlies the temporary storage and manipulation of information, is critical for multiple aspects of cognition and everyday life. Nevertheless, research examining WM specifically in older adults remains limited, despite the global rapid increase in human life expectancy. We examined WM in a large sample ( N = 754) of healthy older adults (aged 58-89) in a non-Western population (Chinese speakers) in Taiwan, on a digit n-back task. We tested not only the influence of age itself and of load (1-back vs. 2-back) but also the effects of both sex and education, which have been shown to modulate WM abilities. Mixed-effects regression revealed that, within older adulthood, age negatively impacted WM abilities (with linear, not nonlinear, effects), as did load (worse performance at 2-back). In contrast, education level was positively associated with WM. Moreover, both age and education interacted with sex. With increasing age, males showed a steeper WM decline than females; with increasing education, females showed greater WM gains than males. Together with other findings, the evidence suggests that age, sex, and education all impact WM in older adults, but interact in particular ways. The results have both basic research and translational implications and are consistent with particular benefits from increased education for women.

Inflectional morphology has been intensively studied as a model of language productivity. However, little is known about how properties of the input affect the emergence of productive affixation. W...

Procedural memory, which is rooted in the basal ganglia, underlies the learning and processing of numerous automatized motor and cognitive skills, including in language. Not surprisingly, disorders with basal ganglia abnormalities have been found to show impairments of procedural memory. However, brain abnormalities could also lead to atypically enhanced function. Tourette syndrome (TS) is a candidate for enhanced procedural memory, given previous findings of enhanced TS processing of grammar, which likely depends on procedural memory. We comprehensively examined procedural learning, from memory formation to retention, in children with TS and typically developing (TD) children, who performed an implicit sequence learning task over two days. The children with TS showed sequence learning advantages on both days, despite a regression of sequence knowledge overnight to the level of the TD children. This is the first demonstration of procedural learning advantages in any disorder. The findings may further our understanding of procedural memory and its enhancement. The evidence presented here, together with previous findings suggesting enhanced grammar processing in TS, underscore the dependence of language on a system that also subserves visuomotor sequencing.

Do the mechanisms underlying language in fact serve general-purpose functions that preexist this uniquely human capacity? To address this contentious and empirically challenging issue, we systematically tested the predictions of a well-studied neurocognitive theory of language motivated by evolutionary principles. Multiple metaanalyses were performed to examine predicted links between language and two general-purpose learning systems, declarative and procedural memory. The results tied lexical abilities to learning only in declarative memory, while grammar was linked to learning in both systems in both child first language and adult second language, in specific ways. In second language learners, grammar was associated with only declarative memory at lower language experience, but with only procedural memory at higher experience. The findings yielded large effect sizes and held consistently across languages, language families, linguistic structures, and tasks, underscoring their reliability and validity. The results, which met the predicted pattern, provide comprehensive evidence that language is tied to general-purpose systems both in children acquiring their native language and adults learning an additional language. Crucially, if language learning relies on these systems, then our extensive knowledge of the systems from animal and human studies may also apply to this domain, leading to predictions that might be unwarranted in the more circumscribed study of language. Thus, by demonstrating a role for these systems in language, the findings simultaneously lay a foundation for potentially important advances in the study of this critical domain.

We investigated whether learning and retaining vocabulary in a second language (L2) can be improved by leveraging a combination of memory enhancement techniques. Specifically, we tested whether combining retrieval practice, spacing, and related manipulations in a ‘multidomain’ pedagogical approach enhances vocabulary acquisition as compared to a typical learning approach. In a classroom-laboratory design, 48 Turkish university students studying L2 English were trained on 64 English words over 17 days. They were assigned to either a ‘typical’ study regimen of (re)studying the words on the first day (initial study) and last day (cramming) of training, or an ‘optimized’ regimen of retrieval practice (retrieving the words), moreover with feedback, spaced throughout the period, moreover with expanding gaps. The target words were tested before training (pre-test) and one and 11 days afterwards (post-tests). Mixed-effects modeling revealed a training-group by test-session interaction, due to greater improvements from optimized training (a striking 18 percentage-point accuracy increase from pre-test to both post-tests) than typical training (an 8 percentage-point increase). Further analyses showed that the optimized training advantages were mainly driven by high (rather than low) frequency words. Overall, the results suggest that a multidomain approach of combining different memory enhancement techniques can lead to substantial gains in both the learning and retention of L2 words, as compared to a typical study pattern. The findings have implications for L2 learning and pedagogy.

It has been suggested that bilinguals learn additional languages ‘better’ than monolinguals. However, evidence is sparse, particularly for grammar. We examined behavioral and neural correlates of learning an additional (artificial) language in early Mandarin–English bilinguals, compared to English monolinguals. Following grammar instruction, participants practiced comprehension and production, and judged grammaticality at low and high proficiency while event-related potentials (ERPs) were acquired. Bilinguals and monolinguals did not differ on behavioral measures, but showed distinct ERP patterns. At low proficiency only bilinguals showed a P600, a common ERP correlate of syntactic processing in native speakers of languages. At high proficiency both groups showed P600s, though the monolinguals also evidenced an anterior positivity not typically found in native speakers of languages during syntactic processing. These findings suggest that, even without bilingual/monolingual behavioral differences, bilinguals show ERP patterns for an additional language that are more similar to those of native speakers of languages.

OBJECTIVES: To determine the association of biomedical and socio-environmental risk factors during pregnancy, early, and later childhood with cognitive (IQ), motor, social-emotional (SE), and executive function (EF) at age 3.5 and 9–12 y in Indonesia. METHODS: Children born to pregnant women enrolled in the Supplementation with Multiple Micronutrients Intervention Trial (SUMMIT) in 2001–2004 participated in follow-up studies at age 3.5 y in 2006 and 9–12 y in 2013. We assessed 359 children at both time points for outcomes of IQ, motor, SE and EF. We also assessed predictors of outcomes including biomedical risks (small for gestational age at birth: SGA; height-for-age z-score: HAZ; and child hemoglobin: Hb) and socio-environmental risks (HOME Inventory; maternal depression: MD). We calculated the residuals of earlier risks predicting the later scores, e.g., the residual of SGA at birth predicting HAZ at 3.5 y (rHAZ1), representing the deviation of HAZ at 3.5 y from the child's expected HAZ based on SGA. In Model 1, we entered SGA, representing in utero exposures. In Model 2, we added indicators at 3.5 y (rHAZ1, Hb, HOME, MD). In Model 3, we added indicators at 9–12 y (rHAZ2, rHb, rHOME, rMD) and the corresponding 3.5 y IQ, motor, SE, or EF scores. RESULTS: The coefficients for outcomes at early and later time points (Figure 1) show that SGA was not associated with any scores. Early (3.5 y) childhood rHAZ1 was associated with early IQ, motor, and EF, but was not independently associated with later (9–12 y) IQ, motor, or EF. Later childhood rHAZ2 was not associated with any scores. Early childhood HOME was independently associated with both early and later IQ, motor, and EF, while later childhood rHOME was not associated with any scores. Early Hb was not associated with any scores and later rHb was associated with motor scores only. MD during early childhood and rMD during later childhood were independently associated with later childhood SE. CONCLUSIONS: These findings support the importance of early and continual intervention throughout childhood to support healthy growth and even more importantly maternal mental health and nurturing home environments. This is essential for longer-term IQ, motor, SE, and EF. FUNDING SOURCES: Grand Challenges Canada, Allen & Turner Foundations, UNICEF, Centre for Health and Human Development, USAID-Indonesia, USDA NIFA #CA-D-NTR-2493-H. SUPPORTING TABLES, IMAGES AND/OR GRAPHS

The primary motor area (M1) has been implicated in visuomotor sequence learning. However, it has been suggested there are multiple neural networks that undertake visuomotor sequence learning. The role of M1 in sequence learning may be specific to learning simple sequences comprising predictable associations between adjacent movements. This study aimed to investigate the role of M1 in learning simple ("first-order conditional") and more complex ("second-order conditional") sequences. It was hypothesized that continuous theta burst stimulation (cTBS) over M1 would result in poorer learning of the simple sequence only. Forty-eight healthy adults received cTBS to either M1 or the parietal lobe or received sham cTBS before immediately completing 2 visuomotor sequence learning tasks. The tasks only differed in relation to the structure (i.e., simple vs. complex) of the sequence. The group who received cTBS over M1 demonstrated significantly poorer learning of the simple sequence in comparison to the more complex sequence. The parietal lobe stimulation and sham stimulation did not affect learning of either sequence. This is the first study to show differential involvement of M1 in visuomotor sequence learning, dependent on sequence structure. The study provides new evidence that sequence learning might be supported by different networks in the brain. Specifically, M1 sequence learning appears to be important for learning simple item-to-item associations but not for more complex sequences. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Objective Parkinson's disease (PD), which involves the degeneration of dopaminergic basal ganglia neurons, appears to affect language. We investigated which aspects of language are impaired in PD and what moderates these impairments. Our predictions were based on the declarative/procedural model of language, which links grammar, including in regular inflection, to procedural memory and left-lateralized basal ganglia dopaminergic circuits but links lexical memory, including irregulars, to declarative memory. Because females tend to show declarative memory advantages as compared to males, the model predicts that females rely more on this system for regulars, which can be stored as chunks. Method We probed regular/irregular Farsi past-tense production in 40 Farsi-speaking patients with moderate-to-severe nondemented PD (half female) and 40 normal controls (half female). Results Consistent with our predictions, we found that male, but not female, PD patients showed greater deficits at regular than irregular past-tense production. The females' impairment was mildest for regulars, likely from compensatory storage, as revealed by regular past-tense frequency effects only in females. Right-side hypokinesia (linked to left basal ganglia degeneration) correlated negatively with accuracy of regulars but not irregulars. Similarly, the levodopa equivalent dose of patients' last medication correlated only with regulars. Conclusions The results suggest that language is impaired in PD, but the impairments are moderated by multiple factors, including the type of linguistic knowledge, the degree of left basal ganglia degeneration, dopamine, and sex. The findings underscore the impact of sex on the neurocognition of language and the roles of left basal ganglia dopaminergic circuits in aspects of rule-governed grammar. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Procedural memory underpins the learning of skills and habits. It is often tested in children and adults with sequence learning on the serial reaction time (SRT) task, which involves manual motor control. However, due to infants slowly developing control of motor actions, most procedures that require motor control cannot be examined in infancy. Here, we investigated procedural memory using an SRT task adapted for infants. During the task, images appeared at one of three locations on a screen, with the location order following a five-item recurring sequence. Three blocks of recurring sequences were followed by a random-order fourth block and finally another block of recurring sequences. Eye movement data were collected for infants (n = 35) and adults (n = 31). Reaction time was indexed by calculating the saccade latencies for orienting to each image as it appeared. The entire protocol took less than 3 min. Sequence learning in the SRT task can be operationalized as an increase in latencies in the random block as compared with the preceding and following sequence blocks. This pattern was observed in both the infants and adults. This study is the first to report learning in an SRT task in infants as young as 9 months. This SRT protocol is a promising procedure for measuring procedural memory in infants. (C) 2019 Elsevier Inc. All rights reserved. Funding Agencies|Swedish Research Council (Vetenskapsradet)Swedish Research Council [2016-01033]

This study examined whether the P1, N1, and P3 ERP components would be sensitive to sequence learning effects on the serial reaction time task. On this task, participants implicitly learn a visuospatial sequence. Participants in this study were 35 healthy adults. Reaction time (RT) data revealed that, at the group level, participants learned the sequence. Specifically, RT became faster following repeated exposure to the visuospatial sequence and then slowed down in a control condition. Analyses of ERP data revealed no evidence for sequence learning effects for the N1 or P3 component. However, sequence learning effects were observed for the P1 component. Mean P1 amplitude mirrored the RT data. The analyses showed that P1 amplitude significantly decreased as participants were exposed to the sequence but then significantly increased in the control condition. This suggests that visuospatial sequence learning can modulate visual attention levels. Specifically, it seems that, as sequence knowledge is acquired, fewer demands are placed on visual attention resources.

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.

Tourette syndrome (TS) is characterized by motor and vocal tics, and frontal/basal-ganglia abnormalities. Whereas cognitive strengths have been found in other neurodevelopmental disorders, less attention has been paid to strengths in TS, or to verbal strengths in any neurodevelopmental disorder. We examined whether the finding of speeded TS production of rule-governed morphological forms (e.g., "slipped") that involve composition (Walenski, Mostofsky, & Ullman, 2007) might extend to another language domain, phonology. Thirteen children with TS and 14 typically-developing (TD) children performed a non-word repetition task: they repeated legal phonological strings (e.g.,"naichovabe"), a task that taps rule-governed (de)composition. Parallel to the morphology findings, the children with TS showed speeded production, while the two groups had similar accuracy. The results were not explained by potentially confounding factors, including IQ. Overall, the findings suggest that rule-governed grammatical composition may be speeded in TS, perhaps due to frontal/basal-ganglia abnormalities.

Sequence learning underlies numerous motor, cognitive, and social skills. Previous models and empirical investigations of sequence learning in humans and non-human animals have implicated cortico-basal ganglia-cerebellar circuitry as well as other structures. To systematically examine the functional neuroanatomy of sequence learning in humans, we conducted a series of neuroanatomical meta-analyses. We focused on the serial reaction time (SRT) task. This task, which is the most widely used paradigm for probing sequence learning in humans, allows for the rigorous control of visual, motor, and other factors. Controlling for these 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 (in a global analysis with all sequence-baseline contrasts, not just sequence-random contrasts), premotor cortical and cerebellar activation were additionally observed. The study provides solid evidence that, at least as tested with the visuo-motor SRT 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. The findings have both basic research and translational implications.

Parkinson's disease (PD), which involves basal ganglia degeneration, affects language as well as motor function. However, which aspects of language are impaired in PD and under what circumstances remains unclear. We examined whether lexical and grammatical aspects of language are differentially affected in PD, and whether this dissociation is moderated by sex as well as the degree of basal ganglia degeneration. Our predictions were based on the declarative/procedural model of language. The model posits that grammatical composition, including in regular inflection, depends importantly on left basal ganglia procedural memory circuits, whereas irregular and other lexicalized forms are memorized in declarative memory. Since females tend to show declarative memory advantages as compared to males, the model further posits that females should tend to rely on this system for regulars, which can be stored as lexicalized chunks. We tested non-demented male and female PD patients and healthy control participants on the intensively studied paradigm of English regular and irregular past-tense production. Mixed-effects regression revealed PD deficits only at regular inflection, only in male patients. The degree of left basal ganglia degeneration, as reflected by right-side hypokinesia, predicted only regular inflection, and only in male patients. Left-side hypokinesia did not show this pattern. Past-tense frequency effects suggested that the female patients retrieved regular as well as irregular past-tense forms from declarative memory, whereas the males retrieved only irregulars. Sensitivity analyses showed that the pattern of findings was robust. The results, which are consistent with the declarative/procedural model, suggest a grammatical deficit in PD due to left basal ganglia degeneration, with a relative sparing of lexical retrieval. Female patients appear to compensate for this deficit by relying on chunks stored in declarative memory. More generally, the study elucidates the neurocognition of inflectional morphology and provides evidence that sex can influence how language is computed in the mind and brain.

The U.S. National Institutes of Health (NIH) announced last May that steps will be taken to address the over-reliance on male cells and animals in preclinical research. To further address this announcement, in September 2014, scientists with varying perspectives came together at Georgetown University to discuss the following questions. (1) What metrics should the NIH use to assess tangible progress on policy changes designed to address the over-reliance on male cells and animals in preclinical research? (2) How effective can education be in reducing the over-reliance on male cells and animals in preclinical research and what educational initiatives sponsored by the NIH would most likely effect change? (3) What criteria should the NIH use to determine rigorously defined exceptions to the future proposal requirement of a balance of male and female cells and animals in preclinical studies? (4) What additional strategies in addition to proposal requirements should NIH use to reduce the overreliance of male cells and animals in preclinical research? The resulting consensus presented herein includes input from researchers not only from diverse disciplines of basic and translational science including biology, cell and molecular biology, biochemistry, physiology, pharmacology, neuroscience, cardiology, endocrinology, nephrology, psychiatry, and obstetrics and gynecology, but also from recognized experts in publishing, industry, advocacy, science policy, clinical medicine, and population health. We offer our recommendations to aid the NIH as it selects, implements, monitors, and optimizes strategies to correct the over-reliance on male cells and animals in preclinical research.—Sandberg, K., Umans, J. G., Georgetown Consensus Conference Work Group. Recommendations concerning the new U.S. National Institutes of Health initiative to balance the sex of cells and animals in preclinical research.

Apolipoprotein E (APOE) genotype is believed to play a role in the onset of dementia, though less is known about its relationship with non-pathogenic age-related cognitive decline. We assessed whether APOE was a risk factor for cognitive decline among older Taiwanese adults using nationally representative data. General cognition was measured longitudinally over eleven years; domain-specific cognitive assessments of working memory, declarative learning and three aspects of attention (executive function, alerting, and orientation) were performed once. Having at least one risky APOE allele was associated with more rapid longitudinal cognitive decline compared to those with no risky alleles. Some evidence from the cross-sectional analysis of domain-specific cognitive assessments suggested that APOE genotype may be more closely associated with working memory and declarative learning than with attention. Most genetic studies of cognition include only populations of European descent; extension is crucial. This study confirmed the association between APOE genotype and the rate of cognitive decline in a predominantly Han Chinese population. Additional studies on diverse populations are warranted.

Procedural memory, which is rooted in the basal ganglia, plays an important role in the implicit learning of motor and cognitive skills. Few studies have examined procedural learning in either Tourette syndrome (TS) or Attention Deficit Hyperactivity Disorder (ADHD), despite basal ganglia abnormalities in both of these neurodevelopmental disorders. We aimed to assess procedural learning in children with TS (n = 13), ADHD (n = 22), and comorbid TS-ADHD (n = 20), as well as in typically developing children (n = 21). Procedural learning was measured with a well-studied implicit probabilistic sequence learning task, the alternating serial reaction time task. All four groups showed evidence of sequence learning, and moreover did not differ from each other in sequence learning. This result, from the first study to examine procedural memory across TS, ADHD and comorbid TS-ADHD, is consistent with previous findings of intact procedural learning of sequences in both TS and ADHD. In contrast, some studies have found impaired procedural learning of non-sequential probabilistic categories in TS. This suggests that sequence learning may be spared in TS and ADHD, while at least some other forms of learning in procedural memory are impaired, at least in TS. Our findings indicate that disorders associated with basal ganglia abnormalities do not necessarily show procedural learning deficits, and provide a possible path for more effective diagnostic tools, and educational and training programs.

Summary Background Brain and cognitive development during the first 1000 days from conception are affected by multiple biomedical and socioenvironmental determinants including nutrition, health, nurturing, and stimulation. An improved understanding of the long-term influence of these factors is needed to prioritise public health investments to optimise human development. Methods We did a follow-up study of the Supplementation with Multiple Micronutrients Intervention Trial (SUMMIT), a double-blind, cluster-randomised trial of maternal supplementation with multiple micronutrients (MMN) or iron and folic acid (IFA) in Indonesia. Of 27 356 live infants from birth to 3 months of age in 2001–04, we re-enrolled 19 274 (70%) children at age 9–12 years, and randomly selected 2879 from the 18 230 who were attending school at a known location. Of these, 574 children were oversampled from mothers who were anaemic or malnourished at SUMMIT enrolment. We assessed the effects of MMN and associations of biomedical (ie, maternal and child anthropometry and haemoglobin and preterm birth) and socioenvironmental determinants (ie, parental education, socioeconomic status, home environment, and maternal depression) on general intellectual ability, declarative memory, procedural memory, executive function, academic achievement, fine motor dexterity, and socioemotional health. The SUMMIT trial was registered, number ISRCTN34151616. Findings Children of mothers given MMN had a mean score of 0·11 SD (95% CI 0·01–0·20, p=0·0319) higher in procedural memory than those given IFA, equivalent to the increase in scores with half a year of schooling. Children of anaemic mothers in the MMN group scored 0·18 SD (0·06–0·31, p=0·0047) higher in general intellectual ability, similar to the increase with 1 year of schooling. Overall, 18 of 21 tests showed a positive coefficient of MMN versus IFA (p=0·0431) with effect sizes from 0·00–0·18 SD. In multiple regression models, socioenvironmental determinants had coefficients of 0·00–0·43 SD and 22 of 35 tests were significant at the 95% CI level, whereas biomedical coefficients were 0·00–0·10 SD and eight of 56 tests were significant, indicating larger and more consistent impact of socioenvironmental factors (p Interpretation Maternal MMN had long-term benefits for child cognitive development at 9–12 years of age, thereby supporting its role in early childhood development, and policy change toward MMN. The stronger association of socioenvironmental determinants with improved cognition suggests present reproductive, maternal, neonatal, and child health programmes focused on biomedical determinants might not sufficiently enhance child cognition, and that programmes addressing socioenvironmental determinants are essential to achieve thriving populations. Funding Grand Challenges Canada Saving Brains Program.

Autism is characterized by language and communication deficits. We investigated grammatical and lexical processes in high-functioning autism by contrasting the production of regular and irregular past-tense forms. Boys with autism and typically-developing control boys did not differ in accuracy or error rates. However, boys with autism were significantly faster than controls at producing rule-governed past-tenses (slip-slipped, plim-plimmed, bring-bringed), though not lexically-dependent past-tenses (bring-brought, squeeze-squeezed, splim-splam). This pattern mirrors previous findings from Tourette syndrome attributed to abnormalities of frontal/basal-ganglia circuits that underlie grammar. We suggest a similar abnormality underlying language in autism. Importantly, even when children with autism show apparently normal language (e.g., in accuracy or with diagnostic instruments), processes and/or brain structures subserving language may be atypical in the disorder.

Language is often assumed to rely on domain-specific neurocognitive substrates. However, this human capacity in fact seems to crucially depend on general-purpose memory systems in the brain. Evidence suggests that lexical memory relies heavily on declarative memory, which is specialized for arbitrary associations and is rooted in temporal lobe structures. The mental grammar instead relies largely on procedural memory, a system that underlies rules and sequences, and is rooted in frontal/basal-ganglia structures. Developmental and adult-onset disorders such as Specific Language Impairment, autism, Tourette syndrome, Parkinson’s disease, Huntington’s disease, and non-fluent aphasia each seem to involve particular grammatical deficits and analogous non-linguistic procedural memory impairments, as well as abnormalities of procedural memory brain structures. Lexical and declarative memory remain relatively intact in these disorders, and may play compensatory roles. In contrast, Alzheimer’s disease, semantic dementia, fluent aphasia and amnesia each affect lexical and declarative memory, and involve abnormalities of declarative memory brain structures, while leaving grammar and procedural memory largely intact. Overall, the evidence suggests that declarative and procedural memory play critical roles in language disorders, as well as in language more generally.