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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.

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.

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.

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.

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.

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.

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.

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.

Affixal inflectional morphology has been intensively examined as a model of productive aspects of language. Nevertheless, little is known about the neurocognition of the learning and generalization of affixal inflection, or the influence of certain factors that may affect these processes. In an event-related fMRI study, we examined the neurocognition of the learning and generalization of plural inflections in an artificial language, as well as the influence of both affix type frequency (the proportion of words receiving a given affix) and affix predictability (based on phonological cues in the stem). Adult participants were trained in three sessions, and were scanned after the first and last sessions while inflecting trained and untrained words. Untrained words yielded more activation than trained words in medial frontal (including pre-SMA) and left inferior frontal cortices, which have previously shown activation in compositional grammatical processing. A reliance on phonological cues for untrained word inflection correlated positively with pre-SMA activation, but negatively with activation in the pars triangularis. Thus, pre-SMA may be involved in phonological cue-based composition, while the pars triangularis underlies alternative processes. Inflecting trained items yielded activation in the caudate head bilaterally, only in the first session, consistent with a role for procedural memory in learning grammatical regularities. The medial frontal and left inferior regions activated by untrained items were also activated by trained items, but more weakly than untrained items, with weakest activation for trained-items taking the high-frequency affix. This suggests less involvement of compositional processes for inflecting trained than untrained items, and least of all for trained inflected forms with high-frequency affixes, consistent with the storage of such forms (e.g., in declarative memory). Overall, the findings further elucidate the neural bases of the learning and generalization of affixal morphology, and the roles of affix type frequency and affix phonological predictability in these processes. Moreover, the results support and further specify the declarative/procedural model, in particular in adult language learning.

A limited number of studies have investigated language in Huntington's disease (HD). These have generally reported abnormalities in rule-governed (grammatical) aspects of language, in both syntax and morphology. Several studies of verbal inflectional morphology in English and French have reported evidence of over-active rule processing, such as over-suffixation errors (e.g., walkeded) and over-regularizations (e.g., digged). Here we extend the investigation to noun inflection in Hungarian, a Finno-Ugric agglutinative language with complex morphology, and to genetically proven pre-symptomatic Huntington's disease (pre-HD). Although individuals with pre-HD have no clinical, motor or cognitive symptoms, the underlying pathology may already have begun, and thus sensitive behavioral measures might reveal already-present impairments. Indeed, in a Hungarian morphology production task, pre-HD patients made both over-suffixation and over-regularization errors. The findings suggest the generality of over-active rule processing in both HD and pre-HD, across languages from different families with different morphological systems, and for both verbal and noun inflection. Because the neuropathology in pre-HD appears to be largely restricted to the caudate nucleus and related structures, the findings further implicate these structures in language, and in rule-processing in particular. Finally, the need for effective treatments in HD, which will likely depend in part on the ability to sensitively measure early changes in the disease, suggests the possibility that inflectional morphology, and perhaps other language measures, may provide useful diagnostic, tracking, and therapeutic tools for assessing and treating early degeneration in pre-HD and HD.

According to the Procedural Deficit Hypothesis (PDH), abnormalities of brain structures underlying procedural memory largely explain the language deficits in children with specific language impairment (SLI). These abnormalities are posited to result in core deficits of procedural memory, which in turn explain the grammar problems in the disorder. The abnormalities are also likely to lead to problems with other, non-procedural functions, such as working memory, that rely at least partly on the affected brain structures. In contrast, declarative memory is expected to remain largely intact, and should play an important compensatory role for grammar. These claims were tested by examining measures of working, declarative and procedural memory in 51 children with SLI and 51 matched typically-developing (TD) children (mean age 10). Working memory was assessed with the Working Memory Test Battery for Children, declarative memory with the Children's Memory Scale, and procedural memory with a visuo-spatial Serial Reaction Time task. As compared to the TD children, the children with SLI were impaired at procedural memory, even when holding working memory constant. In contrast, they were spared at declarative memory for visual information, and at declarative memory in the verbal domain after controlling for working memory and language. Visuo-spatial short-term memory was intact, whereas verbal working memory was impaired, even when language deficits were held constant. Correlation analyses showed neither visuo-spatial nor verbal working memory was associated with either lexical or grammatical abilities in either the SLI or TD children. Declarative memory correlated with lexical abilities in both groups of children. Finally, grammatical abilities were associated with procedural memory in the TD children, but with declarative memory in the children with SLI. These findings replicate and extend previous studies of working, declarative and procedural memory in SLI. Overall, we suggest that the evidence largely supports the predictions of the PDH. (C) 2011 Elsevier Srl. All rights reserved.

Patients with psychiatric disorders such as schizophrenia commonly present with impaired language. Here we investigate language in schizophrenia with a focus on inflectional morphology, using an intensively studied and relatively well-understood linguistic paradigm. Patients with schizophrenia (n=43) and age-matched healthy control subjects (n=42) were asked to produce past tenses of regular (slip), irregular (swim), and novel (plag) English verbs. Patients were impaired at regulars and novels (slipped, plagged), with relative sparing of irregulars (swam), controlling for numerous subject- and item-specific factors (e.g., IQ, phonological complexity). Additionally, patients' thought-disorder scores significantly predicted their performance at regular and novel (but not irregular) past-tense production. The results support grammatical deficits in schizophrenia, with a relative sparing of lexical memory, and suggest that thought disorder may be linked with grammatical impairments in the disorder.

Studies of English have shown that temporal-lobe patients, including those with Alzheimer's disease, are spared at processing real and novel regular inflected forms (e.g., blick → blicked; walk → walked), but impaired at real and novel irregular forms (e.g., spling → splang; dig → dug). Here we extend the investigation cross-linguistically to the more complex system of Italian verbal morphology, allowing us to probe the generality of the previous findings in English, as well as to test different explanatory accounts of inflectional morphology. We examined the production of real and novel regular and irregular past-participle and present-tense forms by native Italian-speaking healthy control subjects and patients with probable Alzheimer's disease. Compared to the controls, the patients were impaired at inflecting real irregular verbs but not real regular verbs both for past-participle and present-tense forms, but were not impaired at real regular verbs either for past-participle or present-tense forms. For novel past participles, the patients exhibited this same pattern of impaired production of class II (irregular) forms but spared class I (regular) production. In the present tense, patients were impaired at the production of class II forms (which are regular in the present tense), but spared at production of class I (regular) forms. Contrary to the pattern observed in English, the errors made by the patients on irregulars did not reveal a predominance of regularization errors (e.g., dig → digged). The findings thus partly replicate prior findings from English, but also reveal new patterns from a language with a more complex morphological system that includes verb classes (which are not possible to test in English). The demonstration of an irregular deficit following temporal-lobe damage in a language other than English reveals the cross-linguistic generality of the basic effect, while also elucidating important language-specific differences in the neuro-cognitive basis of regular and irregular morphological forms.

Language requires both storage and composition. However, exactly what is retrieved from memory and what is assembled remains controversial, especially for inflected words. Here, "imageability effects" is introduced as a new diagnostic of storage and a complement to frequency effects. In 2 studies of past-tense morphology, more reliable imageability and frequency effects were found on irregulars than on regulars. An interaction with sex was also observed: Males but not females showed more reliable frequency and imageability effects for irregulars than for regulars; females but not males showed signs of storage for regulars, particularly among higher frequency forms. Overall, the findings validate imageability effects as another diagnostic of storage and suggest that the line between storage and computation is not a simple function; rather, it depends upon the interplay of both item- and subject-specific factors.

Tourette's syndrome (TS) is a developmental disorder characterized by motor and verbal tics. The tics, which are fast and involuntary, result from frontal/basal-ganglia abnormalities that lead to unsuppressed behaviors. Language has not been carefully examined in TS. We tested the processing of two basic aspects of language: idiosyncratic and rule-governed linguistic knowledge. Evidence suggests that idiosyncratic knowledge (e.g., in irregular past tense formation; bring-brought) is stored in a mental lexicon that depends on the temporal-lobe-based declarative memory system that also underlies conceptual knowledge. In contrast, evidence suggests that rule-governed combination (e.g., in regular past tenses; walk+-ed) takes place in a mental grammar that relies on the frontal/basal-ganglia-based procedural memory system, which also underlies motor skills such as how to use a hammer. We found that TS children were significantly faster than typically developing control children in producing rule-governed past tenses (slip-slipped, plim-plimmed, bring-bringed) but not irregular and other unpredictable past tenses (bring-brought, splim-splam). They were also faster than controls in naming pictures of manipulated (hammer) but not non-manipulated (elephant) items. These data were not explained by a wide range of potentially confounding subject- and item-level factors. The results suggest that the processing of procedurally based knowledge, both of grammar and of manipulated objects, is particularly speeded in TS. The frontal/basal-ganglia abnormalities may thus lead not only to tics, but also to a wider range of rapid behaviors, including the cognitive processing of rule-governed forms in language and other types of procedural knowledge.

Clahsen and Felser (CF) have written a beautiful and important paper. I applaud their integrative empirical approach, and believe that their theoretical account is largely correct, if not in some of its specific claims, at least in its broader assumptions. CF directly compare their shallow structure hypothesis (SSH) with a model that my colleagues and I have proposed for aspects of the neurocognition of first and second language: the “declarative/procedural” (DP) model. Although some of CF's discussion accurately depicts the DP model and its relation to the data, they also make a few critical errors.Here, I first summarize the DP model in both first language (L1) and adult-learned second language (L2), in order to be able to contrast it with the SSH, and then address the relevant problems in CF. For further details on the DP model and L1, see Ullman (2001a, 2001c, 2004) and Ullman et al. (1997). For the model as it applies to L2, see Ullman (2001b, 2005).

Specific Language Impairment (SLI) has been explained by two broad classes of hypotheses, which posit either a deficit specific to grammar, or a non-linguistic processing impairment. Here we advance an alternative perspective. According to the Procedural Deficit Hypothesis (PDH), SLI can be largely explained by the abnormal development of brain structures that constitute the procedural memory system. This system, which is composed of a network of inter-connected structures rooted in frontal/basal-ganglia circuits, subserves the learning and execution of motor and cognitive skills. Crucially, recent evidence also implicates this system in important aspects of grammar. The PDH posits that a significant proportion of individuals with SLI suffer from abnormalities of this brain network, leading to impairments of the linguistic and non-linguistic functions that depend on it. In contrast, functions such as lexical and declarative memory, which depend on other brain structures, are expected to remain largely spared. Evidence from an in-depth retrospective examination of the literature is presented. It is argued that the data support the predictions of the PDH, and particularly implicate Broca's area within frontal cortex, and the caudate nucleus within the basal ganglia. Finally, broader implications are discussed, and predictions for future research are presented. It is argued that the PDH forms the basis of a novel and potentially productive perspective on SLI.

What is the interaction between storage and computation in language processing? What is the psychological status of grammatical rules? What are the relative strengths of connectionist and symbolic models of cognition? How are the components of language implemented in the brain? The English past tense has served as an arena for debates on these issues. We defend the theory that irregular past-tense forms are stored in the lexicon, a division of declarative memory, whereas regular forms can be computed by a concatenation rule, which requires the procedural system. Irregulars have the psychological, linguistic and neuropsychological signatures of lexical memory, whereas regulars often have the signatures of grammatical processing. Furthermore, because regular inflection is rule-driven, speakers can apply it whenever memory fails.

This study evaluates the input-processing deficit/single system and the grammar-specific deficit/dual system models to account for past tense formation in impaired and normal language development. We investigated regular and irregular past tense formation of 60 real and novel regular and irregular verbs in "Grammatical (G)-SLI" children (aged 9:3 to 12:10) and morphological- or vocabulary-matched younger control children. The G-SLI children and language ability (LA) controls showed quantitatively and qualitatively different patterns of performance. The LA controls, but not the G-SLI children, showed a significant advantage of regular over irregular past tense marking for real and novel verbs. Past tense frequency affected the GSLI children, but not the controls' production of regular verbs, even with stem access controlled for. The G-SLI children's production of regular forms was significantly lower than that of the control groups. Frequency and phonological properties had a similar and significant effect...

Our use of language depends upon two capacities: a mental lexicon of memorized words and a mental grammar of rules that underlie the sequential and hierarchical composition of lexical forms into predictably structured larger words, phrases, and sentences. The declarative/procedural model posits that the lexicon/grammar distinction in language is tied to the distinction between two well-studied brain memory systems. On this view, the memorization and use of at least simple words (those with noncompositional, that is, arbitrary form-meaning pairings) depends upon an associative memory of distributed representations that is subserved by temporal-lobe circuits previously implicated in the learning and use of fact and event knowledge. This "declarative memory" system appears to be specialized for learning arbitrarily related information (i.e., for associative binding). In contrast, the acquisition and use of grammatical rules that underlie symbol manipulation is subserved by frontal/basal-ganglia circuits previously implicated in the implicit (nonconscious) learning and expression of motor and cognitive "skills" and "habits" (e.g., from simple motor acts to skilled game playing). This "procedural" system may be specialized for computing sequences. This novel view of lexicon and grammar offers an alternative to the two main competing theoretical frameworks. It shares the perspective of traditional dual-mechanism theories in positing that the mental lexicon and a symbol-manipulating mental grammar are subserved by distinct computational components that may be linked to distinct brain structures. However, it diverges from these theories where they assume components dedicated to each of the two language capacities (that is, domain-specific) and in their common assumption that lexical memory is a rote list of items. Conversely, while it shares with single-mechanism theories the perspective that the two capacities are subserved by domain-independent computational mechanisms, it diverges from them where they link both capacities to a single associative memory system with broad anatomic distribution. The declarative/procedural model, but neither traditional dual- nor single-mechanism models, predicts double dissociations between lexicon and grammar, with associations among associative memory properties, memorized words and facts, and temporal-lobe structures, and among symbol-manipulation properties, grammatical rule products, motor skills, and frontal/basal-ganglia structures. In order to contrast lexicon and grammar while holding other factors constant, we have focused our investigations of the declarative/procedural model on morphologically complex word forms. Morphological transformations that are (largely) unproductive (e.g., in go-went, solemn-solemnity) are hypothesized to depend upon declarative memory. These have been contrasted with morphological transformations that are fully productive (e.g., in walk-walked, happy-happiness), whose computation is posited to be solely dependent upon grammatical rules subserved by the procedural system. Here evidence is presented from studies that use a range of psycholinguistic and neurolinguistic approaches with children and adults. It is argued that converging evidence from these studies supports the declarative/procedural model of lexicon and grammar.

We used event-related functional magnetic resonance imaging to identify brain regions involved in syntactic and semantic processing. Healthy adult males read well-formed sentences randomly intermixed with sentences which either contained violations of syntactic structure or were semantically implausible. Reading anomalous sentences, as compared to well-formed sentences, yielded distinct patterns of activation for the two violation types. Syntactic violations elicited significantly greater activation than semantic violations primarily in superior frontal cortex. Semantically incongruent sentences elicited greater activation than syntactic violations in the left hippocampal and parahippocampal gyri, the angular gyri bilaterally, the right middle temporal gyrus, and the left inferior frontal sulcus. These results demonstrate that syntactic and semantic processing result in nonidentical patterns of activation, including greater frontal engagement during syntactic processing and larger increases in temporal and temporo-parietal regions during semantic analyses.

The production of regular and irregular past tense forms was investigated among the members of an English-speaking family with a hereditary disorder of language. Unlike the control subjects, the family members affected by the disorder failed to generate overregularizations (e.g., digged) or novel regular forms (plammed, crived), whereas they did produce novel irregularizations (crive–crove). They showed word frequency effects for regular past tense forms (looked) and had trouble producing regulars and irregulars (looked, dug). This pattern cannot be easily explained by deficits of articulation or of perceptual processing, by previous simulations of impairments to a single-mechanism system, or by the extended optional infinitive hypothesis. We argue that the pattern is consistent with a three-level explanation. First, we posit a grammatical deficit of rules or morphological paradigms. This may be caused by a dysfunction of a frontal/basal-ganglia “procedural memory” system previously implicated in the implicit learning and use of motor and cognitive skills. Second, in contexts requiring inflection in the normal adult grammar, the affected subjects appear to retrieve word forms as a function of their accessibility and conceptual appropriateness (“conceptual selection”). Their acquisition and use of these word forms may rely on a “declarative memory” system previously implicated in the explicit learning and use of facts and events. Third, a compensatory strategy may be at work. Some family members may have explicitly learned a strategy of adding suffix-like endings to forms retrieved by conceptual selection. The morphological errors of young normal children appear to be similar to those of the affected family members, who may have been left stranded with conceptual selection by a specific developmental arrest. The same underlying deficit may also explain the impaired subjects' difficulties with derivational morphology.

What are the computational and representational bases of the mental lexicon of words, and of the rules of grammar which productively combine lexical forms into larger words, phrases and sentences? “Dual-system” theories posit that lexical forms with non-compositional (arbitrary) sound-meaning pairings are stored in memory, whereas compositional structures are subserved by a distinct rule-processing system. “Single-system” theories claim that lexicon and grammar are both subserved by a single associative memory. Investigations of English past tense may help to resolve this controversy. On the dual-system view, irregular past-tense forms (e.g. blowblew) are retrieved from memory, whereas regular past-tense forms (e.g. walk-walked) are produced by the application of an -ed -suffixation rule. On the single-system view, both types of past-tense forms are learned and computed in associative memory. To test these competing theories, acceptability ratings were elicited from native English-speaking adults for regu...

Using event-related potentials (ERPs), we examined the neurocognition of late-learned second language (L2) Spanish in two groups of typical university foreign-language learners (as compared to native (L1) speakers): one group with only one year of college classroom experience, and low-intermediate proficiency (L2 Low), and another group with over three years of college classroom experience as well as 1-2 semesters of immersion experience abroad, and advanced proficiency (L2 Advanced). Semantic violations elicited N400s in all three groups, whereas syntactic word-order violations elicited LAN/P600 responses in the L1 and L2 Advanced groups, but not the L2 Low group. Indeed, the LAN and P600 responses were statistically indistinguishable between the L1 and L2 Advanced groups. The results support and extend previous findings. Consistent with previous research, the results suggest that L2 semantic processing always depends on L1-like neurocognitive mechanisms, whereas L2 syntactic processing initially differs from L1, but can shift to native-like processes with sufficient proficiency or exposure, and perhaps with immersion experience in particular. The findings further demonstrate that substantial native-like brain processing of syntax can be achieved even by typical university foreign-language learners.

Logic has been intertwined with the study of language and meaning since antiquity, and such connections persist in present day research in linguistic theory (formal semantics) and cognitive psychology (e.g., studies of human reasoning). However, few studies in cognitive neuroscience have addressed logical dimensions of sentence-level language processing, and none have directly compared these aspects of processing with syntax and lexical/conceptual-semantics. We used ERPs to examine a violation paradigm involving “Negative Polarity Items” or NPIs (e.g., ever/any), which are sensitive to logical/truth-conditional properties of the environments in which they occur (e.g., presence/absence of negation in: John hasn’t ever been to Paris, versus: John has *ever been to Paris). Previous studies examining similar types of contrasts found a mix of effects on familiar ERP components (e.g., LAN, N400, P600). We argue that their experimental designs and/or analyses were incapable of separating which effects are connected to NPI-licensing violations proper. Our design enabled statistical analyses teasing apart genuine violation effects from independent effects tied solely to lexical/contextual factors. Here unlicensed NPIs elicited a late P600 followed in onset by a late left anterior negativity (or “L-LAN”), an ERP profile which has also appeared elsewhere in studies targeting logical semantics. Crucially, qualitatively distinct ERP-profiles emerged for syntactic and conceptual semantic violations which we also tested here. We discuss how these findings may be linked to previous findings in the ERP literature. Apart from methodological recommendations, we suggest that the study of logical semantics may aid advancing our understanding of the underlying neurocognitive etiology of ERP components.

The cortex constituting Broca's area does not exist in isolation. Rather, like other cortical regions, Broca's area is connected to other brain structures, which likely play closely related functional roles. This paper focuses on the basal ganglia, a set of subcortical structures that project through topographically organized "channels" via the thalamus to different frontal regions. It is hypothesized that the basal ganglia project to Broca's area. This circuitry is further posited to encompass at least two channels. One channel can be characterized as subserving procedural memory, while the other underlies the retrieval of knowledge from declarative memory. These hypotheses are supported by both anatomical and functional evidence. Implications and issues for further investigation are discussed.

The structure of the brain and the nature of evolution suggest that, despite its uniqueness, language likely depends on brain systems that also subserve other functions. The declarative/procedural (DP) model claims that the mental lexicon of memorized word-specific knowledge depends on the largely temporal-lobe substrates of declarative memory, which underlies the storage and use of knowledge of facts and events. The mental grammar, which subserves the rule-governed combination of lexical items into complex representations, depends on a distinct neural system. This system, which is composed of a network of specific frontal, basal-ganglia, parietal and cerebellar structures, underlies procedural memory, which supports the learning and execution of motor and cognitive skills, especially those involving sequences. The functions of the two brain systems, together with their anatomical, physiological and biochemical substrates, lead to specific claims and predictions regarding their roles in language. These predictions are compared with those of other neurocognitive models of language. Empirical evidence is presented from neuroimaging studies of normal language processing, and from developmental and adult-onset disorders. It is argued that this evidence supports the DP model. It is additionally proposed that "language" disorders, such as specific language impairment and non-fluent and fluent aphasia, may be profitably viewed as impairments primarily affecting one or the other brain system. Overall, the data suggest a new neurocognitive framework for the study of lexicon and grammar.

We agree that connectionist networks are not always analogy mechanisms. Our point (based on explications by McClelland and other connectionists) is that pattern associators (the most common connectionist model of the past tense) tend towards analogy when learning competing patterns under standard training regimes. This is what gives such models their predictive power with irregular forms. The claim that some connectionist model can, given a specific architecture, training schedule and input features, approximate any linguistic phenomenon might be true, but it is in danger of reducing connectionism to a universal statistical approximation technique rather than a source of empirical predictions. Language cannot be treated as just a collection of ‘regularities in the input’ that can be approximated by some mechanism; those regularities are themselves the products of human minds and need to be explained.

Are the linguistic forms that are memorized in the mental lexicon and those that are specified by the rules of grammar subserved by distinct neurocognitive systems or by a single computational system with relatively broad anatomic distribution? On a dual-system view, the productive – ed -suffixation of English regular past tense forms (e.g., look – looked ) depends upon the mental grammar, whereas irregular forms (e.g., dig – dug ) are retrieved from lexical memory. On a single-mechanism view, the computation of both past tense types depends on associative memory. Neurological double dissociations between regulars and irregulars strengthen the dual-system view. The computation of real and novel, regular and irregular past tense forms was investigated in 20 aphasic subjects. Aphasics with non-fluent agrammatic speech and left frontal lesions were consistently more impaired at the production, reading, and judgment of regular than irregular past tenses. Aphasics with fluent speech and word-finding difficulties, and with left temporal/temporo-parietal lesions, showed the opposite pattern. These patterns held even when measures of frequency, phonological complexity, articulatory difficulty, and other factors were held constant. The data support the view that the memorized words of the mental lexicon are subserved by a brain system involving left temporal/temporo-parietal structures, whereas aspects of the mental grammar, in particular the computation of regular morphological forms, are subserved by a distinct system involving left frontal structures.

study, taking truly independent ratings to see which verbs participants considered to be denominal or deverbal (i.e. exocentric or not). The results of this new experiment were clear. The semantic similarity (or otherwise) of verbs-incontext to ordinary irregular usage predicted the acceptability of past-tense forms. Whether or not verbs were perceived to be exocentric was irrelevant to this. It is worth noting that these results were obtained using the verbs put forward by Kim et al. [5] to try to demonstrate their theory. Thetheorythathomophoneverbprocessingcanbeexplained by exocentricity fails completely in the face of examples like shoe–shoo, where it is the denominal verb that is irregular (shoe–shod) and the deverbal verb regular (shoo–shooed). (Further support for these findings comes from on-line studies that have shown that semantics – and not exocentric form – predictcomprehensiontimeforhomophoneverbs[7].) What is the relevance of these data to the past-tense debate? First, they demonstrate that the ‘in-principle’ objection to single-route models supposedly posed by homophone verbs is wrong. Inflections of homophone verbs are determined by complex semantic and phonological patterns, not grammatical status. Second, they show that children’s ability to process homophone verbs is not indicative of their innate sensitivity to nouns and verbs [8], but rather is indicative of children’s ability to learn languages. Finally, because the exocentricity thesis is false, the dual-route theory itself cannot account for the processing of homophone verbs. Providing an account of homophone-verb inflection is vital to explaining past-tense processing [1–4]; the evidence suggests that it is two routes that this phenomenon rules out, not one.