The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
David A Ziegler - One of the best experts on this subject based on the ideXlab platform.
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brain asymmetries in autism and Developmental Language Disorder a nested whole brain analysis
Brain, 2004Co-Authors: Martha R Herbert, David A Ziegler, Curtis K Deutsch, Liam M Obrien, David N Kennedy, Pauline A Filipek, A I Bakardjiev, J Hodgson, Masanori TakeokaAbstract:We report a whole-brain MRI morphometric survey of asymmetry in children with high-functioning autism and with Developmental Language Disorder (DLD). Subjects included 46 boys of normal intelligence aged 5.7-11.3 years (16 autistic, 15 DLD, 15 controls). Imaging analysis included grey-white segmentation and cortical parcellation. Asymmetry was assessed at a series of nested levels. We found that asymmetries were masked with larger units of analysis but progressively more apparent with smaller units, and that within the cerebral cortex the differences were greatest in higher-order association cortex. The larger units of analysis, including the cerebral hemispheres, the major grey and white matter structures and the cortical lobes, showed no asymmetries in autism or DLD and few asymmetries in controls. However, at the level of cortical parcellation units, autism and DLD showed more asymmetry than controls. They had a greater aggregate volume of significantly asymmetrical cortical parcellation units (leftward plus rightward), as well as a substantially larger aggregate volume of right-asymmetrical cortex in DLD and autism than in controls; this rightward bias was more pronounced in autism than in DLD. DLD, but not autism, showed a small but significant loss of leftward asymmetry compared with controls. Right : left ratios were reversed, autism and DLD having twice as much right- as left-asymmetrical cortex, while the reverse was found in the control sample. Asymmetry differences between groups were most significant in the higher-order association areas. Autism and DLD were much more similar to each other in patterns of asymmetry throughout the cerebral cortex than either was to controls; this similarity suggests systematic and related alterations rather than random neural systems alterations. We review these findings in relation to previously reported volumetric features in these two samples of brains, including increased total brain and white matter volumes and lack of increase in the size of the corpus callosum. Larger brain volume has previously been associated with increased lateralization. The sizeable right-asymmetry increase reported here may be a consequence of early abnormal brain growth trajectories in these Disorders, while higher-order association areas may be most vulnerable to connectivity abnormalities associated with white matter increases.
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localization of white matter volume increase in autism and Developmental Language Disorder
Annals of Neurology, 2004Co-Authors: Martha R Herbert, David A Ziegler, David N Kennedy, Pauline A Filipek, Nikos Makris, Thomas L Kemper, Joseph J Normandin, Heather A Sanders, Verne S CavinessAbstract:Increased brain volume in autism appears to be driven mainly by an unexplained white matter enlargement, and we have reported a similar phenomenon in Developmental Language Disorder (DLD). Localization of this enlargement would strongly guide research into its cause, tissue basis, and functional implications. We utilized a white matter parcellation technique that divides cerebral white matter into an outer zone containing the radiate compartment and an inner zone containing sagittal and bridging system compartments. In both high-functioning autism and DLD, enlargement localized to the radiate white matter (all lobes in autism, all but parietal in DLD), whereas inner zone white matter compartments showed no volume differences from controls. Furthermore, in both autism and DLD, later or longer-myelinating regions showed greater volume increases over controls. Neither group showed cerebral cortex, corpus callosum, or internal capsule volume differences from control. Radiate white matter myelinates later than deep white matter; this pattern of enlargement thus is consistent with striking postnatal head circumference percentile increases reported in autism. These findings suggest an ongoing postnatal process in both autism and DLD that is probably intrinsic to white matter, that primarily affects intrahemispheric and corticocortical connections, and that places these two Disorders on the same spectrum. Ann Neurol 2004;55:530 –540
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larger brain and white matter volumes in children with Developmental Language Disorder
Developmental Science, 2003Co-Authors: Martha R Herbert, David A Ziegler, David N Kennedy, Pauline A Filipek, A I Bakardjiev, Nikos Makris, James Hodgson, Kristen T Adrien, Verne S CavinessAbstract:Developmental Language Disorder (DLD) is predominantly a Language Disorder, but children with DLD also manifest nonLanguage impairments, and neuroanatomical abnormalities have been found in multiple areas of the brain, not all Languageassociated. We therefore performed a whole brain general segmentation analysis of all major brain regions on MRI scans of 24 DLD subjects (16M, 8F) and 30 controls (15M, 15F), ages 5.7 to 11.3 years. Children with DLD showed increased total brain volume, driven predominantly by a substantial increase in the volume of cerebral white matter. Cerebral cortex and caudate were relatively but not absolutely smaller in DLD. These findings are discussed in relation to issues of specificity vs. generality as they arise in debates about (1) modular vs. general processing deficits and connectionist modeling in DLD, (2) Languagespecific vs. pervasive, non-specific deficits in DLD and (3) specificity of the Disorder vs. overlap with other Disorders, notably autism.
Martha R Herbert - One of the best experts on this subject based on the ideXlab platform.
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brain asymmetries in autism and Developmental Language Disorder a nested whole brain analysis
Brain, 2004Co-Authors: Martha R Herbert, David A Ziegler, Curtis K Deutsch, Liam M Obrien, David N Kennedy, Pauline A Filipek, A I Bakardjiev, J Hodgson, Masanori TakeokaAbstract:We report a whole-brain MRI morphometric survey of asymmetry in children with high-functioning autism and with Developmental Language Disorder (DLD). Subjects included 46 boys of normal intelligence aged 5.7-11.3 years (16 autistic, 15 DLD, 15 controls). Imaging analysis included grey-white segmentation and cortical parcellation. Asymmetry was assessed at a series of nested levels. We found that asymmetries were masked with larger units of analysis but progressively more apparent with smaller units, and that within the cerebral cortex the differences were greatest in higher-order association cortex. The larger units of analysis, including the cerebral hemispheres, the major grey and white matter structures and the cortical lobes, showed no asymmetries in autism or DLD and few asymmetries in controls. However, at the level of cortical parcellation units, autism and DLD showed more asymmetry than controls. They had a greater aggregate volume of significantly asymmetrical cortical parcellation units (leftward plus rightward), as well as a substantially larger aggregate volume of right-asymmetrical cortex in DLD and autism than in controls; this rightward bias was more pronounced in autism than in DLD. DLD, but not autism, showed a small but significant loss of leftward asymmetry compared with controls. Right : left ratios were reversed, autism and DLD having twice as much right- as left-asymmetrical cortex, while the reverse was found in the control sample. Asymmetry differences between groups were most significant in the higher-order association areas. Autism and DLD were much more similar to each other in patterns of asymmetry throughout the cerebral cortex than either was to controls; this similarity suggests systematic and related alterations rather than random neural systems alterations. We review these findings in relation to previously reported volumetric features in these two samples of brains, including increased total brain and white matter volumes and lack of increase in the size of the corpus callosum. Larger brain volume has previously been associated with increased lateralization. The sizeable right-asymmetry increase reported here may be a consequence of early abnormal brain growth trajectories in these Disorders, while higher-order association areas may be most vulnerable to connectivity abnormalities associated with white matter increases.
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localization of white matter volume increase in autism and Developmental Language Disorder
Annals of Neurology, 2004Co-Authors: Martha R Herbert, David A Ziegler, David N Kennedy, Pauline A Filipek, Nikos Makris, Thomas L Kemper, Joseph J Normandin, Heather A Sanders, Verne S CavinessAbstract:Increased brain volume in autism appears to be driven mainly by an unexplained white matter enlargement, and we have reported a similar phenomenon in Developmental Language Disorder (DLD). Localization of this enlargement would strongly guide research into its cause, tissue basis, and functional implications. We utilized a white matter parcellation technique that divides cerebral white matter into an outer zone containing the radiate compartment and an inner zone containing sagittal and bridging system compartments. In both high-functioning autism and DLD, enlargement localized to the radiate white matter (all lobes in autism, all but parietal in DLD), whereas inner zone white matter compartments showed no volume differences from controls. Furthermore, in both autism and DLD, later or longer-myelinating regions showed greater volume increases over controls. Neither group showed cerebral cortex, corpus callosum, or internal capsule volume differences from control. Radiate white matter myelinates later than deep white matter; this pattern of enlargement thus is consistent with striking postnatal head circumference percentile increases reported in autism. These findings suggest an ongoing postnatal process in both autism and DLD that is probably intrinsic to white matter, that primarily affects intrahemispheric and corticocortical connections, and that places these two Disorders on the same spectrum. Ann Neurol 2004;55:530 –540
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larger brain and white matter volumes in children with Developmental Language Disorder
Developmental Science, 2003Co-Authors: Martha R Herbert, David A Ziegler, David N Kennedy, Pauline A Filipek, A I Bakardjiev, Nikos Makris, James Hodgson, Kristen T Adrien, Verne S CavinessAbstract:Developmental Language Disorder (DLD) is predominantly a Language Disorder, but children with DLD also manifest nonLanguage impairments, and neuroanatomical abnormalities have been found in multiple areas of the brain, not all Languageassociated. We therefore performed a whole brain general segmentation analysis of all major brain regions on MRI scans of 24 DLD subjects (16M, 8F) and 30 controls (15M, 15F), ages 5.7 to 11.3 years. Children with DLD showed increased total brain volume, driven predominantly by a substantial increase in the volume of cerebral white matter. Cerebral cortex and caudate were relatively but not absolutely smaller in DLD. These findings are discussed in relation to issues of specificity vs. generality as they arise in debates about (1) modular vs. general processing deficits and connectionist modeling in DLD, (2) Languagespecific vs. pervasive, non-specific deficits in DLD and (3) specificity of the Disorder vs. overlap with other Disorders, notably autism.
Elena L. Grigorenko - One of the best experts on this subject based on the ideXlab platform.
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syntactic complexity effects of russian relative clause sentences in children with and without Developmental Language Disorder
Language Acquisition, 2016Co-Authors: Natalia Rakhlin, Sergey A. Kornilov, Tatiana V Kornilova, Elena L. GrigorenkoAbstract:ABSTRACTWe investigated relative clause (RC) comprehension in 44 Russian-speaking children with typical Language (TD) and Developmental Language Disorder (DLD) (M age = 10;67, SD = 2.84) and 22 adults. Flexible word order and morphological case in Russian allowed us to isolate factors that are obscured in English, helping us to identify sources of syntactic complexity and evaluate their roles in RC comprehension by children with typical Language and their peers with DLD. We administered a working memory and an RC comprehension (picture-choice) task, which contained subject- and object-gap center-embedded and right-branching RCs. The TD group, but not adults, demonstrated the effects of gap, embedding, and case. Their lower accuracy relative to adults was not fully attributable to differences in working memory. The DLD group displayed lower than TD children overall accuracy, accounted for by their lower working memory scores. While the effect of gap and embedding on their performance was not different from...
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lexical processing deficits in children with Developmental Language Disorder an event related potentials study
Development and Psychopathology, 2015Co-Authors: Sergey A. Kornilov, Nicole Landi, Natalia Rakhlin, James S. Magnuson, Elena L. GrigorenkoAbstract:Lexical processing deficits in children with Developmental Language Disorder (DLD) have been postulated to arise as sequelae of their grammatical deficits (either directly or via compensatory mechanisms) and vice versa. We examined event-related potential indices of lexical processing in children with DLD (n = 23) and their typically developing peers (n = 16) using a picture-word matching paradigm. We found that children with DLD showed markedly reduced N400 amplitudes in response both to auditorily presented words that had initial phonological overlap with the name of the pictured object and to words that were not semantically or phonologically related to the pictured object. Moreover, this reduction was related to behavioral indices of phonological and lexical but not grammatical development. We also found that children with DLD showed a depressed phonological mapping negativity component in the early time window, suggesting deficits in phonological processing or early lexical access. The results are partially consistent with the overactivation account of lexical processing deficits in DLD and point to the relative functional independence of lexical/phonological and grammatical deficits in DLD, supporting a multidimensional view of the Disorder. The results also, although indirectly, support the neuroplasticity account of DLD, according to which Language impairment affects brain development and shapes the specific patterns of brain responses to Language stimuli.
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interpretation of anaphoric dependencies in russian speaking children with and without Developmental Language Disorder
Language Acquisition, 2015Co-Authors: Natalia Rakhlin, Sergey A. Kornilov, Jodi Reich, Elena L. GrigorenkoAbstract:We examined anaphora resolution in children with and without Developmental Language Disorder (DLD) to clarify whether 1) DLD is best understood as missing knowledge of certain linguistic operations/elements or as unreliable performance and 2) if comprehension of sentences with anaphoric expressions as objects and exceptionally case marked (ECM) subjects supports a particular theoretical account of anaphora. Fifty-four native-Russian-speaking children (age M = 7;6, SD = 1;9) were tested on a picture selection task. Children with DLD (n=18) underperformed overall, but displayed similar patterns to the typically developing (TD) group with respect to the extra difficulty of the ECM relative to the transitive and ECM pronouns relative to all other conditions. However, whereas pronouns were more difficult than reflexives for the TD children, this effect was not significant for the DLD group, whose reduced accuracy on reflexives washed out the effect of pronouns in that group. These results are consistent with performance-level vulnerability in DLD, arguably related to weaknesses in lexical processing and with the Reflexivity framework of Binding phenomena.
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Attentional But Not Pre-Attentive Neural Measures of Auditory Discrimination Are Atypical in Children With Developmental Language Disorder
Developmental neuropsychology, 2014Co-Authors: Sergey A. Kornilov, Nicole Landi, Natalia Rakhlin, Shin Yi Fang, Elena L. Grigorenko, James S. MagnusonAbstract:We examined neural indices of pre-attentive phonological and attentional auditory discrimination in children with Developmental Language Disorder (DLD, n = 23) and typically developing (n = 16) peers from a geographically isolated Russian-speaking population with an elevated prevalence of DLD. Pre-attentive phonological MMN components were robust and did not differ in two groups. Children with DLD showed attenuated P3 and atypically distributed P2 components in the attentional auditory discrimination task; P2 and P3 amplitudes were linked to working memory capacity, development of complex syntax, and vocabulary. The results corroborate findings of reduced processing capacity in DLD and support a multifactorial view of the Disorder.
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Spelling well despite Developmental Language Disorder: what makes it possible?
Annals of Dyslexia, 2013Co-Authors: Natalia Rakhlin, Sergey A. Kornilov, Cláudia Cardoso-martins, Elena L. GrigorenkoAbstract:The goal of the study was to investigate the overlap between Developmental Language Disorder (DLD) and Developmental dyslexia, identified through spelling difficulties (SD), in Russian-speaking children. In particular, we studied the role of phoneme awareness (PA), rapid automatized naming (RAN), pseudoword repetition (PWR), morphological (MA), and orthographic awareness (OA) in differentiating between children with DLD who have SD from children with DLD who are average spellers by comparing the two groups to each other, to typically developing children as well as children with SD but without spoken Language deficits. One hundred forty-nine children, aged 10.40 to 14.00 years, participated in the study. The results indicated that the SD, DLD, and DLD/SD groups did not differ from each other on PA and RAN Letters and underperformed in comparison to the control groups. However, whereas the children with written Language deficits (SD and DLD/SD groups) underperformed on RAN Objects and Digits, PWR, OA, and MA, the children with DLD and no SD performed similarly to the children from the control groups on these measures. In contrast, the two groups with spoken Language deficits (DLD and DLD/SD) underperformed on RAN Colors in comparison to the control groups and the group of children with SD only. The results support the notion that those children with DLD who have unimpaired PWR and RAN skills are able to overcome their weaknesses in spoken Language and PA and acquire basic literacy on a par with their age peers with typical Language. We also argue that our findings support a multifactorial model of DLD.
Pauline A Filipek - One of the best experts on this subject based on the ideXlab platform.
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sensorimotor performance in school age children with autism Developmental Language Disorder or low iq
Developmental Medicine & Child Neurology, 2005Co-Authors: David E Mandelbaum, Pauline A Filipek, Michael C Stevens, Eric Rosenberg, Max Wiznitzer, Mitchell Steinschneider, Isabelle RapinAbstract:The purpose of the study was to determine the prevalence of ‘soft’ motor deficits in school-aged children with either Developmental Language Disorder (DLD), autism (with high IQ [HiAD] or low IQ [LoAD]), or low IQ without autism (LoIQ), and to evaluate the utility of a refined neurological examination to discriminate between these groups. A total of 242 children (74% male), aged 7 or 9 years, were evaluated as part of a longitudinal, multi-institutional study, with a standardized neurological examination that included Denckla's Physical and Neurological Examination for Soft Signs. Most of the scores separated children into two groups defined by nonverbal IQ, with the DLD and HiAD groups performing better than the LoAD and LoIQ groups. Exceptions included motor impersistence and stereotypies, which were more likely in the autistic groups. The neurologists ‘summary clinical impressions indicated better sensory’ motor skills, oromotor skills, and praxis in the HiAD than in the DLD children. Inability/unwillingness to perform tasks was much more frequent in LoAD than LoIQ children.
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brain asymmetries in autism and Developmental Language Disorder a nested whole brain analysis
Brain, 2004Co-Authors: Martha R Herbert, David A Ziegler, Curtis K Deutsch, Liam M Obrien, David N Kennedy, Pauline A Filipek, A I Bakardjiev, J Hodgson, Masanori TakeokaAbstract:We report a whole-brain MRI morphometric survey of asymmetry in children with high-functioning autism and with Developmental Language Disorder (DLD). Subjects included 46 boys of normal intelligence aged 5.7-11.3 years (16 autistic, 15 DLD, 15 controls). Imaging analysis included grey-white segmentation and cortical parcellation. Asymmetry was assessed at a series of nested levels. We found that asymmetries were masked with larger units of analysis but progressively more apparent with smaller units, and that within the cerebral cortex the differences were greatest in higher-order association cortex. The larger units of analysis, including the cerebral hemispheres, the major grey and white matter structures and the cortical lobes, showed no asymmetries in autism or DLD and few asymmetries in controls. However, at the level of cortical parcellation units, autism and DLD showed more asymmetry than controls. They had a greater aggregate volume of significantly asymmetrical cortical parcellation units (leftward plus rightward), as well as a substantially larger aggregate volume of right-asymmetrical cortex in DLD and autism than in controls; this rightward bias was more pronounced in autism than in DLD. DLD, but not autism, showed a small but significant loss of leftward asymmetry compared with controls. Right : left ratios were reversed, autism and DLD having twice as much right- as left-asymmetrical cortex, while the reverse was found in the control sample. Asymmetry differences between groups were most significant in the higher-order association areas. Autism and DLD were much more similar to each other in patterns of asymmetry throughout the cerebral cortex than either was to controls; this similarity suggests systematic and related alterations rather than random neural systems alterations. We review these findings in relation to previously reported volumetric features in these two samples of brains, including increased total brain and white matter volumes and lack of increase in the size of the corpus callosum. Larger brain volume has previously been associated with increased lateralization. The sizeable right-asymmetry increase reported here may be a consequence of early abnormal brain growth trajectories in these Disorders, while higher-order association areas may be most vulnerable to connectivity abnormalities associated with white matter increases.
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localization of white matter volume increase in autism and Developmental Language Disorder
Annals of Neurology, 2004Co-Authors: Martha R Herbert, David A Ziegler, David N Kennedy, Pauline A Filipek, Nikos Makris, Thomas L Kemper, Joseph J Normandin, Heather A Sanders, Verne S CavinessAbstract:Increased brain volume in autism appears to be driven mainly by an unexplained white matter enlargement, and we have reported a similar phenomenon in Developmental Language Disorder (DLD). Localization of this enlargement would strongly guide research into its cause, tissue basis, and functional implications. We utilized a white matter parcellation technique that divides cerebral white matter into an outer zone containing the radiate compartment and an inner zone containing sagittal and bridging system compartments. In both high-functioning autism and DLD, enlargement localized to the radiate white matter (all lobes in autism, all but parietal in DLD), whereas inner zone white matter compartments showed no volume differences from controls. Furthermore, in both autism and DLD, later or longer-myelinating regions showed greater volume increases over controls. Neither group showed cerebral cortex, corpus callosum, or internal capsule volume differences from control. Radiate white matter myelinates later than deep white matter; this pattern of enlargement thus is consistent with striking postnatal head circumference percentile increases reported in autism. These findings suggest an ongoing postnatal process in both autism and DLD that is probably intrinsic to white matter, that primarily affects intrahemispheric and corticocortical connections, and that places these two Disorders on the same spectrum. Ann Neurol 2004;55:530 –540
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larger brain and white matter volumes in children with Developmental Language Disorder
Developmental Science, 2003Co-Authors: Martha R Herbert, David A Ziegler, David N Kennedy, Pauline A Filipek, A I Bakardjiev, Nikos Makris, James Hodgson, Kristen T Adrien, Verne S CavinessAbstract:Developmental Language Disorder (DLD) is predominantly a Language Disorder, but children with DLD also manifest nonLanguage impairments, and neuroanatomical abnormalities have been found in multiple areas of the brain, not all Languageassociated. We therefore performed a whole brain general segmentation analysis of all major brain regions on MRI scans of 24 DLD subjects (16M, 8F) and 30 controls (15M, 15F), ages 5.7 to 11.3 years. Children with DLD showed increased total brain volume, driven predominantly by a substantial increase in the volume of cerebral white matter. Cerebral cortex and caudate were relatively but not absolutely smaller in DLD. These findings are discussed in relation to issues of specificity vs. generality as they arise in debates about (1) modular vs. general processing deficits and connectionist modeling in DLD, (2) Languagespecific vs. pervasive, non-specific deficits in DLD and (3) specificity of the Disorder vs. overlap with other Disorders, notably autism.
Bruce J Tomblin - One of the best experts on this subject based on the ideXlab platform.
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procedural and declarative memory brain systems in Developmental Language Disorder dld
Brain and Language, 2020Co-Authors: Peggy Nopoulos, Bruce J TomblinAbstract:Abstract The aim of the current study was to examine microstructural differences in white matter relevant to procedural and declarative memory between adolescents/young adults with and without Developmental Language Disorder (DLD) using diffusion tensor imaging (DTI). The findings showed atypical age-related changes in white matter structures in the corticostriatal system, in the corticocerebellar system, and in the medial temporal region in individuals with DLD. Results highlight the importance of considering the age factor in research on DLD. Future studies are needed to examine the Developmental relationship between long-term memory and individual differences in Language development and learning.
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a real time mechanism underlying lexical deficits in Developmental Language Disorder between word inhibition
Cognition, 2019Co-Authors: Bob Mcmurray, Jamie Kleinpackard, Bruce J TomblinAbstract:Abstract Eight to 11% of children have a clinical Disorder in oral Language (Developmental Language Disorder, DLD). Language deficits in DLD can affect all levels of Language and persist through adulthood. Word-level processing may be critical as words link phonology, orthography, syntax and semantics. Thus, a lexical deficit could cascade throughout Language. Cognitively, word recognition is a competition process: as the input (e.g., lizard) unfolds, multiple candidates (liver, wizard) compete for recognition. Children with DLD do not fully resolve this competition, but it is unclear what cognitive mechanisms underlie this. We examined lexical inhibition—the ability of more active words to suppress competitors—in 79 adolescents with and without DLD. Participants heard words (e.g. net) in which the onset was manipulated to briefly favor a competitor (neck). This was predicted to inhibit the target, slowing recognition. Word recognition was measured using a task in which participants heard the stimulus, and clicked on a picture of the item from an array of competitors, while eye-movements were monitored as a measure of how strongly the participant was committed to that interpretation over time. TD listeners showed evidence of inhibition with greater interference for stimuli that briefly activated a competitor word. DLD listeners did not. This suggests deficits in DLD may stem from a failure to engage lexical inhibition. This in turn could have ripple effects throughout the Language system. This supports theoretical approaches to DLD that emphasize lexical-level deficits, and deficits in real-time processing.