Aneta Kielar

Interests

Teaching

Neurobiology of Communication SLHS 362,Language Perception,Cognitive Psychology

Research

Key words: Neuroimaging, fMRI, ERPs/EEG, Electromagnetoencephalography (MEG), electrophysiology, connectivity, Diffusion Tensor Imaging, language disorders, stroke-induced aphasia, Primary Progressive Aphasia, cognitive aging. My current research program is centered on investigating the neurobiology of healthy language system, and changes in cognitive and language processing associated with stroke and neurological disorders. My interests include incorporating cognitive measures and multimodal neuroimaging methods, with a goal to understand the relationship between language and other aspects of cognition, as well as the neural dynamics related to brain damage, resilience, and recovery. I direct my research efforts to identify factors which affect language comprehension and production, and how these change with development and are influenced by aging, stroke, brain injury, and neurodegenerative disorders, such as Primary Progressive Aphasia (PPA) and Alzheimer’s disease (AD). The long-term goal of my research is to understand the cognitive and neural processes that support recovery of cognitive and language functions after stroke. I study language processing at the multiple levels, using behavioral experiments and both structural (DTI, lesion-symptom mapping, voxel-based morphometry) and functional neuroimaging (fMRI, EEG, MEG). In addition, I am interested in neuroplasticity and application of noninvasive brain stimulation techniques (e.g., TMS, tDCS) to the treatment of aphasia and dementia.

Courses

Scholarly Contributions

Books

• Thompson, C. K., & Kielar, A. (2014).

  Neural Bases of Sentence Processing

  . doi:10.1093/OXFORDHB/9780199735471.013.020
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  The Oxford Handbook of Language Production

Chapters

• Kielar, A., & Thompson, C. K. (2014). Neural Bases of Sentence Processing: Evidence from Neurolinguistic and Neuroimaging Studies. In The Oxford Handbook of Language Production(pp 47-69). New York, NY, USA: Oxford University Press. doi:0.1093/oxfordhb/9780199735471.013.020
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  Sentence processing requires rapid integration of information over a short period of time. Models of language processing suggest that syntactic,semantic, and phonological detail must be accessed and coordinated within milliseconds to successfully produce or understand sentences. Exactlyhow this is accomplished and what neural mechanisms are engaged in real time to carry out these processes is not completely understood. Researchexamining the neural mechanisms associated with sentence processing elucidates a left hemisphere network involving both anterior and posteriorbrain regions, although studies show that the right hemisphere is also engaged to some extent. This chapter discusses what is known about the neural systems involved in sentence production and comprehension. Two bodies of research are discussed: neurolinguistic evidence derived from lesion deficit studies with brain-damaged people, and neuroimaging research examining the neural correlates of sentence processing in healthy individuals.
• Thompson, C. K., Kielar, A., & Fix, S. (2012).

  Morphological aspects of agrammatic aphasia: Brain, Behaviour and Cognition

  . In Perspectives on Agrammatism(pp 75-105). Psychology Press.
• Thompson, C. K., Kielar, A., & Fix, S. (2012).

  Morphological aspects of agrammatic aphasia

  . In Perspectives on Agrammatism(pp 75-105). Sussex, UK:: Psychology Press. doi:10.4324/9780203120378
• Thompson, C. K., Kielar, A., & Fix, S. F. (2012). Morphological aspects of agrammatic aphasia. In Perspectives on Agrammatism(pp 75-105). Sussex, UK: Psychology Press.
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  One of the primary characteristics of agrammatism is impaired production (and sometimes comprehension) of grammatical morphology or functional categories, which affects both bound grammatical morphemes and freestanding function words. On most accounts, agrammatism is associated with relatively preserved derivational morphology (Caramazza & Miceli, 1989; Faroqi-Shah & Thompson, 2004; Miceli & Caramaza, 1988), although there are exceptions to this (see Fix, Dickey, & Thompson, 2005; Kohn & Melvold, 2000; Mathews & Obler, 1997; also see Luzzatti, Mondini, & Semenza, this volume). This chapter addresses patterns of impaired functional categories in agrammatism and discusses theories that attempt to determine the source of such deficits.

Journals/Publications

• Jebahi, F., & Kielar, A. (2024). The relationship between semantics, phonology, and naming performance in aphasia: a structural equation modeling approach. Cognitive neuropsychology, 41(3-4), 113-128.
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  The exploration of naming error patterns in aphasia provides insights into the cognitive processes underlying naming performance. We investigated how semantic and phonological abilities correlate and how they influence naming performance in aphasia. Data from 296 individuals with aphasia, drawn from the Moss Aphasia Psycholinguistics Project Database, were analyzed using a structural equation model. The model incorporated latent variables for semantics and phonology and manifest variables for naming accuracy and error patterns. There was a moderate positive correlation between semantics and phonology after controlling for overall aphasia severity. Both semantic and phonological abilities influenced naming accuracy. Semantic abilities negatively related to semantic, mixed, unrelated errors, and no responses. Interestingly, phonology positively affected semantic errors. Additionally, phonological abilities negatively related to each of phonological and neologism errors. These results highlight the role of semantic and phonological skills on naming performance in aphasia and reveal a relationship between these cognitive processes.
• Jebahi, F., Lai, V. T., & Kielar, A. (2024). Psycholinguistic predictors of naming accuracy and decline in bilingual logopenic primary progressive aphasia: a cross-linguistic case study. Neurocase, 30(5), 181-188.
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  Naming impairment is a hallmark of logopenic primary progressive aphasia (lvPPA), yet its effects in bilingualism remain understudied. This study examined naming accuracy in a 78-year-old Chinese-English bilingual woman with lvPPA over two years using a modified Boston Naming Test. Naming accuracy was higher in her second, but more frequently used language (English) than her first, but less frequently used language (Chinese). Regression analyses revealed that familiarity predicted naming in Chinese, while word length and age of acquisition influenced English. Decline was linked to age of acquisition in Chinese and emotional properties in English, highlighting language-specific patterns in bilingual lvPPA.
• Jebahi, F., Nickels, K. V., & Kielar, A. (2024). Patterns of performance on the animal fluency task in logopenic variant of primary progressive aphasia: A reflection of phonological and semantic skills. Journal of communication disorders, 108, 106405.
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  This study aimed to characterize the quantitative (total number of correct words generated) and qualitative (psycholinguistic properties of correct words generated) performance patterns on the animal fluency task in individuals with the logopenic variant of primary progressive aphasia and to investigate the influence of phonological and semantic abilities to these patterns.
• Jebahi, F., Nickels, K. V., & Kielar, A. (2023).

  Predicting Confrontation Naming in the Logopenic Variant of Primary Progressive Aphasia

  . Aphasiology, 1-32. doi:10.1080/02687038.2023.2221998
• Kielar, A., & Jebahi, F. (2023). Predicting Confrontation Naming in the Logopenic Variant of Primary Progressive Aphasia. Aphasiology. doi:https://doi.org/10.1080/02687038.2023.2221998
• Kielar, A., Beeson, P. M., & Nickels, K. V. (2023). Positive changes to written language following phonological treatment in logopenic variant primary progressive aphasia. Frontiers in Human Neuroscience, Speech and Language. doi:10.3389/fnhum.2022.1006350
• Kielar, A., Shah-Basak, P., Meyer, L., & Fujioka, T. (2023). Editorial: Oscillatory brain activity as a marker of brain function and dysfunction in aging and in neurodegenerative disorders. Frontiers in aging neuroscience, 15, 1153150.
• Kielar, A., Patterson, D., & Chou, Y. H. (2022). Efficacy of repetitive transcranial magnetic stimulation in treating stroke aphasia: Systematic review and meta-analysis. Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 140, 196-227.
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  This meta-analysis examined the effectiveness of repetitive Transcranial Magnetic Stimulation (rTMS) in treating post-stroke aphasia with a goal to identify parameters that are associated with successful treatment outcomes.
• Kielar, A., Shah-Basak, P. P., Patterson, D. K., Jokel, R., & Meltzer, J. A. (2022). Electrophysiological abnormalities as indicators of early-stage pathology in Primary Progressive Aphasia (PPA): A case study in semantic variant PPA. Neurocase, 1-13.
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  Language induced and spontaneous oscillatory activity was measured using MEG in a patient with the semantic variant of Primary Progressive Aphasia (svPPA) and 15 healthy controls.The patient showed oscillatory slowing in the left anterior temporal lobe (ATL) that extended into non-atrophied brain tissue in left and right frontal areas. The white matter connections were reduced to the left and right ATL and left frontal regions, exhibiting electrophysiological abnormalities. Altered diffusion metrics in all four language tracts, indicted compromised white matter integrity. Task-related and spontaneous oscillatory abnormalities can indicate early neurodegeneration in svPPA, providing promising targets for intervention.
• Nickels, K., Beeson, P. M., Rising, K., Jebahi, F., & Kielar, A. (2022). Positive changes to written language following phonological treatment in logopenic variant primary progressive aphasia: Case report. Frontiers in human neuroscience, 16, 1006350.
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  Phonological impairment contributes to deficits in repetition and spoken naming in logopenic variant Primary Progressive Aphasia (lvPPA), but weakened phonology can also affect written language skills. In this experimental case report, we demonstrate phonological text agraphia in a 71-year-old woman in the early stages of lvPPA that undermined her ability to write meaningful, grammatical sentences. We investigated the therapeutic value of a rigorous treatment protocol to strengthen phonological manipulation skills coupled with transcranial direct current stimulation (tDCS). Intervention took place 5 days a week for 2 weeks with active tDCS, followed by a 2-month rest period, and then a second period of phonological treatment with sham tDCS. Over the course of treatment, our participant demonstrated improved phonological transcoding and manipulation skills as well as marked improvement in the proportion of grammatically well-formed, meaningful written narratives. Improvements in spelling and letter selection were also observed. Treatment gains were documented during phonological intervention in both active tDCS and sham treatment phases and were maintained 2 months after the conclusion of intervention. Importantly, improvements were observed in the context of a progressive disorder. These data present compelling evidence regarding the impairment-based approach that targets compromised phonological skills, presenting opportunity for improving functional written communication skills relevant to the everyday lives of individuals with lvPPA.
• Shah-Basak, P., Sivaratnam, G., Teti, S., Deschamps, T., Kielar, A., Jokel, R., & Meltzer, J. A. (2022). Electrophysiological connectivity markers of preserved language functions in post-stroke aphasia. NeuroImage. Clinical, 34, 103036.
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  Post-stroke aphasia is a consequence of localized stroke-related damage as well as global disturbances in a highly interactive and bilaterally-distributed language network. Aphasia is increasingly accepted as a network disorder and it should be treated as such when examining the reorganization and recovery mechanisms after stroke. In the current study, we sought to investigate reorganized patterns of electrophysiological connectivity, derived from resting-state magnetoencephalography (rsMEG), in post-stroke chronic (>6 months after onset) aphasia. We implemented amplitude envelope correlations (AEC), a metric of connectivity commonly used to describe slower aspects of interregional communication in resting-state electrophysiological data. The main focus was on identifying the oscillatory frequency bands and frequency-specific spatial topology of connections associated with preserved language abilities after stroke. RsMEG was recorded for 5 min in 21 chronic stroke survivors with aphasia and in 20 matched healthy controls. Source-level MEG activity was reconstructed and summarized within 72 atlas-defined brain regions (or nodes). A 72 × 72 leakage-corrected connectivity (of AEC) matrix was obtained for frequencies from theta to low-gamma (4-50 Hz). Connectivity was compared between groups, and, the correlations between connectivity and subscale scores from the Western Aphasia Battery (WAB) were evaluated in the stroke group, using partial least squares analyses. Posthoc multiple regression analyses were also conducted on a graph theory measure of node strengths, derived from significant connectivity results, to control for node-wise properties (local spectral power and lesion sizes) and demographic and stroke-related variables. Connectivity among the left hemisphere regions, i.e. those ipsilateral to the stroke lesion, was greatly reduced in stroke survivors with aphasia compared to matched healthy controls in the alpha (8-13 Hz; p = 0.011) and beta (15-30 Hz; p = 0.001) bands. The spatial topology of hypoconnectivity in the alpha vs. beta bands was distinct, revealing a greater involvement of ventral frontal, temporal and parietal areas in alpha, and dorsal frontal and parietal areas in beta. The node strengths from alpha and beta group differences remained significant after controlling for nodal spectral power. AEC correlations with WAB subscales of object naming and fluency were significant. Greater alpha connectivity was associated with better naming performance (p = 0.045), and greater connectivity in both the alpha (p = 0.033) and beta (p = 0.007) bands was associated with better speech fluency performance. The spatial topology was distinct between these frequency bands. The node strengths remained significant after controlling for age, time post stroke onset, nodal spectral power and nodal lesion sizes. Our findings provide important insights into the electrophysiological connectivity profiles (frequency and spatial topology) potentially underpinning preserved language abilities in stroke survivors with aphasia.
• Kielar, A., Shah-Basak, P. P., Deschamps, T., Jokel, R., & Meltzer, J. (2019). Slowing is slowing: Delayed neural responses to words are linked to abnormally slow resting state activity in primary progressive aphasia. Neuropsychologia. doi:https://doi.org/10.1016/j.neuropsychologia.2019.04.007
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  Neurodegenerative disorders are often characterized by neuronal "slowing," which may be assessed in different ways. In the present study, we examined the latency of neural responses to linguistic stimuli in participants diagnosed with primary progressive aphasia (PPA), as well as changes in the power spectra of resting state activity, both measured with MEG. Compared to both age-matched and younger controls, patients with PPA showed a delayed latency of 8-30 Hz event-related desynchronization (ERD) in response to semantic anomalies. In addition, resting-state MEG revealed increased power in the lower frequency delta and theta bands, but decreased activity in the higher alpha and beta bands. The task-induced and spontaneous measures of neural dynamics were related, such that increased peak latencies in response to words was correlated with a shift of spontaneous oscillatory dynamics towards lower frequencies. In contrast, older controls showed similar task related ERD latencies as younger controls, but also "speeding" of spontaneous activity, i.e. a shift towards faster frequencies. In PPA patients both increased peak latencies on task and increased slow oscillations at rest were associated with less accurate performance on the language task and poorer performance on offline cognitive measures, beyond variance accounted for by structural atrophy. A mediation analysis indicated that increased theta power accounted for the relationship between delayed electrophysiological responses and reduced accuracy in PPA patients. These results indicate that the neuropathological changes in PPA result in slowing of both task-related and spontaneous neuronal activity, linked to functional decline, whereas the speeding of spontaneous activity in healthy aging seems to have a protective or compensatory effect.
• Kielar, A., Deschamps, T., Jokel, R., & Meltzer, J. (2018). Language-related oscillatory abnormalities in primary progressive aphasia. Neuroimage: Clinical, 18, 560-574. doi:https://doi.org/10.1016/j.nicl.2018.02.028
• Shah-Basak, P. P., Kielar, A., Deschamps, T., Verhoeff, N. P., Jokel, R., & Meltzer, J. (2018). Spontaneous oscillatory markers of cognitive status in two forms of dementia. Human Brain Mapping HBM.
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  Abnormal oscillatory brain activity in dementia may indicate incipient neuronal/synaptic dysfunction, rather than frank structural atrophy. Leveraging a potential link between the degree of abnormal oscillatory activity and cognitive symptom severity, one could localize brain regions in a diseased but pre-atrophic state, which may be more amenable to interventions. In the current study, we evaluated the relationships among cognitive deficits, regional volumetric changes, and resting-state magnetoencephalography abnormalities in patients with mild cognitive impairment (MCI; N = 10; age: 75.9 ± 7.3) or primary progressive aphasia (PPA; N = 12; 69.7 ± 8.0), and compared them to normal aging [young (N = 18; 24.6 ± 3.5), older controls (N = 24; 67.2 ± 9.7]. Whole-brain source-level resting-state estimates of relative oscillatory power in the delta (1-4 Hz), theta (4-7 Hz), alpha (8-12 Hz), and beta (15-30 Hz) bands were combined with gray matter volumes and cognitive scores to examine between-group differences and brain-behavior correlations. Language and executive function (EF) abilities were impaired in patients with PPA, while episodic memory was impaired in MCI. Widespread oscillatory speeding and volumetric shrinkage was associated with normal aging, whereas the trajectory in PPA indicated widespread oscillatory slowing with additional volumetric reductions. Increases in delta and decreases in alpha power uniquely predicted group membership to PPA. Beyond volumetric reductions, more delta predicted poorer memory. In patients with MCI, no consistent group difference among oscillatory measures was found. The contributions of delta/alpha power on memory abilities were larger than volumetric differences. Spontaneous oscillatory abnormalities in association with cognitive symptom severity can serve as a marker of neuronal dysfunction in dementia, providing targets for promising treatments.
• Meltzer, J. A., Kielar, A., Panamsky, L., Links, K. A., Deschamps, T., & Leigh, R. C. (2017). Electrophysiological signatures of phonological and semantic maintenance in sentence repetition. NeuroImage, 156, 302-314.
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  Verbal short-term memory comprises resources for phonological rehearsal, which have been characterized anatomically, and for maintenance of semantic information, which are less understood. Sentence repetition tasks tap both processes interactively. To distinguish brain activity involved in phonological vs. semantic maintenance, we recorded magnetoencephalography during a sentence repetition task, incorporating three manipulations emphasizing one mechanism over the other. Participants heard sentences or word lists and attempted to repeat them verbatim after a 5-second delay. After MEG, participants completed a cued recall task testing how much they remembered of each sentence. Greater semantic engagement relative to phonological rehearsal was hypothesized for 1) sentences vs. word lists, 2) concrete vs. abstract sentences, and 3) well recalled vs. poorly recalled sentences. During auditory perception and the memory delay period, we found highly left-lateralized activation in the form of 8-30 Hz event-related desynchronization. Compared to abstract sentences, concrete sentences recruited posterior temporal cortex bilaterally, demonstrating a neural signature for the engagement of visual imagery in sentence maintenance. Maintenance of arbitrary word lists recruited right hemisphere dorsal regions, reflecting increased demands on phonological rehearsal. Sentences that were ultimately poorly recalled in the post-test also elicited extra right hemisphere activation when they were held in short-term memory, suggesting increased demands on phonological resources. Frontal midline theta oscillations also reflected phonological rather than semantic demand, being increased for word lists and poorly recalled sentences. These findings highlight distinct neural resources for phonological and semantic maintenance, with phonological maintenance associated with stronger oscillatory modulations.
• Jokel, R., Kielar, A., Anderson, N. D., Black, S. E., Rochon, E., Graham, S., Freedman, M., & Tang-Wai, D. F. (2016). Behavioural and neuroimaging changes after naming therapy for semantic variant primary progressive aphasia. NEUROPSYCHOLOGIA, 89, 191-216.
• Jokel, R., Kielar, A., Anderson, N. D., Black, S. E., Rochon, E., Graham, S., Freedman, M., & Tang-Wai, D. F. (2016). Behavioural and neuroimaging changes after naming therapy for semantic variant primary progressive aphasia. Neuropsychologia, 89, 191-216.
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  The objectives of this study were to examine the effects of a successful naming intervention on naming performance and brain activity in individuals with the semantic variant of primary progressive aphasia (svPPA). Four participants with svPPA were scanned while performing phonologically- and semantically-based tasks before and after an intense, 20-h naming therapy that followed the principles of errorless learning whereby errors were eliminated from the learning process. Five healthy control participants were scanned at the outset of the study and did not receive treatment. The results showed that in svPPA participants, successful re-learning of forgotten vocabulary was accompanied by activation of a larger network in bilateral brain regions and that the level of activation in the left anterior lobe may be inversely correlated with severity of semantic impairment. Our findings have implications for treatment in svPPA patients and suggest that semantic cues can improve naming, in spite of significant semantic impairment. The results indicate that intensive language therapy can lead to behavioural gains and neuroplastic changes even in individuals with more advanced anterior temporal lobe atrophy.
• Kielar, A., Deschamps, T., Chu, R. K., Jokel, R., Khatamian, Y. B., Chen, J. J., & Meltzer, J. A. (2016). Identifying Dysfunctional Cortex: Dissociable Effects of Stroke and Aging on Resting State Dynamics in MEG and fMRI. Frontiers in aging neuroscience, 8, 40.
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  Spontaneous signals in neuroimaging data may provide information on cortical health in disease and aging, but the relative sensitivity of different approaches is unknown. In the present study, we compared different but complementary indicators of neural dynamics in resting-state MEG and BOLD fMRI, and their relationship with blood flow. Participants included patients with post-stroke aphasia, age-matched controls, and young adults. The complexity of brain activity at rest was quantified in MEG using spectral analysis and multiscale entropy (MSE) measures, whereas BOLD variability was quantified as the standard deviation (SDBOLD), mean squared successive difference (MSSD), and sample entropy of the BOLD time series. We sought to assess the utility of signal variability and complexity measures as markers of age-related changes in healthy adults and perilesional dysfunction in chronic stroke. The results indicate that reduced BOLD variability is a robust finding in aging, whereas MEG measures are more sensitive to the cortical abnormalities associated with stroke. Furthermore, reduced complexity of MEG signals in perilesional tissue were correlated with hypoperfusion as assessed with arterial spin labeling (ASL), while no such relationship was apparent with BOLD variability. These findings suggest that MEG signal complexity offers a sensitive index of neural dysfunction in perilesional tissue in chronic stroke, and that these effects are clearly distinguishable from those associated with healthy aging.
• Kielar, A., Deschamps, T., Chu, R., Jokel, R., Khatamian, Y. B., Chen, J. J., & Meltzer, J. A. (2016). Identifying Dysfunctional Cortex: Dissociable Effects of Stroke and Aging on Resting State Dynamics in MEG and fMRI. FRONTIERS IN AGING NEUROSCIENCE, 8.
• Kielar, A., Deschamps, T., Jokel, R., & Meltzer, J. A. (2016). Functional Reorganization of Language Networks for Semantics and Syntax in Chronic Stroke: Evidence From MEG. HUMAN BRAIN MAPPING, 37(8), 2869-2893.
• Kielar, A., Deschamps, T., Jokel, R., & Meltzer, J. A. (2016). Functional reorganization of language networks for semantics and syntax in chronic stroke: Evidence from MEG. Human brain mapping, 37(8), 2869-93.
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  Using magnetoencephalography, we investigated the potential of perilesional and contralesional activity to support language recovery in patients with poststroke aphasia. In healthy young controls, left-lateralized ventral frontotemporal regions responded to semantic anomalies during sentence comprehension and bilateral dorsal frontoparietal regions responded to syntactic anomalies. Older adults showed more extensive bilateral responses to the syntactic anomalies and less lateralized responses to the semantic anomalies, with decreased activation in the left occipital and parietal regions for both semantic and syntactic anomalies. In aphasic participants, we observed compensatory recruitment in the right hemisphere (RH), which varied depending on the type of linguistic information that was processed. For semantic anomalies, aphasic patients activated some preserved left hemisphere regions adjacent to the lesion, as well as homologous parietal and temporal RH areas. Patients also recruited right inferior and dorsolateral frontal cortex that was not activated in the healthy participants. Responses for syntactic anomalies did not reach significance in patients. Correlation analyses indicated that recruitment of homologous temporoparietal RH areas is associated with better semantic performance, whereas higher accuracy on the syntactic task was related to bilateral superior temporoparietal and right frontal activity. The results suggest that better recovery of semantic processing is associated with a shift to ventral brain regions in the RH. In contrast, preservation of syntactic processing is mediated by dorsal areas, bilaterally, although recovery of syntactic processing tends to be poorer than semantic. Hum Brain Mapp 37:2869-2893, 2016. © 2016 Wiley Periodicals, Inc.
• Kielar, A., Panamsky, L., Links, K. A., & Meltzer, J. A. (2015). Localization of electrophysiological responses to semantic and syntactic anomalies in language comprehension with MEG. NeuroImage, 105, 507-24.
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  Syntactically and semantically anomalous words encountered during sentence comprehension are known to elicit dissociable electrophysiological responses, which are thought to reflect distinct aspects of language processing. However, the sources of these responses have not been well characterized. We used beamforming analysis of magnetoencephalography (MEG) data to map generators of electrophysiological responses to linguistic anomalies. Anomalous words occurred in the context of a sentence acceptability judgement task conducted in both visual and auditory modalities. Time-frequency analysis revealed that both kinds of violations elicited event-related synchronization (ERS) in the delta-theta frequency range (1-5 Hz), and desynchronization (ERD) in the alpha-beta range (8-30 Hz). In addition, these responses were differentially modulated by violation type and presentation modality. 1-5 Hz responses were consistently localized within medial prefrontal cortex and did not vary significantly across violation types, but were stronger for visual presentation. In contrast, 8-30 Hz ERD occurred in different regions for different violation types. For semantic violations the distribution was predominantly in the bilateral occipital cortex and left temporal and inferior frontal regions, and these effects did not differ for visual and auditory presentation. In contrast, syntactic responses were strongly affected by presentation modality. Under visual presentation, syntactic violations elicited bilateral 8-30 Hz ERD extending into dorsal parietal and frontal regions, whereas effects were much weaker and mostly statistically insignificant in the auditory modality. These results suggest that delta-theta ERS reflects generalized increases in working memory demands related to linguistic anomaly detection, while alpha-beta ERD reflects specific activation of cortical regions involved in distinct aspects of linguistic processing, such as semantic vs. phonological short-term memory. Beamforming analysis of time-domain average signals (ERFs) revealed an N400m effect for semantic anomalies in both modalities, localized to left superior temporal and posterior frontal regions, and a later P600-like effect for syntactic anomalies in both modalities, widespread over bilateral frontal, posterior temporal, and parietal regions. These results indicate that time-domain averaged responses and induced oscillatory responses have distinct properties, including localization and modality dependence, and likely reflect dissociable and complementary aspects of neural activity related to language comprehension and additional task-related processes.
• Kielar, A., & Joanisse, M. F. (2014). The role of semantic and phonological factors in word recognition: An ERP cross-modal priming study of derivational morphology. NEUROPSYCHOLOGIA, 49(2), 161-177. doi:doi: 10.1016/j.neuropsychologia.2010.11.027
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  Theories of morphological processing differ on the issue of how lexical and grammatical information are stored and accessed. A key point of contention is whether complex forms are decomposed during recognition (e.g., establish+ment), compared to forms that cannot be analyzed into constituent morphemes (e.g., apartment). In the present study, we examined these issues with respect to English derivational morphology by measuring ERP responses during a cross-modal priming lexical decision task. ERP priming effects for semantically and phonologically transparent derived words (government-govern) were compared to those of semantically opaque derived words (apartment-apart) as well as "quasi-regular" items that represent intermediate cases of morphological transparency (dresser-dress). Additional conditions independently manipulated semantic and phonological relatedness in non-derived words (semantics: couch-sofa; phonology: panel-pan). The degree of N400 ERP priming to morphological forms varied depending on the amount of semantic and phonological overlap between word types, rather than respecting a bivariate distinction between derived and opaque forms. Moreover, these effects could not be accounted for by semantic or phonological relatedness alone. The findings support the theory that morphological relatedness is graded rather than absolute, and depend on the joint contribution of form and meaning overlap.
• Kielar, A., Meltzer, J. A., Moreno, S., Alain, C., & Bialystok, E. (2014). Oscillatory Responses to Semantic and Syntactic Violations. JOURNAL OF COGNITIVE NEUROSCIENCE, 26(12), 2840-2862. doi:doi: 10.1162/jocn_a_00670
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  EEG studies employing time-frequency analysis have revealed changes in theta and alpha power in a variety of language and memory tasks. Semantic and syntactic violations embedded in sentences evoke well-known ERPs, but little is known about the oscillatory responses to these violations. We investigated oscillatory responses to both kinds of violations, while monolingual and bilingual participants performed an acceptability judgment task. Both violations elicited power decreases (event-related desynchronization, ERD) in the 8-30 Hz frequency range, but with different scalp topographies. In addition, semantic anomalies elicited power increases (event-related synchronization, ERS) in the 1-5 Hz frequency band. The 1-5 Hz ERS was strongly phase-locked to stimulus onset and highly correlated with time domain averages, whereas the 8-30 Hz ERD response varied independently of these. In addition, the results showed that language expertise modulated 8-30 Hz ERD for syntactic violations as a function of the executive demands of the task. When the executive function demands were increased using a grammaticality judgment task, bilinguals but not monolinguals demonstrated reduced 8-30 Hz ERD for syntactic violations. These findings suggest a putative role of the 8-30 Hz ERD response as a marker of linguistic processing that likely represents a separate neural process from those underlying ERPs.
• Kielar, A., Meltzer, J. A., Moreno, S., Alain, C., & Bialystok, E. (2014). Oscillatory responses to semantic and syntactic violations. Journal of cognitive neuroscience, 26(12), 2840-62.
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  EEG studies employing time-frequency analysis have revealed changes in theta and alpha power in a variety of language and memory tasks. Semantic and syntactic violations embedded in sentences evoke well-known ERPs, but little is known about the oscillatory responses to these violations. We investigated oscillatory responses to both kinds of violations, while monolingual and bilingual participants performed an acceptability judgment task. Both violations elicited power decreases (event-related desynchronization, ERD) in the 8-30 Hz frequency range, but with different scalp topographies. In addition, semantic anomalies elicited power increases (event-related synchronization, ERS) in the 1-5 Hz frequency band. The 1-5 Hz ERS was strongly phase-locked to stimulus onset and highly correlated with time domain averages, whereas the 8-30 Hz ERD response varied independently of these. In addition, the results showed that language expertise modulated 8-30 Hz ERD for syntactic violations as a function of the executive demands of the task. When the executive function demands were increased using a grammaticality judgment task, bilinguals but not monolinguals demonstrated reduced 8-30 Hz ERD for syntactic violations. These findings suggest a putative role of the 8-30 Hz ERD response as a marker of linguistic processing that likely represents a separate neural process from those underlying ERPs.
• Kielar, A., & Joanisse, M. F. (2012). Graded Effects of Regularity in Language Revealed by N400 Indices of Morphological Priming. JOURNAL OF COGNITIVE NEUROSCIENCE, 22(7), 1373-1398. doi:doi: 10.1162/jocn.2009.21353.
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  Differential electrophysiological effects for regular and irregular linguistic forms have been used to support the theory that grammatical rules are encoded using a dedicated cognitive mechanism. The alternative hypothesis is that language systematicities are encoded probabilistically in a way that does not categorically distinguish rule-like and irregular forms. In the present study, this matter was investigated more closely by focusing specifically on whether the regular-irregular distinction in English past tenses is categorical or graded. We compared the ERP priming effects of regulars (baked-bake), vowel-change irregulars (sang-sing), and "suffixed" irregulars that display a partial regularity (suffixed irregular verbs, e.g., slept-sleep), as well as forms that are related strictly along formal or semantic dimensions. Participants performed a visual lexical decision task with either visual (Experiment 1) or auditory prime (Experiment 2). Stronger N400 priming effects were observed for regular than vowel-change irregular verbs, whereas suffixed irregulars tended to group with regular verbs. Subsequent analyses decomposed early versus late-going N400 priming, and suggested that differences among forms can be attributed to the orthographic similarity of prime and target. Effects of morphological relatedness were observed in the later-going time period, however, we failed to observe true regular-irregular dissociations in either experiment. The results indicate that morphological effects emerge from the interaction of orthographic, phonological, and semantic overlap between words.
• Kielar, A., Meltzer-Asscher, A., & Thompson, C. K. (2012). Electrophysiological responses to argument structure violations in healthy adults and individuals with agrammatic aphasia. Neuropsychologia, 50(14), 3320-37.
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  Sentence comprehension requires processing of argument structure information associated with verbs, i.e. the number and type of arguments that they select. Many individuals with agrammatic aphasia show impaired production of verbs with greater argument structure density. The extent to which these participants also show argument structure deficits during comprehension, however, is unclear. Some studies find normal access to verb arguments, whereas others report impaired ability. The present study investigated verb argument structure processing in agrammatic aphasia by examining event-related potentials associated with argument structure violations in healthy young and older adults as well as aphasic individuals. A semantic violation condition was included to investigate possible differences in sensitivity to semantic and argument structure information during sentence processing. Results for the healthy control participants showed a negativity followed by a positive shift (N400-P600) in the argument structure violation condition, as found in previous ERP studies (Friederici & Frisch, 2000; Frisch, Hahne, & Friederici, 2004). In contrast, individuals with agrammatic aphasia showed a P600, but no N400, response to argument structure mismatches. Additionally, compared to the control groups, the agrammatic participants showed an attenuated, but relatively preserved, N400 response to semantic violations. These data show that agrammatic individuals do not demonstrate normal real-time sensitivity to verb argument structure requirements during sentence processing.
• Kielar, A., & Joanisse, M. F. (2011). The role of semantic and phonological factors in word recognition: an ERP cross-modal priming study of derivational morphology. Neuropsychologia, 49(2), 161-77.
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  Theories of morphological processing differ on the issue of how lexical and grammatical information are stored and accessed. A key point of contention is whether complex forms are decomposed during recognition (e.g., establish+ment), compared to forms that cannot be analyzed into constituent morphemes (e.g., apartment). In the present study, we examined these issues with respect to English derivational morphology by measuring ERP responses during a cross-modal priming lexical decision task. ERP priming effects for semantically and phonologically transparent derived words (government-govern) were compared to those of semantically opaque derived words (apartment-apart) as well as "quasi-regular" items that represent intermediate cases of morphological transparency (dresser-dress). Additional conditions independently manipulated semantic and phonological relatedness in non-derived words (semantics: couch-sofa; phonology: panel-pan). The degree of N400 ERP priming to morphological forms varied depending on the amount of semantic and phonological overlap between word types, rather than respecting a bivariate distinction between derived and opaque forms. Moreover, these effects could not be accounted for by semantic or phonological relatedness alone. The findings support the theory that morphological relatedness is graded rather than absolute, and depend on the joint contribution of form and meaning overlap.
• Kielar, A., Meltzer-asscher, A., & Thompson, C. K. (2011).

  ERP Responses to Argument Structure and Semantic Violations in Sentence Context in Healthy and Agrammatic Aphasic Adults

  . Procedia - Social and Behavioral Sciences, 23, 45-46. doi:10.1016/j.sbspro.2011.09.162
• Kielar, A., Milman, L., Bonakdarpour, B., & Thompson, C. K. (2011). Neural correlates of covert and overt production of tense and agreement morphology: Evidence from fMRI. Journal of neurolinguistics, 24(2), 183-201.
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  Most neuroimaging studies examining verb morphology have focused on verb tense, with fewer examining agreement morphology, and no previous fMRI studies have investigated distinctions between past and present tense inflection. However, models of language representation and processing suggest differences in where these inflections are instantiated in the phrase structure as well as differences in the linguistic functions they serve, suggesting unique neural networks for these forms. In addition, results of available neuroimaging studies of grammatical morphology vary considerably due to methodological differences. Some studies have used overt production tasks, whereas others have used covert tasks. In the present study we examined brain activation associated with past tense and present tense/agreement morphology under overt and covert production conditions in 13 healthy adults using an event-related functional magnetic resonance imaging (fMRI) design. Production of verbs inflected for past tense (V + -ed) and present tense/agreement (V -s) was elicited using temporal adverbs (i.e. Yesterday, Nowadays). Results showed that in healthy adults inflecting both past tense and agreement morphology (compared to a verb stem production condition) recruited not only left inferior frontal structures, but also motor and premotor cortices, and posterior parietal regions. Activation also was observed in the basal ganglia, thalamus, and the cingulate gyrus. Past tense and present tense/agreement recruited partially overlapping tissue in these regions, with distinctions observed for the two forms in frontal and parietal brain areas. We also found that activation varied with task demands, with more extensive frontal activation noted in the overt compared to the covert verb inflection task. These results are consistent with the hypothesis that the neural signatures for verb inflection differ from that for verb stems alone and involve a distributed frontal and parietal network of brain regions. Further, the neural tissue recruited for instantiation of past tense versus present tense/agreement morphology is distinct, supporting linguistic theories that differentiate the two forms.
• Kielar, A., & Joanisse, M. F. (2010). Graded effects of regularity in language revealed by N400 indices of morphological priming. Journal of cognitive neuroscience, 22(7), 1373-98.
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  Differential electrophysiological effects for regular and irregular linguistic forms have been used to support the theory that grammatical rules are encoded using a dedicated cognitive mechanism. The alternative hypothesis is that language systematicities are encoded probabilistically in a way that does not categorically distinguish rule-like and irregular forms. In the present study, this matter was investigated more closely by focusing specifically on whether the regular-irregular distinction in English past tenses is categorical or graded. We compared the ERP priming effects of regulars (baked-bake), vowel-change irregulars (sang-sing), and "suffixed" irregulars that display a partial regularity (suffixed irregular verbs, e.g., slept-sleep), as well as forms that are related strictly along formal or semantic dimensions. Participants performed a visual lexical decision task with either visual (Experiment 1) or auditory prime (Experiment 2). Stronger N400 priming effects were observed for regular than vowel-change irregular verbs, whereas suffixed irregulars tended to group with regular verbs. Subsequent analyses decomposed early versus late-going N400 priming, and suggested that differences among forms can be attributed to the orthographic similarity of prime and target. Effects of morphological relatedness were observed in the later-going time period, however, we failed to observe true regular-irregular dissociations in either experiment. The results indicate that morphological effects emerge from the interaction of orthographic, phonological, and semantic overlap between words.
• Kielar, A., Milman, L., Bonakdarpour, B., & Thompson, C. K. (2010). Neural correlates of covert and overt production of tense and agreement morphology: Evidence from fMRI. JOURNAL OF NEUROLINGUISTICS, 24(2), 183-201.
  More info

  Most neuroimaging studies examining verb morphology have focused on verb tense, with fewer examining agreement morphology, and no previous fMRI studies have investigated distinctions between past and present tense inflection. However, models of language representation and processing suggest differences in where these inflections are instantiated in the phrase structure as well as differences in the linguistic functions they serve, suggesting unique neural networks for these forms. In addition, results of available neuroimaging studies of grammatical morphology vary considerably due to methodological differences. Some studies have used overt production tasks, whereas others have used covert tasks. In the present study we examined brain activation associated with past tense and present tense/agreement morphology under overt and covert production conditions in 13 healthy adults using an event-related functional magnetic resonance imaging (fMRI) design. Production of verbs inflected for past tense (V + -ed) and present tense/agreement (V -s) was elicited using temporal adverbs (i.e. Yesterday, Nowadays). Results showed that in healthy adults inflecting both past tense and agreement morphology (compared to a verb stem production condition) recruited not only left inferior frontal structures, but also motor and premotor cortices, and posterior parietal regions. Activation also was observed in the basal ganglia, thalamus, and the cingulate gyrus. Past tense and present tense/agreement recruited partially overlapping tissue in these regions, with distinctions observed for the two forms in frontal and parietal brain areas. We also found that activation varied with task demands, with more extensive frontal activation noted in the overt compared to the covert verb inflection task. These results are consistent with the hypothesis that the neural signatures for verb inflection differ from that for verb stems alone and involve a distributed frontal and parietal network of brain regions. Further, the neural tissue recruited for instantiation of past tense versus present tense/agreement morphology is distinct, supporting linguistic theories that differentiate the two forms.
• Kielar, A., & Joanisse, M. (2008). Priming English past tense verbs: Rules or statistics?. Journal of Memory and Language, 58(2), 327-346. doi:10.1016/j.jml.2007.10.002
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  A key question in language processing concerns the rule-like nature of many aspects of grammar. Much research on this topic has focused on English past tense morphology, which comprises a regular, rule-like pattern (e.g., bake-baked) and a set of irregular forms that defy a rule-based description (e.g., take-took). Previous studies have used past tense priming to support the theory that the two forms are processed using different cognitive mechanisms. In the present study we investigated this distinction more closely, focusing specifically on whether the regular/irregular distinctionis categorical or graded. Priming for regular and irregular forms was compared, as well as for forms that are irregular but display a partial regularity (suffixed irregular verbs, e.g., sleep-slept). Participants performed a lexical decision task with either a masked visual (Experiment 1) or an auditory prime (Experiment 2). We also manipulated prime-target ISI(0 vs. 500 ms), given previous studies indicating this factor might also influence the magnitude and quality of effects. Weobserved priming effects for both regular and irregular verbs, however the degree of priming of both was influenced byprime modality and processing time. When the prime was masked and presented for 66 ms regulars and suffixed irregularspatterned together, and were different from vowel change irregular forms. As the processing time increased (usinglonger ISI or cross-modal presentation), all morphologically related words showed facilitation. The results suggest thatpriming arises as a convergence of orthographic, phonological and semantic overlap that is especially strong for morphologicallyrelated words.
• Abel, S. M., Sass-Kortsak, A., & Kielar, A. (2002). The effects on earmuff attenuation and other safety gear worn in combination. Noise and Health, 5(17), 13.
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  This study assessed the effect of other safety gear worn in proximity on the attenuation afforded by earmuffs attached to a hard hat. Seventy-two males and females participated: 24 under the age of 40 years with normal hearing, and 48 over the age of 40 years, half with normal hearing and half with bilateral high-tone hearing loss. Measurements were made with the ears unoccluded, with the muffs on hard hat alone, and with the muffs on hard hat in combination with safety glasses, an air-purifying half mask respirator or both glasses and respirator. They included (1) diffuse field hearing thresholds from 0.25-8 kHz, and (2) consonant discrimination in quiet and in 80-dB SPL speech spectrum noise. Attenuation was derived by subtracting the unoccluded from the protected hearing threshold at each frequency. Muff attenuation was within 6 dB of the manufacturer's specifications but decreased by as much as 5 dB when the glasses or respirator were worn and by 9 dB with both these devices. Males achieved 3 dB higher attenuation than females. However, hearing status had no effect. Consonant discrimination was significantly worse in noise. The impaired subjects performed more poorly when wearing the muff on hard hat but there was no additional effect of wearing the glasses and/or respirator. These results demonstrate that wearing other protective safety gear around the head can interfere with the hearing protection provided by earmuffs. They also confirm that for people with a hearing loss, the use of earmuffs may increase the communication handicap.
• Abel, S. M., Sass-Kortsak, A., & Kielar, A. (2001). The effects of safety gear worn in combination and hearing loss on earmuff attenuation and speech understanding. Canadian Acoustics, 29(3), 50-51.
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  This study was designed to determine whether the wearingof other safety gear in combination would decrease thesound attenuation of hearing protective ear muffs.Preliminary results showed that, in young normal-hearinglisteners, the wearing of safety glasses and a half mask respiratorsignificantly decreased the attenuation provided by aClass A earmuff, particularly in the low frequencies. Thiswas due to leakage of sound under the ear cup. A questionof interest was the interactive effect of the hearing status ofthe listener. In previous studies we had demonstrated that,while the amount of sound attenuation achieved was notaffected by hearing loss, speech understanding was compromisedby the wearing of conventional muffs and plugs.We hypothesized that a decrease in attenuation due to thewearing of devices in combination might improve speechunderstanding in the hearing-impaired listener.
• Zakzanis, K. K., Kielar, A., Young, D. A., & Boulos, M. (2001). Neuropsychological differentiation of late onset schizophrenia and fronto-temporal dementia. Cognitive Neuropsychiatry, 6(1), 63-77.

Proceedings Publications

• Kielar, A. (2018, Fall). Modulation of Task-Related and Resting-State Oscillatory Responses in Primary Progressive Aphasia. In Academy of Aphasia 56th Annual Meeting.
• Kielar, A., Jokel, R., Chu*, R. K., Deschamps*, T., Panamsky*, L., Chen, J. J., Khatamian, Y. B., & Meltzer, J. A. (2015, September 17). Distinguishing the effects of stroke and healthy aging with resting state MEG and fMRI. In International Journal of Stroke: 6th Canadian Stroke Congress, 10, 50.
• Kielar, A., Deschamps, T., Chu, R. K., Panamsky, L., Chen, J. J., Khatamian, Y. B., & Meltzer, J. A. (2014, October 5-7). Stroke induced reorganization of the neural networks for sentence comprehension, and relationship to perilesional dysfunction revealed by MEG and ASL. In 52nd Annual Meeting of Academy of Aphasia.
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  Introduction: Considerable changes in the cortical representation of language processing can occur following stroke. Both left and right hemisphere regions are thought to support language recovery; however the relative contributions of each hemisphere and neural mechanisms mediating this process are not well understood (Meltzer et al., 2013; Price & Crinion, 2005; Saur et al., 2006; Thompson, 2000; 2010). It is generally thought that recovery of function in perilesional areas offers the best prognosis for clinical improvement (Heiss, 2003; Heiss & Thiel, 2006). Therefore, assessing the functionality of these areas is essential to targeting interventions. One potential biomarker of perilesional function and dysfunction relates to abnormalities in spontaneous neural activity (Meinzer et al., 2007; Poza et al., 2007). Perilesional tissue produces a large amount of high amplitude slow-wave activity, which can be quantified using algorithms that examine frequency spectra or complexity (e.g. multiscale entropy: MSE). This slowed spontaneous activity is a marker of subtle neural damage associated with the long-term effects of stroke beyond the primary infarct zone, and may be an indicator of “functional lesion” extent. Many questions remain unanswered regarding its potential associations with 1) cognitive dysfunction, 2) anatomical damage such as white matter disconnection, and 3) decreased blood flow (hypoperfusion). Method: In the present study we used magnetoencephalography (MEG) to clarify the roles of dorsal and ventral language pathways in processing of semantic and syntactic information in healthy adults and participants with stroke-induced aphasia. In addition, we used functional and structural imaging to understand the roles of perilesional and contralesional activity in recovery from post-stroke aphasia, and to explore the potential of right hemisphere activity to support recovery. Using resting MEG and ASL, we developed a paradigm to identify perilesional cortex that is structurally intact, but not functioning optimally. We mapped the distribution of spontaneous slow-wave activity, its relationship to task-related activation during language comprehension, and decreased blood flow (hypoperfusion) in a group of stroke participants. Results: We found that in healthy controls, activation of a temporo-frontal “ventral network” was involved in semantic processing, and a fronto-parietal “dorsal network” was associated with syntax (Figure 1A). Patients with aphasia activated homologous RH areas and dorsal LH regions; however they failed to activate ventral cortex adjacent to the lesion (Figure 1B). In addition, these perilesional regions consistently produced slow-wave activity, indicating that they are dysfunctional even though the tissue was not infarcted (Figure 1 C and D). Furthermore, abnormalities in spontaneous neural activity were associated with less task-related activation, and hypoperfusion in the affected regions These results suggest that the reduced task-related responses in perilesional tissue and the degree of RH recruitment during language processing, are related to abnormal slowing of neural activity, and to reduced blood flow (hypoperfusion). Reversal of such abnormalities may be a fruitful target for interventions such as noninvasive brain stimulation. Conclusion: Our results provide a basis for identifying a relationship between functional, structural and vascular markers of intact/impaired language function and recovery in patients with post-stroke aphasia.
• Kielar, A., Meltzer-Asscher, A., & Thompson, C. K. (2012, May 20-25). Electrophysiological responses to argument structure violations in healthy adults and individuals with nonfluent aphasia.. In 42nd Clinical Aphasiology Conference,.
• Meltzer-Asscher, A., Kielar, A., Mack, J., Weintraub, S., Mesulam, M. M., & Thompson, C. K. (2012, October). Electrophysiological Responses to Semantic and Argument Structure Violations in Agrammatic Primary Progressive Aphasia. In 50th Annual Meeting of Academy of Aphasia, 61, 266-268.
• Kielar, A., Meltzer-Asscher, A., & Thompson, C. K. (2011, Fall). ERP responses to argument structure and semantic violations in sentence context in healthy and agrammatic aphasic adults. In Academy of Aphasia, 23, 45-46.
• Kielar, A. (2008).

  Representation of language in the brain : behavioural and imaging investigations of English past tense morphology

  . In Doctoral Dissertation.
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  A main question in language processing concerns the rule-like nature of many aspects of grammar. Previous studies investigating these patterns of language have used differences between regular and irregular past tense verbs to support the theory that these types of forms are processed using different cognitive mechanisms. In the present set of experiments this matter was investigated more closely by focusing specifically on whether the regular/irregular distinction in English past tenses is categorical or graded. In a series of visual and cross-modal behavioural and imaging priming studies, I compared priming effects of regular (baked-bake) and irregular (sang-sing) past tense verbs, as well as forms that are irregular but display a partial regularity (suffixed irregular verbs, e.g., sleep-slept). Study 1 examined this issue with respect to reaction time in a classical behavioural priming task; Studies 2 and 3 used a similar technique while recording neural responses using event-related potentials (ERPs) and functional Magnetic Resonance Imaging (fMRI). The results provide support for the theory that rules of language are graded and probabilistic, such that there is continuity in processing of regular and irregular forms rather than a categorical distinction. The size of priming effects seems to reflect the amount of phonological and semantic overlap between words. These results support the hypothesis that individuals process morphologically complex words through the joint contribution of phonology, orthography and semantics. During on-line processing, morphological effects seem to stabilize with time in a way that reveals task sensitivity to both meaning and form overlap between words. This effect is the strongest for morphologically related words for which the similarity between form and meaning is the strongest and most consistent (i.e., regulars) but it can also be observed for inconsistent cases as well (i.e., irregulars). For more info, contact: ************************************ Dirk-Bart den Ouden, Ph.D. Aphasia & Neurolinguistics Research Laboratory Dept. of Communication Sciences & Disorders Northwestern University 2240 Campus Drive, Evanston IL 60208-3066 Phone: (office) 1-847-467-2515; (lab) 1-847-467-7591 ************************************
• Kielar, A., & Orange, J. B. (2007, Summer). Processing of nouns and verbs in Dementia of Alzheimer’s Type (DAT). In International Conferences on Caregiving, Disability, Aging and Technology: Advances in NeuroRehabilitation (FICCDAT)..

Presentations

• Kielar, A., Patterson, D., Guzik, A., & Chou, Y. (2021, October). Effectiveness of rTMS in treating post-stroke aphasia: Role of stimulation parameters and individual characteristics. Slide Slam Presentation. 13th Meeting of the Society for Neurobiology of Language. Virtual.
• Kielar, A. (2020, Spring). Effect of rTMS on spontaneous brain connectivity. Research Innovating Showcase, BIO5 Institute. University of Arizona: BIO5.
• Kielar, A. (2019, Spring). Slowing of Language-Related and Resting-State Oscillatory Responses in Primary Progressive Aphasia (PPA).. SLHS Colloquium, University of Arizona. SLHS , University of Arizona.
• Kielar, A. (2019, Spring). Slowing of Language-Related and Resting-State Oscillatory Responses in Primary Progressive Aphasia (PPA). SLHS Colloquium. University of Arizona.
• Kielar, A. (2018, April). Individualized neuromodulation protocol for the treatment of language deficits in aphasia. 2018 Transcranial Magnetic Stimulation. BIO5, University of Arizona.
• Kielar, A. (2018, Fall). Modulation of task related and resting state oscillatory responses in Primary Progressive Aphasia.. Academy of Aphasia 56th Annual Meeting,. Montreal, Canada: Academy of Aphasia.
• Kielar, A. (2018, February). Talking the Talk: Priming past tense in aphasia. Speech Language and Hearing Sciences Spring Data Blitz. University of Arizona.
• Kielar, A. (2018, May). Language related and resting-state oscillatory responses in primary progressive aphasia. 48th Clinical Aphasiology Conference.
• Kielar, A. (2018, October). Neural dynamics of language-related and spontaneous activity in aphasia. Barrow Stroke Symposium. Phoenix, AZ.
• Kielar, A. (2017, April). Language Related and Spontaneous Oscillatory Responses in Acquired Language Disorders. COGNITIVE SCIENCE COLLOQUIUM Spring 2017. UA.
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  TITLE: Language Related and Spontaneous Oscillatory Responses in Acquired Language DisordersABSTRACT: Mapping oscillatory neural activity with magnetoencephalography (MEG) is a powerful method forrevealing the functional organization of different aspect of language, and the changes associated with stroke.Considerable changes in the cortical representation of language processing can follow stroke. However, the neuralmechanisms mediating recovery and relative contributions of each hemisphere are not well understood. In thepresent set of studies I used MEG to understand the roles of perilesional and contralesional activity in recovery ofsemantic and syntactic processing in patients with poststrokeaphasia, and to explore the role of right hemispherein language recovery. The resting state MEG and fMRI, as well as blood flow measures were used to identifydysfunctional cortex.In healthy controls, a leftlateralizedtemporofrontal“ventral network” responded to semantic anomalies duringsentence comprehension, and a bilateral frontoparietal“dorsal network” responded to syntactic anomalies. Forparticipants with aphasia, I observed compensatory recruitment in the right hemisphere. Interestingly, thedistribution of this effect was depended on the type of linguistic information that was processed. Better recovery ofsemantic processing was associated with a shift to the right hemisphere components of the ventral network. Incontrast, recovery of syntax was mediated by dorsal brain regions, bilaterally.The analysis of resting state activity indicated that reduced BOLD variability was associated with aging, whereasspontaneous MEG measures were more sensitive to the cortical abnormalities associated with stroke. Furthermore,reduced MEG complexity in perilesional tissue was correlated with hypoperfusion as assessed with arterial spinlabeling, while no such relationship was apparent with BOLD variability. These findings suggest that MEG signalcomplexity offers a sensitive index of neural dysfunction in perilesional tissue in chronic stroke, and that theseeffects are distinguishable from those associated with healthy aging. The resting state measures may be usefulindicators of cortical dysfunction that is potentially reversible with treatment, and may be used to assess theeffectiveness of interventions.
• Kielar, A. (2017, September). Language Responses in Primary Progressive Aphasia. SLHS Data Blitz. University of Arizona.
• Jokel, R., Meltzer, J. A., & Kielar, A. (2016, May 2). Innovative services for clients with PPA. GTA Rehabilitation Best Practices Day. Toronto, Ontario, Canada.
• Kielar, A. (2014, January 9). Supporting stroke recovery: Localization of neural networks for sentence processing in healthy adults and stroke participants. Seniors Health Knowledge Network Making Connections Webinar Series. Toronto, Canada: Seniors Health Knowledge Network.
• Kielar, A. (2014, November). Pathways for semantic and syntactic processing: Evidence from MEG and Aphasia. Colloquium Series Talk. University of California at Riverside, Department of Psychology: University of California at Riverside.
• Kielar, A., Oppermann, F., Panamsky, L., & Meltzer, J. (2013, November 17). Alpha and beta power decrease as a neural correlates of semantic and phonological processing in a language task. Psychonomics Society Annual Meeting. Toronto, Canada: Psychonomics Society.
• Kielar, A., Panamsky, L., & Meltzer, J. A. (2013, February 13). Localization of neural networks for sentence processing using Magnetoencephalography. ORC and OLTCA Applied Research Education Day. Toronto, Canada: Ontario Research Coalition (ORC) and Ontario Long Term Care Association (OLTCA).
• Kielar, A., Schuchard, J., Barbieri, E., & Thompson, C. K. (2012, Spring). Neural Correlates of Unnacusative and unergative verb processing.. The 19th Cognitive Neuroscience Society Meeting. Chicago, Il: Cognitive Neuroscience Society.
• Kielar, A. (2011, November 23). Neural correlates of language recovery in aphasia: An fMRI study of treatment related effects.. OLTCA Applied Research Education Day. Toronto, Canada: Ontario Long Term Care Association (OLTCA).
• Kielar, A., Fix, S., Bonakdarpour, B., Parrish, T. B., & Thompson,, C. K. (2010, June). Neural correlates of treatment-induced functional category recovery: An fMRI study of tense and agreement production. 14th International Aphasia Rehabilitation Conference. Montreal, Quebeck, Canada.
• Kielar, A., & Orange, J. (2007, February). Processing of nouns and verbs by individuals with Dementia of Alzheimer’s Type. The Canadian Institute of Health Research Symposium. Ottawa, Ontario, Canada: The Canadian Institute of Health Research.
• Kielar, A., Joanisse, M. F., & Newman, R. L. (2006, April). How does the brain processes complex words? ERP cross-modal priming study of derivational morphology. The Cognitive Neuroscience Society Meeting. San Francisco, California, USA: The Cognitive Neuroscience Society.
• Kielar, A., Joanisse, M. F., Hare, M. L., & Seidenberg, M. S. (2004, November). Past tense priming: Rules and exceptions or phonology and semantics?. The 45th Psychonomic Society Annual Meeting. Minneapolis, MIN: Psychonomic Society.
• Kielar, A. (2000, April 28). Neuropsychological differentiation of late life schizophrenia and fronto-temporal dementia. 30th Psychology Undergraduate Thesis Conference. Guelph, Ontario, Canada: University of Guelph.

Poster Presentations

• Kielar, A. (2020, Fall). Altered oscillatory responses to language in the semantic variant of PPA: Converging evidence from MEG. 12th Meeting of the Society for Neurobiology of Language..
• Kielar, A. (2020, Fall). Effect of excitatory and inhibitory theta burst stimulation (TBS) on resting state connectivity. 12th Meeting of the Society for Neurobiology of Language.NSL.
• Kielar, A. (2020, Fall). Electrophysiological connectivity and network changes after high-definition transcranial direct current stimulation in post-stroke aphasia. 12th Meeting of the Society for Neurobiology of Language.SNL.
• Kielar, A. (2020, May). fMRI Localizer Task for Cortical Responses to Phonology, Semantics, and Orthography: A Pilot Study. NSCS Honors Thesis Presentations 2020..
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  NSCS Honors Thesis Presentations
• Kielar, A. (2020, Spring). Changes in Functional Connectivity Induced by rTMS to the left supramarginal gyrus. Research Innovating Showcase, BIO5 Institute,. University of Arizona: BIO5.
• Kielar, A., & Pertsovsky,, S. H. (2020, May). Effects of Stroke Lesion on Language Performance and White Matter Connectivity in Post-Stroke Aphasia.. NSCS Honors Thesis Presentations 2020.
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  NSCS Honors thesis
• Kielar, A., Rice, L. C., Mohr, S., Lughes, P., & McConville, K. (2019, March 23-29). Relationship between phonology, semantics and paste tense inflection in post-stroke aphasia. Cognitive Neuroscience Society Conference (CNS). San Francisco, CA, USA: Cognitive Neuroscience Society.
• Kielar, A., Shah-Basak, P., Sivaratnam, G., Teti, S., Francois-Nienaber, A., & Meltzer, J. (2019, Fall 2019). Functional connectivity underlying language reorganization in chronic post-stroke aphasia using resting-state magnetoencephalography. SNL August 20-22, 2019the Neurobiology of Language.
• Mike, S., Moohr, S., Patterson, D., & Kielar, A. (2019, August). Facilitating phonological processing with repetitive transcranial magnetic stimulation (rTMS). 24th Annual UROC Research Conference, University of Arizona, Graduate College. Tucson, AZ.
• Morrison, A., Rice, L., Mohr, S., & Kielar, A. (2019, April). Speech deficits in patients with stroke-related aphasia: Analysis of narrative speech. Neuroscience & Cognitive Science Poster Forum, University of Arizona, College of Science. Tucson, AZ.
• Skvarla, K., Mohr, S., & Kielar, A. (2019, April). Electrophysiological signature of verb argument processing: ERP study. Neuroscience & Cognitive Science Poster Forum, University of Arizona, College of Science. Tucson, AZ.
• Kielar, A., Rice, L. C., & Mohr, S. (2018, Fall). Priming Past-Tense in Aphasia: Contribution of Sound and Meaning. American Speech-Language Hearing Association Conference (ASHA). Boston, MA: ASHA.
• Morrison, A., Rice, L., Mohr, S., & Kielar, A. (2018, Summer). Narrative production in stroke related aphasia and older adults. Undergraduate Biology Research Project Day, University of Arizona. Tucson, AZ.
• Deschamps*, T., Kielar, A., Jokel, R., & Meltzer, J. A. (2017, March). Resting state MEG biomarkers of cognitive status across healthy aging and two forms of dementia. 27th Annual Rotman Research Institute Conference. Toronto.
• Kielar, A., Deschamps*, T., Regina, J., & Jed, M. A. (2017, Fall). Oscillatory Abnormalities in Primary Progressive Aphasia. Society for the Neurobiology of Language. Baltimore, MD: Society for the Neurobiology of Language,.
• Kielar, A. (2016, December). Oscillatory responses associated with recovery of semantic and syntax in stroke aphasia.. 7th ASUA Cognitive Science Conclave. Tempe, Arizona: ASU.
• Meltzer, J. A., Kielar, A., Chu*, R., & Deschamps*, T. (2016, March 21-22). Spontaneous MEG as a biomarker for cortical health in aging, stroke, dementia, and ordinary cognitive decline. 26th Rotman Research Institute Conference. Toronto, Ontario, Canada: Rotman Research Institute.
• Kielar, A., Deschamps*, T., Chu*, R., Panamsky*, L., Khatamian, Y. B., Chen, J. J., & Metzer, J. A. (2015, October 5-7). Stroke induced reorganization of the neural networks for sentence comprehension, and relationship to perilesional dysfunction revealed by MEG and ASL. 52nd Meeting of Academy of Aphasia. Miami, FL, USA: Academy of Aphasia.
• Kielar, A., Deschamps, T., Chu, R. K., Panamsky, L., Chen, J. J., & Khatamian, Y. B. (2015, October 15-17). Alterations of language related oscillatory activity and spontaneous neural dynamics after stroke. 7th Annual Meeting of the Society for the Neurobiology of Language. Chicago, Illinois: Society for the Neurobiology of Language.
• Kielar, A., Jokel, R., Chu, R. K., Deschamps, T., Panamsky, L., Chen, J. J., Khatamian, Y. B., & Meltzer, J. A. (2015, March 9-11). Altered neural dynamics in stroke and aging: sensitivity of resting state MEG vs. fMRI.. 25th Rotman Research Institute Conference. Toronto, Ontario, Canada: Rotman Research Institute.
• Kielar, A., Jokel, R., Chu, R. K., Deschamps, T., Panamsky, L., Chen, J. J., Khatamian, Y. B., & Meltzer, J. A. (2015, September 17 -19). Distinguishing the effects of stroke and healthy aging with resting state MEG and fMRI. 6th Canadian Stroke Congress. Toronto, Ontario, Canada: HEART AND STROKE FOUNDATION, CANADIAN STROKE CONSORTIUM.
• Meltzer, J. A., Kielar, A., D'Angelo, M. C., Ryan, J. D., & Barense, M. D. (2015, March 9-11). Electrophysiological abnormalities in older adults at risk for dementia: language lateralization and resting state changes. 25 years of Brain and Aging: 25th Rotman Research Institute Conference. Toronto, Ontario, Canada: Rotman Research Institute.
• Kielar, A., Deschamps, T., Chu, R., Panamsky, L., Khatamian, Y. B., Chen, J. J., & Meltzer, J. A. (2014, June 9-10). Functional reorganization of the neural networks for language after stroke and relationship to perilesional dysfunction revealed by MEG. Advances in Stroke Recovery Meeting. Ottawa, Ontario, Canada: Canadian Partnership for Stroke Recovery.
• Kielar, A., Meltzer, J. A., Moreno, S., Alain, C., & Bialystok, E. (2014, May 25-28). Oscillatory responses to sentence embedded semantic and syntactic violations: Effect of bilingualism. 8th Annual Canadian Association for Neuroscience Meeting. Montreal, Quebec, Canada: Canadian Association for Neuroscience.
• Kielar, A., Panamsky, L., Links, K., & Meltzer, J. A. (2012, August). Mapping of neural generators of electrophysiological responses to semantic and syntactic anomalies using MEG.. 18th International Conference on Biomagnetism. Paris, France.
• Kielar, A. (2013, Spring). Localization of neural networks for semantic and syntactic processing using MEG. 20th Annual Cognitive Neuroscience Meeting. San Francisco, CA, USA: Cognitive Neuroscience Society.
• Kielar, A., Panamsky, L., & Meltzer, J. A. (2013, March 4-6). Mapping brain networks for semantic and syntactic processing using MEG in healthy and damaged brains. 23rd Annual Neuroscience Conference: Brain Plasticity and Rehabilitation. Toronto, Canada: Rotman Research Institute.
• Kielar, A., Panamsky, L., & Meltzer, J. A. (2013, May 23). Brain networks for semantic and syntactic processing: Converging evidence from MEG and DTI.. 7th Annual Canadian Association for Neuroscience Meeting. Toronto, Ontario, Canada: Canadian Association for Neuroscience.
• Kielar, A. (2012, May). Electrophysiological responses to argument structure violations in healthy adults and individuals with nonfluent aphasia. The 42nd Clinical Aphasiology Conference. Lake Tahoe, California: Clinical Aphasiology.
• Kielar, A., Meltzer-Asscher, A., Mack, J., Weintraub, S., Mesulam, M. M., & Thompson, C. K. (2012, October). Electrophysiological responses to semantic and argument structure violations in agrammatic Primary Progressive Aphasia. 50th Annual Meeting of Academy of Aphasia. San Francisco, CA: Academy of Aphasia.
• Kielar, A., Meltzer-Asscher, A., Wali, E., & Thompson, C. K. (2012, April). Neuronal Interactions for Words and Pseudowords during Lexical Decision. The 19th Cognitive Neuroscience Society Meeting,. Chicago, IL: Cognitive Neuroscience Society.
• Kielar, A. (2011, November). Neuronal Interactions for Words and Pseudowords during Lexical Decision: DCM model of lexical processing. Society for the Neurobiology of Language. Annapolis, MD, USA: Society for the Neurobiology of Language.
• Kielar, A., Meltzer-Asscher, A., & Thompson, C. K. (2011, October). ERP Responses to Argument Structure and Semantic Violations in Sentence Context in Healthy and Agrammatic Aphasic Adults. 49th Annual Meeting of the Academy of Aphasia. Montreal, Quebec: Academy of Aphasia.
• Kielar, A., Fix, S. C., Bonakdarpour, B., Parrish, T., & Thompson, C. K. (2010, Summer). Neural Correlates of Functional Category Recovery in Aphasia: An fMRI Study of Verb Inflection Production. 16th Annual Meeting of the Organization for Human Brain Mapping. Barcelona, Spain: Organization for Human Brain Mapping.
• Kielar, A., Fix, S. C., Bonakdarpour, B., Parrish, T. B., & Thompson, C. K. (2009, November). Neural correlates of verb inflection production: fMRI study of tense and agreement morphology. Neurobiology of Language Conference. Chicago, Illinois: Neurobiology of Language.
• Kielar, A., Fix, S. C., Bonakdarpour, B., Parrish, T., & Thompson, C. K. (2009, November). Neural correlates of functional category learning and recovery: An fMRI study of verb inflection production. 47th Annual Meeting of Academy of Aphasia. Boston, USA: Academy of Aphasia.
• Kielar, A., Fix, S., Bonakdarpour, B., Parrish, T. B., & Thompson, C. K. (2009, June). Neural correlates of verb production: fMRI study of tense and agreement morphology.. 15th Annual Meeting of the Organization for Human Brain Mapping. San Francisco, California, USA: Organization for Human Brain Mapping.
• Kielar, A., & Orange, J. B. (2007, June). Processing of nouns and verbs by individuals with Dementia of Alzheimer’s Type.. The Festival of International Conferences on Caregiving, Disability, Aging and Technology: Advances in NeuroRehabilitation. Toronto, Ontario, Canada.
• Kielar, A., Joanisse, M. F., & Newman, R. L. (2007, May). Neural processing of rule like and irregular patterns in language: An fMRI study of past tense priming.. The Cognitive Neuroscience Society, Meeting. New York: The Cognitive Neuroscience Society.
• Kielar, A., & Joanisse, M. F. (2003, June). Individual differences in working memory and sentence comprehension.. The Canadian Society for Brain, Behaviour and Cognitive Sciences. Hamilton, Ontario, Canada: Canadian Society for Brain, Behaviour and Cognitive Sciences.
• Kielar, A., & Joanisse, M. F. (2003, November). Individual differences in working memory and sentence comprehension under load. The 44th Psychonomic Society Annual Meeting. Vancouver, B.C., Canada: Psychonomic Society.
• Abel, S. M., Sass-Kortsak, A., & Kielar, A. (2001, October). The effects of safety gear worn in combination and hearing loss on earmuff attenuation and speech understanding. The Annual Meeting of the Canadian Acoustical Association. Allison, Ontario, Canada: Canadian Acoustical Association.

Reviews

• Shah-Basak, P., Boukrina, O., Li, X. R., Jebahi, F., & Kielar, A. (2023. Targeted neurorehabilitation strategies in post-stroke aphasia(pp 129-191).
  More info

  Aphasia is a debilitating language impairment, affecting millions of people worldwide. About 40% of stroke survivors develop chronic aphasia, resulting in life-long disability.
• Kielar, A. (2020. Systematic review and meta-analysis of repetitive transcranial magnetic stimulation (rTMS) effects on treating language symptoms in post-stroke aphasia.(p. 3).
  More info

  PROSPERO 2020 CRD42020180104 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020180104

Others

• Kielar, A. (2021, September). Systematic review and meta-analysis of repetitive transcranial magnetic stimulation (rTMS) effects on treating language symptoms in post-stroke aphasia.. PROSPERO 2020 CRD42020180104 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020180104.
  More info

  Meta-analysis Protocol