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Schevenels K, Michiels L, Lemmens R, De Smedt B, Zink I, Vandermosten M. The role of the hippocampus in statistical learning and language recovery in persons with post stroke aphasia. Neuroimage Clin 2022; 36:103243. [PMID: 36306718 PMCID: PMC9668653 DOI: 10.1016/j.nicl.2022.103243] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/17/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022]
Abstract
Although several studies have aimed for accurate predictions of language recovery in post stroke aphasia, individual language outcomes remain hard to predict. Large-scale prediction models are built using data from patients mainly in the chronic phase after stroke, although it is clinically more relevant to consider data from the acute phase. Previous research has mainly focused on deficits, i.e., behavioral deficits or specific brain damage, rather than compensatory mechanisms, i.e., intact cognitive skills or undamaged brain regions. One such unexplored brain region that might support language (re)learning in aphasia is the hippocampus, a region that has commonly been associated with an individual's learning potential, including statistical learning. This refers to a set of mechanisms upon which we rely heavily in daily life to learn a range of regularities across cognitive domains. Against this background, thirty-three patients with aphasia (22 males and 11 females, M = 69.76 years, SD = 10.57 years) were followed for 1 year in the acute (1-2 weeks), subacute (3-6 months) and chronic phase (9-12 months) post stroke. We evaluated the unique predictive value of early structural hippocampal measures for short-term and long-term language outcomes (measured by the ANELT). In addition, we investigated whether statistical learning abilities were intact in patients with aphasia using three different tasks: an auditory-linguistic and visual task based on the computation of transitional probabilities and a visuomotor serial reaction time task. Finally, we examined the association of individuals' statistical learning potential with acute measures of hippocampal gray and white matter. Using Bayesian statistics, we found moderate evidence for the contribution of left hippocampal gray matter in the acute phase to the prediction of long-term language outcomes, over and above information on the lesion and the initial language deficit (measured by the ScreeLing). Non-linguistic statistical learning in patients with aphasia, measured in the subacute phase, was intact at the group level compared to 23 healthy older controls (8 males and 15 females, M = 74.09 years, SD = 6.76 years). Visuomotor statistical learning correlated with acute hippocampal gray and white matter. These findings reveal that particularly left hippocampal gray matter in the acute phase is a potential marker of language recovery after stroke, possibly through its statistical learning ability.
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Affiliation(s)
- Klara Schevenels
- Research Group Experimental Oto-Rhino-Laryngology, Department of Neurosciences, KU Leuven, Onderwijs en Navorsing 2 (O&N2), Herestraat 49 box 721, Leuven 3000, Belgium; Leuven Brain Institute, KU Leuven, Onderwijs en Navorsing 5 (O&N 5), Herestraat 49 box 1020, Leuven 3000, Belgium.
| | - Laura Michiels
- Department of Neurology, University Hospitals Leuven, Herestraat 49, Leuven 3000, Belgium; Research Group Experimental Neurology, Department of Neurosciences, KU Leuven, Herestraat 49 box 7003, Leuven 3000, Belgium; Laboratory of Neurobiology, VIB Center for Brain & Disease Research, Onderwijs en Navorsing 5 (O&N 5), Herestraat 49 box 602, Leuven 3000, Belgium; Leuven Brain Institute, KU Leuven, Onderwijs en Navorsing 5 (O&N 5), Herestraat 49 box 1020, Leuven 3000, Belgium.
| | - Robin Lemmens
- Department of Neurology, University Hospitals Leuven, Herestraat 49, Leuven 3000, Belgium; Research Group Experimental Neurology, Department of Neurosciences, KU Leuven, Herestraat 49 box 7003, Leuven 3000, Belgium; Laboratory of Neurobiology, VIB Center for Brain & Disease Research, Onderwijs en Navorsing 5 (O&N 5), Herestraat 49 box 602, Leuven 3000, Belgium; Leuven Brain Institute, KU Leuven, Onderwijs en Navorsing 5 (O&N 5), Herestraat 49 box 1020, Leuven 3000, Belgium.
| | - Bert De Smedt
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU leuven, Leopold Vanderkelenstraat 32 box 3765, Leuven 3000, Belgium; Leuven Brain Institute, KU Leuven, Onderwijs en Navorsing 5 (O&N 5), Herestraat 49 box 1020, Leuven 3000, Belgium.
| | - Inge Zink
- Research Group Experimental Oto-Rhino-Laryngology, Department of Neurosciences, KU Leuven, Onderwijs en Navorsing 2 (O&N2), Herestraat 49 box 721, Leuven 3000, Belgium; Leuven Brain Institute, KU Leuven, Onderwijs en Navorsing 5 (O&N 5), Herestraat 49 box 1020, Leuven 3000, Belgium.
| | - Maaike Vandermosten
- Research Group Experimental Oto-Rhino-Laryngology, Department of Neurosciences, KU Leuven, Onderwijs en Navorsing 2 (O&N2), Herestraat 49 box 721, Leuven 3000, Belgium; Leuven Brain Institute, KU Leuven, Onderwijs en Navorsing 5 (O&N 5), Herestraat 49 box 1020, Leuven 3000, Belgium.
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Language learning in aphasia: A narrative review and critical analysis of the literature with implications for language therapy. Neurosci Biobehav Rev 2022; 141:104825. [PMID: 35963544 DOI: 10.1016/j.neubiorev.2022.104825] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 11/24/2022]
Abstract
People with aphasia (PWA) present with language deficits including word retrieval difficulties after brain damage. Language learning is an essential life-long human capacity that may support treatment-induced language recovery after brain insult. This prospect has motivated a growing interest in the study of language learning in PWA during the last few decades. Here, we critically review the current literature on language learning ability in aphasia. The existing studies in this area indicate that (i) language learning can remain functional in some PWA, (ii) inter-individual variability in learning performance is large in PWA, (iii) language processing, short-term memory and lesion site are associated with learning ability, (iv) preliminary evidence suggests a relationship between learning ability and treatment outcomes in this population. Based on the reviewed evidence, we propose a potential account for the interplay between language and memory/learning systems to explain spared/impaired language learning and its relationship to language therapy in PWA. Finally, we indicate potential avenues for future research that may promote more cross-talk between cognitive neuroscience and aphasia rehabilitation.
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Kéri S, Kállai I, Csigó K. Enhanced Verbal Statistical Learning in Glossolalia. Cogn Sci 2020; 44:e12865. [PMID: 32573809 DOI: 10.1111/cogs.12865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 05/06/2020] [Accepted: 05/13/2020] [Indexed: 11/30/2022]
Abstract
Glossolalia ("speaking in tongues") is a rhythmic utterance of word-like strings of sounds, regularly occurring in religious mass gatherings or various forms of private religious practices (e.g., prayer and meditation). Although specific verbal learning capacities may characterize glossolalists, empirical evidence is lacking. We administered three statistical learning tasks (artificial grammar, phoneme sequence, and visual-response sequence) to 30 glossolalists and 30 matched control volunteers. In artificial grammar, participants decide whether pseudowords and sentences follow previously acquired implicit rules or not. In sequence learning, they gradually draw out rules from repeating regularities in sequences of speech sounds or motor responses. Results revealed enhanced artificial grammar and phoneme sequence learning performances in glossolalists compared to control volunteers. There were significant positive correlations between daily glossolalia activity and artificial grammar learning. These results indicate that glossolalists exhibit enhanced abilities to extract the statistical regularities of verbal information, which may be related to their unusual language abilities.
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Affiliation(s)
- Szabolcs Kéri
- Department of Cognitive Science, Budapest University of Technology and Economics.,Nyírő Gyula National Institute of Psychiatry and Addictions.,Department of Physiology, University of Szeged
| | - Imre Kállai
- Department of Psychiatry, University of Debrecen
| | - Katalin Csigó
- Nyírő Gyula National Institute of Psychiatry and Addictions
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Lee J, Hosokawa E, Meehan S, Martin N, Branigan HP. Priming sentence comprehension in aphasia: Effects of lexically independent and specific structural priming. APHASIOLOGY 2019; 33:780-802. [PMID: 31814655 PMCID: PMC6897506 DOI: 10.1080/02687038.2019.1581916] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
PURPOSE Impaired message-structure mapping results in deficits in both sentence production and comprehension in aphasia. Structural priming has been shown to facilitate syntactic production for persons with aphasia (PWA). However, it remains unknown if structural priming is also effective in sentence comprehension. We examined if PWA show preserved and lasting structural priming effects during interpretation of syntactically ambiguous sentences and if the priming effects occur independently of or in conjunction with lexical (verb) information. METHODS Eighteen PWA and 20 healthy older adults (HOA) completed a written sentence-picture matching task involving the interpretation of prepositional phrases (PP; the chef is poking the solider with an umbrella) that were ambiguous between high (verb modifier) and low attachment (object noun modifier). Only one interpretation was possible for prime sentences, while both interpretations were possible for target sentences. In Experiment 1, the target was presented immediately after the prime (0-lag). In Experiment 2, two filler items intervened between the prime and the target (2-lag). Within each experiment, the verb was repeated for half of the prime-target pairs, while different verbs were used for the other half. Participants' off-line picture matching choices and response times were measured. RESULTS After reading a prime sentence with a particular interpretation, HOA and PWA tended to interpret an ambiguous PP in a target sentence in the same way and with faster response times. Importantly, both groups continued to show this priming effect over a lag (Experiment 2), although the effect was not as reliable in response times. However, neither group showed lexical (verb-specific) boost on priming, deviating from robust lexical boost seen in the young adults of prior studies. CONCLUSIONS PWA demonstrate abstract (lexically-independent) structural priming in the absence of a lexically-specific boost. Abstract priming is preserved in aphasia, effectively facilitating not only immediate but also longer-lasting structure-message mapping during sentence comprehension.
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Cope TE, Wilson B, Robson H, Drinkall R, Dean L, Grube M, Jones PS, Patterson K, Griffiths TD, Rowe JB, Petkov CI. Artificial grammar learning in vascular and progressive non-fluent aphasias. Neuropsychologia 2017; 104:201-213. [PMID: 28843341 PMCID: PMC5637161 DOI: 10.1016/j.neuropsychologia.2017.08.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/15/2017] [Accepted: 08/17/2017] [Indexed: 11/24/2022]
Abstract
Patients with non-fluent aphasias display impairments of expressive and receptive grammar. This has been attributed to deficits in processing configurational and hierarchical sequencing relationships. This hypothesis had not been formally tested. It was also controversial whether impairments are specific to language, or reflect domain general deficits in processing structured auditory sequences. Here we used an artificial grammar learning paradigm to compare the abilities of controls to participants with agrammatic aphasia of two different aetiologies: stroke and frontotemporal dementia. Ten patients with non-fluent variant primary progressive aphasia (nfvPPA), 12 with non-fluent aphasia due to stroke, and 11 controls implicitly learned a novel mixed-complexity artificial grammar designed to assess processing of increasingly complex sequencing relationships. We compared response profiles for otherwise identical sequences of speech tokens (nonsense words) and tone sweeps. In all three groups the ability to detect grammatical violations varied with sequence complexity, with performance improving over time and being better for adjacent than non-adjacent relationships. Patients performed less well than controls overall, and this was related more strongly to aphasia severity than to aetiology. All groups improved with practice and performed well at a control task of detecting oddball nonwords. Crucially, group differences did not interact with sequence complexity, demonstrating that aphasic patients were not disproportionately impaired on complex structures. Hierarchical cluster analysis revealed that response patterns were very similar across all three groups, but very different between the nonsense word and tone tasks, despite identical artificial grammar structures. Overall, we demonstrate that agrammatic aphasics of two different aetiologies are not disproportionately impaired on complex sequencing relationships, and that the learning of phonological and non-linguistic sequences occurs independently. The similarity of profiles of discriminatory abilities and rule learning across groups suggests that insights from previous studies of implicit sequence learning in vascular aphasia are likely to prove applicable in nfvPPA.
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Affiliation(s)
- Thomas E Cope
- Department of Clinical Neurosciences, University of Cambridge, UK; Institute of Neuroscience, Newcastle University, UK.
| | | | - Holly Robson
- School of Psychology and Clinical Language Sciences, University of Reading, UK
| | - Rebecca Drinkall
- School of Psychology and Clinical Language Sciences, University of Reading, UK
| | - Lauren Dean
- Institute of Neuroscience, Newcastle University, UK
| | - Manon Grube
- Institute of Neuroscience, Newcastle University, UK
| | - P Simon Jones
- Department of Clinical Neurosciences, University of Cambridge, UK
| | - Karalyn Patterson
- Department of Clinical Neurosciences, University of Cambridge, UK; Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK
| | | | - James B Rowe
- Department of Clinical Neurosciences, University of Cambridge, UK; Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK
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Cho-Reyes S, Mack JE, Thompson CK. Grammatical Encoding and Learning in Agrammatic Aphasia: Evidence from Structural Priming. JOURNAL OF MEMORY AND LANGUAGE 2016; 91:202-218. [PMID: 28924328 PMCID: PMC5600488 DOI: 10.1016/j.jml.2016.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The present study addressed open questions about the nature of sentence production deficits in agrammatic aphasia. In two structural priming experiments, 13 aphasic and 13 age-matched control speakers repeated visually- and auditorily-presented prime sentences, and then used visually-presented word arrays to produce dative sentences. Experiment 1 examined whether agrammatic speakers form structural and thematic representations during sentence production, whereas Experiment 2 tested the lasting effects of structural priming in lags of two and four sentences. Results of Experiment 1 showed that, like unimpaired speakers, the aphasic speakers evinced intact structural priming effects, suggesting that they are able to generate such representations. Unimpaired speakers also evinced reliable thematic priming effects, whereas agrammatic speakers did so in some experimental conditions, suggesting that access to thematic representations may be intact. Results of Experiment 2 showed structural priming effects of comparable magnitude for aphasic and unimpaired speakers. In addition, both groups showed lasting structural priming effects in both lag conditions, consistent with implicit learning accounts. In both experiments, aphasic speakers with more severe language impairments exhibited larger priming effects, consistent with the "inverse preference" prediction of implicit learning accounts. The findings indicate that agrammatic speakers are sensitive to structural priming across levels of representation and that such effects are lasting, suggesting that structural priming may be beneficial for the treatment of sentence production deficits in agrammatism.
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Affiliation(s)
- Soojin Cho-Reyes
- Department of Communication Sciences and Disorders, Northwestern University
| | - Jennifer E. Mack
- Department of Communication Sciences and Disorders, Northwestern University
| | - Cynthia K. Thompson
- Department of Communication Sciences and Disorders, Northwestern University
- Cognitive Neurology and Alzheimer's Disease Center, Northwestern University
- Department of Neurology, Northwestern University
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Schuchard J, Nerantzini M, Thompson CK. Implicit learning and implicit treatment outcomes in individuals with aphasia. APHASIOLOGY 2016; 31:25-48. [PMID: 28603329 PMCID: PMC5461970 DOI: 10.1080/02687038.2016.1147526] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
BACKGROUND Implicit learning is a process of learning that occurs outside of conscious awareness and may be involved in implicit, exposure-based language training. However, research shows that implicit learning abilities are variable among individuals with aphasia, and it remains unknown whether individuals who show basic implicit learning abilities also benefit from implicit language training. AIMS The aims of this series of experiments were to test implicit learning in individuals with agrammatic aphasia, examine the effects of a novel implicit language treatment, and investigate whether individuals with aphasia who show implicit learning ability also benefit from implicit treatment focused on passive sentence comprehension. METHODS & PROCEDURES Nine participants with chronic agrammatic aphasia and 21 neurologically intact participants completed a visuomotor serial reaction time test of implicit learning (Experiment 1). The participants with aphasia also completed a short-term novel implicit sentence comprehension treatment (Experiment 2) that consisted of five sessions of repeated exposure to grammatically correct passive sentences and matching photographs. Sentence comprehension was tested in multiple baseline sessions and on each day of training using a sentence-picture matching task. The relation between participants' learning patterns across experiments was also examined. OUTCOMES & RESULTS Individuals with agrammatic aphasia as well as neurologically intact adults demonstrated significant implicit sequence learning in the serial reaction time task. However, the participants with aphasia did not show concomitant improvement in sentence comprehension as a result of the implicit treatment protocol. CONCLUSIONS This study suggests that individuals with agrammatic aphasia demonstrate implicit learning ability; however, this ability does not necessarily promote successful outcomes in treatment that is based solely on implicit training methods.
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Affiliation(s)
- Julia Schuchard
- Department of Communication Sciences and Disorders, Northwestern University
| | | | - Cynthia K Thompson
- Department of Communication Sciences and Disorders, Northwestern University
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