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Electrophysiological correlates of recovery from anomia
Poster E56 in Poster Session E, Thursday, October 26, 10:15 am - 12:00 pm CEST, Espace Vieux-Port
Julie Franco1, Bertrand Glize2, Marina Laganaro1; 1Faculty of Psychology and Educational Science, University of Geneva, 2Handicap Activité Cognition Santé, BPH U1219 Inserm, Université de Bordeaux, F-33000, Bordeaux, France
After stroke, a reorganization of the language network is generally observed, both spontaneously (Cappa et al., 1997) and induced by therapy (Saur et al., 2006). Most studies were carried out with neuroimaging techniques with high spatial resolution (PET or fMRI), but recovery may also induce changes in brain activation dynamics during language processes. Few studies have investigated event-related potential (ERP) changes during recovery from aphasia showing normalization relative to control participants in pre- and post-test comparisons (Cocquyt et al. 2020), even though difference increases have also been observed (resting state: Meinzer et al., 2004). Laganaro and colleagues (2008) reported in four patients with anomia simultaneously normalization in time-windows associated with preserved encoding processes and abnormal amplitudes and/or topographic maps in time-windows associated with the language processes responsible for the underlying impairment. However, ERP studies of word production in larger groups of patients with anomia remain limited, especially when trying to link with recovery. Thus, the present study aims to explore the electrophysiological correlates of anomia recovery in a group of patients with aphasia after a two-week of therapy. 12 patients with aphasia suffering from anomia following stroke underwent a two-week therapy protocol of digitalized treatment. A first assessment (pretest) was performed at the beginning of the two weeks followed by three posttests (one after the first week when only half the stimuli were treated, a second after the second week and one as a follow-up one week later). Test sessions included a 56-items picture naming task presented twice and EEG recordings. So far analyses have been carried out only on the comparison between the pretest and the second posttest. Accuracy analysis on the group demonstrated significant improvement between the pretest and the second posttest (z = 7.2, p <.001, β = 0.97, SE = 0.13). On ERPs, amplitudes and the global dissimilarity index were compared for each patient based on matched epochs between pretest and posttest2 using parametrical analyses with FDR for amplitudes and a permutation procedure on the global dissimilarity (TANOVA). Across 12 patients, waveforms differed in four time-windows: from 125 to 190 ms after picture onset, from 245 to 330 ms, from 370 to 420 ms and from 600 to 750 ms; the same time-windows yielded differences in the TANOVA analyses, except for the 370 to 420 ms. A spearman correlation was performed between the number of electrodes yielding significant differences in each participant in each of these time-windows and the percentage recovery in the naming task following therapy. Changes in the time period between 245 and 290 ms are highly correlated with recovery, for both changes in amplitudes (r = 0.72, p < .01) and in global dissimilarity (r = 0.71, p < .01). These results thus indicate changes in brain activity in the 245-330 ms time period, that has previously been associated to lexical selection and phonological processes and are positively correlated with a good recovery after anomia therapy on 12 patients. Further analyses will be performed on the same data and on a larger group.
Topic Areas: Disorders: Acquired, Speech-Language Treatment