Autor:innen:
Wiebke Grohmann | Klinik für Neurologie, Medizinische Fakultät, RWTH Aachen | Germany
Birte Reißner | Klinik für Psychiatrie, Psychotherapie und Psychosomatik, Medizinische Fakultät, RWTH Aachen
Dr. Katja Hußmann | Klinik für Neurologie, Medizinische Fakultät, RWTH Aachen
Dr. Cornelius Werner | Johanniter Krankenhaus Stendal
Prof. Dr. Stefan Heim | Institut für Neurowissenschaften und Medizin, Forschungszentrum Jülich
Natalja Peiseler | Fakultät für Linguistik, Heinrich Heine Universität
João Pinho | Klinik für Neurologie, Medizinische Fakultät, RWTH Aachen
ZWECK/ZIEL
Quantifiers (e.g. MANY, MORE THAN HALF) are words denoting amounts or relationships of amounts. Some (such as MANY) are highly subjectively interpreted: e.g. the semantics of MANY COOKIES may differ greatly between people and also season. In healthy participants (Heim et al., 2012; Shikhare et al., 2015), there is a robust polarity effect of proportional quantifiers (MANY, FEW): The probability of acceptance forms a mirror image for positive vs. negative quantifiers. For low proportions of objects, the probability of a YES response is high for FEW and low for MANY, and vice versa for high proportions. The two respective sigmoidal curves intersect at a proportion of 50%. In the brain, the left Brodmann area 45 (BA 45) and left temporal regions (Agmon et al., 2021) seem to be crucial for the polarity processing of quantifiers. These regions are often affected in aphasia (Nasios et al., 2019). Hence, aim of this study is to reveal the characteristics of the polarity processing in aphasia.
RELEVANZ/BEZUG LOGOPÄDISCHE PRAXIS
With regard to different concepts (money, time, food) often described with the help of quantifiers, the study makes a further contribution to pragmatic language comprehension in aphasia.
METHODE/VORGEHEN/DIDAKTIK
21 adult patients with aphasia were recruited. Except for 5 dropouts, 16 subjects performed two experiments each holding a truth value judgement task adapted from Heim et al. (2012). Each experiment required participants to evaluate auditorily presented sentences containing one quantifier (e.g. “Many of the circles are blue.”) in relation to a picture with blue and yellow circles and a varied proportion of the target colour. Participants decided whether the sentence adequately described the picture by pressing a green (YES) or red (NO) button on the computer keyboard. The experiment was replicated after a delay of at least one day in order to assess the stability of the effects over time.
ERGEBNIS
In comparison to previous data from healthy participants, MANY seems to be processed similarly since acceptance curves differed only minimally in participants with aphasia. In contrast, the processing of FEW demonstrated a flattened curve in participants with aphasia. On average, these patients neither showed complete acceptance at the lowest proportion of 20% nor complete refusal at the highest proportion of 80%. Analyses showed significant differences for the extreme proportions in both experiments when there was only one negation to process (affirmation of MANY / FEW; t(15) = -4.220, p < 0.001; z = 3.100, p = 0.002). In contrast, there were no significant differences in acceptance when subjects had to process more than one negation (denial of MANY / FEW; sign test, p = 0.227; z = 0.361, p = 0.718).
SCHLUSSFOLGERUNG
Considering the nearly unimpaired processing of MANY, results indicate a largely intact quantity evaluation concerning positive quantifiers. However, the flattened curve in the processing of FEW could be evidence for higher processing costs for negative quantifiers (Grodzinsky et al., 2021) which require one extra processing step (negation). The distinctive polarity effect in patients with aphasia might be caused by a damage of BA 45 (Heim et al., 2012) or temporal regions (Agmon et al., 2021).
BESCHREIBUNG DES INHALTS
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