Effects of age and language proficiency in the processing of morphologically complex words

• Applicant: Dr. Antje Lorenz
• Subject Area: General, Cognitive and Mathematical Psychology ; General and Comparative Linguistics, Experimental Linguistics, Typology, Non-European Languages
• Term: from 2014 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 270844290

The project examines the lexical representation and processing of compound nouns (e.g., goldfish) in speech production. Both, healthy adult speakers and individuals with aphasia are tested. Our data show that older healthy speakers (65 + years) do worse than younger speakers (18-35 years) in the naming of compound nouns. The data are in line with the hypothesis that word-finding difficulties in the elderly result from deficient access to word-form representations in speech production. However, it is still unresolved whether and in which way reduced or decelerated semantic processing affects speech production in the elderly. This will be examined in the continuation of the project. While we did not obtain any empirical evidence for a specific change of the underlying morpho-phonological representation of compounds with age, the representational structure of compounds at the lemma level is still a matter of debate – especially for older healthy speakers and individuals with aphasia. With regard to these research questions, spoken picture naming of compound targets will be investigated in different experimental paradigms. In addition, learning of new (unfamiliar) compounds (e.g., *piano fish) will be examined (lexicalization). In picture-naming tasks with compounds as targets, both syntactic (grammatical gender) and semantic effects will be assessed. First, effects of gender-marked determiner primes on compound production will be tested. Second, semantic effects on the production of compounds and simple nouns (constituents of compounds) will be tested in the continuous (cumulative semantic) picture-naming paradigm, and these data will be complemented by semantic effects in a receptive semantic categorization task in the continuous paradigm. Reaction times and errors will be measured. In addition, the continuous electroencephalogram (EEG) will be extracted, in order to examine the underlying processes in speech production. Furthermore, the impact of non-verbal cognitive functions (attentional control and inhibition) in speech production will be assessed.The following research questions are tested: 1) How are compounds lexically stored and how are they accessed during speech production? 2) How does the lexical acquisition of new (unfamiliar) compounds work? 3) How do semantic and lexical functions affect compound retrieval in healthy older and aphasic speakers? 4) What is the role of non-verbal attentional control processes in speech production?In summary, the project aims at a better understanding of the functional processes underlying word retrieval in speech production, and of the role of non-verbal cognitive functions. Until now, there are almost no studies that have assessed all of these aspects in one experimental program.The results can be used to improve existing treatment approaches for word-finding difficulties in aphasia and to develop methods to train word-finding in the aging population without aphasia.

• DFG Programme: Research Grants
• Cooperation Partners: Professorin Dr. Rasha Abdel Rahman; Professorin Dr. Pienie Zwitserlood