Age-related effects in compound production: Intact lexical representations but more effortful encoding

Abstract

The production of nominal compounds in the presence of morphological, semantic, and unrelated distractor words (picture-word interference paradigm) was investigated in young (M = 27 years) and older (M = 70.5 years) German speakers to test models of speech production and lexical representation. Constituent distractors of compound targets (lip or stick for the target LIPSTICK) speeded compound naming, while naming was slowed by distractors that were categorically related to the compound as a whole (powder → LIPSTICK). Furthermore, no effects were obtained for distractors from the same category as the first constituent of compound targets in picture-naming latencies (toe → LIPSTICK). These effects were present in both age groups and indicate that compounds are stored holistically at the lemma level, and as morphemes at the word-form level, unaffected by age. Main effects of age revealed overall slower picture naming and less accurate responses in the elderly. Furthermore, older speakers showed stronger morphological facilitation, while semantic distractor effects were unaffected by age. In a non-verbal attentional control task (Simon task), older speakers were slower overall and showed larger processing costs than young speakers in the conflict (incongruent) condition. Our data replicate a decline in non-verbal attentional control with age and also reveal slower and more error-prone picture-naming in the elderly. These language-specific changes, however, seem to be independent from attentional control and are likely to result from less fluent morpho-phonological encoding in the elderly.