We investigated in two picture–word-interference experiments whether there is evidence for composition during compound production (Experiment 1). In Experiment 2, we tried to determine the level at which composition takes place. In Experiment 1, shared morphemes between distractor and target (HANDTASCHE, handbag) sped up naming regardless of category membership: semantically opaque (Plaudertasche, chatterbox) and semantically transparent distractors (Reisetasche, travelling bag) facilitated picture naming to a comparable degree. In Experiment 2, targets (BROTMESSER, bread knife) were combined with a simple word distractor (Kuchen, cake) categorically related to a target compound constituent but not related to the compound as a whole. This target was further paired with a categorically related compound distractor (Kochlöffel, wooden spoon). The simple word distractor was also paired with a categorically related compound constituent (BROT, bread). Whenever distractor (e.g., Kochlöffel, Kuchen) and target (BROTMESSER, BROT, respectively) were categorically related, semantic inhibition was observed. Distractors (e.g., Kuchen) related to only one compound constituent did not affect compound production. Taken together, our results indicate that during compound production a single lemma node is activated and that morphological composition takes place at the form level of representation. Current lexical selection mechanisms in language production models are not supported by these data.

We investigated the impact of derived German verbs on the production and recognition of morphologically related simple verbs. In order to disentangle effects of morphological, semantic, and phonological relatedness, target verbs were combined (e.g., zählen--to count) with four context verbs: Two morphologically related context verbs that were either semantically transparent (verzählen--to miscount) or semantically opaque (erzählen--to tell), a semantically related (rechnen--to calculate) and a phonologically related (zähmen--to tame) context verb. Morphologically related complex verbs reduced picture naming latencies as well as lexical decision latencies. Semantically related verbs did not show any reliable effects. In production, morphological facilitation was almost four times larger than phonological facilitation. In comprehension, pure form overlap produced inhibition. We argue that in German, production and comprehension processes operate on morphologically decomposed lexical form representations. Independent from semantic transparency, complex verbs are broken down into their morphemes during comprehension and are assembled during production.