THE COMPOSITIONALITY OF LEXICAL SEMANTIC REPRESENTATIONS - CLUES FROMSEMANTIC ERRORS IN OBJECT NAMING

We present evidence that semantic errors in object naming can arise no t only from impairment to the semantic system but also from damage to input and output processes. Although each of these levels of disruptio n can result in similar types of semantic errors in object naming, the y have different types of consequences for performance on other lexica l tasks, such as comprehension and naming to definition. We show that the analysis of the co-occurrence of semantic errors in naming with di fferent patterns of performance in other lexical processing tasks can be used to localise the source of semantic errors in the naming proces s. Finally, we argue that the similarity of semantic errors in object naming, resulting from damage to different components of the naming pr ocess, reflects the compositional nature of lexical semantic represent ations, and the processes by which they are activated by visual input, as well as the processes by which they activate output representation s.