Trouble articulating the right words: Evidence for a response-exclusion account of distraction during semantic fluency.

It is widely held that single-word lexical access is a competitive process, a view based largely on the observation that naming a picture is slowed in the presence of a distractor-word. However, problematic for this view is that a low-frequency distractor-word slows the naming of a picture more than does a high-frequency word. This supports an alternative, response-exclusion, account in which a distractor-word interferes because it must be excluded from an articulatory output buffer before the right word can be articulated (the picture name): A high, compared to low, frequency word accesses the buffer more quickly and, as such, can also be excluded more quickly. Here we studied the respective roles of competition and response-exclusion for the first time in the context of semantic verbal fluency, a setting requiring the accessing of, and production of, multiple words from long-term memory in response to a single semantic cue. We show that disruption to semantic fluency by a sequence of to-be-ignored spoken distractors is also greater when those distractors are low in frequency, thereby extending the explanatory compass of the response-exclusion account to a multiple-word production setting and casting further doubt on the lexical-selection-by-competition view. The results can be understood as reflecting the contribution of speech output processes to semantic fluency.