Semantic Interference in Blocked Naming: Does It Become Cumulative with Large Local Response Sets?

The production of a word is delayed by the recent production of one or more semantically related words. This phenomenon, known as semantic interference, has been observed in picture naming tasks involving either large sets of pictures named once (continuous naming) or small sets of pictures named repeatedly (blocked-cyclic naming). It has been attributed to an adaptive learning mechanism that operates after each naming episode. However, the interference develops differently in these tasks: it is cumulative in continuous naming and non-cumulative in blocked-cyclic naming. It has been suggested that the small local response sets in blocked naming are easily identified and stored in working memory, which then introduces an additional process that constrains the interference. We reasoned that this process would be less effective as the local response sets increased in size, resulting in cumulative interference. In blocked naming experiments involving local response sets of ten or nineteen items, we found that the interference did not increase continuously; rather, it carried on across more presentations than for the typically used small sets. This finding lends support to the notion of a control mechanism that operates gradually and interacts with an adaptive learning mechanism.