Response to Seidenberg and Hoeffner

Abstract

Seidenberg & Hoeffner (hereafter SH they lack independent motivation and they are not internally consistent'. In fact, we supported our functional analysis with approximately 35 references to the neurolinguistic literature, documenting that our functional interpretation is consistent with findings from other studies. The two interpretations particularly singled out for criticism are our functional analysis of left dorsolateral prefrontal cortex and left superior frontal gyrus. They offer an alternative hypothesis on the function of DLPFC, which is that it maintains in working memory the information that 'the regular suffix was required'. This is an interesting suggestion (although supported by only one reference to the primate literature), and in fact it would fit very well with our hypothesis that during this task this area of the brain was activated to facilitate regular past-tense formation. As far as the left superior frontal gyrus is concerned, we documented that it is usually activated during novel linguistic tasks and not during practiced tasks; we suggested that this general function would be manifested differently in different tasks, depending on which aspects of the task were 'novel', which is why the details of performance would differ in the Irregular Past vs. Nonce Past tasks. Overall, we presented a unified theory as to what the areas of the brain activated in each task could be contributing to the performance of that task, and the S&H critique makes no attempt to address the entire pattern of activation. Finally, S&H point out that in other neurolinguistic studies which have also found dissociations between regular and irregular processes, each study has found a somewhat different pattern of association between brain areas and function. This suggests that much work remains to be done in order to determine the exact contributions of each brain area to the processes, but it also highlights a crucial fact: S&H report no neurolinguistic studies