Stretched, jumped, and fell: An fMRI investigation of reflexive verbs and other intransitives

This study used fMRI to inform a debate between two theories concerning the representation of reflexive verbs. Reflexives are verbs that denote an action that the subject applies on herself (e.g., The woman stretched). These verbs are derived by a lexical operation that creates a reflexive from its transitive counterpart. Theories differ with respect to which thematic role is reduced by the lexical operation: the agent or the theme, and, consequently, whether the construction of sentences with reflexives in subject-verb order includes movement of the object to the subject position. To test this, we compared reflexive verbs with unaccusative verbs (e.g., The woman fell), and with unergative verbs (e.g., The woman jumped). Unaccusatives are derived by reduction of the role of the agent, and thus SV sentences with unaccusatives include movement to subject position. Unergatives do not undergo lexical operations and do not involve movement in SV sentences. The reflexives behaved like unergatives, and differently from unaccusatives: the activation pattern of unaccusatives compared with reflexives showed similar cortical pattern to that of unaccusatives compared with unergatives, with activations in the left inferior frontal gyrus and the left middle temporal gyrus (MTG). Comparing reflexives and unergatives revealed activation in the right MTG. These results indicate that reflexives differ from unaccusatives in their derivation. That is, reflexives do not involve the reduction of the agent of the parallel transitive, and hence no syntactic movement is involved in sentences in which the subject precedes the reflexive verb.