title: Language and motor cortex response to comprehending accidental and intentional action sentences.
abstract: Understanding the meaning of others' actions involves mentally simulating those actions by oneself. Embodied theories of language espouse a prominent role for motor simulation in reading comprehension, especially when words, sentences, or narratives portray everyday actions. Inherent in these actions is the level of agency of the actor. Motor cortex activity in response to processing action verbs has been relatively well-established. What has been less explored, however, are: (1) the neural bases of determining whether an action is intentional or accidental (agency); and (2) whether agency influences level of motor simulation. This functional MRI study investigated how language and motor areas of the brain respond to sentences depicting intentional versus accidental action. 25 healthy adults read a series of sentences in the MRI scanner and determined whether the actions described were accidental or intentional. The main results include: (1) left hemisphere language areas (left inferior frontal gyrus, LIFG; left superior temporal gyrus, LSTG), premotor cortex (PM), and presupplementary motor area (pSMA) were strongly activated by both sentence types; (2) processing accidental action, relative to intentional action, elicited greater activity in LIFG, medial prefrontal cortex (MPFC), and left amygdala; no statistically significant activity was found in the opposite contrast; and (3) greater percent signal change was observed in LIFG while processing accidental action and in right precentral gyrus for intentional action. The results of this study support language and motor region involvement in action sentence comprehension in accordance with embodiment theories. Additionally, it provides new insight into the linguistic, integrative, and emotional demands of comprehending accidental action, its underlying neural circuitry, and its relationship to intentionality bias: the predisposition to ascribe purpose to action.
authors: Departmentof Psychology, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: rkana@uab.edu.
authors: Rajesh K
authors: RK
authors: Kana
authors: Departmentof Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors: Carla J
authors: CJ
authors: Ammons
authors: Departmentof Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors: Constance F
authors: CF
authors: Doss
authors: Departmentof Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors: Megan E
authors: ME
authors: Waite
authors: Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
authors: Bhumika
authors: B
authors: Kana
authors: Departmentof Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors: Abbey J
authors: AJ
authors: Herringshaw
authors: Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors: Lawrence
authors: L
authors: Ver Hoef
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D032882:Comprehension / Q000502:physiology*; D005260:Female; D006801:Humans; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011932:Reading; D055815:Young Adult
keywords: Accidental action; Embodied cognition; Intentional action; Intentionality bias; Sentence comprehension; fMRI