Poster A51, Thursday, August 16, 10:15 am – 12:00 pm, Room 2000AB

Testing embodied cognition with a large premotor cortex lesion - a single case study

Hanna Gauvin1,2, Kori Ramajoo1,2, Sonia Brownsett1,2, Katie McMahon3,4, Greig de Zubicaray1;1Faculty of Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia, 2School of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia, 3. School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia, 4Herston Imaging Research Facility, Royal Brisbane & Womens Hospital, Brisbane, QLD, Australia

Over the last decade, multiple “embodied cognition” theories have proposed conceptual representations are grounded in the perceptual and motor systems involved in the execution of those actions (e.g., Barsalou, 2008; Gallese & Lakoff, 2005; Pulvermüller, 2005; Glenberg & Kaschak, 2002). Support for these accounts is assumed by fMRI studies demonstrating involvement of premotor and motor cortex in the processing of action words, although it is debatable whether this activity represents evidence for embodiment, spreading activation mechanisms or whether they are merely epiphenomenal. Recently, single case studies of focal brain lesion patients have been used to support a causal role for these regions in category specific action and emotion word recognition problems (e.g., Dreyer et al. 2015) We present data from a patient who underwent gross total resection of a grade II astrocytoma in the premotor cortex. The discrete lesion following the surgical resection extended from the left frontal gyrus anteriorly to the superior frontal sulcus and posteriorly encompassed the left precentral gyrus, but did not involve the post-central gyrus. The patient received no adjuvant therapy. Given the importance of the premotor area for theories of embodied word meaning representation, the patient was invited to perform a series of tasks previously employed to investigate theories of embodied action and emotion word processing. [Methods] The patient was tested on multiple aphasia batteries to investigate the impact of the tumour resection on language processing at 8 months post-surgery. Furthermore, she performed a battery of lexical decision tasks aimed to test theories of embodied cognition at 10 months post-surgery. Performance was measured on the following lexical decision tasks: (I) Effector specific verbs (arm, face or leg related) and non-words, presented aurally. (II) Disyllabic verbs of manual actions, nouns of non-manipulable entities and non-words with verb-like ending and noun-like ending (de Zubicaray, Arciuli & McMahon, 2013) (III) Trisyllabic nouns and verbs with orthographic cues that are consistent or inconsistent with the spelling patterns of words from that grammatical category (Arciuli, McMahon & de Zubicaray, 2012). (IV) Words with positive, neutral or negative emotional valence and non-words. [Results] Aphasia batteries indicated near ceiling language performance. The performance of the patient on all lexical decision tasks was very accurate and highly comparable to that of healthy participants. [Conclusion] The lesion location presents a near perfect case to test the proposed function of premotor cortex according to theories of embodied cognition. No evidence was found for category specific language impairments or deficits in processing specific effector verbs, or on any other categories across any of the lexical decision tasks. It is worth noting here that the premotor cortex lesion of this patient is much larger than that of patient HS (Dreyer et al.) The current study does not support an indispensable role for the premotor cortex in processing the meanings of action or emotion words.

Topic Area: Language Disorders