Poster F97, Tuesday, March 27, 8:00-10:00 am, Exhibit Hall C
Deaf signers’ sensorimotor system activity during perception of one and two handed signs
Emily Kubicek1, Lorna C. Quandt1; 1Gallaudet University
When a person observes someone else performing an action, the observer’s sensorimotor cortex activates as if the observer is the one performing the action, a phenomenon known as action simulation. While this process has been well-established for basic (e.g. grasping) and complex (e.g. dancing) actions, it remains unknown if the framework of action simulation is applicable to visual languages such as American Sign Language (ASL). We performed an EEG experiment to test whether deaf signers’ sensorimotor systems are differentially sensitive to signs that are produced with one hand (“1H”) or two hands (“2H”). We predicted greater alpha event-related desynchronization (ERD; previously correlated with action simulation) during the perception of 2H ASL signs compared to 1H ASL signs, due to greater demands on sensorimotor processing systems required for producing two-handed actions. The two groups of signs were matched for frequency, iconicity, and flexion. We recorded EEG from deaf participants fluent in ASL as they observed videos of ASL signs, half 1H and half 2H. Event-related spectral perturbations (ERSPs) in the alpha range were computed for the two conditions at central electrode sites overlying the sensorimotor cortex and paired comparisons showed significantly more alpha ERD when participants observed 2H signs as compared to 1H signs (ps <.05, FDR corrected). This finding suggests action simulation processes contribute to deaf fluent signers’ observations of ASL, and that these processes are sensitive to linguistic/motoric parameters of sign language. This work provides the first investigation of alpha oscillations during sign language perception.
Topic Area: PERCEPTION & ACTION: Other