Christopher L. Striemer^1,2 (), Avery S. Hudson¹, Cameron D. Hassall¹; ¹MacEwan University, Edmonton, Alberta, Canada, ²Neuroscience and Mental Health Institute, University of Alberta

Previous research indicates that the visuomotor system contains an “automatic pilot” that can make rapid online corrections to reaches in response to sudden changes in target position. These automatic corrections can occur even when participants are instructed not to correct (i.e., to inhibit) their movements. Furthermore, recent work suggests the ability to inhibit online reach corrections is related to individual differences in executive function. One important question that remains unanswered is whether one’s intention to correct their reach to a target jump requires the inhibition of the response to the initial target location, the engagement of a second response to the new target location, or a combination of the two. We examined this question in the current study by recording EEG while healthy adults (n=34) completed a double-step reaching task on a touch screen where they were instructed to either “correct” their movement to the target jump, or to “ignore” the target jump, and reach to the initial target location. To index response inhibition, we analyzed the anterior N200 (N2) ERP component, and frontal midline theta (4-8 Hz), both of which have been linked with response inhibition and cognitive control in previous studies. Consistent with previous research, participants made significantly more online corrections when they were told to “correct” their reach to the target jump, compared to when they were told to “ignore” the target jump. Interestingly, both the anterior N2 and frontal midline theta were significantly larger in response to target jumps in the “correct” condition, compared to the “ignore” condition. These results are consistent with the notion that, in order to initiate an online correction to a target jump, the movement to the initial target location must first be inhibited before the correction to the new target location can be initiated.

Acknowledgements: This work was supported through Natural Sciences and Engineering Research Council of Canada Discovery Grants awarded to C.L.S. and C.D.H.