title: Measurement of the extraocular spike potential during saccade countermanding.
abstract: The stop signal task is used to investigate motor inhibition. Several groups have reported partial electromyogram (EMG) activation when subjects successfully withhold manual responses and have used this finding to define the nature of response inhibition properties in the spinal motor system. It is unknown whether subthreshold EMG activation from extraocular muscles can be detected in the saccadic response version of the stop signal task. The saccadic spike potential provides a way to examine extraocular EMG activation associated with eye movements in electroencephalogram (EEG) recordings. We used several techniques to isolate extraocular EMG activation from anterior electrode locations of EEG recorded from macaque monkeys. Robust EMG activation was present when eye movements were made, but no activation was detected when saccades were deemed canceled. This work highlights a key difference between the spinal motor system and the saccade system.
authors.affiliation: Department of Psychology, Vanderbilt Vision Research Center, Center for Integrative and Cognitive Neuroscience, Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee 37240-7817, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Godlove
authors.forename: Anna K
authors.initials: AK
authors.lastname: Garr
authors.forename: Geoffrey F
authors.initials: GF
authors.lastname: Woodman
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Schall
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D004569:Electroencephalography; D004576:Electromyography; D005260:Female; D008251:Macaca; D008297:Male; D012438:Saccades / Q000502:physiology*