%0 Journal Article %J Exp Brain Res %D 2012 %T Electrocorticographic (ECoG) Correlates of Human Arm Movements. %A Nicholas R Anderson %A Blakely, Timothy %A Gerwin Schalk %A Leuthardt, E C %A Moran, Daniel W %K arm tuning %K brain-computer interfaces %K cosine tuning %K Electrocorticography %K Motor Cortex %K subdural electroencephalography %X Invasive and non-invasive brain-computer interface (BCI) studies have long focused on the motor cortex for kinematic control of artificial devices. Most of these studies have used single-neuron recordings or electroencephalography (EEG). Electrocorticography (ECoG) is a relatively new recording modality in BCI research that has primarily been built on successes in EEG recordings. We built on prior experiments related to single-neuron recording and quantitatively compare the extent to which different brain regions reflect kinematic tuning parameters of hand speed, direction, and velocity in both a reaching and tracing task in humans. Hand and arm movement experiments using ECoG have shown positive results before, but the tasks were not designed to tease out which kinematics are encoded. In non-human primates, the relationships among these kinematics have been more carefully documented, and we sought to begin elucidating that relationship in humans using ECoG. The largest modulation in ECoG activity for direction, speed, and velocity representation was found in the primary motor cortex. We also found consistent cosine tuning across both tasks, to hand direction and velocity in the high gamma band (70-160 Hz). Thus, the results of this study clarify the neural substrates involved in encoding aspects of motor preparation and execution and confirm the important role of the motor cortex in BCI applications. %B Exp Brain Res %V 223 %P 1-10 %8 11/2012 %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/23001369 %N 1 %R 10.1007/s00221-012-3226-1 %0 Conference Proceedings %B Conf Proc IEEE Eng Med Biol Soc %D 2008 %T Three cases of feature correlation in an electrocorticographic BCI. %A Miller, John W %A Blakely, Timothy %A Gerwin Schalk %A den Nijs, Marcel %A Rao, Rajesh P N %A Ojemann, J G %K Adolescent %K Adult %K Algorithms %K Electrocardiography %K Evoked Potentials, Motor %K Female %K Humans %K Male %K Middle Aged %K Motor Cortex %K Pattern Recognition, Automated %K Statistics as Topic %K Task Performance and Analysis %K User-Computer Interface %X Three human subjects participated in a closed-loop brain computer interface cursor control experiment mediated by implanted subdural electrocorticographic arrays. The paradigm consisted of several stages: baseline recording, hand and tongue motor tasks as the basis for feature selection, two closed-loop one-dimensional feedback experiments with each of these features, and a two-dimensional feedback experiment using both of the features simultaneously. The two selected features were simple channel and frequency band combinations associated with change during hand and tongue movement. Inter-feature correlation and cross-correlation between features during different epochs of each task were quantified for each stage of the experiment. Our anecdotal, three subject, result suggests that while high correlation between horizontal and vertical control signal can initially preclude successful two-dimensional cursor control, a feedback-based learning strategy can be successfully employed by the subject to overcome this limitation and progressively decorrelate these control signals. %B Conf Proc IEEE Eng Med Biol Soc %P 5318-21 %8 2008 %G eng %R 10.1109/IEMBS.2008.4650415 %0 Conference Paper %B Engineering in Medicine and Biology Society, 2008. %D 2008 %T Three cases of feature correlation in an electrocorticographic BCI. %A Miller, Kai J %A Blakely, Timothy %A Gerwin Schalk %A den Nijs, Marcel %A Rao, Rajesh PN %A Ojemann, Jeffrey G %K Adolescent %K Adult %K Algorithms %K automated pattern recognition %K control systems %K decorrelation %K Electrocardiography %K Electrodes %K Electroencephalography %K evoked motor potentials %K Feedback %K Female %K frequency %K hospitals %K Humans %K Male %K Middle Aged %K Motor Cortex %K Signal Processing %K Statistics as Topic %K Task Performance and Analysis %K Tongue %K User-Computer Interface %X Three human subjects participated in a closed-loop brain computer interface cursor control experiment mediated by implanted subdural electrocorticographic arrays. The paradigm consisted of several stages: baseline recording, hand and tongue motor tasks as the basis for feature selection, two closed-loop one-dimensional feedback experiments with each of these features, and a two-dimensional feedback experiment using both of the features simultaneously. The two selected features were simple channel and frequency band combinations associated with change during hand and tongue movement. Inter-feature correlation and cross-correlation between features during different epochs of each task were quantified for each stage of the experiment. Our anecdotal, three subject, result suggests that while high correlation between horizontal and vertical control signal can initially preclude successful two-dimensional cursor control, a feedback-based learning strategy can be successfully employed by the subject to overcome this limitation and progressively decorrelate these control signals. %B Engineering in Medicine and Biology Society, 2008. %I IEEE %C Vancouver, BC %8 08/2008 %G eng %U http://www.ncbi.nlm.nih.gov/pubmed/19163918 %R 10.1109/IEMBS.2008.4650415