Empirical models of scalp-EEG responses using non-concurrent intracranial responses.
OBJECTIVE
This study presents inter-subject models of scalp-recorded electroencephalographic (sEEG) event-related potentials (ERPs) using intracranially recorded ERPs from electrocorticography and stereotactic depth electrodes in the hippocampus, generally termed as intracranial EEG (iEEG).


METHODS
The participants were six patients with medically-intractable epilepsy that underwent temporary placement of intracranial electrode arrays to localize seizure foci. Participants performed one experimental session using a brain-computer interface matrix spelling paradigm controlled by sEEG prior to the iEEG electrode implantation, and one or more identical sessions controlled by iEEG after implantation. All participants were able to achieve excellent spelling accuracy using sEEG, four of the participants achieved roughly equivalent performance in the iEEG sessions, and all participants were significantly above chance accuracy for the iEEG sessions. The sERPs were modeled using a linear combination of iERPs using two different optimization criteria.


RESULTS
The results indicate that sERPs can be accurately estimated from the iERPs for the patients that exhibited stable ERPs over the respective sessions, and that the transformed iERPs can be accurately classified with an sERP-derived classifier.


CONCLUSIONS
The resulting models provide a new empirical representation of the formation and distribution of sERPs from underlying composite iERPs. These new insights provide a better understanding of ERP relationships and can potentially lead to the development of more robust signal processing methods for noninvasive EEG applications.
Old Dominion University, Department Electrical & Computer Engineering, Norfolk, VA, USA.
Komalpreet
K
Kaur
Jerry J
JJ
Shih
Dean J
DJ
Krusienski
D001921:Brain / Q000503:physiopathology*; D062207:Brain-Computer Interfaces; D003143:Communication Devices for People with Disabilities; D003198:Computer Simulation; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000503:physiopathology*; D005071:Evoked Potentials; D006801:Humans; D008959:Models, Neurological; D012535:Scalp / Q000503:physiopathology; D014796:Visual Perception