title: Using Objective Response Detection techniques for detecting the tibial somatosensory evoked response with different stimulation rates.
abstract: This work investigates the influence of the stimulus frequency in the performance of two Objective Response Detection (ORD) techniques, the Magnitude-Squared Coherence (MSC) and the Component Synchrony Measure (CSM), as applied in somatosensory stimulation. Electroencephalographic signals were collected (10-20 International System) from forty adult volunteers without history of neurological pathologies. The stimuli were applied to the right posterior tibial nerve at the frequencies of 2, 5, 7 and 9 Hz and motor threshold intensity level. The detection was based on the rejection of the null hypothesis of response absence (significance level α=0.05 and M=100 and 500 epochs). The performances of the MSC at the four stimulation frequencies were compared, two-by-two, using the Proportion Test applied to the mean percentage rates in the total (2-100 Hz) and optimal (20-60 Hz) bands. The same was proceeded to the CSM. The evaluated derivations were Cz, C4, Pz and P4. No significant difference was found for any studied technique (MSC or CSM), any M-value, at any derivation. Thus, the highest stimulation frequency (9 Hz) can be used in order to obtain a reduction in the time of response detection in an ORD approach for a fixed M-value.
authors.affiliation: Biomedical Engineering Program-Federal University of Rio de Janeiro (UFRJ), Av. Horácio Macedo 2030, Centro de Tecnologia, Bloco H, Sala 327, Cidade Universitária, P.O. Box 68510, Rio de Janeiro 21941-972, RJ, Brazil. danilomelges@yahoo.com
authors.forename: Danilo Barbosa
authors.initials: DB
authors.lastname: Melges
authors.forename: Antonio Fernando Catelli
authors.initials: AF
authors.lastname: Infantosi
authors.forename: Antonio Mauricio Ferreira Leite
authors.initials: AM
authors.lastname: Miranda de Sá
mesh_terms: D000328:Adult; D001703:Biophysics; D004558:Electric Stimulation; D004569:Electroencephalography / Q000379:methods*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time; D013003:Somatosensory Cortex / Q000502:physiology*; D013979:Tibial Nerve / Q000502:physiology*; D055815:Young Adult