OBJECTIVE: To evaluate the test-retest reliability of event-related power changes in the 30-150 Hz gamma frequency range occurring in the first 150 ms after presentation of an auditory stimulus. METHODS: Repeat intracranial electrocorticographic (ECoG) recordings were performed with 12 epilepsy patients, at ≥1-day intervals, using a passive odd-ball paradigm with steady-state tones. Time-frequency matching pursuit analysis was used to quantify changes in gamma-band power relative to pre-stimulus baseline. Test-retest reliability was estimated based on within-subject comparisons (paired t-test, McNemar's test) and correlations (Spearman rank correlations, intra-class correlations) across sessions, adjusting for within-session variability. Reliability estimates of gamma-band response robustness, spatial concordance, and reproducibility were compared with corresponding measurements from concurrent auditory evoked N1 responses. RESULTS: All patients showed increases in gamma-band power, 50-120 ms post-stimulus onset, that were highly robust across recordings, comparable to the evoked N1 responses. Gamma-band responses occurred regardless of patients' performance on behavioral tests of auditory processing, medication changes, seizure focus, or duration of test-retest interval. Test-retest reproducibility was greatest for the timing of peak power changes in the high-gamma range (65-150 Hz). Reliability of low-gamma responses and evoked N1 responses improved at higher signal-to-noise levels. CONCLUSIONS: Early cortical auditory gamma-band responses are robust, spatially concordant, and reproducible over time. SIGNIFICANCE: These test-retest ECoG results confirm the reliability of auditory gamma-band responses, supporting their utility as objective measures of cortical processing in clinical and research studies.
OBJECTIVE: To evaluate the test-retest reliability of event-related power changes in the 30-150 Hz gamma frequency range occurring in the first 150 ms after presentation of an auditory stimulus. METHODS: Repeat intracranial electrocorticographic (ECoG) recordings were performed with 12 epilepsypatients, at ≥1-day intervals, using a passive odd-ball paradigm with steady-state tones. Time-frequency matching pursuit analysis was used to quantify changes in gamma-band power relative to pre-stimulus baseline. Test-retest reliability was estimated based on within-subject comparisons (paired t-test, McNemar's test) and correlations (Spearman rank correlations, intra-class correlations) across sessions, adjusting for within-session variability. Reliability estimates of gamma-band response robustness, spatial concordance, and reproducibility were compared with corresponding measurements from concurrent auditory evoked N1 responses. RESULTS: All patients showed increases in gamma-band power, 50-120 ms post-stimulus onset, that were highly robust across recordings, comparable to the evoked N1 responses. Gamma-band responses occurred regardless of patients' performance on behavioral tests of auditory processing, medication changes, seizure focus, or duration of test-retest interval. Test-retest reproducibility was greatest for the timing of peak power changes in the high-gamma range (65-150 Hz). Reliability of low-gamma responses and evoked N1 responses improved at higher signal-to-noise levels. CONCLUSIONS: Early cortical auditory gamma-band responses are robust, spatially concordant, and reproducible over time. SIGNIFICANCE: These test-retest ECoG results confirm the reliability of auditory gamma-band responses, supporting their utility as objective measures of cortical processing in clinical and research studies.
Authors: Alon Sinai; Christopher W Bowers; Ciprian M Crainiceanu; Dana Boatman; Barry Gordon; Ronald P Lesser; Frederick A Lenz; Nathan E Crone Journal: Brain Date: 2005-04-07 Impact factor: 13.501
Authors: A Korzeniewska; M C Cervenka; C C Jouny; J R Perilla; J Harezlak; G K Bergey; P J Franaszczuk; N E Crone Journal: Neuroimage Date: 2014-07-06 Impact factor: 6.556