[Eeglablist] Source localization and hippocanpus

[Евгений Машеров]

> I see a lot of papers, mainly MEG, that use forward solutions from beamformers and claim to be measuring activity in subcortical structures with no measure of forward model errors or cross-validation with other modalities. It seems to me that if you can't localize a pattern of activity using an inverse method, you can't just generate a forward solution from a region of interest and assume your results are valid.
> 
> There are old papers (late 80s - 90s) from when people first started using dipole localization to measure activity in auditory subcortical structures (MGN, IC, etc.). Those data seemed reasonable to me because of the SNR of the input data, the spatial separation between cortical and putative subcortical sources, and the comparison of different dipole models to establish validity.
> 
> Kevin
> ---------------------------------------------------------------------------------
> Kevin M. Spencer, Ph.D.
> Research Health Scientist, VA Boston Healthcare System
> Associate Professor of Psychiatry, Harvard Medical School
A study was recently conducted that involved recording signals from the brainstem while simultaneously recording an EEG from the scalp.

EVOKED POTENTIALS OF THE MIDBRAIN ASSOCIATED WITH THE BEGINNING AND END OF A SOUND OF A SIMPLE TONE Kantserova A.O., Oknina L.B., Pitskhelauri D.I., Podlepich V.V., Masherov E.L., Vologdina Y.O. Human Physiology. 2022. Т. 48. № 3. С. 229-236.
EVOKED POTENTIALS APPEARING IN THE HUMAN MIDBRAIN AFTER SOUNDING OF A SIMPLE TONE Kantserova A.O., Oknina L.B., Pitskhelauri D.I., Podlepich V.V., Masherov E.L., Vologdina Ya.O., Sieber I.A. Neuroscience and Behavioral Physiology. 2023. Т. 53. № 3. С. 358-364.
THE ROLE OF THE MIDBRAIN IN THE PERCEPTION OF TONE SEQUENCES AND SPEECH: AN ANALYSIS OF INDIVIDUAL STUDIES Oknina L.B., Kantserova A.O., Pitskhelauri D.I., Podlepich V.V., Portnova G.V., Sieber I.A., Vologdina Y.O., Slezkin A.A., Lange A.M., Masherov E.L., Strelnikova E.V. Human Physiology. 2023. Т. 49. № 4. С. 347-356.
INCREASES IN THE PEAK FREQUENCY OF THE EEG ALPHA RHYTHM ON PRESENTATION OF OWN NAMES DURING DEEP ANESTHESIA Portnova G.V., Kantserova A.O., Oknina L.B., Pitskhelauri D.I., Podlepich V.V., Vologdina Ya.O., Masherov E.L. Neuroscience and Behavioral Physiology. 2024. Т. 54. № 1. С. 91-101.
FEATURES OF PERCEPTION OF A PERSON’S OWN NAME COMPARED TO THE PERCEPTION OF NAMES WITH SIMILAR AND DIFFERENT SOUNDS: ANALYSIS OF EVENT-RELATED POTENTIALS Oknina L.B., Podlepich V.V., Vologdina Ya.O., Sieber I.A., Masherov E.L., Slezkin A.A., Strelnikova E.V., Kantserova A.O. Human Physiology. 2025. Т. 51. № 2. С. 79-88.


Using the surviving recordings, the correlation between the brainstem signal and a linear combination of scalp signals reached 17%. The reference leads for the brainstem and scalp recordings are different, so this is not a common electrode effect. On the other hand, this recording was made during surgery, so cortical activity is suppressed. Nevertheless, this demonstrates signal transmission even over such a long distance.

Your truly

Eugen Masherov