Magnetic sources of the M50 response are localized to frontal cortex.
Clin Neurophysiol
; 119(2): 388-98, 2008 Feb.
Article
en En
| MEDLINE
| ID: mdl-18078782
ABSTRACT
OBJECTIVE:
To determine the source localization(s) of the midlatency auditory magnetic response M50, the equivalent of the P50 potential, a sleep state-dependent waveform known to habituate to repetitive stimulation.METHODS:
We used a paired stimulus paradigm at interstimulus intervals of 250, 500 and 1000 ms, and magnetoencephalographic (MEG) recordings were subjected to computational methods for current density reconstruction, blind source separation, time-frequency analysis, and data visualization to characterize evoked dynamics.RESULTS:
Each subject showed localization of a source for primary auditory evoked responses in the region of the auditory cortex, usually at a 20-30 ms latency. However, responses at 40-70 ms latency that also decreased following the second stimulus of a pair were not localizable to the auditory cortex, rather showing multiple sources usually including the frontal lobes.CONCLUSIONS:
The M50 response, which shows habituation to repetitive stimulation, was not localized to the auditory cortex, but showed multiple sources including frontal lobes.SIGNIFICANCE:
These MEG results suggest that sources for the M50 response may represent non-auditory, perhaps arousal-related, diffuse projections to the cortex.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Localización de Sonidos
/
Mapeo Encefálico
/
Potenciales Evocados Auditivos
/
Lóbulo Frontal
Tipo de estudio:
Clinical_trials
Límite:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Año:
2008
Tipo del documento:
Article