TY - JOUR
T1 - District-related frequency specificity in hand cortical representation
T2 - Dynamics of regional activation and intra-regional synchronization
AU - Tecchio, Franca
AU - De Lucia, Marzia
AU - Salustri, Carlo
AU - Montuori, Marco
AU - Bottaccio, Maurizio
AU - Babiloni, Claudio
AU - Pietronero, Luciano
AU - Zappasodi, Filippo
AU - Rossini, Paolo M.
PY - 2004/7/16
Y1 - 2004/7/16
N2 - The aim of this work was to study the degree of neuronal synchronization occurring within the portion of the somatosensory cortex devoted to hand control during an external sensory stimulation. In this way, we focused on the properties of the sensory cortical representation, rather than the more investigated motor one. To this aim, we collected magnetoencephalograhic data from healthy subjects during separate stimulation of their thumbs and little fingers and analyzed these data by means of a time-dependent 'synchronization index'. The properties of this index within the beta [16-32 Hz] and gamma [36-44 Hz] frequency bands suggest that the hand representation in the human primary cortex follows a frequency coding, in addition to the somatotopic one, for discriminating different districts. Our results showed that the gamma synchronization is higher following stimulation of the thumb than of the little finger and we suggest that the strength of gamma band synchronization works as a code for functional prevalence. In particular, our comparative analysis of the dynamic synchronization index and the signal amplitude suggests that a prevalent district (thumb) recruits a smaller number of higher-synchronic gamma band tuned neurons than a non-prevalent district (little finger).
AB - The aim of this work was to study the degree of neuronal synchronization occurring within the portion of the somatosensory cortex devoted to hand control during an external sensory stimulation. In this way, we focused on the properties of the sensory cortical representation, rather than the more investigated motor one. To this aim, we collected magnetoencephalograhic data from healthy subjects during separate stimulation of their thumbs and little fingers and analyzed these data by means of a time-dependent 'synchronization index'. The properties of this index within the beta [16-32 Hz] and gamma [36-44 Hz] frequency bands suggest that the hand representation in the human primary cortex follows a frequency coding, in addition to the somatotopic one, for discriminating different districts. Our results showed that the gamma synchronization is higher following stimulation of the thumb than of the little finger and we suggest that the strength of gamma band synchronization works as a code for functional prevalence. In particular, our comparative analysis of the dynamic synchronization index and the signal amplitude suggests that a prevalent district (thumb) recruits a smaller number of higher-synchronic gamma band tuned neurons than a non-prevalent district (little finger).
KW - Dynamical synchronization
KW - Frequency selectivity
KW - Magnetoencephalography
KW - Regional activation
KW - Sensory cortical hand
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U2 - 10.1016/j.brainres.2004.04.028
DO - 10.1016/j.brainres.2004.04.028
M3 - Article
C2 - 15212994
AN - SCOPUS:2942707621
SN - 0006-8993
VL - 1014
SP - 80
EP - 86
JO - Brain Research
JF - Brain Research
IS - 1-2
ER -