Spatio-temporal correlates of taste processing in the human primary gustatory cortex.
In humans the identification of the primary gustatory cortex (PGC) is still under debate. Neuroimaging studies indicate insula and overlying opercula as the best candidates but the exact position of the PGC within this region is not entirely clear. Moreover, inconsistencies appear when comparing results from studies using functional magnetic resonance imaging (fMRI), and gustatory event-related potentials (gERP), or gustatory event-related magnetic fields (gERMF). fMRI indicates activations in the anterior part of the insula and frontal operculum, while gERP and/or gERMF indicate activations at the transition between the parietal operculum and insula in its posterior part. Here it is important to note that for gERP and gERMF temporal and spatial characteristics of the stimulus must be well controlled to evoke a useful brain response. In the present study gERMF and gERP were recorded simultaneously using a whole-head system with 249 magnetometers and 32 electrodes, respectively; taste stimuli were applied using a stimulator providing excellent temporal and spatial control of the stimulus. Separate ERP and ERMF averaged waveforms were derived time-locked to the onset of the taste stimuli. The source analysis for the early time range revealed activity in the left and right anterior and mid part of the insula, where in the later time range the sources were located more in the posterior part of the insula.
Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, 01307 Dresden, Germany. Electronic address: emilia.iannilli@googlemail.com.
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Iannilli
Department of Neurology, Otto-von-Guericke University, 39120 Magdeburg, Germany.
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Noennig
Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, 01307 Dresden, Germany.
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Hummel
Department of Neurology, Otto-von-Guericke University, 39120 Magdeburg, Germany.
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Schoenfeld
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D060526:Magnetic Fields; D015225:Magnetoencephalography; D008297:Male; D010812:Physical Stimulation; D011601:Psychophysics; D012815:Signal Processing, Computer-Assisted; D055697:Taste Perception / Q000502:physiology*; D013995:Time
EEG; MEG; gustometry; insula; primary taste cortex; source localization