Wavelet analysis of the parietal areas. X-axis represents time in seconds related to M1. Y-axis represents frequencies in Hertz. a + b) In both conditions distinct activation in the higher alpha and lower beta frequency band can be seen with a reduction of activation at about M1 and a re-increase after about 400 – 600 ms in both hemispheres. c) The difference plot of both measurements (without oropharyngeal stimulation minus with oropharyngeal stimulation) reveals variations mainly during deglutition (after M1). Similar activation is found in both hemispheres before swallowing onset. Colors represent the level of frequency power (fT/Hz), with lower numbers (blue) indicating a decrease in power (ERD) and higher numbers (red) an increase in power (ERS). In the difference plot blue corresponds to stronger activation in the measurement after stimulation, while red demonstrates stronger activation in the condition without stimulation.
Teismann et al. BMC Neuroscience 2009 10:71 doi:10.1186/1471-2202-10-71