Slow cortical DC-potential responses to sweet and bitter tastes in humans.
Processing of hedonic stimulus quality is assumed to be accompanied by a tuning of cortical arousal and excitability. In this pilot study in 11 healthy humans scalp-recorded DC potentials were assessed during application of a sweet (sucrose) and bitter (quinine hydrochloride) taste, i.e., primary reinforcers of positive and negative quality. Muscular, ocular, and skin potential activity were controlled. Application of sucrose induced a widespread positive DC-potential shift with an amplitude of 40-50 microV and persisting for more than 120-s post-stimulus onset. Following administration of quinine hydrochloride, this positive shift was reduced, most distinctly between 48- and 88-s post-stimulus onset. The reduction appeared to be most consistent at anterior midline recording sites (Fz, Cz). It is assumed that the higher DC-potential positivity during sweetness than during bitterness points to a differential tuning of cortical excitability by a widespread decrease in depolarization of apical dendrites.
Schmitt
B
B
Physiological Psychology, University of Bamberg, 96045, Bamberg, Germany.
Marshall
L
L
Nitsche
M
M
Hallschmid
M
M
Eulitz
C
C
Born
J
J
D000328:Adult; D004569:Electroencephalography; D004576:Electromyography; D004585:Electrooculography; D005260:Female; D006801:Humans; D008297:Male; D011803:Quinine; D012201:Reward; D012881:Skin Temperature / Q000502:physiology; D013395:Sucrose; D013649:Taste / Q000502:physiology*
D013395:Sucrose; D011803:Quinine