Increases in total respiratory resistance during forehead temperature stimulation.
We investigated the effects of forehead temperature stimulation on total respiratory resistance in healthy individuals. In two experiments involving a total of 38 participants we studied the time course and stability of the response at moderate temperature (20-23 degrees C). Small plastic bags filled with water were positioned on the forehead for a duration of 60 s. Oscillatory resistance (R(os)), heart period (HP), respiratory sinus arrhythmia (RSA), and ventilatory parameters were measured continuously. Experiment 1 showed similar phasic increases in R(os) during the first 20 s of stimulation with moderate (20-23 degrees C) as compared to cold (8-11 degrees C) temperature. Phasic increases by moderate temperature were replicated in Experiment 2 over five successive stimulation trials. Within-session stability of individual differences in response was only modest. Ventilatory adjustments did not facilitate the phasic R(os) increases. As increases were mainly due to the inspiratory component of R(os), a substantial contribution of upper airway artifacts was less likely. Increases in HP were the most pronounced responses to all stimulation conditions, while RSA did not increase significantly.
Ritz
T
T
Department of Psychiatry, Stanford University and VA Palo Alto Health Care System, 3801 Miranda Ave., Palo Alto, CA 94304, USA. tritz@stanford.edu
Thöns
M
M
Dahme
B
B
D000328:Adult; D000403:Airway Resistance / Q000502:physiology*; D001143:Arousal / Q000502:physiology*; D001341:Autonomic Nervous System / Q000502:physiology; D005260:Female; D005546:Forehead / Q000294:innervation*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D012881:Skin Temperature / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology