Meeting Abstract

61.5  Sunday, Jan. 5 14:30  Somatosensory feedback during vocal production in a nonhuman mammal RIEDE, T; University of Utah t.riede@utah.edu

Feedback mechanisms (somatosensory and auditory) are critical for vocal learners such as songbirds and humans in order to develop and maintain normal singing behavior or speech. Feedback is also important in some nonhuman mammals (primates, bat echolocation). In many mammals feedback control may play a smaller role during vocal production, because vocal patterns are mostly hard-wired. To extend comparative data on feedback control, two types of subglottal pressure pertubations were made in awake and spontaneously behaving rats during male-female interactions while recording movements of larynx and respiratory system. When subglottal pressure was suddenly increased by injection of a very small amount of compressed air into the trachea, vocalization can be interrupted prematurely terminating vocalization. In contrast, call duration increased, sometimes dramatically, when subglottal pressure increased slowly and continuously, but only slightly above baseline for a long time. The call elongating effect is probably facilitated via lung stretch receptors, whereby lung inflation causes inspiratory termination and expiratory prolongation. Surprisingly, not only was the expiratory phase elongated, as reported previously for rats, but the association between laryngeal vocal motor pattern and respiration was maintained like during normal ultrasound vocalization. Lung pressure and electromyogram traces indicated that motor patterns of the respiratory system and the vocal organ remain synchronized during the perturbation. Results suggest that somatosensory feedback for vocal control can be facilitated via respiratory receptors, and can, depending on the type of pertubation, lead to different acoustic changes.