Communication sounds and their cortical representation

Abstract

Communications sounds of most mammals have common acoustic properties that derive from the information bearing elements (IBEs) constant-frequency tones, frequency modulations, and noise bursts. IBEs contain information bearing parameters (IBPs) such as frequency and amplitude, duration, and amplitude modulations. IBPs may be mapped in continuous scales and/or represented in patchy distributions in the activation of neurons in fields of the auditory cortex (AC). The spatial superposition of the maps or patchy distributions of responses to different IBPs creates local sensitivities of neurons (hot spots) to certain IBP combinations. Gamma-band oscillations across the AC may bind the hot spot activities leading to the meaning of sounds. The perception of the three basic meanings - attraction, cohesion, aversion - in communication sounds reflect one simple form of processing in the ventral stream from the AC to the frontal cortex.