Temporal-coherence induces binding of responses to sound sequences in ferret auditory cortex

Binding the attributes of a sensory source is necessary to perceive it as a unified entity within its surrounding scene as in the cocktail party problem in auditory perception. It is postulated that coherent temporal modulation of a source's features binds them and enhances their perception. This study seeks evidence for rapid binding among coherently responsive single-neurons in ferret auditory cortex. In one experiment, ferrets attended to a sequence of noise bursts while we contrasted responses to simultaneous synchronized versus alternating tone sequences. We found that the contrast between synchronized (enhanced) and desynchronized (suppressed) responses rapidly increased, thus promoting their segregation. In another experiment, a sequence of an irregularly repeated multi-tone complex was embedded in a background of randomly dispersed tones. Single-unit and functional ultrasound imaging of responses to the temporally coherent tones of the complex became rapidly enhanced against the background responses, demonstrating the role of temporal-coherence in binding and segregation.