Evidence for time division multiplexing of multiple simultaneous items in a sensory coding bottleneck
Dr. Valeria Caruso, Jeffrey Mohl, Chris Glynn, Jungha Lee, Shawn Willett, Azeem Zaman, Dr. Akinori Ebihara, Rolando Estrada, Winrich Freiwald, Surya Tokdar, Jennifer Groh
Received: 27th September 17
How the brain preserves information about multiple simultaneous items is poorly understood. We provide evidence that single neurons can represent multiple different stimuli by interleaving different signals across time (aka time-division multiplexing). We recorded single units in an auditory region, the inferior colliculus, while monkeys localized 1 or 2 simultaneous sounds. During dual-sound trials, we found that some neurons fluctuated between firing rates observed for each single sound, either on a whole-trial or on a sub-trial timescale. These fluctuations were correlated in pairs of neurons, could be predicted by the state of local field potentials prior to sound onset, and, in one monkey, predicted which sound would be reported first. Alternation between activity patterns corresponding to each of multiple items may be a general strategy to enhance the brain processing capacity, suggesting a potential connection between such disparate phenomena as variable neural firing, neural oscillations, and limits in attentional/memory capacity.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.