Signal switching may enhance processing power of the brain

Different stimuli can potentially activate overlapping populations of neurons in the brain. How does the brain maintain information about multiple items?Here, we describe a new theory: neurons might switch back and forth between encoding each item across time.Recent statistical advances have allowed neurophysiology studies to probe for such activity fluctuations, generating support for this theory and opening intriguing new research directions.Many open questions remain, such as the time scale of activity fluctuations, the manner in which they are coordinated across (and read out from) neural ensembles, and the implications for perceptual binding, neural oscillations, and cognitive processes like attention, memory, and thought. Our ability to perceive multiple objects is mysterious. Sensory neurons are broadly tuned, producing potential overlap in the populations of neurons activated by each object in a scene. This overlap raises questions about how distinct information is retained about each item. We present a novel signal switching theory of neural representation, which posits that neural signals may interleave representations of individual items across time. Evidence for this theory comes from new statistical tools that overcome the limitations inherent to standard time-and-trial-pooled assessments of neural signals. Our theory has implications for diverse domains of neuroscience, including attention, figure binding/scene segregation, oscillations, and divisive normalization. The general concept of switching between functions could also lend explanatory power to theories of grounded cognition. Our ability to perceive multiple objects is mysterious. Sensory neurons are broadly tuned, producing potential overlap in the populations of neurons activated by each object in a scene. This overlap raises questions about how distinct information is retained about each item. We present a novel signal switching theory of neural representation, which posits that neural signals may interleave representations of individual items across time. Evidence for this theory comes from new statistical tools that overcome the limitations inherent to standard time-and-trial-pooled assessments of neural signals. Our theory has implications for diverse domains of neuroscience, including attention, figure binding/scene segregation, oscillations, and divisive normalization. The general concept of switching between functions could also lend explanatory power to theories of grounded c