From Medical Xpress:
Distinct patterns of neural activation simulate the cocktail party effect of hearing multiple speakers. (Isomura et al., 2015)
While dining with a friend at a noisy restaurant, you listen attentively to her entertaining account of last night’s date. Despite the cacophony flooding your auditory system, your brain remarkably filters your friend’s voice from the irrelevant conversations at neighboring tables. This “cocktail party effect,” the ability to attend to select input amidst a distracting background, has fascinated researchers since its characterization in the 1950’s. Although psychological and sensory models have offered insight into why human brains are so exquisitely equipped to perform this selective attention, researchers haven’t yet pinned down how neurons process mixed information to respond to the important and suppress the irrelevant. In their new paper published in PLOS Computational Biology, researchers from the University of Tokyo revealed that individual neurons learn to “tune in” to one input while ignoring others, offering an intriguing explanation for how rapid neural plasticity may give rise to the cocktail party effect.
Sending neurons mixed messages
Based on many earlier studies showing that neural networks can learn by changing their activity based on experience, the authors wondered whether neurons could also be trained to distinguish among sensory experiences. To test this idea, they recorded electrical activity from cultured rat cortical neurons. They electrically stimulated the neurons according to two stimulation patterns, to provide two unique hidden sources of input, simulating the cocktail party effect of hearing a mixture of voices. In…