Publication DetailsJ Neuroscience Acute Ferret Cortex Auditory Penetrating Electrode A1x16-5mm-150-177|A4x8-5mm-50-200-177
AdaptationÂ to stimulus statistics, such as theÂ meanÂ levelÂ and contrast of recently heard sounds, has been demonstrated at various levels of theauditoryÂ pathway. It allows the nervous system to operate over the wide range of intensities and contrasts found in the natural world. Yet current standardÂ modelsÂ of the response properties ofÂ auditoryÂ neurons do not incorporate suchÂ adaptation. Here we present a model of neural responses in the ferretÂ auditoryÂ cortex (the ICÂ AdaptationÂ model), which takes into accountÂ adaptationÂ toÂ meanÂ soundÂ levelÂ at a lowerÂ levelÂ ofÂ processing: the inferior colliculus (IC). The model performs high-pass filtering with frequency-dependent time constants on theÂ soundÂ spectrogram, followed by half-wave rectification, and passes the output to a standard linear-nonlinear (LN) model. We find that the ICÂ AdaptationÂ model consistently predictscorticalÂ responses better than the standard LN model for a range of synthetic and natural stimuli. The ICÂ AdaptationÂ model introduces no extra free parameters, so itÂ improvesÂ predictions without sacrificing parsimony. Furthermore, the time constants ofÂ adaptationÂ in the IC appear to be matched to the statistics of natural sounds, suggesting that neurons in theÂ auditoryÂ midbrainÂ predict theÂ meanÂ levelÂ of future sounds and adapt their responses appropriately.
J Neurosci.Â 2016 Jan 13;36(2):280-9. doi: 10.1523/JNEUROSCI.2441-15.2016.http://www.jneurosci.org/content/36/2/280.long January 13, 2016 University of Oxford