An essential role of random arrangement of coincidence detection neurons in hyperaccurate sound location of owl
The sound location of owl with respect to horizontal direction is made based on analyses of the interaural differences in arrival time of which minimum value is of the order of . We proposed that this hyperacuity for detection of the difference is accomplished through a combination of four kinds of functional factors: (1) the functional structure of neural unit (CD unit) for coincidence detection; (2) projection of CD units randomly arranged in every array of the units in nucleus laminaris (NL) to ITD sensitive neurons arranged regularly and densely in a single array in central nucleus of the inferior colliculus (ICc); (3) convergence of outputs of all the arrays in NL tuned to a single sound frequency in NL into a single array of the neurons in ICc; and (4) integration of outputs of frequency tuned arrays in ICc over all frequencies in external nucleus of inferior colliculus (ICx).
sound location hyperacuity nucleus laminaris neural model auditory system