The Jeffress Model - Animation


The Jeffress Model has long been a popular model for trying to exlpain how the mammalian Medial Superior Olive (MSO) or the bird nucleus laminaris may extract interaural time differences for sound localization. The Jeffress model posits a "delay line and coincidence detector" arrangement which is illustrated in the animation shown here. The animation nicely conveys the appeal of the Jeffress model. Due to a systematic delay line arrangement and a requirement for precise synchrony in the activation of MSO neurons, different parts of the MSO become sensitive to sounds from particular directions. But note that the cartoon shown here is in many ways "biologically naive", oversimplifying the anatomy and physiology. Whether the Jeffress model, such as it is shown here, is really a good description of the operation of the mammalian MSO is becoming increasingly controversial.
(Note: the video contains no sound).

Acknowledgement: this video is from the web page of the laboratory of Prof. Tom Yin of the University of Wisconsin, one of the pioneers of research on the physiology of the mammalian MSO.