Overlapping bilateral neural representation and confined receptive fields make frontal audio localization most accurate

Evidence

Previous barn owl studies indicated that the frontal space is represented by a larger population of neurons than the lateral space (e.g., as reflected by the distribution of best ITDs in the IC; Wagner et al. 2007 ). Furthermore, the space maps in each IC represent the contralateral space plus an angular range of about 15° from the midline in the ipsilateral space (Knudsen and Konishi 1978a , 1978b ). This results in an overlap in the representation of the frontal space (‑15° to 15°) by IC neurons from both sides of the brain. Finally, neurons in the IC tuned to locations in the frontal space have more confined spatial receptive fields (Knudsen and Konishi 1978b ). The neurophysiological results have prompted Knudsen and Konishi ( 1978b ) to predict that localization accuracy should be larger in the frontal space than in the lateral space. As expected, Knudsen et al. ( 1979 ) observed a smaller localization error in the frontal field than in the lateral field when measuring the barn owls’ head orienting response towards a stationary sound source. Our results are consistent with these findings. The barn owls’ motion direction discrimination was more sensitive for stimuli being presented in the frontal space compared to stimuli presented in the lateral space. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3222

Categorization

• XREF: Resonates with psychophysical work showing humans locate frontal/azimuth sources more precisely than lateral ones — a comparative angle across species.