Pigeons and chickens display an asymmetry of their visual system which closely reassembles each other in behavior but not on anatomical level. While pigeons show an asymmetrically organized tectofugal system, only transient lateralizations of the thalamofugal system have been observed in chickens. By using neuronal tracing, scientists from the Biopsychology lab now analyzed if the thalamofugal system in adult, post hatch and dark incubated/monocular deprived pigeons show a comparable lateralization pattern to chickens. In all three conditions this was not the case. This indicates that visual lateralization in pigeons and chickens depends on tectofugal and thalamofugal asymmetries, respectively. Thus, in different species a highly similar pattern of behavioral asymmetries can be subserved by diverse neural systems.

Ströckens, F., Freund, N., Manns, M., Ocklenburg, S., Güntürkün, O. (2013). Visual asymmetries and the ascending thalamofugal pathway in pigeons. Brain Structure and Function, 218, 1197-1209.