Partial prefrontal lesions and go-no go symmetrically reinforced differentiation test in dogs.

The effects of partial bilateral lesions situated in the prefrontal region on go-no go differentiation with symmetrical reinforcement were investigated in dogs. Bilateral removals of proreal gyri and medial cortical surface involving pregenual, genual, precruciatal (XM), subcallosal or medial subproreal areas did not impair performance of this test. Very small cortical lesions of proreal areas located under presylvian fissure impaired transiently the differentiation. Removals of the orbital gyri to the presylvian fissure caused severe and long lasting impairment of this differentiation. It was concluded that the orbital areas situated on the lateral aspect of the hemisphere in dogs was responsible for correct performance of go-no go symmetrically reinforced differentiation task.