Early sensory determinants of locomotor speed in adult cats: II. Effects of strobe rearing on vestibular functions.

Cats raised under stroboscopic illumination are known to exhibit oculomotor and visuomotor deficits, but little is known about their locomotor abilities. Four strobe-reared cats with intact labyrinths were tested in a locomotor test involving various walking surfaces and various illumination conditions. Apart from their general slowness under all the experimental conditions, these strobe cats showed no special deficit on narrow rails, which indicates that their dynamic balancing abilities were normal. In these subjects, the decrease in the use of kinetic visual cues was roughly compensated for by an increase in the use of position cues. When tested after chronic bilateral labyrinthectomy, the strobe-reared cats' locomotor speeds were identical to those of control labyrinthectomized cats, except on wide platforms involving orientation towards a visual goal. These results show that in the absence of motion-vision, vestibular control of dynamic balance can mature normally, but they suggest that other aspects of locomotion involving the processing of vestibular and kinesthetic inputs may be impaired.