knee-jerk reaction. Fig. an automatic or reflex reaction; an immediate reaction made without examining causes or facts. With one of his typical knee-jerk reactions, he said no immediately, citing some moral argument that no one understood. See also: reaction.
What did you see when the patients head was rolled to the opposite side? In horizontal canal BPPV, you should have seen a direction change. When the horizontal nystagmus is geotropic, the BPPV is suspected to be canalithiasis, occurring on the side with the more intense nystagmus.
Phototropism- Plant shoots display positive phototropism: when illuminated from one direction, the shoot proceeds to grow in that direction. Geotropism- Geotropism is a plant growth response to gravity. Plant shoots display negative geotropism: when placed on its side, a plant shoot will grow up.