When humans do not perceive objects, they continue to exist because God is perceiving them. This perception can be ambiguous without the person perceiving it as ambiguous. Rand argued that consciousness is "the faculty of perceiving that which exists". For this school, there are no objects which are entities external to a perceiving consciousness. The universe cannot exist as it appears if there is no perceiving mind. Hz is optimal for perceiving visual hallucinations. This organizing aids the olfactory cortices in its functions of perceiving and discriminating odors. It was one of several words related to thought, thinking, and perceiving with the mind. In ambiguous images, detecting edges still seems natural to the person perceiving the image. To go further than just perceiving the object is to recognize the object. Examples include perceiving hyperbolic geometry or seeing Escher-like impossible objects. The effect is probably related to rubbing the area or the mind perceiving benefit. He described "seeing" as being the sum of sensing, selecting, and perceiving. It is believed amphibians are capable of perceiving pain. The spt is important for perceiving and reproducing sounds.