Pavlov proposed that conditioning involved a connection between brain centers for conditioned and unconditioned stimuli. Vowel breaking may be unconditioned or conditioned. Classical conditioning occurs when a conditioned stimulus (CS) is paired with an unconditioned stimulus (US). Nirvana is also called "unconditioned" ("asankhata"), meaning it is unlike all other conditioned phenomena. This mind is unconditioned, deathless and an independent reality. Meat powder is the unconditioned stimulus (US) and the salivation is the unconditioned response (UR). Rahula also agrees that nirvana is unconditioned. This compartment will become associated with the motivational effects of the unconditioned stimulus. Without conditioning, there is already a relationship between the unconditioned stimulus and the unconditioned response. The other is by giving them a small dose of the unconditioned stimulus. This recovery happened in the absence of any further unconditioned stimulation. The first palatalization was unconditioned&colon; the was vocalized to or spirantized to . This vowel shift is unconditioned, happening in all cases, and not triggered by another sound. Many scholars consider this shift to be unconditioned.