any activity

that the organism is capable of can be conditioned, and these responses can be

conditioned to any stimulus the organism can perceive

positive

reinforcement can be used to enhance repetition of behaviours that are part of

an animal’s natural repertoire of behaviour

all

of these

only biologically/evolutionary salient stimuli can act as a conditioned

stimulus and the unconditioned response need not follow immediately

any

perceivable stimuli can act as a conditioned stimulus and the unconditioned

response must follow immediately