Understanding Associative Learning Through Higher-Order Conditioning.

Associative learning is often considered to require the physical presence of stimuli in the environment in order for them to be linked. This, however, is not a necessary condition for learning. Indeed, associative relationships can form between events that are never directly paired.

Mechanisms of higher-order learning in the amygdala.

Adaptive behaviour is under the potent control of environmental cues. Such cues can acquire value by virtue of their associations with outcomes of motivational significance, be they appetitive or aversive. There are at least two ways through which an environmental cue can acquire value, through first-order and higher-order conditioning.