4.2 Classical Conditioning o 4.2.2 Main ideas and concept ts x Spontaneous recovery: after a period of time following extinction, if the cs is again presented to the animal, the cr will temporarily reappear. x Higher-order conditioning: Cs(light) CR(salivation). A new Cs(buzzer) o the original cs(ight). The buzzer) CR(Salivation). o UCS is called a primary reinforcer. Cs is called secondary reinforcer.4.2 Classical Conditioning ⚫ 4.2.2 Main ideas and concepts ⚫ ＊Spontaneous recovery: after a period of time following extinction, if the CS is again presented to the animal, the CR will temporarily reappear. ⚫ ＊Higher-order conditioning: CS(light) ⚫ CR(salivation). A new CS(buzzer) ⚫ the original CS(light). The buzzer) CR(salivation). ⚫ UCS is called a primary reinforcer. CS is called secondary reinforcer