Second-order conditioning Cat and Can opener and door sound

classical conditioning Classical conditioning (also respondent conditioning and Pavlovian conditioning) is a behavioral procedure in which a biologically potent Stimulus (physiology), stimulus (e.g. food, a puff of air on the eye, a potential rival) is paired with a n ...

, second-order conditioning or higher-order conditioning is a form of

learning Learning is the process of acquiring new understanding, knowledge, behaviors, skills, value (personal and cultural), values, Attitude (psychology), attitudes, and preferences. The ability to learn is possessed by humans, non-human animals, and ...

in which the first stimulus is classically conditioned to an unconditioned stimulus, then a second stimulus is classically conditioned to the first, thereby conditioning it back to the original unconditioned stimulus. For example, an animal might first learn to associate a bell with food (first-order conditioning), but then learn to associate a light with the bell (second-order conditioning), associating the light to food (unconditioned stimulus).

Honeybee A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to mainland Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the c ...

s show second-order conditioning during

proboscis extension reflex Proboscis extension reflex (PER) is the extension by an insect with an extendable proboscis (e.g. a bee or fly) of her proboscis (sticking out of her tongue) as a reflex to antennal stimulation. It is evoked when a sugar solution is touched to a bee ...

conditioning.Bitterman et al. 1983. Classical Conditioning of Proboscis Extension in Honeybees (''Apis mellifera''). J. Comp. Psych. 97: 107-119. Second-order conditioning (SOC) occurs in three phases. In the first training phase, a conditioned stimulus, (CS1) is followed by an unconditioned stimulus (US). In the second phase, a second-order conditioned stimulus (CS2) is presented along with CS1. Finally, in the test phase, CS2 is presented alone to the subjects while their responses are recorded. Evidence suggests that a second-order conditioned stimulus is able to persist for weeks, and that a third or higher order may be possible. The first-order conditioned stimulus can stabilize and serve as the foundation for multiple conditioned stimuli "superimposed upon it" as opposed to just one.

Models of second-order conditioning

Theoretical models for how second-order conditioning (SOC) works have a basis in

associative learning Learning is the process of acquiring new understanding, knowledge, behaviors, skills, values, attitudes, and preferences. The ability to learn is possessed by humans, non-human animals, and some machines; there is also evidence for some kin ...

theories. There are four broad models based on the associations formed during SOC. The first model suggests that the second-order stimulus (CS2) and the conditioned response (CR) form a direct link which is strengthened by the presence of the first-order stimulus (CS1). The second model suggests that in successful SOC an associative representation of each stimulus is created. The presentation of the CS2 would evoke a representation of the CS1, which would evoke a representation of the unconditioned stimulus (US), thus leading to the CR. The third model suggests a direct link between the CS2 and a representation of the US which leads to the CR. The fourth model suggests that the CS2 elicits a CR through a CS1 representation because a connection exists between the CS2 and the CS1 representation. Second-order conditioning helps explain why some people desire money to the point that they hoard it and value it even more than the objects it purchases. Money is initially used to purchase objects that produce gratifying outcomes, such as an expensive car. Although money is not directly associated with the thrill of a drive in a new sports car, through second-order conditioning, money can become linked with this type of desirable quality. Money (CS2) becomes directly associated with a conditioned response because of its link to physical assets (CS1) that lead to a satisfying unconditioned stimulus.

In fear conditioning

{{See also, Fear conditioning It has been demonstrated in an associative fear conditioning chain, such as CS₂ --> CS₁ --> US, that

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

of freezing responses to the first-order stimulus (CS₁) leads to responding impairments in CS₂, but extinction of the second-order stimulus (CS₂), does not have any effect on CS₁ (Debiec et al.). In the same study, the effect of activation (

memory retrieval Recall in memory refers to the mental process of retrieving information from the past. Along with encoding (memory), encoding and storage (memory), storage, it is one of the three core processes of memory. There are three main types of recall: fr ...

) on such an associative chain has been examined. Results demonstrated that protein synthesis inhibition after exposure to a single CS₁ impairs responses to both CS₁ and CS₂, but protein synthesis inhibition after exposure to a single CS₂, only disrupts CS₂ and leaves CS₁ freezing intact. Therefore, it is believed that when the first-order association is directly activated, it is placed into a

labile Lability refers to the degree that something is likely to undergo change. It is the opposite ( antonym) of stability. Biochemistry In reference to biochemistry, this is an important concept as far as kinetics is concerned in metalloprotein ...

state (as we would expect from

memory reconsolidation Memory consolidation is a category of processes that stabilize a memory trace after its initial acquisition. A memory trace is a change in the nervous system caused by memorizing something. Consolidation is distinguished into two specific processe ...

research) which may affect dependent associations. However, when the first-order association is only indirectly activated (through the associative chain), it appears that there is not sufficient stimulation to kick off cellular processes which would place it in a labile state, so it remains fixed.Debiec, J., Doyere, V., Nader, K., LeDoux, J.E. (February 28, 2006). Directly reactivated, but not indirectly reactivated, memories undergo reconsolidation in the amygdala. PNAS, Volume 103, Number 9, 3428-3433.

References

Learning