Higher-order conditioning, also known as second-order conditioning, in classical conditioning is when a neutral stimulus becomes linked to a conditioned stimulus. All that's required for this process is for the neutral stimulus to become associated with a prior conditioned stimulus. For instance, in terms of Pavlov's experiment, if a tone triggers salivation, then a flashing light that becomes associated with the tone will trigger salivation. However, second-order conditioning is weaker than first-order.

In classical conditioning, when a conditioned stimulus is repeatedly administered without the unconditioned stimulus following, the conditioned response will diminish. For example, with regards to Pavlov's experiment, the tone would be played but the food would not arrive. Over time this causes a diminishing of the dogs salivating. This is known as extinction. 

Acquisition would be an incorrect choice as it is the initial step in classical conditioning where a neutral stimulus is linked to an unconditioned stimulus and the respondent behavior. Respondent behavior is the automatic behavior triggered by some stimulus. An example of this would be salivation with the sight of food, where salivation is the response and the food is the stimulus. 

Higher-order conditioning, also known as second-order conditioning, would also be incorrect because it is the process of a neutral stimulus associating with a previously conditioned stimulus. For example, a strobing light associated with the previously conditioned stimulus (tone) would yield salivation. 

Spontaneous recovery would be an incorrect choice because it refers to the reappearance of a weakened conditioned response. This would occur in the case of a CR being suppressed rather than completely eliminated. 

Ivan Pavlov is one of the earliest psychologists known for classical conditioning and is particularly famous for his experiments in which he got dogs to associate food with sounds, leading them to salivate when there was a bell even when there was not food present. 

John Watson was a classical conditioning psychologist who is most famous for his "Little Albert" experiment in which he trained a young boy to be afraid of a rat (or anything like looked like a white rat) because he made an unpleasant noise while presenting the rat. This research indicated that humans too could be classically conditioned.

Edward Thorndike came up with the law of effect, which states that positive consequences increase the likelihood that an action will be repeated and negative consequences decrease the likelihood that it will.

B.F. Skinner based his research off of Thorndike's law of effect and is considered to be the founder of operant conditioning (the type of learning in which the effects of an action determine whether it will be repeated in the future). He is most famous for Skinner's box-- a box in which he placed animals to conduct operant conditioning experiments.  

Sigmund Freud is not a psychologist associated with conditioning at all. Instead, he came up with psychodynamic theories that explained people's actions in terms of conflicts in their unconscious.

John Watson was a classical conditioning psychologist who is most famous for his "Little Albert" experiment in which he trained a young boy to be afraid of a rat (or anything like looked like a white rat) because he made an unpleasant noise while presenting the rat. This research indicated that humans too could be classically conditioned.

Ivan Pavlov is one of the earliest psychologists known for classical conditioning and is particularly famous for his experiments in which he got dogs to associate food with sounds, leading them to salivate when there was a bell even when there was not food present. 

Edward Thorndike came up with the law of effect, which states that positive consequences increase the likelihood that an action will be repeated and negative consequences decrease the likelihood that it will.

B.F. Skinner based his research off of Thorndike's law of effect and is considered to be the founder of operant conditioning (the type of learning in which the effects of an action determine whether it will be repeated in the future). He is most famous for Skinner's box-- a box in which he placed animals to conduct operant conditioning experiments.  

Sigmund Freud is not a psychologist associated with conditioning at all. Instead, he came up with psychodynamic theories that explained people's actions in terms of conflicts in their unconscious. 

Generalization occurs when the conditioned response (fear) occurs even when the conditioned stimulus (cello) is slightly different from the original CS (violin). 

Discrimination is the ability to differentiate between similar stimuli.

Extinction is the cessation of the conditioned response when the unconditioned stimulus is no longer presented. 

Spontaneous recovery is the comeback of a conditioned response after extinction when the unconditioned stimulus is presented again.

Acquisition is the learning period of a conditioned response when the unconditioned stimulus and the conditioned stimulus are being presented together.

Discrimination is the ability to differentiate between similar stimuli (violins and basses). 

Generalization occurs when the conditioned response occurs even when the conditioned stimulus is slightly different from the original CS. 

Extinction is the cessation of the conditioned response when the unconditioned stimulus is no longer presented. 

Spontaneous recovery is the comeback of a conditioned response after extinction when the unconditioned stimulus is presented again.

Acquisition is the learning period of a conditioned response when the unconditioned stimulus and the conditioned stimulus are being presented together.

Extinction is the cessation of the conditioned response (fear) when the unconditioned stimulus (noise) is no longer presented. 

Discrimination is the ability to differentiate between similar stimuli. 

Generalization occurs when the conditioned response occurs even when the conditioned stimulus is slightly different from the original CS. 

Spontaneous recovery is the comeback of a conditioned response after extinction when the unconditioned stimulus is presented again.

Acquisition is the learning period of a conditioned response when the unconditioned stimulus and the conditioned stimulus are being presented together.

Spontaneous recovery is the comeback of a conditioned response (fear) after extinction when the unconditioned stimulus (noise) is presented again.

Extinction is the cessation of the conditioned response when the unconditioned stimulus is no longer presented. 

Discrimination is the ability to differentiate between similar stimuli. 

Generalization occurs when the conditioned response occurs even when the conditioned stimulus is slightly different from the original CS. 

Acquisition is the learning period of a conditioned response when the unconditioned stimulus and the conditioned stimulus are being presented together.

Acquisition is the learning period of a conditioned response (fear) when the unconditioned stimulus (noise) and the conditioned stimulus (violin) are being presented together.

Spontaneous recovery is the comeback of a conditioned response after extinction when the unconditioned stimulus is presented again.

Extinction is the cessation of the conditioned response when the unconditioned stimulus is no longer presented. 

Discrimination is the ability to differentiate between similar stimuli. 

Generalization occurs when the conditioned response occurs even when the conditioned stimulus is slightly different from the original CS. 

Second-order conditioning is when the conditioned stimulus from a previous round of conditioning (violin) becomes the unconditioned stimulus for a new round.

Spontaneous recovery is the return or reoccurrence of a conditioned response after extinction when the unconditioned stimulus is presented again.

Extinction is the cessation of the conditioned response when the unconditioned stimulus is no longer presented. 

Discrimination is the ability to differentiate between similar stimuli. 

Generalization occurs when the conditioned response occurs even when the conditioned stimulus is slightly different from the original CS.