I've got a bu neng shuo de mi mi.

Anyway 3 down 2 to go! Really must pray friday's L&C won't be a killer. It's gan pua chim.

Okay there's plenty of Motivation Mechanisms, which are backed up by many theories of reinforcement.

Thorndike's Law of Effect.
Focuses on the effect created by the reinforcer. Emphasize that the only role of the reinforcer is to create the S-R association. Magnitude of the association is dependent on the outcome.
Cons: There's no role for rewards/expectations in this framework, and that it does not address what makes a reinforcer effective.

Hull's Drive Reduction Theory.
Concentrates on what makes a reinforcer effective. Concept of homeostasis: The need to maintain the ideal level with respect to certain biological factors. Hunger: If the animal is deprived of food, then the drive state of hunger will occur and this motivates the animal to engage in behaviors that will lead to food. If stimulus can effectively reduce a drive state, it is then a reinforcer. Primary reinforcers - Stimuli effective in reducing a biological need w/o training
Secondary reinforcers - Stimuli that are not primary reinforcers in their own right and become associated with the reduction of drive states.
Instrumental response is motivated by two factors: S-R and S-O.
Cons: Fell out of favour because of growing evidence of sensory reinforcement effects and the development of other conceptual frameworks to account for reinforcement effects. (Animals will do stuff just to receive sensory input.)

Modern Two Process Theory.
Claims Pavlovian and Instrumental Conditioning are distinct forms of learning. Stimulus present when response is reinforced, becomes associated with outcome. S-O association formed.
Stimulus motivates behavior by activating Central Emotional State via the S-O association.
If we are able to manipulate the CES, then we are able to control the response. Positive mood will increase response, vice versa.
Thus, stimulus which activates a CES would allow the presentation of a classically conditioned stimulus to influence the instrumental response rate.
Evidence: Transfer of control experiments. Conditioned emotional suppression did not elicit a response.

Premack Principle aka Differential Probability Principle.
Focuses on response rather than on stimuli. (Act of eating instead of food itself)
Critical determinant of whether a response would be reinforcing would be the PROBABILITY of the response.
The opportunity to engage in a higher probability response could serve as a reinforcer for a lower probability response.
Cons: Difficult to assign precise probability to responses and these probabilities change unexpectedly. Answers what makes a response effective, but does not answer the question of how a reinforcer increases the probability of a response.

Response Deprivation Hypothesis.
Similar to Premack Principle: Thought of reinforcers as responses instead of stimuli, and focused on the difference between instrumental and reinforcer responses.
Differences: Performance of a reinforcer response is restricted, but performance of the instrumental response is not. Also, a low probability response can reinforce a high probability response is the former is held at a level below its baseline level.
It is the response DEPRIVATION that makes the response reinforcing. Reinforcement effects are due to the response restriction placed upon the animal by the conditioning procedure rather than due to factors external to the conditioning procedure.

Behavioural Regulation Approach. ARGGHH help.
Does not treat reinforcers as special stimuli or responses.
Build on Response Deprivation Hypothesis, assumes restrictions on responses determine reinforcement effects.
Attempt to explain how a reinforcer increases the probability of a response. (Premack Principle's con)
Bliss Point: Preferred distribution of responses.
When an instrumental contingency is placed upon the animal such that it cannot distribute its responses in the preferred manner, it will attempt to approach the bliss point.
Animal in the absence of any behavioural constraints, will always respond at the bliss point.
Example of studying 15mins and TV 60mins.
However, if another activity can replace the reinforcer, then the reinforcer is not a very strong one.
Cons: Does not require information about molecular choice patterns which is crucial for influencing bliss point. Does not account that different activities may have different values depending on circumstances. Attempts to provide an understanding of the tradeoff between behaviours, but does not explain what processes are involved.

See that's the problem. Everyone wants a piece of the pie.