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The Psychology of Everyday Life: Motivation and the Search for Happiness - The Biology of Money

6 important questions on The Psychology of Everyday Life: Motivation and the Search for Happiness - The Biology of Money

How much is the prefrontal cortex involved in purchasing decisions?

Because purchasing decisions are primarily about personal value, about how much we gain or lose, the prefrontal cortex does not seem to be the dominant player in our brain's response to purchasing decisions.

According to a 2007 fMRI experiment by Brian Knutson, George Lowestein, and colleagues, the frontal cortex was less activated during purchasing decisions than either the nucleus accumbens (which processes rewards), or the insula (which processes pain). This suggests that purchasing decisions are driven more by the balance of pain and desire than by a rational assessment of our options.

How strongly does the reward system affect motivation?

It must be kept in mind that the reward system has a very powerful effect on motivation. When it is really firing, our desire can be overwhelming. In the most extreme state, we experience addictive craving, which can overpower any consideration of danger or future consequences. So, when we are caught up in the thrill of making money, our reward system can overpower the inhibiting (and cautionary) effect of the frontal lobe.

How does the dopamine system set expectations?

The dopaminergic reward system not only responds to the presence of rewards, it learns which cues signal reward and which do not. Therefore the reward circuitry is centrally involved with setting expectations.

It is in the business of distinguishing which cues do and do not signal reward and in priming us to pursue a reward when it detects a relevant cue.

What are the drawbacks of the dopamine system?

The reward system has evolved over millions of years to help us recognize the presence of rewards and to motivate us to expend considerable energy to pursue and obtain them. However, it is not foolproof. For one, it responds to the intensity of a reward but not the probability. Secondly, it is over-responsive to novelty, or intermittent reinforcement. Thirdly, it does not do well with randomness.

How is the reward system reactive to intermittent reinforcement?

Our dopaminergic reward system is particularly sensitive to intermittent reinforcement. When a behavior is intermittently reinforced, the reward for a given behavior is irregular and unpredictable.

Dopamine neurons are particularly sensitive to novelty and surprise, so when behavior is unpredictably reinforced, each experience of reward comes as a surprise. In fact an unpredicted reward is perhaps three to four times as activating as a predictable reward.

This pattern contributes to our vulnerability to gambling, which is defined by intermittent reinforcement.

What is the role of the insula?

The insula is an area of the cortex that is sandwiched between the frontal, parietal, and temporal lobes. It communicates information about our internal bodily states to our cortex. In this way, it contributes to experiences of disgust and pain.

The insula is activated when we experience the pain of losing money. For example, activity in the insula increases when we look at the price tags of our purchases and it decreases when we pay with credit cards as opposed to cash.