# Motivation and emotion/Book/2024/Dopamine and social behaviour

* Multimedia presentation (3 min)

## Overview

* Dopamine affecting social interactions scenario
* Figure 1. Is a depiction of how different interactions can cause different responses
* Imagine that you have just met two different people, Jack and Richard. When talking to Jack he was highly enthusiastic when talking to you. You immediately connect with him and suddenly you have this desire to continue interacting with him in the future. When looking at your interaction with Richard, however, you found him to be quite rude and blunt to you for no foreseeable reason. This led to you just wanting to leave as quickly as possible and not interact with him in the future.
Dopamine (DA) and its effects on social behaviour can be viewed through various perspectives. All of which shows how DA has an important role in how individuals interact in social settings[grammar?]. Research shows that DA has its greatest responsibility in incentivising reward-seeking behaviours. As such, social interactions that are perceived to be positive are rewarded, and those interactions perceived to be negative in some way cause DA release to decrease, incentivising behavioural extinction. Similar effects are present in relationships, however, relationships differ from basic social interactions, as relationships persist over time, causing DA release to decrease due to the reduced novelty of the situation. This has caused researchers to attribute other factors as being more critical to maintaining relationships rather than DA by itself. That being said, there are indirect effects of DA that can affect relationships which is largely attributed to some form of dysfunction in the DA system.
* Focus questions:
* How does dopamine affect an individual after a social interaction?
* How does dopamine release effect[spelling?] long-term relationships?
* How does a dysfunctional dopaminergic system result in negative social behaviours?

## What is dopamine?

Dopamine (DA) is a neurotransmitter which plays a key role in reward-seeking behaviour, learning, mood regulation and is linked with being involved in aversive and alerting processes (Bromberg-Martin et al., 2010). DA has a primary role is incentivising reward-seeking behaviour through the release of DA in the nucleus accumbens (Lewis et al., 2021). This unconscious processes following an event. It is what drives us to continuing doing something.
Furthermore, DA is not restricted to one particular site in the brain, and rather is a complex system that is connected via dopaminergic pathways (See Figure 2.). This allows DA to affect and trigger specific areas within the brain (Lewis et al., 2021). Moreover, DA is broken down into five different receptors, each receptor has there own specific function (see Table 1).
Table 1.
Types of Receptors and their Respective Functions[factual?]
| Type | Function | Location in the brain |
| D1 | Memory, attention, impulse control, regulation of renal function, locomotion | Striatum, nucleus accumbens, olfactory bulb, and substantia nigra |
| D2 | Locomotion, attention, sleep, memory, learning | Striatum, external globus pallidus, nucleus accumbens, hippocampus, amygdala, and cerebal cortex |
| D3 | Cognition, impulse control, attention, sleep | Striatum, external globus pallidus, nucleus accumbens, hippocampus, amygdala, and cerebal cortex |
| D4 | Cognition, memory, fear, impulse control, attention, sleep | Striatum, external globus pallidus, nucleus accumbens, hippocampus, amygdala, and cerebal cortex |
| D5 | Decision making, cognition, attention, renin secretion | Striatum, nucleus accumbens, olfactory bulb, and substantia nigra |
Note. The location of each receptor is only considering where the receptor is found in high concentration (Bhatia et al., 2023).

## Psychological processes of dopamine on social behaviour

The psychological processes of dopamine on social behaviour are quite extensive and there are many theories. This section overviews a few key theories and models.

### Reward error prediction theory

Dopamine has its strongest routes in incentivising reward-seeking behaviour[factual?]. This has led to many reward-related theories, however, the most common and widely accepted theory is the [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4826767/ reward prediction error (RPE) theory (see Figure 3.). This theory attempts to explain why certain interactions persist, and others diminish overtime.
Due to RPE having its roots in Pavlovian learning through incentivisation (Bromberg-Martin et al., 2010; Ranaldi, 2014)[grammar?]. Those social interactions or relationships that are perceived to be positive and desirable receive larger amounts of phasic DA bursts, which further encourages a pairing of the social behaviour, and the DA reward to occur, consequently making it more likely for an individual to seek out that interaction again. Whereas, if the situation is perceived as undesirable, the individual will learn to associate that interaction and relationship as non-rewarding, and over time behavioural extinction will occur (Collins & Saunders, 2019). This consequently means that RPE theory affects social behaviour not by initiating specific social interactions but rather providing incentivised learning to increase motivation to return to that specific relationship, and or interaction.
Notably, reward-related stimuli is not the only cause for DA release in social interactions and relationships. Research has suggested that DA also has a role in non-rewarding events, such as alerting and aversive stimuli (Horvitz, 2000; Shultz, 1998). This connection can be linked through Bromberg-Martin et al.[grammar?] (2010) review as it shows individuals interpreting rewarding and non-rewarding stimuli in a relatively similar manner. They ascribe this to motivational salience being assigned to both forms of stimuli, one simply has a positive value, and the other a negative value. By this interpretation, DA also assists in motivating extinction of negative interactions and relationships by providing phasic DA bursts when aversive or altering action is taken.

### Tonic and phasic model

The tonic and phasic model of DA is important to note, as it shows the two states of DA release, that affect interactions. The tonic stage is important as it maintains a slow steady state of DA which flows through the neural structures to maintain baseline function such as assisting with motor movement. Whereas the phasic mode of DA, is activated through reward-related sensory cues, and consists of short rapid bursts of DA over a short period of time[grammar?]. This process acts as an incentive to re-engage with that stimulus (Bromberg-Martin et al., 2010; Collins & Sanders, 2019; Schultz, 1998). This model can the be used to explain how tonic and phasic DA release stages affect our motivation, learning. and motor movement to a specific setting.

### Psychological disorder theories

When determining the effects that DA has on social behaviour, it is important to consider how DA can affect other processes in our lives, which causes a knock on affect which can effect[spelling?] social interactions and relationships. Due to DA having ties to many disorders, this has caused many different theories that relate psychological disorders to a dysfunctional DA system. For example if the an individual is experiencing depression or anxiety the monoamine theory can be used to show the link between DA and the specific disorder (Boku et al., 2018; Delgado, 2000). Whereas those experiencing psychotic episodes can use the dopamine hypothesis of schizophrenia to help explain the link (Howes & Kapur, 2009). Notably, these are not the only disorders that DA can affect, and other disorders such as attention deficit hyperactivity disorder, or Parkinson's disease also have theories around DA and its casual relationship. This therefore, shows how DA can indirectly affect social behaviour by affecting other areas of the individuals[grammar?] life.
Content review
1
What is the main theory that supports dopamine, as a reward-seeking behaviour through learning?
Decision making theory
Monoamine hypothesis
Reward prediction error theory (RPE)
2
Does dopamine have an affect on psychological disorders?
True
False :

## How does dopamine effect social interactions?

Due to DA having its roots predominately in reward-seeking behaviours, it is no surprise that the most prevalent theory, RPE, incentivises and motivates us to continue seeking positive interactions. Alongside this theory, there is also evidence to suggest that DA has a role in the moments following an interaction as well as motivating an individual to engage in social interactions (Schultz, 2019). Lastly dopamine can also be affected by social isolation, causing various issues.

### Incentivising interactions

RPE theory shows that dopamine is released following a positive interaction, and thereby causing Pavlovian learning to associate that interaction positively, therefore providing us with motivation to re-engage with that specific interaction. Furthermore, Christian & Ernst (2014) review shows that when the interaction is perceived to be greater than initially expected, those interactions receive greater phasic DA bursts, and thereby, increasing the motivation and learning attached to that specific interaction. This shows that DA incentivises continued engagement, as opposed to motivating initiation of the interaction.

### Dopamine motivating interactions

While the current idea is that dopamine only affects the individual following an interaction, current research, has suggested it also has a role in the early stages of initiation. Through Dai et al. (2022) research, they were able to find that by blocking DA receptors in dogs it caused a reduction in motivation to reach their pups, although they did show that motivation wasn't completely extinguished indicating other processes are at play. Similarly Solié et al. (2022) found that the ventral tegmental area (VTA) leaves traces, for phasic DA bursts to later strengthen the interaction if it is perceived to be rewardingly stimulant. This indicates, that while there is DA release at the initiation stage of interactions it is not the only factor, and is rather a small cog in a larger system creating motivation to initiate.

### Scenario example

Using our earlier scenario following the interaction with Jack and Richard, we can see that the individual would have received a larger DA burst with Jack as opposed to Richard. Over time ,if these interactions persisted, we would see pavlovian learning begin to occur, which would cause greater DA bursts with Jack as opposed to Richard. It is worth noting that as Richards[grammar?] interaction was abnormally negative, it is suggested according to Collins & Saunders (2019) that aversive DA release would occur to prevent further interaction with Richard.

### Effects of social isolation on dopamine

DA can incentivise us to engage with specific stimuli through learning, however, this is not the only role that DA plays in social behaviour. What research finds is that when social isolation begins to occur, there is a significant drop in phasic DA bursts causing issues with their locomotion, and is also linked with the development of psychological disorders (Shams et al., 2017). With this in mind, while DA has its main importance in motivation and seeking rewards through interacting with others, there is alternative process where the absence of social interaction results in reduced DA levels in the dopaminergic system, which can cause dysfunctional adaptations to occur.
Content review
1
What has research on animals shown in terms of how dopamine affects the early stages of an interaction?
Nothing, animal research has amounted to no further advancements
The ventral tegmental area is responsible for engaging in social interactions
Blocking dopamine release results in decreased motivation to engage in social interaction
Dopamine release only follows an event
2
Does social isolation affect the dopaminergic system?
Yes
No :

## Dopamine and relationships

* Psychological disorder scenario
* Figure 4. A woman socially isolating herself in a social setting.
* Imagine you are at a party, and you meet a girl named Charlie. You notice that Charlie seems quite shy and isn't talking to anyone. You approach her and try to talk to her. As you are talking to her [missing something?] notice that she is very negative in the way she talks, you find out that her friends aren't talking to her because she kills the vibe and she also appears [missing something?] to care about anything. You end up leaving feeling something was off with that interaction.
While the RPE theory shows dopamine affecting social interactions through learning and reward based mechanisms[grammar?]. Different processes of dopamine can be shown in relationships. Research finds that as an individual moves from social interactions to developing a relationship there is a shift in dopamine receptors and activation[factual?].

### Changes in dopamine receptors and brain structures

The change in dopamine receptors can best be shown through DA and its effect on romantic relationships. Takahashi et al. (2015) show that the D1 and D2 receptors are important for novel social interactions, and there is a shift to activation of the D2 and D3 receptors as relationships are developed. Alongside this there is also a shift from activation in the nucleus accumbens, to the medial orbitofrontal cortex and medial prefrontal cortex, both of which are responsible for higher cognitive function, from which love and beauty perceptions are developed (Takahashi et al., 2015). Therefore, as the relationship develops into a romantic one, there is a shift in locations within the brain, which creates other rewarding stimuli, which are more cognitive in nature and provide intrinsic reward for DA release, as opposed to novel stimuli providing that stimulation.

### Scenario example

To provide another perspective on dopamine and its effects on relationships, consider the scenario about Charlie having issues with her friends, due to her depression. From this it can be inferred that Charlie's change in mood and communication with her friends has caused her friendships to deteriorated over time, so much to the point where her friends are now avoiding her at social events. What this shows, is that while DA wasn't necessarily the direct cause of Charlie's friendships deteriorating, it rather caused a specific set of responses, that ended up negatively effecting[spelling?] her relationships, which consequently causes further dysfunction in the dopaminergic system due to social isolation (Shams et al., 2017).

### Other confounding variables

Although DA does persist as relationships becomes more established[grammar?]. The main process for DA is around novel stimuli (Bromberg-Martin et al., 2010), hence the evidence to suggest that DA has a significant effect on relationships directly is insufficient, and it is rather posited that DA can provide closeness in relationships, by doing rewardingly stimulant[spelling?] activities together (Walton & Bouret, 2019), similarly there can also be deterioration in relationships through dysfunction dopaminergic systems. With this in mind, DA and its effect on relationships seems to have largely indirect effects, that can cause positive and negative relationships. Further research is suggested to see how different DA receptors effect[grammar?] an individuals[grammar?] relationships directly.

## Dysfunctional adaptations

The DA system, when functioning correctly, can effectively modulate motivation and the likelihood that an individual will engage in social behaviour. However, when the dopaminergic system is no longer functioning as expected we can begin to see maladaptive behaviours occur. This can take the form of either psychological disorders or addiction.

### Psychological disorders

There are various theories that provide evidence for DA and its effects on causing a broad range of psychological disorders. This is crucial because psychological disorders have been shown to negatively impact an individuals[grammar?] ability to positively interact with others, as well as being able to maintain relationships[factual?]. For our scenario above, depression was used as our psychological disorder of choice, as this is the most prevalent disorder in our society[factual?], and there is substantial evidence over the last few decades [factual?] showing DA deficiency being a causal trigger for depression (monoamine hypothesis). Now looking at how depression effects[grammar?] social interactions, a systematic review by Santini et al. (2015) shows that those with depression suffer from having low social support, lack of social networks and feel socially disconnected, all of which is shown to negatively impact how someone interacts with others. Therefore, rather than DA directly affecting social behaviour, DA can also impact our mood and attitudes, which can cause adverse social effects.

### Scenario

Charlie is having issues with communicating with others at the party, as she is perceived to be negative, alongside being unmotivated to interact with others. Using the monoamine hypothesis, it is determined that Charlie is having insufficient DA bursts, which consequently, is resulting in a lack of of motivation to engage with other people at the party. Furthermore this can be tied to research by Kupferberg et al. (2016) where they show through rat studies that by increasing phasic DA firing in the nucleus accumbens core, the motivation of the rats can be increased indicating that sufficient DA release is important for motivation to engage.
Notably however, when this concept is applied to people, we don't quite see the same results. A study by Belujon & Grace (2017) show[grammar?] how medication such as anti-depressants[Move to external links] are shown to be ineffective at increasing motivation and reward-seeking behaviour, [grammar?] this means that while conceptually increasing DA release is effective for a typical functioning DA system, those with psychological disorders have other factors that may contribute to decreased motivation. That being said, DA does provide an improvement on mood regulation, which could improve other factors like avoiding social isolation.

### Addiction

Addiction to a particular stimulus occurs when there is dysfunctional learning that has occurred through repeated DA release, resulting in Pavlovian learning. Typically addiction is shown to develop from highly rewarding stimuli, from which the most common types of addiction is gambling, and or drug-related use(Collins & Sanders, 2019). When a reliance on these highly rewarding stimuli occurs, research has found that it can negatively impact your day to day life, and can cause many issues in relationships as well as how an individual interacts with others. For example, Ponti et al. (2019) shows that those who struggle with a gambling addiction have lower levels of companionship, more conflict with their significant other and aren't as close to their significant other. Similarly, those with drug-related addictions, have issues with their relationships, quicker to display aggression as well as being cruel in social interactions (Sommer et al., 2017). From this research it appears that addiction develops and becomes more severe through repeated DA burst pairings, and that relationships and social interactions can become negatively impacted, through the desire to get that DA burst from that stimulus.

## Conclusion

DA can effect[spelling?] social behaviour through various DA responses, including typical, and dysfunctional processes from the dopaminergic system. DA plays its greatest role in incentivising reward-seeking behaviour, which typically has been shown to proceed an event. However, there is contention about DA and its effect in motivating initiation of social interactions, as well as how it affects non-rewarding stimuli such as aversive and alerting responses. As such it is suggested that more research accesses how DA affects these alternative processes to create a more complete role on DA and its affects[spelling?] on social behaviour. Alongside additional research in these fields, it is also recommended to conduct more research on DA and its progression over time in relationships, as there isn't a great deal of information showing the transition of DA transmitters and how this affects relationship maintenance. Lastly, DA can effect and cause psychological disorders and addiction, from which it was shown how these dysfunction adaptations can result in negative social behaviours.