Article: How the brain makes play fun by Louk J. M. J. Vanderschuren
Personally, for me a very difficult article to read, about rats playing and choosing to play. I wonder; how is playfull behavior defined and measured? Apparently it is possible, some quotes from the article:
Research has taught us a lot about brain reward mechanisms. This research has developed specific models to study mental subcomponents of the behaviors that constitute pleasure and fun, such as motivation and approach behavior. Clearly, knowing intuitively that play is fun may help us understand and conceptualize it, but in order to investigate how the brain makes such behavior fun, we need to conduct studies that specifically address the pleasurable properties of play Research has taught us…… a lot about brain reward mechanisms. This research has developed specific models to study mental subcomponents of the behaviors that constitute pleasure and fun, such as motivation and approach behavior. Clearly, knowing intuitively that play is fun may help us understand and conceptualize it, but in order to investigate how the brain makes such behavior fun, we need to conduct studies that specifically address the pleasurable properties of play.
The most prominent neurotransmitters are dopamine, endogenous opioids (often referred to as endorphins, although the endorphins are actually only one subclass of opioids), and endogenous cannabinoids (or endocannabinoids)These neurotransmitters also play an important role in social play (Vanderschuren, Niesink, and Van Ree 1995; Siviy 1998)
In recent years, the mental processes that create enjoyment have been subdivided into motivation (wanting) and hedonics (pleasure or liking) (Berridge and Robinson 2003; Berridge, Robinson, Aldridge 2009). Clearly, this distinction also pertains to play, but not many studies have been done that directly address which brain mechanisms underlie the separate motivational and hedonic properties of play. However, the studies on other rewarded behaviors have indicated that the dopaminergic pathway from the ventral tegmental area to the nucleus accumbens, also known as the mesolimbic dopamine pathway, mediates motivation rather than pleasure (Cardinal, Parkinson, Hall, and Everitt 2002; Kelley, Baldo, Pratt, and Will 2005; Barbano and Cador 2007; Berridge 2007; Berridge and Kringelbach 2008; Salamone, Correa, Mingote, and Weber 2005)
Apparently, play is hard to stimulate by mimicking or enhancing the effect of dopamine in the brain, which suggests that when play occurs, it is accompanied by an optimal dopamine signal, and further stimulating this signal does not enhance play. On the other hand, when this dopamine signal is blocked, then play slacks off, likely because the blockage decreases an animal’s motivation to play. As stated above, dopamine plays a critical role in the motivational, but not the hedonic properties, of rewards (Cardinal, Parkinson, Hall, and Everitt 2002; Kelley, Baldo, Pratt, and Will 2005; Barbano and Cador 2007; Berridge 2007; Berridge and Kringelbach 2008; Salamone, Correa, Mingote, and Weber 2005).
Conclusion (only detail):
First, there is ample empirical evidence that social play has positive subjective, reinforcing effects.
Second, neurotransmitter systems that are intimately implicated in the motivational and pleasurable properties of food, drugs, and sex—such as endogenous opioids, endogenous cannabinoids, and dopamine—modulate social play to an important extent.
Third, the regions of the brain where positive emotions and motivation originate—such as the nucleus accumbens, amygdala, and frontal cortex—also mediate social play. Together, these studies demonstrate that play is fun and that there are pathways in the brain that make it so.
