What Drives Play and the Motivation of Playing Just to Play?
Part 1: Joys of play we share with some young creatures.
Posted Sep 18, 2019
Doing something for the sheer joy and playfulness of it – just because it is fun and feels good in and of itself – is a key impetus behind many of our creative and life projects.
But what, really, is this elusively powerful driver of our playful activity? How does the urge to play arise? What's happening differently in our minds-brains-bodies when our urge to play is burning bright and strong, compared to when it's gone, or has diminished to a mere dull flicker?
How might we study play and begin to piece together parts of these deep puzzles? Although there are many places we could look, a team of ingenious behavioral neuroscience researchers recently rigged together a new way to let us peer into brains and bodies at play, of interacting creatures small, and large. But before we take a closer look at their animal study, and their findings, we first need to take a small detour, into the surprisingly complex playworld of hide-and-seek.
Let's play hide-and-seek
Playing hide-and-seek is complicated. To sometimes assume the role of the one who is hiding, but at other times to take on the role of the seeker, draws on a surprisingly large and complex array of cognitive, social, motivational, and physical skills.
For example, if a child is playing the role of the hider she must remain quiet and hidden even while the seeker closely approaches her or passes nearby her hiding place, inhibiting any urges to move, burst into giggles, or otherwise reveal her hidden presence. When playing the role of the seeker, the child must wait and fully and loudly count out the required time, keeping her eyes closed or her back turned, and not peeking while her playmates stealthily find and slide into their hiding places. Other flexible perspective-taking abilities are also needed. For example, the hiding child needs to know that just because she can see the seeker, it does not necessarily mean that the seeker can also see her.
Some of this complexity is revealed by the age at which young children first begin to fully succeed at the game. A laboratory-based study conducted by researchers from Canada and Italy found that only a few 3-year-olds could successfully play hide-and-seek, but children who were a little older, including most 4-year-olds and nearly all 5-year-olds, were adept at the game. The mistakes the youngest children made were often ones of not alternating the role of hider and seeker (for example, telling the experimenter to hide, but then also themselves hiding) or not really "hiding" (as in telling the experimenter where he or she was going to hide, not trying to hide from view, or not remaining physically hidden, or not remaining quiet). The children's skill at playing hide-and-seek was strongly positively correlated with another ability related to understanding another person's perspective and knowledge – that of keeping a secret.
Given this complexity – and the clear challenges the game poses to young human children – could other creatures really learn to play hide-and-seek? And, if they could, might this provide some insights into the deep motivational and rewarding origins of play?
Small creatures with big play urges
Behavioral neuroscience researchers have known for some time that young adolescent male laboratory rats are eager and enthusiastic playmates. They jump into lots of rough-and-tumble play with their adolescent peers, and joyfully engage in all sorts of hand-and-finger chasing and tickling exploits with their human handlers. But what are the neural underpinnings of the drive to play in these small young creatures? And could such play urges extend to more complex and rule-based games requiring them to take on different roles at different times, such as those in hide-and-seek?
To begin to examine the neural correlates of these small furry creatures' big motivation to play researchers at the Bernstein Center for Computational Neuroscience and Humboldt University in Berlin devised a novel two-player rat-and-human hide-and-seek game.
Placed around a large nearly 100-square-foot (5 x 6m2) dimly lit lab room were several smaller hiding places (two transparent and two opaque boxes), three large human-size "cardboard" hiding places, and a shoebox-sized "start box" with a remote cable-controlled opening mechanism.
At three weeks of age, each animal individually began a five-to-ten-day familiarization with the room and with the experimenter – starting with lots of gentle handling, touching, and carrying, and later more vigorous and energetic tickling and hand games. Next, the rats were successively first trained to either hide or to seek. Crucially, throughout the training the animals only ever received "social play rewards" – touching, and hand games and playful interactions with the experimenter. No food or other tangible rewards were offered.
In "seek" trials, the experimenter closed the lid of the start box, and hid at one of the larger hiding places. In "hide" trials, the experimenter left the start box open, and the experimenter assumed a very still posture next to the start box, and began counting out loud. When the experimenter hid, the sounds made while she moved to her chosen hiding place were masked with white noise. There were also multiple decoy "cables" to each of the possible hiding places so the animals could not simply follow the cable that provided the hidden experimenter remote control for opening of the start box.
Of the six animals initially trained by one experimenter, all six learned to seek, and five learned both to hide and to successfully switch between the hiding and seeking roles. Of four additional animals, trained by a different experimenter in the same setting, all four learned to seek, hide, and also to switch roles.
But, you may ask: What did the animals actually learn? Were they really playing the game? Did the animals actually enjoy the game? Were they actually playing just for the fun and joy of it?
This post will be continued in Part 2.
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Reinhold, A. S., Sanguinetti-Scheck, J. I., Hartmann, K., & Brecht, M. (2019). Behavioral and neural correlates of hide-and-seek in rats. Science, 365 (Sept. 13), 1180–1183.