Everyone loves a high five. They are the ultimate crowd pleaser. Thankfully, I’m a pretty good high-fiver myself, and as you can see, I like to leverage the skills I have. It turns out, there’s more to the high five than you may think. Not only has research shown that these palm-pats can help foster teamwork, soothe depression and even strengthen relationships, but there’s actually a lot that goes into coordinating these happy-claps.
STEP 1: FIND A HIGH-FIVE WORTHY SITUATION
The brain is incredibly skilled at controlling how we move. It’s so good, in fact, that we’re often not aware of how much work goes in to performing these seemingly simple actions. Take the high five for example. You may think that the most difficult thing about a high five is using it in the appropriate situation. Fair enough, you probably don’t want to be high-fiving your boss when she’s reprimanding you for being late… again. Or in my case, after hiding yet another half-chewed treat under my girl’s pillow—I like to share. On top of navigating these awkward situations, the brain must also determine how to move the arm to ensure that we successfully land that glorious high five.
STEP 2: PLANNING YOUR HIGH FIVE
The brain uses sensory information to help us make sense of the world. For instance, we use vision to provide information about our surroundings. Specifically, we can use vision to determine the location of the other person’s hand (i.e., the target), whether or not it’s moving, and if so, how it’s moving (e.g., the speed and direction of the hand). We can also use information from within the body to help us determine the position of our limbs and body in space (i.e., proprioception). For instance, muscle- and joint-based sensory organs in the arm provide information about its position and how it is moving relative to the rest of our body. The brain needs to combine all this sensory information and then convert it into a “common language” that the motor regions understand. This conversion is known as sensorimotor transformation. The transformed sensory information is used by the motor regions to calculate the necessary motor command. This entails determining the desired limb trajectory and movement dynamics to ensure you reach your movement goal. This motor plan is then sent to the appropriate limbs to execute the movement.
STEP 3: EXECUTION
Motor regions in the brain are also involved in movement execution. That is, they ensure that the arm is moved in the appropriate way according to the motor plan. This entails moving the arm in such a way that the correct joint angles are used throughout the movement. This also means that we need to activate the appropriate muscles, in the appropriate way, and at the appropriate time. All of this is achieved while simultaneously coordinating the movement of the rest of our body and while managing our excitement in this high-five worthy situation.
There are multiple regions in the brain that are involved in this miraculous feat. For instance, the visual cortex is involved in sending information about what we see to the posterior parietal cortex (PPC). The PCC receives and integrates the sensory information from the various sources in the body and is involved in converting this into usable information for the motor regions, such as the premotor and motor cortex. Additionally, there are other regions in the brain, such as the basal ganglia and the cerebellum, that are involved in the control of movement—but that’s a topic for another day. And…
STEP 4: BASK IN THE GLORY THAT IS YOUR HIGH FIVE
There you have it, in all its glory. Not only is the high five a great way to form social bonds and leverage for some treats and attention, it’s also just another way your brain shows you how awesome it is. Now that’s a reason to high five!