There are 11 players on a soccer team, but goalkeepers stand alone, wearing different shirts, playing by different rules, and often positioned far from their teammates. Now new research suggests goalies process the world around them in a different way too.
Researchers in Ireland looked at a group of 60 individuals, including professional soccer players (20 goalkeepers and 20 outfield players), as well as 20 people who didn't play the game at all.
"Unlike other football players, goalkeepers are required to make thousands of very fast decisions based on limited or incomplete sensory information," says behavioral neuroscientist and former professional goalkeeper Michael Quinn, from Dublin City University.
"This led us to predict that goalkeepers would possess an enhanced capacity to combine information from the different senses, and this hypothesis was confirmed by our results."
Trials were run to test how quickly the study participants could process and integrate the information coming in from their senses – technically, the temporal binding window. In each test, one or two flashes (visual stimuli) were shown and accompanied by one, two, or no beeps (auditory stimuli).
In the test with one flash and two beeps, most people thought they saw two flashes, showing the effects of visual and auditory stimuli integration gone awry. As the time between the stimuli increased, the mistake was less often made, providing a way of measuring the temporal binding window.
Goalkeepers had a distinctly narrower temporal binding window compared to outfielders and non-players, demonstrating more efficient multisensory processing – being able to more precisely and quickly estimate the timing of audiovisual cues.
What's more, goalies showed less interaction between the visual and auditory stimuli, suggesting they're more likely to separate sensory signals. The next question is whether this superior multisensory processing is the reason these people became goalkeepers, or a result of them playing the goalie position.
"Could the narrower temporal binding window observed in goalkeepers stem from the rigorous training regimens that goalkeepers engage in from an early age?" says psychologist David McGovern, from Dublin City University.
"Or could it be that these differences in multisensory processing reflect an inherent, natural ability that draws young players to the goalkeeping position?"
Perhaps more than anyone else on the field, goalies have to interpret visual and auditory cues incredibly quickly, such as the sound of a ball being kicked and its flight through the air. It depends where on the pitch this is happening though, as to whether or not the goalkeeper actually has to make a response.
The research team wants to build on the study in the future to look at other specialist positions, such as striker and center back, to see if there are any significant differences in their multisensory processing.
"While many football players and fans worldwide will be familiar with the idea that goalkeepers are just different from the rest of us, this study may actually be the first time that we have proven scientific evidence to back up this claim," says McGovern.
The research has been published in Current Biology.